Frequently Asked Questions About Concrete
We have divided the questions in to categories to share with domestic customers.
Concrete for DIY projects
Concrete Calculators, tips & advice to successfully build these popular home & garden projects.
Delivery & General FAQs
Concrete Delivery FAQs
Yes. After placing and finishing, concrete needs protection and proper curing. Have plastic sheeting, curing membranes, or covers ready to prevent rapid drying, rain damage, or frost. Good aftercare is just as important as good preparation for long‑term performance.
Check that the delivery matches what you ordered, including mix type and quantity on the delivery ticket. If anything looks wrong, raise it with the driver immediately before discharge begins. Once concrete is poured, it is assumed to be accepted.
It’s very important to estimate volumes carefully. Running short can delay the job and lead to visible joints, while over‑ordering can increase costs. Many domestic customers order a small extra allowance to avoid running out. Some suppliers offer flexible or part‑load solutions to reduce waste.
If the lorry cannot reach the pouring area, the concrete will need to be moved by wheelbarrow or pumped. This must be planned in advance. Trying to improvise on the day often leads to delays, stress, and extra cost. Always discuss access challenges with your supplier beforehand.
Concrete should normally be placed within about two hours of batching, depending on traffic, mix type, and weather. Once the lorry is on site, you have a limited discharge window. Anything that causes delays—such as poor access or lack of labour—can affect the quality of the concrete.
Light rain is usually not a problem, but heavy rain, frost, or extreme heat can affect both delivery and concrete performance. In poor weather, you may need protective sheeting, covers, or curing methods ready on site. If conditions are severe, it is sometimes better to postpone the pour.
You should have all necessary tools ready before the lorry arrives, including shovels, rakes, tampers, screeds, floats, and edging tools. If you are barrowing concrete, ensure you have enough wheelbarrows and helpers. Delays caused by missing equipment can lead to wasted material or extra charges.
Yes. A responsible person must always be on site to receive the concrete, direct where it is poured, and sign the delivery ticket. The driver cannot make decisions about placement or waiting time, so someone familiar with the job should be present from start to finish.
A standard ready‑mix concrete lorry is large and heavy. Ideally, you’ll need a minimum clear width of around 3 metres, firm ground, and enough turning or reversing space. If access is limited, you should arrange barrowing, wheelbarrows, or a concrete pump in advance and inform the supplier when ordering.
Before your delivery, make sure all groundwork is fully completed. This includes excavation, formwork, reinforcement, and sub‑base preparation. Access routes should be clear and safe for a concrete lorry, and all tools, labour, and finishing equipment must be ready. Concrete has a limited working time once delivered, so good preparation is essential.
Pumping Concrete FAQs
Yes. It pumps very well and is often used on sites where access is limited or concrete needs to be placed at a distance.
(From: Pumping Concrete) (Flowing Concrete)
Yes, concrete can be pumped in most weather conditions, including rain. However, in extremely cold temperatures, the pipeline must be insulated or pre-warmed to prevent the mix from freezing inside the hose. In very hot weather, the speed of delivery becomes even more critical to prevent the concrete from curing prematurely inside the pump.
(From: Pumping Concrete)
Most standard concrete mixes can be pumped, but you must specify a “pump mix” when ordering from your concrete supplier. This mix contains a higher proportion of sand and smaller aggregates (typically 10mm or 20mm) to prevent blockages. Most specialised liquid floor screeds are also suitable for pumping.
You must provide a level, hard-standing area approximately 20 metres long (roughly the length of 4 cars) for both the pump and the mixer truck to park. It is recommended to lay tarpaulin under the pump’s hopper to simplify cleanup.
Concrete pump hire typically costs between £300 and £500 for a half-day hire of a line pump. For larger boom pumps, prices generally start around £450 to £600. Total costs are influenced by the volume of concrete, the duration on-site, and the amount of additional pipeline required.
(From: Pumping Concrete)
A standard line pump can typically reach 150 metres horizontally and up to 1,000 metres with additional piping, making it highly versatile for long-distance pours. A boom pump generally offers a reach of 20 to 70 metres horizontally or vertically, depending on the size of the truck and the number of arm sections.
(From: Pumping Concrete)
Line Pumps use flexible hoses laid along the ground and are ideal for residential projects like driveways, garden paths, or internal floors where access is tight.
Boom Pumps feature a hydraulic, robotic arm that can reach up and over obstacles like houses or walls. They are best for high-rise projects, deep foundations, or large commercial slabs where speed and height are critical.
You should hire a pump if the pour site is more than 20–30 metres from where a mixer truck can park, or if you have restricted access such as narrow alleyways, stairs, or indoor areas. Pumping is also essential for volumes over 5m³, as it delivers approximately 1m³ per minute, preventing “cold joints” by ensuring the concrete is placed before it begins to set.
Concrete pumping is the method of transporting freshly mixed concrete from the mixer truck to the placement area using mechanical pumps, hoses, or pipes. It enables fast, efficient, and accurate concrete placement.
(From: Pumping Concrete)
The two main types are boom pumps—truck-mounted pumps with a hydraulic arm for high or distant pours—and line pumps, which use hoses laid on the ground for smaller or harder-to-access pours.
(From: Pumping Concrete)
Pumping is used when access is restricted, when concrete must be delivered over long distances or height, when large volumes need rapid placement, or when a continuous pour is required.
(From: Pumping Concrete)
Pumping requires cohesive concrete with good workability. Mixes may include plasticisers, superplasticisers, and well-graded aggregates to prevent blockages. Most mixes from C20 to C60 can be pumped when properly designed.
(From: Pumping Concrete)
Boom pumps can reach approximately 50–70 metres vertically depending on the model, while line pumps can extend several hundred metres horizontally with additional hoses and proper pressure management.
(From: Pumping Concrete)
Benefits include faster placement, reduced labour, improved accuracy, the ability to work in tight-access areas, and a cleaner, more controlled pour.
(From: Pumping Concrete)
Yes. Risks include line blockages, hose whipping, pressure surges, and issues related to weather conditions. Proper training, setup, and supervision minimise risks.
(From: Pumping Concrete)
Concrete pumps can typically place between 30 and 100 m³ per hour, depending on the equipment and mix. Setup generally takes 30–60 minutes.
(From: Pumping Concrete)
The site must allow clear access for the pump truck, provide a safe hose route, ensure reinforcement and formwork are ready, and include suitable washout facilities.
(From: Pumping Concrete)
Pump hire adds cost, but improved efficiency, reduced labour, and faster completion often make pumping more cost‑effective overall.
(From: Pumping Concrete)
Domestic Concrete FAQs
Concrete supply itself does not require permission, but the construction project may — check with your local council.
(From: Domestic Concrete)
We take care to minimise risk and advise on suitable delivery locations.
(From: Domestic Concrete)
Both are suitable; mixed on site often reduces waste for domestic volumes.
(From: Domestic Concrete)
Yes, subject to availability and order time we can even deliver in just 2 hours of ordering.
(From: Domestic Concrete)
Initial set occurs within hours, with full strength developing over 28 days.
(From: Domestic Concrete)
Some projects benefit from fibres or mesh; we advise based on usage and ground conditions.
(From: Domestic Concrete)
C25 concrete is the most commonly used for domestic foundations.
(From: Domestic Concrete)
Yes. We regularly deliver to tight access streets across North and East London using suitable vehicles.
(From: Domestic Concrete)
This depends on length, width, and depth. Homeowners can use our concrete calculators to work out exact volumes to avoid waste.
(From: Domestic Concrete)
Same Day Delivery FAQs
Yes, it’s strongly recommended. You’ll need to:
- Direct the driver
- Confirm placement location
- Ensure access is clear
- Sign off on delivery
Being present helps avoid delays, mistakes, or additional waiting time charges.
Light rain is usually not a problem, but severe weather (heavy rain, frost, or extreme heat) can affect delivery or concrete performance. If weather conditions are unsuitable, suppliers will advise on the best course of action, which may include rescheduling for quality and safety reasons.
Many domestic customers estimate, and that’s common. Suppliers often recommend ordering a small amount extra to avoid running short. Some companies offer part‑load or volumetric options that allow you to adjust the amount on site, reducing waste and extra costs. To work out how much you need use our free concrete calculator.
(From: Free Concrete Calculators)
Same‑day concrete may carry a small premium due to urgent scheduling and logistics, but prices are often comparable to next‑day delivery. Additional costs may apply if specialist mixes, short‑notice labour, or restricted access equipment is required.
You’ll typically need:
- The amount of concrete required (in cubic metres)
- The type of mix (e.g. foundations, driveway, footing, shed base)
- Delivery address and access details
- Whether you need barrowing or pumping
- Your preferred delivery time window
If you’re unsure about mix or volume, most suppliers can help calculate this for you.
For the best chance of same‑day delivery, orders are usually required by mid‑morning. However, some suppliers can accommodate urgent afternoon requests. Providing all details up front—such as quantity, mix type, access, and preferred delivery time—helps avoid delays.
Yes, same‑day concrete delivery from Mix It is often possible, especially if you place your order early in the morning and flexibility exists in the delivery schedule. Availability depends on local demand, plant capacity, and your location, so the sooner you call, the better the chance of securing a same‑day slot.
Small Load Concrete FAQs
It’s wise to allow a small margin for uneven ground or minor changes, but over‑ordering on small loads can be costly. Your supplier can help you calculate volumes accurately so you get enough concrete without unnecessary waste or extra charges.
Small load deliveries can be as little as 1m³ to 2m³, depending on supplier capability and location. These quantities are ideal for minor domestic works where hand‑mixing would be time‑consuming and inconsistent.
Additional charges may apply depending on your site and order, including:
- Part‑load or short‑load fees
- Concrete pump hire (if access is restricted)
- Waiting time if unloading is delayed
- Difficult or restricted site access
Your supplier can explain these upfront so there are no surprises.
Yes. Small loads generally cost more per cubic metre than full loads because the delivery vehicle still incurs the same operating costs. As a guide, small loads can cost around 30–60% more per m³ compared to full loads. It’s always best to ask for the total delivered price, not just the rate per cubic metre.
Small loads are usually delivered using a standard ready‑mix concrete lorry, the same as full loads. You simply order the volume you need. Because the lorry is not fully utilised, a part‑load (short‑load) charge may apply. This is the most common method for residential deliveries with good access.
Small loads are ideal for domestic and light construction work, including:
- Shed and garage bases
- Patios and garden slabs
- Paths and pathways
- Strip footings for walls or extensions
- Repair and infill works
These projects typically don’t require the volume of a full ready‑mix load.
A small load of concrete typically refers to anything under 6m³, with many domestic jobs requiring between 1m³ and 4m³. Small loads are common for household projects where a full lorry load would result in waste and unnecessary cost.
Concrete Calculator FAQs
Many domestic customers estimate, and that’s common. Suppliers often recommend ordering a small amount extra to avoid running short. Some companies offer part‑load or volumetric options that allow you to adjust the amount on site, reducing waste and extra costs. To work out how much you need use our free concrete calculator.
(From: Free Concrete Calculators)
To calculate a slope, you must find the average depth. Measure the depth at the highest point (D1) and the lowest point (D2), add them together, and divide by two. Use this average depth in your standard volume formula: Length x Width x Average Depth.
(From: Free Concrete Calculators)
The most accurate method is to split the area into simple rectangles. Calculate the volume (Length x Width x Depth) for each rectangle separately and then add the totals together. Be careful not to overlap the measurements at the corner where the two rectangles meet.
(From: Free Concrete Calculators)
The 1.54 conversion factor accounts for the “shrinkage” that occurs when dry ingredients (cement, sand, and stone) are mixed with water. Because dry materials contain air pockets, you need roughly 1.54m³ of dry volume to produce 1.0m³ of wet, compacted concrete. This is vital for DIYers mixing their own materials on-site.
(From: Free Concrete Calculators)
Use the cylinder volume formula: 3.14 x (Radius x Radius) x Depth. For a hole that is 0.3m wide (0.15m radius) and 0.6m deep, the calculation is 3.14 x 0.0225 x 0.6, which equals approximately 0.042m³ per hole. Multiply this by the total number of posts to get your total order volume.
(From: Free Concrete Calculators)
For a domestic driveway carrying standard cars, a minimum depth of 150mm (0.15m) is recommended for structural integrity. For a garden path or patio intended only for foot traffic, a depth of 100mm (0.1m) is usually sufficient.
(From: Free Concrete Calculators)
For a standard C25 (1:2:3) mix, you would need approximately 10 to 12 bags (25kg each) of cement per cubic metre, provided you are mixing with the correct ratio of ballast. If you are mixing individual sand and stone, a C20 (1:2:4) mix typically requires 8 to 10 bags of cement per cubic metre.
(From: Free Concrete Calculators)
Calculate volume by multiplying Length (M) by Width (M) by Depth (M). For example, a 4 metre x 3 metre Patio at 100mm depth (0.1M) is 4 x 3 x 0.1M = 1.2 cubic metres. Always add a 10% contingency for uneven ground or spillage. Or you can use the free concrete calculators on our website.
(From: Free Concrete Calculators)
DIY Projects FAQs
DIY Driveway FAQs
Light foot traffic may be allowed after a day or two, but vehicles should generally be kept off the driveway for at least 7 days. Heavier vehicles are best avoided for 14–28 days, depending on weather conditions and concrete strength. Proper curing during this early period is crucial to achieving long‑term durability and strength.
(From: Concrete for Driveways)
Concrete naturally shrinks as it cures, so cracking cannot be completely avoided. Instead, it is controlled using well‑planned joints. Control joints are typically installed at 3–4 metre intervals and cut to around one‑quarter of the slab depth. These joints encourage cracks to form neatly in predetermined locations rather than randomly across the surface.
(From: Concrete for Driveways)
The sub‑base provides the foundation for the entire driveway. Even high‑quality concrete will fail if laid on poorly prepared ground. A minimum of 100–150 mm of well‑compacted MOT Type 1 sub‑base is recommended. Proper excavation, layered compaction, and drainage provision are essential to prevent settlement, cracking, and water‑related problems.
(From: Concrete for Driveways)
Yes, reinforcement is strongly recommended for most concrete driveways. Steel mesh, such as A142 for standard use, helps control cracking and distributes loads more evenly across the slab. The mesh must be positioned in the upper third of the concrete for it to work effectively. Fibre reinforcement can also be added to reduce early‑age shrinkage cracking, but it does not replace steel mesh.
(From: Concrete for Driveways)
Concrete driveways should generally be 125–150 mm thick for standard domestic use. Where heavier vehicles are expected or usage is more demanding, a thickness of 150–175 mm is advisable. The slab thickness should remain consistent, with extra attention given to turning areas and zones directly in front of garages.
(From: Concrete for Driveways)
For most domestic driveways, C25/30 (often referred to as C30) concrete is sufficient and widely used. If the driveway will carry heavier vehicles such as delivery vans, motorhomes, or frequent traffic, a stronger mix such as C30/37 (often supplied as C35) is recommended. In colder or more exposed locations, air‑entrained concrete can improve resistance to freeze–thaw damage.
(From: Concrete for Driveways)
A well‑designed and properly installed concrete driveway can last 30–40 years or more. Longevity depends on factors such as correct concrete strength, adequate thickness, good sub‑base preparation, proper jointing, and appropriate curing. With minimal maintenance, concrete offers one of the best long‑term values for domestic driveways.
(From: Concrete for Driveways)
DIY Paving FAQs
Concrete paths are usually walkable within 24–48 hours. However, full strength develops over a longer curing period. Heavy loads should be avoided for at least 7 days, and longer curing times are advisable in cold weather to ensure durability and reduce the risk of damage.
(From: Concrete for Paths)
A brushed finish is the most common and practical choice for paths, as it provides good slip resistance in wet or icy conditions. Decorative options such as exposed aggregate, coloured concrete, and patterned finishes are also available, but slip resistance should always be a priority—especially on access routes and sloping paths.
(From: Concrete for Paths)
All concrete will crack to some degree. The aim is to control where cracks occur rather than prevent them entirely. This is achieved using control joints, typically spaced 1.5–2.5 metres apart, as well as expansion joints where the path meets walls or other rigid structures.
(From: Concrete for Paths)
Reinforcement is not always essential but is strongly recommended in many cases. For typical domestic paths, polypropylene fibres can help control shrinkage cracking. For wider paths, longer runs, or heavier use, A142 steel mesh provides improved load distribution and crack control. Reinforcement helps maintain integrity but does not eliminate cracks completely.
(From: Concrete for Paths)
Yes. A properly prepared sub‑base is essential for long‑term performance. Most concrete paths should be laid on a well‑compacted MOT Type 1 sub‑base, usually 75–100 mm deep. The sub‑base provides a stable, free‑draining foundation and helps prevent settlement and structural failure.
(From: Concrete for Paths)
The required thickness depends on how the path will be used. Standard pedestrian paths typically need a concrete thickness of 75–100 mm. For heavy‑use or access paths, a thicker slab of 100–125 mm is recommended to better distribute loads and reduce the risk of cracking.
(From: Concrete for Paths)
For most domestic garden paths and light pedestrian use, C25 concrete is generally recommended. It offers sufficient strength for foot traffic and garden equipment while remaining cost‑effective. Where heavier loads are expected, such as wheelchairs, mobility scooters, or ride‑on mowers, C30 concrete provides added durability and resistance to cracking.
(From: Concrete for Paths)
DIY Patio FAQs
When installed correctly with the right concrete strength, thickness, reinforcement, and drainage, a concrete patio can last 25–40 years or more with minimal maintenance. Its durability makes it one of the longest-lasting patio options available.
Concrete patios can be finished in multiple ways, including brushed, smooth trowelled, stamped (imprinted), and coloured finishes. Brushed concrete is the most popular for residential use due to its slip resistance and practicality. Decorative finishes may require additional sealing and maintenance.
Yes. All concrete patios should be installed with a minimum fall of 1:60, sloping away from buildings to prevent standing water. In larger areas or poor ground conditions, additional drainage measures such as channels or soakaways may be required.
Concrete patios should be protected and allowed to cure properly. Light foot traffic should be avoided for 24–48 hours, furniture should not be placed for at least 7 days, and full strength is typically achieved after 28 days. Proper curing significantly improves long-term performance.
Yes. Although concrete is strong in compression, it is weak in tension. Using steel reinforcement mesh (such as A142 or A193) and/or fibre reinforcement helps control cracking and improves durability. For best results, both systems are often used together.
A standard patio should be 100–125 mm thick. If the patio will carry heavier loads or frequent traffic, a thickness of 125–150 mm is advised. For hot tubs or heavy structures, thickness may need to increase to 150–200 mm to prevent cracking and structural failure.
For most domestic patios, C25 concrete is sufficient for seating and light use. C30 is recommended where there will be heavier foot traffic, pergolas, or outdoor kitchens, while C35 should be used for hot tubs or garden buildings due to its higher load-bearing capacity.
Garden DIY Projects FAQs
DIY installation can be suitable for small and straightforward garden projects if proper preparation and curing methods are followed. However, for larger or more complex concrete bases, professional installation is recommended. Experienced contractors ensure correct excavation, reinforcement placement, finishing, and long‑term durability, reducing the risk of costly mistakes.
(From: Concrete for Garden Projects)
Concrete usually gains enough strength for light foot traffic within 3–7 days, but full curing takes up to 28 days. Garden structures can often be installed after several days, provided heavy loads are avoided. Protecting the slab from frost, heavy rain, and rapid drying during early curing is essential to prevent surface damage and cracking.
(From: Concrete for Garden Projects)
Proper ground preparation is critical to the success of any concrete garden project. The ground is typically excavated and filled with 100–150 mm of compacted MOT Type 1 sub‑base, which creates a stable, free‑draining foundation. In some cases, a damp proof membrane (DPM) is added to reduce moisture transfer, particularly for garden rooms or enclosed spaces.
(From: Concrete for Garden Projects)
Reinforcement is not always essential for very small projects, but it is strongly recommended for most concrete garden bases. Steel mesh reinforcement, such as A142 or A193, helps control cracking caused by temperature changes, ground movement, and shrinkage. Fibre reinforcement may also be added for additional crack control throughout the slab.
(From: Concrete for Garden Projects)
Concrete thickness depends on the size and function of the garden structure. Small garden sheds usually require 75–100 mm, medium sheds 100–125 mm, and larger garden rooms or workshops 125–150 mm. Increasing thickness improves load capacity and reduces the risk of cracking over time.
(From: Concrete for Garden Projects)
The most commonly used concrete types for garden projects are C25, C30, and C35, depending on the size and use of the structure.
- C25 is suitable for small to medium sheds and light storage.
- C30 is recommended for larger sheds or areas with heavier loads.
- C35 is best for workshops, garden rooms, or projects involving heavy machinery or permanent fixtures
(From: Concrete for Garden Projects)
Concrete is one of the most reliable materials for garden structures because it provides a strong, level, and long‑lasting foundation. Unlike timber, gravel, or paving slabs, a poured concrete base forms a single solid slab that evenly distributes weight and resists movement over time. It also performs well in the UK climate, where wet ground and freeze‑thaw cycles can cause issues with weaker base systems.
(From: Concrete for Garden Projects)
The ideal concrete mix for a UK garden path is a C25 strength grade (ST5), which typically uses a 1:2:3 or 1:2:4 ratio of cement, sand, and aggregate.
- Standard DIY mix: A ratio of 1 part cement, 2 parts sharp sand, and 3 parts 10-20mm aggregate is a reliable “strong mix” for paths exposed to British weather.
- All-in Ballast: For simpler mixing, use 1 part cement to 4 or 5 parts all-in ballast.
- Crack prevention: To stop your path from cracking during winter freeze-thaw cycles, keep the water-cement ratio below 0.45; too much water makes the concrete easier to pour but significantly weaker once cured.
- Expansion joints: Install control joints every 2.5 to 3 metres to manage natural expansion and contraction, preventing unsightly random cracks.
(From: Concrete for Garden Projects)
For standard domestic use, a concrete garden path should be 100mm (4 inches) thick. This depth provides sufficient structural integrity for foot traffic, wheelbarrows, and garden machinery.
- Sub-base requirements: A 100mm thickness of concrete should be laid over a 100mm compacted MOT Type 1 sub-base.
- Total excavation depth: To achieve a professional finish, you should dig down approximately 200mm to allow for both the sub-base and the concrete slab.
- Clay soil adjustment: If your garden has heavy clay soil—common in the some parts of London & Essex and South East—increase the sub-base to 150mm to prevent shifting during wet-dry cycles.
- Edge clearance: If the path runs alongside a house, ensure the surface is at least 150mm below the Damp Proof Course (DPC) and sloped at a 1:80 gradient to direct rainwater away from the foundations.
(From: Concrete for Garden Projects)
DIY installation can be suitable for small and straightforward garden projects if proper preparation and curing methods are followed. However, for larger or more complex concrete bases, professional installation is recommended. Experienced contractors ensure correct excavation, reinforcement placement, finishing, and long‑term durability, reducing the risk of costly mistakes
(From: Concrete for Garden Projects)
Concrete usually gains enough strength for light foot traffic within 3–7 days, but full curing takes up to 28 days. Garden structures can often be installed after several days, provided heavy loads are avoided. Protecting the slab from frost, heavy rain, and rapid drying during early curing is essential to prevent surface damage and cracking
(From: Concrete for Garden Projects)
Proper ground preparation is critical to the success of any concrete garden project. The ground is typically excavated and filled with 100–150 mm of compacted MOT Type 1 sub‑base, which creates a stable, free‑draining foundation. In some cases, a damp proof membrane (DPM) is added to reduce moisture transfer, particularly for garden rooms or enclosed spaces
(From: Concrete for Garden Projects)
Reinforcement is not always essential for very small projects, but it is strongly recommended for most concrete garden bases. Steel mesh reinforcement, such as A142 or A193, helps control cracking caused by temperature changes, ground movement, and shrinkage. Fibre reinforcement may also be added for additional crack control throughout the slab
(From: Concrete for Garden Projects)
The most commonly used concrete types for garden projects are C25, C30, and C35, depending on the size and use of the structure.
- C25 is suitable for small to medium sheds and light storage.
- C30 is recommended for larger sheds or areas with heavier loads.
- C35 is best for workshops, garden rooms, or projects involving heavy machinery or permanent fixtures
(From: Concrete for Garden Projects)
Concrete is one of the most reliable materials for garden structures because it provides a strong, level, and long‑lasting foundation. Unlike timber, gravel, or paving slabs, a poured concrete base forms a single solid slab that evenly distributes weight and resists movement over time. It also performs well in the UK climate, where wet ground and freeze‑thaw cycles can cause issues with weaker base systems
(From: Concrete for Garden Projects)
Concrete Foundation FAQs
Concrete prices vary by area, volume, strength, and delivery method. As a general guide, ready‑mixed concrete for foundations typically costs between £125 and £170 + vat per cubic metre. Additional costs may apply for pumping, difficult access, deeper excavations, or reinforcement requirements.
Wherever possible, foundation concrete should be poured in one continuous operation. Pouring in stages can create cold joints, which may weaken the foundation and reduce uniform strength. Continuous placement ensures better load transfer, durability, and long‑term performance.
Strip foundations involve pouring concrete into a trench and building masonry walls up from that point. Trench‑fill foundations use a larger volume of concrete to fill the trench closer to ground level, reducing below‑ground brickwork and speeding up construction. Trench‑fill foundations are particularly popular for domestic projects and may require higher‑strength concrete mixes.
Not all foundations require reinforcement, but it is commonly used where foundations are subject to bending, uneven loading, or ground movement. Reinforcement, usually in the form of steel mesh or rebar, improves tensile strength and helps control cracking. It is especially important in clay soils, deep trench‑fill foundations, and areas near trees.
Foundation width ensures that structural loads are spread evenly onto the ground below. Typical widths range from 450 mm to 1,200 mm, depending on building load and ground bearing capacity. Insufficient width can overstress the soil, leading to settlement or cracking, while correctly sized foundations improve long‑term stability.
Foundation depth depends on soil type, structural load, and nearby influences such as trees. For standard domestic buildings, foundations are usually 600 mm to 900 mm deep. In clay soils, depths often increase to 900 mm–1,200 mm to reduce the risk of movement. Where trees are present, depths can extend up to 2,500 mm, depending on species and proximity.
For most domestic housing projects, C25 concrete is the standard choice. It offers an effective balance of strength, durability, and cost, making it suitable for typical residential loads and ground conditions. Higher grades such as C35 or C40 may be required for heavier structures, deeper trench‑fill foundations, or challenging ground conditions such as clay soils.
Footings FAQs
Supply-only concrete costs for footings typically range from £123 to £170 +vat per cubic metre, depending on location and concrete strength. Total installed costs can vary significantly based on excavation, access, labour, reinforcement, and whether pump hire is required.
Concrete should ideally be placed in a continuous pour to avoid cold joints and ensure a monolithic footing. Where access is restricted, a concrete line pump is often used, allowing accurate and efficient placement while reducing manual labour and site disruption.
Some simple footings can be unreinforced, but many require steel reinforcement to improve tensile strength and control cracking. Reinforcement is commonly used where loads are high, ground conditions are variable, or there is a risk of uneven settlement. The type and layout of reinforcement should be specified by a structural engineer or building control.
Yes. Soil type plays a major role in determining footing depth, width, and concrete specification. Clay soils, in particular, are prone to moisture-related movement, while weaker soils may require wider footings to reduce bearing pressure. Footing design should always be adjusted to suit the ground conditions identified on site.
Footing depth depends largely on soil conditions and nearby vegetation. Typical guidance suggests depths of 450–600 mm for standard ground, 600–1,000 mm for clay soils, and up to 2,500 mm where trees or deep-rooted vegetation are present. Deeper footings help reduce the risk of movement caused by soil shrinkage or expansion.
In UK residential construction, C25 concrete is the most commonly specified strength for footings, offering a reliable balance between strength, durability, and workability. Lower strengths such as C20 may be suitable for lightly loaded structures, while C35 or C40 may be required for heavier loads or challenging ground conditions
Concrete footings transfer the load of a structure—such as walls, columns, or posts—safely into the ground. They spread the load over a sufficient area to prevent excessive settlement, differential movement, or instability, forming the critical link between the building and the supporting soil.
DIY Shed Base FAQs
Although concrete bases usually have a higher upfront cost than paving slabs, timber, or gravel systems, they offer superior durability, stability, and minimal maintenance over time. With typical material costs of £123–£170 +vat per cubic metre (excluding installation), concrete bases often prove to be the most cost‑effective solution across the lifespan of the shed.
Concrete typically gains sufficient strength to support light loads within 3–7 days, but full curing takes up to 28 days. In most cases, sheds can be installed after several days, provided heavy loads are avoided. Protecting the slab from frost, heavy rain, and rapid drying during early curing is essential to prevent surface defects and cracking.
Yes. Where access is restricted, concrete pumps, particularly line pumps, are commonly used to deliver concrete to the rear of properties. Pumping allows accurate placement of concrete without excessive manual handling and is especially effective for residential gardens with limited or no vehicle access.
A properly constructed sub‑base is critical for long‑term performance. Most concrete shed bases require 100–150 mm of compacted MOT Type 1 stone beneath the slab. This provides a stable, free‑draining foundation and prevents settlement by evenly distributing loads across the ground. In some cases, a damp proof membrane is also installed above the sub‑base to reduce moisture ingress.
Reinforcement is not always essential for very small sheds, but it is strongly recommended for anything beyond light domestic use. Steel reinforcement mesh such as A142 or A193 improves tensile strength and helps control cracking caused by shrinkage, temperature changes, and minor ground movement. Fibre reinforcement may also be used to enhance crack control throughout the slab.
Concrete base thickness depends on shed size and usage. Small sheds typically need a slab 75–100 mm thick, while medium sheds benefit from 100–125 mm. Larger sheds, workshops, or garden rooms usually require a minimum thickness of 125–150 mm to ensure adequate load‑bearing capacity and resistance to cracking.
For most domestic shed bases, C25 concrete is the most commonly recommended option. It provides sufficient strength for small to medium sheds used for general storage and garden equipment. Where heavier loads are expected—such as workshops or sheds housing machinery—C30 or C35 concrete offers increased strength and durability. The choice should always reflect the intended use and load requirements of the structure.
DIY Garage Base FAQs
Concrete must be allowed to cure properly to achieve full strength:
- Light foot traffic: 24–48 hours
- Garage installation: 5–7 days
- Vehicle parking: 7–14 days
- Full design strength: 28 days
Using the slab too early—particularly parking vehicles—can permanently weaken the surface.
Air-entrained concrete is highly recommended for unheated or exposed garages. The entrained air bubbles reduce the risk of surface damage caused by freeze–thaw cycles, especially in detached garages or locations prone to damp conditions. While slightly more expensive, it significantly improves long-term durability.
Yes. A polythene damp-proof membrane (DPM) should be installed beneath the concrete slab to prevent moisture rising through the floor. This protects vehicles, tools, and stored items. For garages attached to houses, a DPM is particularly important for moisture control and building regulation compliance.
A well-prepared sub-base is essential. Most garage bases require 100–150 mm of compacted MOT Type 1 aggregate, laid in layers and mechanically compacted. Poor sub-base preparation can lead to settlement and cracking regardless of concrete quality.
Yes, reinforcement is strongly recommended. Concrete is strong in compression but weak in tension, so reinforcement helps control cracking and distribute loads. Welded steel mesh such as A142 or A193 is commonly used. Fibre reinforcement can reduce shrinkage cracking but does not usually replace steel mesh in structural garage slabs.
The required thickness depends on the size and intended use of the garage:
- Single garage: 125–150 mm
- Double garage: 150 mm
- Heavy-duty or workshop use: 150–175 mm
Adequate thickness is critical for load-bearing performance and crack resistance, particularly at door openings and high-traffic areas.
For most domestic garages, C30 concrete is the preferred choice. It provides an excellent balance of strength, durability, and cost, and is suitable for cars, vans, and light commercial vehicles. For garages that will support heavier vehicles or be used as workshops, C35 concrete is recommended due to its higher compressive strength and resistance to long-term wear.
Extensions FAQs
Yes. Building Control normally inspects foundation trenches before concrete is poured to confirm correct depth, width, and ground conditions. Pouring concrete without approval can lead to compliance issues and may require costly remedial work later.
As a general guide, ready-mix concrete for domestic extensions typically costs between £125 and £170 +vat per cubic metre, excluding labour and groundwork. Additional costs may include pump hire, reinforcement, excavation, and spoil removal, depending on site conditions and access.
Yes. Concrete pumping, particularly using a line pump, is very common for house extensions where access is limited. Pumping allows faster placement, reduced manual labour, improved safety, and a cleaner pour. It is especially useful for rear extensions where wheelbarrow access is difficult.
Not always. Many domestic extensions use mass concrete foundations without reinforcement. However, reinforcement may be required where ground conditions are uncertain, loads are higher, or Building Control or a structural engineer specifies it. Common forms include rebar cages in trench fill foundations and steel mesh in ground-bearing slabs.
Yes. Clay soils are prone to shrinkage and expansion, which increases the risk of ground movement. As a result, higher-strength concrete such as C35 is often required, along with deeper foundations, to improve durability and reduce the likelihood of cracking or settlement.
Foundation depth depends on soil type, ground conditions, and nearby trees. On stable ground, foundations are typically 600–900 mm deep. In clay soils, this often increases to 900–1,200 mm. Where trees are present, depths may extend beyond 1,000 mm and in some cases up to 2,500 mm, depending on tree species and distance.
For most domestic house extensions, C25 concrete is commonly used for single-storey extensions on good ground conditions. C35 concrete is often specified for two-storey extensions or where foundations are formed in clay soils. In deeper or more demanding situations, C40 concrete may be required, particularly for trench fill foundations or where specified by a structural engineer or Building Control.
Specific Concrete FAQs
C10 Concrete FAQs
C10 is a low‑strength, non‑structural concrete used for blinding layers, kerb bedding, drainage surrounds, and basic fill work. It provides a level, protective surface and prevents contamination of structural concrete placed above it.
(From: C10 Concrete)
No. C10 is not designed for structural applications. Its low compressive strength makes it unsuitable for foundations, slabs, or any load‑bearing elements. Higher‑strength mixes such as C20 or C25 are recommended for structural work.
(From: C10 Concrete)
C10 provides a clean, stable surface for setting reinforcement and membranes. It prevents contamination from soil and creates an even base that improves accuracy and quality when placing higher‑strength structural concrete.
(From: C10 Concrete)
C10 concrete reaches a compressive strength of around 10 N/mm² after 28 days. This strength level is adequate for light‑duty and preparatory work but not suitable for any structural requirements.
(From: C10 Concrete)
No. Mixes with a higher cement content and sand content will be required for pumping.
(From: C10 Concrete)
C10 begins setting within a few hours, depending on weather conditions. It can often be walked on the following day, but full curing requires 28 days. Proper curing helps prevent dusting and early cracking.
(From: C10 Concrete)
Yes. Because C10 uses less cement than higher‑strength mixes, it is cost‑effective for non‑structural tasks. It is ideal when strength is not required but a clean, level, workable surface is needed.
(From: C10 Concrete)
C15 Concrete FAQs
C15 is a low-strength concrete commonly used for domestic floors, footings for small walls, kerb bedding, pathways, and general construction applications where moderate strength is required.
(From: C15 Concrete)
C15 provides slightly higher strength than C10 but is still not recommended for primary structural elements. It can be suitable for lightly loaded foundations, floors, and slabs, but heavier structural applications require C20 or above.
(From: C15 Concrete)
C15 offers a good balance between strength and workability. It is strong enough for many household applications while remaining cost-effective for non‑structural or lightly loaded work.
(From: C15 Concrete)
C15 concrete reaches a compressive strength of approximately 15 N/mm² at 28 days. This makes it suitable for general-purpose work that requires a moderate load-bearing capacity.
(From: C15 Concrete)
No. Mixes with a higher cement content and sand content will be required for pumping.
(From: C15 Concrete)
C15 begins initial set within a few hours depending on conditions. Light foot traffic is usually possible within 24–48 hours, while full curing takes 28 days.
(From: C15 Concrete)
Yes. C15 is more economical than higher-strength mixes while still providing adequate performance for many light construction tasks. It is commonly chosen for its balance of affordability and strength.
(From: C15 Concrete)
C20 Concrete FAQs
C20 is a medium-strength concrete commonly used for domestic foundations, garage floors, internal floor slabs, lightweight structural applications, and general construction work requiring good durability and strength.
(From: C20 Concrete)
Yes. C20 offers sufficient strength for many load-bearing tasks in residential construction, such as small foundations, floors, and footings. For heavier structural loads, higher grades like C25 or C30 are recommended.
(From: C20 Concrete)
C20 provides a reliable balance between strength, workability, and cost. It is strong enough for typical domestic foundations and floor slabs while being more economical than higher-grade mixes.
(From: C20 Concrete)
C20 reaches a compressive strength of around 20 N/mm² after 28 days, making it suitable for a wide range of medium-duty construction applications.
(From: C20 Concrete)
Yes. C20 can be pumped, and plasticisers or other admixtures may be added to improve flow and workability, especially for areas that are hard to access.
(From: C20 Concrete)
C20 typically begins to set within a few hours depending on temperature and site conditions. Light foot traffic is usually possible within 24–48 hours, but full curing takes approximately 28 days.
(From: C20 Concrete)
Yes. C20 is widely used because it provides a robust level of strength without the higher material costs of stronger mixes. It is ideal for residential and light commercial applications.
(From: C20 Concrete)
C25 Concrete FAQs
C25 is a strong, versatile concrete commonly used for footings, foundations, reinforced bases, driveways, and light to moderate structural applications. It is suitable for both residential and commercial construction.
(From: C25 Concrete)
Yes. C25 offers good compressive strength, making it suitable for many structural elements including footings, slabs, and bases that need to support considerable loads. For heavier-duty structural applications, C30 or higher is often recommended.
(From: C25 Concrete)
C25 provides an excellent balance of strength, durability, and cost. It is often selected for reinforced concrete projects where additional structural reliability is required.
(From: C25 Concrete)
C25 reaches a compressive strength of approximately 25 N/mm² after 28 days, offering reliable performance for medium- to heavy-duty construction tasks.
(From: C25 Concrete)
Yes. C25 can be pumped effectively, and admixtures such as plasticisers can be used to improve workability depending on site conditions.
(From: C25 Concrete)
C25 begins initial set within a few hours depending on weather and site conditions. Light foot traffic is typically possible within 24–48 hours, while full curing takes around 28 days.
(From: C25 Concrete)
Yes. While more expensive than lower grades, C25 provides significant strength at a reasonable cost, making it a popular choice for foundations, driveways, and reinforced structures.
(From: C25 Concrete)
Yes, C25 is compatible with steel reinforcement for garage slabs and other reinforced groundworks.
(From: C25 Concrete)
C25 is generally walkable within 24–48 hours; full strength is achieved around 28 days.
(From: C25 Concrete)
Pump requirement depends on access and volume — use our pump hire options for hard-to-reach pours.
(From: C25 Concrete)
Yes. C25 is commonly used for driveways and slabs up to light vehicle load. For heavier usage, consider C30.
(From: C25 Concrete)
C25 concrete achieves 25 N/mm² compressive strength after 28 days, making it suitable for standard domestic loads.
(From: C25 Concrete)
C25 concrete prices in London typically range £123–£160 + vat per m³ depending on volume, delivery postcode and any pump hire needed. Use our calculator for exact pricing.
(From: C25 Concrete)
C30 Concrete FAQs
C30 is a high‑strength concrete widely used for structural applications including reinforced slabs, beams, columns, driveways, roadways, and commercial foundations.
(From: C30 Concrete)
Yes. C30 provides strong compressive performance suitable for heavy load‑bearing elements in both residential and commercial construction.
(From: C30 Concrete)
C30 delivers excellent durability and strength, making it ideal for reinforced concrete elements requiring long‑term performance under heavier loads.
(From: C30 Concrete)
C30 reaches a compressive strength of approximately 30 N/mm² after 28 days, offering high reliability for demanding construction tasks
(From: C30 Concrete)
Yes. C30 can be pumped effectively, and admixtures may be added to enhance workability depending on access and conditions.
(From: C30 Concrete)
C30 begins to set within a few hours depending on weather conditions. Light traffic is typically possible within 24–48 hours, while full curing takes 28 days.
(From: C30 Concrete)
While more costly than lower grades, C30 is cost‑effective for structural applications due to its strength, durability, and reduced need for repairs over time.
(From: C30 Concrete)
C35 Concrete FAQs
Standard C35 concrete is designed for general structural applications, while DC-rated C35 concrete such as DC-2, DC-3, and DC-4 is specifically formulated for foundations and structures exposed to sulphates and chemically aggressive ground conditions.
(From: C35 Concrete)
Yes. C35 concrete is commonly supplied with concrete pump hire for projects with restricted access, rear gardens, basements, commercial slabs, and large structural pours throughout London and Essex.
(From: C35 Concrete)
C35 concrete usually begins setting within a few hours, but full curing and structural strength development can take up to 28 days depending on temperature, moisture levels, and site conditions.
(From: C35 Concrete)
Yes. C35 concrete can be used for heavy-duty domestic driveways and areas exposed to frequent vehicle traffic, particularly where increased durability and resistance to wear are important.
(From: C35 Concrete)
C35 concrete provides greater compressive strength and durability than C30 concrete. It is typically used for heavier-duty structural applications where increased load-bearing capacity or enhanced durability is required.
(From: C35 Concrete)
Yes. C35 concrete is widely used in commercial and industrial construction because it provides excellent compressive strength and long-term structural performance for reinforced slabs, foundations, and load-bearing applications.
(From: C35 Concrete)
C35 concrete is commonly used for reinforced foundations, structural slabs, commercial flooring, agricultural yards, industrial projects, retaining walls, and heavy-duty domestic construction where increased structural strength and durability are required.
(From: C35 Concrete)
DC4 concrete is a high-strength designated concrete suitable for foundations, slabs, and driveways that demand extra durability and load capacity. It bridges the gap between simpler DC mixes and fully engineered structural concrete, making it a popular choice for domestic and light commercial construction in the UK
DC4 may be preferred because it is:
- Simpler to specify under BS 8500
- Widely accepted by Building Control for many projects
- Consistent and standardised
- Often more cost-effective for domestic works
- Adequate where full structural design is not required
If reinforcement design, exposure class optimisation, or precise load calculations are needed, C‑class designed concrete is the better choice.
Yes. DC4 concrete is well suited for outdoor use, including:
- Exposure to rain and frost
- Driveways and access roads
- External slabs and paving bases
Correct curing, joint detailing, and drainage are still essential to prevent cracking and surface defects.
| Feature | DC3 | DC4 |
| Typical strength | ~20 N/mm² | ~25 N/mm² |
| Durability | Good | Higher |
| Foundation use | Domestic | Domestic & light commercial |
| Driveways | Light traffic | Heavier traffic |
| Cost | Lower | Slightly higher |
DC4 is chosen when extra strength, stiffness, or durability is required compared to DC3.
Yes — to a limited extent.
DC4 is suitable for:
- Simple load-bearing elements such as strip and trench foundations
- Ground-bearing slabs with modest reinforcement
However, it is not suitable for:
- Highly reinforced structural elements
- Beams, columns, suspended slabs
- Complex structural designs
For those applications, a designed concrete (e.g. C30/37) should be specified by an engineer.
DC4 concrete is commonly used for:
- Domestic and low-rise commercial foundations
- Industrial floor bases
- Driveways (including light commercial traffic)
- Garage and workshop slabs
- Oversite concrete with higher load expectations
- Heavier-duty external paving
It is often specified where Building Control requires higher performance but a fully designed mix is not necessary.
DC4 concrete has an approximate compressive strength of 25 N/mm² at 28 days.
This makes it:
- Similar in strength to C25/30 in some domestic situations
- Significantly stronger than DC3
- Suitable for heavier-duty domestic and light commercial applications
DC4 concrete is a designated concrete mix defined under BS 8500.
It is the highest-strength option within the DC (Designated Concrete) range, intended for applications requiring greater strength and durability than DC1–DC3, while still being simpler to specify than designed (C‑class) concretes.
Yes — FND3 is commonly supplied at S3 consistence, making it suitable for pumping into trenches or restricted access sites. Practical tips:
- Ensure thorough compaction and adequate curing (minimum periods per BS 8500) to achieve full durability.
- It is more expensive than GEN or basic FND2 mixes due to higher cementitious content and specialist cements.
- Order only from certified suppliers (QSRMC or BSI Kitemark) and verify the exact designation on the delivery ticket.
- For very aggressive variants or reinforced work, additional protective measures (APMs) like surface protection or enhanced quality may be needed.
- Discuss additives, flow, or aggregate size with the supplier for site-specific placement.
Exact requirements can vary with updates to BS 8500, site conditions, or intended working life (50 vs 100 years). For your project, share ground investigation details or consult a structural/geotechnical engineer and concrete supplier for precise recommendations
(From: C35 DC-3 Concrete)
Yes — a full ground investigation with soil and groundwater sampling/analysis is required to establish the ACEC class and resulting DC class. Key factors tested include sulfate content, pH, magnesium, groundwater mobility, and site history (e.g., brownfield). Without testing, some guidelines conservatively default toward FND2 or higher for safety, but using the wrong class risks premature failure or over-specification/cost. Engage a geotechnical engineer and follow BRE Special Digest 1 for accurate classification.
(From: C35 DC-3 Concrete)
FND3 is mainly intended for unreinforced (plain/mass) foundations. For reinforced foundations in DC-3 ground, many specifiers use FND3 with additional checks (e.g., cover, crack control) or opt for a designed concrete (such as RC30 or equivalent) that satisfies both structural strength and chemical resistance requirements. Reinforcement increases the need for low permeability and proper placement. Consult the structural engineer, as BS 8500 guidance may recommend designed mixes in some reinforced cases.
(From: C35 DC-3 Concrete)
- DC-2 / FND2: Moderately aggressive ground (lower sulfate risk) → Lower minimum cement content (often ~300–320 kg/m³) and higher maximum w/c ratio (e.g., 0.55).
- DC-3 / FND3: More aggressive conditions (higher sulfate, wetter, or more reactive soils) → Higher cement content, lower w/c ratio (better impermeability), and stricter cement type requirements for greater sulfate resistance. Both often have similar nominal strength (~30 N/mm²), but FND3 provides upgraded durability. Variants like FND3Z exist for specific mobility or magnesium issues. Higher DC classes generally demand richer, denser mixes or additional protective measures (APMs).
(From: C35 DC-3 Concrete)
FND3 is primarily for unreinforced foundations in moderately aggressive sulfate-bearing or chemically reactive ground, including:
- Strip footings, trench-fill, mass concrete bases on clays or soils with higher sulfate concentrations, wetter conditions, or increased reactivity.
- Sites where ground testing shows DC-3 conditions (e.g., certain brownfield, pyritic, or sulfate-rich natural soils). It offers enhanced protection compared to FND2 but is not for the most severe cases (those use FND4). Always base the specification on a professional ground investigation report.
(From: C35 DC-3 Concrete)
FND3 is typically a C25/30 or C28/35 strength class (25–35 N/mm² compressive strength at 28 days; often described as ~30 N/mm²). Key limiting values include:
- Minimum cement content: Around 320–340 kg/m³ (higher than many FND2 variants).
- Maximum water/cement ratio: Often 0.50 (tighter than DC-2 for reduced permeability).
- Sulfate-resisting cement combinations, such as CEM III/A or III/B with high slag content plus SR (sulfate-resisting) options, or other approved blends that provide enhanced chemical resistance.
- Default consistence (workability): S3 (target slump around 100–120 mm), suitable for trench fill and pumping. It is a certified designated mix supplied by ready-mixed plants.
(From: C35 DC-3 Concrete)
DC-3 stands for Design Chemical Class 3. It classifies the ground as moderately to highly aggressive to concrete, mainly due to elevated sulfate levels (typically higher than DC-2), lower pH, or more reactive/wetter conditions. This class comes from site-specific ground investigation results that determine the Aggressive Chemical Environment for Concrete (ACEC) class, which is then converted to a DC class. DC-3 requires concrete with greater sulfate resistance than DC-2 to prevent chemical attack, expansion, and long-term deterioration. The corresponding designated concrete is usually FND3 (Foundation concrete for DC-3).
(From: C35 DC-3 Concrete)
Yes — FND2 is often supplied with a consistence suitable for pumping (S3 class). It works well for trench-fill foundations. Practical tips:
- Ensure proper compaction and curing to maintain durability.
- Minimum cover and placement standards still apply if any reinforcement is present.
- It is more expensive than GEN mixes due to the sulfate-resisting cement and tighter limits.
- Always order from a certified supplier (e.g., QSRMC or BSI Kitemark) and confirm the exact designation on the delivery ticket.
- For very deep trenches or restricted access, discuss additives or flow with the supplier.
If your project involves specific ground conditions, reinforcement details, or location-based factors (e.g., near the coast), consult a structural engineer or concrete supplier for tailored advice, as exact requirements can vary slightly by region or updated BS 8500 amendments.
(From: C35 DC-2 Concrete)
Yes — a ground investigation (soil sampling and chemical analysis) is essential to determine the Aggressive Chemical Environment for Concrete (ACEC) class, which leads to the DC class. Factors include sulfate content, pH, groundwater mobility, and presence of brownfield or pyritic materials. Without testing, many UK guidelines default to FND2 for safety on potentially sulfate-bearing clays. Consult a geotechnical engineer or follow BRE Special Digest 1 guidance. Ordering the wrong class can lead to premature concrete failure or unnecessary cost.
(From: C35 DC-2 Concrete)
FND2 is primarily intended for unreinforced (plain mass) foundations. For reinforced foundations in DC-2 ground, specifiers often use FND2 with additional considerations or switch to a designed concrete (e.g., RC30 or similar) that meets both structural and chemical resistance needs. Check the project engineer’s specification, as reinforcement increases durability demands (cover, crack control, etc.). In some cases, FND2 can be used for lightly reinforced elements if the mix and placement comply fully with BS 8500.
(From: C35 DC-2 Concrete)
- DC-1: Non-aggressive or mildly aggressive ground → Often GEN1 or standard mixes (lower sulfate resistance needed).
- DC-2: Moderately aggressive (most common for UK domestic foundations on clay/sulfates) → FND2.
- DC-3 / DC-4: More aggressive conditions → FND3 or FND4 (higher minimum cement content, lower water/cement ratio, or additional protective measures). Variants like DC-2z or FND2Z exist for specific mobility or magnesium conditions. Higher DC classes generally require richer mixes or extra protections (APMs) to achieve greater durability.
(From: C35 DC-2 Concrete)
It is mainly used for unreinforced foundations in moderately sulfate-bearing or chemically aggressive ground, such as:
- Strip footings, trench-fill foundations, mass concrete bases.
- Domestic extensions, new builds, or light commercial structures on clay or sulfate-rich soils.
- Fully buried foundations where ground investigation shows DC-2 conditions. It is not typically for reinforced structural elements (those often use RC mixes) or non-aggressive ground (DC-1, which may use GEN1). Always base the choice on a proper ground investigation report.
(From: C35 DC-2 Concrete)
FND2 is typically a C25/30 or C28/35 strength class concrete (25–35 N/mm² compressive strength at 28 days). Key requirements include:
- Minimum cement content: Often 320–330 kg/m³ (some sources note around 300 kg/m³ with specific cements).
- Maximum water/cement ratio: Around 0.55.
- Sulfate-resisting cement combinations, such as Portland cement with high levels of ground granulated blastfurnace slag (e.g., CEM III/A + SR) or other approved blends that limit permeability and resist chemical attack.
- Default consistence (workability): S3 (slump typically 80–180 mm, target around 120 mm), suitable for trench fill or pumped placement. It is a quality-assured designated mix supplied by ready-mixed concrete plants with certification.
(From: C35 DC-2 Concrete)
DC-2 stands for Design Chemical Class 2. It is a classification of the ground’s chemical aggressiveness, primarily due to sulfates (and sometimes other factors like pH or magnesium), as determined from site soil and groundwater testing. DC-2 indicates moderately aggressive conditions (e.g., sulfate levels roughly 0.5–1.5 g/l in groundwater or corresponding soil concentrations). Concrete specified for DC-2 must have enhanced resistance to sulfate attack to prevent expansion, cracking, and long-term deterioration. The corresponding designated concrete is usually FND2 (Foundation concrete for DC-2).
(From: C35 DC-2 Concrete)
C40 Concrete FAQs
C40 is a very high‑strength concrete commonly used for heavy‑duty structural elements, industrial floors, bridges, foundations for large structures, and applications requiring exceptional durability and load‑bearing capacity.
(From: C40 Concrete)
Yes. C40 provides excellent compressive strength suitable for major structural components subjected to high loads and harsh conditions.
(From: C40 Concrete)
C40 offers outstanding durability, strength, and resistance to wear, making it ideal for demanding environments and long‑term structural performance.
(From: C40 Concrete)
C40 achieves a compressive strength of approximately 40 N/mm² after 28 days, giving it reliability for heavy and complex structural applications.
(From: C40 Concrete)
Yes. C40 can be pumped effectively with the use of suitable admixtures to maintain workability due to its high cement content.
(From: C40 Concrete)
C40 begins its initial set within a few hours depending on temperature and on‑site conditions. Full curing requires approximately 28 days.
(From: C40 Concrete)
C40 is more expensive than lower grades but provides long‑term value for applications where exceptional strength and durability reduce maintenance and repair needs.
(From: C40 Concrete)
C40 Waterproof Concrete FAQs
C40 waterproof concrete is a high‑strength mix designed to achieve 40 N/mm² compressive strength while providing enhanced resistance to water penetration. It is commonly used in environments exposed to moisture, hydrostatic pressure, or aggressive conditions.
(From: C40 Waterproof Concrete)
Typical applications include basements, retaining walls, water tanks, tunnels, lift pits, swimming pools, marine structures, and any construction requiring both strength and watertight performance.
(From: C40 Waterproof Concrete)
Waterproofing is achieved through low‑permeability mix designs, reduced water‑cement ratios, waterproofing admixtures, well‑graded aggregates, and correct compaction and curing.
(From: C40 Waterproof Concrete)
Yes. Crystalline waterproofing agents, PFA, GGBS, superplasticisers, or hydrophobic admixtures may be included to improve impermeability and durability.
(From: C40 Waterproof Concrete)
Yes. With proper workability agents such as plasticisers or superplasticisers, C40 waterproof concrete can be pumped efficiently even with its reduced permeability.
(From: C40 Waterproof Concrete)
It offers reduced permeability, but crack control measures—such as fibres, reinforcement, and proper curing—are still essential to prevent water ingress through shrinkage cracks.
(From: C40 Waterproof Concrete)
Yes. The increased cement content, specialised admixtures, and tighter quality control make it more costly, but it is highly cost‑effective in structures where water resistance is essential.
(From: C40 Waterproof Concrete)
C45 Concrete FAQs
C45 is an ultra high‑strength concrete used for major structural elements, heavy civil engineering works, large foundations, high‑load beams, industrial floors, and infrastructure requiring exceptional strength.
(From: C45 Concrete)
Yes. C45 provides very high compressive strength suitable for bridges, columns, reinforced beams, and critical load‑bearing components.
(From: C45 Concrete)
C45 offers outstanding durability and long‑term performance, making it ideal for structures exposed to heavy loads, harsh weather, or high traffic.
(From: C45 Concrete)
C45 reaches a compressive strength of approximately 45 N/mm² after 28 days.
(From: C45 Concrete)
Yes. C45 can be pumped with appropriate admixtures such as superplasticisers to maintain workability due to its high cement content.
(From: C45 Concrete)
C45 begins initial set within a few hours depending on temperature, with full curing requiring around 28 days.
(From: C45 Concrete)
C45 is more expensive than lower grades but offers exceptional value in high‑strength, long‑lasting structural applications.
(From: C45 Concrete)
C50 Concrete FAQs
C50 is an ultra high‑strength concrete used for major structural elements, heavy civil engineering works, large foundations, high‑load beams, industrial floors, and infrastructure requiring exceptional strength.
(From: C50 Concrete)
Yes. C50 provides very high compressive strength suitable for bridges, columns, reinforced beams, and critical load‑bearing components.
(From: C50 Concrete)
C50 offers outstanding durability and long‑term performance, making it ideal for structures exposed to heavy loads, harsh weather, or high traffic.
(From: C50 Concrete)
C50 reaches a compressive strength of approximately 50 N/mm² after 28 days.
(From: C50 Concrete)
Yes. C50 can be pumped with appropriate admixtures such as superplasticisers to maintain workability due to its high cement content.
(From: C50 Concrete)
C50 begins initial set within a few hours depending on temperature, with full curing requiring around 28 days.
(From: C50 Concrete)
C50 is more expensive than lower grades but offers exceptional value in high‑strength, long‑lasting structural applications.
(From: C50 Concrete)
C55 Concrete FAQs
C55 is an ultra high‑strength concrete used for major structural elements, heavy civil engineering works, large foundations, high‑load beams, industrial floors, and infrastructure requiring exceptional strength.
(From: C55 Concrete)
Yes. C55 provides very high compressive strength suitable for bridges, columns, reinforced beams, and critical load‑bearing components.
(From: C55 Concrete)
C55 offers outstanding durability and long‑term performance, making it ideal for structures exposed to heavy loads, harsh weather, or high traffic.
(From: C55 Concrete)
C55 reaches a compressive strength of approximately 55 N/mm² after 28 days.
(From: C55 Concrete)
Yes. C55 can be pumped with appropriate admixtures such as superplasticisers to maintain workability due to its high cement content.
(From: C55 Concrete)
C55 begins initial set within a few hours depending on temperature, with full curing requiring around 28 days.
(From: C55 Concrete)
C55 is more expensive than lower grades but offers exceptional value in high‑strength, long‑lasting structural applications.
(From: C55 Concrete)
C60 Concrete FAQs
C60 is an ultra high‑strength concrete used for major structural elements, heavy civil engineering works, high‑load beams and infrastructure requiring exceptional strength.
(From: C60 Concrete)
Yes. C60 provides very high compressive strength suitable for bridges, columns, reinforced beams, and critical load‑bearing components.
(From: C60 Concrete)
C60 offers outstanding durability and long‑term performance, making it ideal for structures exposed to heavy loads, harsh weather, or high traffic.
(From: C60 Concrete)
C60 reaches a compressive strength of approximately 60 N/mm² after 28 days.
(From: C60 Concrete)
Yes. C60 can be pumped with appropriate admixtures such as superplasticisers to maintain workability due to its high cement content.
(From: C60 Concrete)
C60 begins initial set within a few hours depending on temperature, with full curing requiring around 28 days.
(From: C60 Concrete)
C60 is more expensive than lower grades but offers exceptional value in high‑strength, long‑lasting structural applications.
(From: C60 Concrete)
DC2 Concrete FAQs
Yes — FND2 is often supplied with a consistence suitable for pumping (S3 class). It works well for trench-fill foundations. Practical tips:
- Ensure proper compaction and curing to maintain durability.
- Minimum cover and placement standards still apply if any reinforcement is present.
- It is more expensive than GEN mixes due to the sulfate-resisting cement and tighter limits.
- Always order from a certified supplier (e.g., QSRMC or BSI Kitemark) and confirm the exact designation on the delivery ticket.
- For very deep trenches or restricted access, discuss additives or flow with the supplier.
If your project involves specific ground conditions, reinforcement details, or location-based factors (e.g., near the coast), consult a structural engineer or concrete supplier for tailored advice, as exact requirements can vary slightly by region or updated BS 8500 amendments.
(From: C35 DC-2 Concrete)
Yes — a ground investigation (soil sampling and chemical analysis) is essential to determine the Aggressive Chemical Environment for Concrete (ACEC) class, which leads to the DC class. Factors include sulfate content, pH, groundwater mobility, and presence of brownfield or pyritic materials. Without testing, many UK guidelines default to FND2 for safety on potentially sulfate-bearing clays. Consult a geotechnical engineer or follow BRE Special Digest 1 guidance. Ordering the wrong class can lead to premature concrete failure or unnecessary cost.
(From: C35 DC-2 Concrete)
FND2 is primarily intended for unreinforced (plain mass) foundations. For reinforced foundations in DC-2 ground, specifiers often use FND2 with additional considerations or switch to a designed concrete (e.g., RC30 or similar) that meets both structural and chemical resistance needs. Check the project engineer’s specification, as reinforcement increases durability demands (cover, crack control, etc.). In some cases, FND2 can be used for lightly reinforced elements if the mix and placement comply fully with BS 8500.
(From: C35 DC-2 Concrete)
- DC-1: Non-aggressive or mildly aggressive ground → Often GEN1 or standard mixes (lower sulfate resistance needed).
- DC-2: Moderately aggressive (most common for UK domestic foundations on clay/sulfates) → FND2.
- DC-3 / DC-4: More aggressive conditions → FND3 or FND4 (higher minimum cement content, lower water/cement ratio, or additional protective measures). Variants like DC-2z or FND2Z exist for specific mobility or magnesium conditions. Higher DC classes generally require richer mixes or extra protections (APMs) to achieve greater durability.
(From: C35 DC-2 Concrete)
It is mainly used for unreinforced foundations in moderately sulfate-bearing or chemically aggressive ground, such as:
- Strip footings, trench-fill foundations, mass concrete bases.
- Domestic extensions, new builds, or light commercial structures on clay or sulfate-rich soils.
- Fully buried foundations where ground investigation shows DC-2 conditions. It is not typically for reinforced structural elements (those often use RC mixes) or non-aggressive ground (DC-1, which may use GEN1). Always base the choice on a proper ground investigation report.
(From: C35 DC-2 Concrete)
FND2 is typically a C25/30 or C28/35 strength class concrete (25–35 N/mm² compressive strength at 28 days). Key requirements include:
- Minimum cement content: Often 320–330 kg/m³ (some sources note around 300 kg/m³ with specific cements).
- Maximum water/cement ratio: Around 0.55.
- Sulfate-resisting cement combinations, such as Portland cement with high levels of ground granulated blastfurnace slag (e.g., CEM III/A + SR) or other approved blends that limit permeability and resist chemical attack.
- Default consistence (workability): S3 (slump typically 80–180 mm, target around 120 mm), suitable for trench fill or pumped placement. It is a quality-assured designated mix supplied by ready-mixed concrete plants with certification.
(From: C35 DC-2 Concrete)
DC-2 stands for Design Chemical Class 2. It is a classification of the ground’s chemical aggressiveness, primarily due to sulfates (and sometimes other factors like pH or magnesium), as determined from site soil and groundwater testing. DC-2 indicates moderately aggressive conditions (e.g., sulfate levels roughly 0.5–1.5 g/l in groundwater or corresponding soil concentrations). Concrete specified for DC-2 must have enhanced resistance to sulfate attack to prevent expansion, cracking, and long-term deterioration. The corresponding designated concrete is usually FND2 (Foundation concrete for DC-2).
(From: C35 DC-2 Concrete)
DC3 Concrete FAQs
Yes — FND3 is commonly supplied at S3 consistence, making it suitable for pumping into trenches or restricted access sites. Practical tips:
- Ensure thorough compaction and adequate curing (minimum periods per BS 8500) to achieve full durability.
- It is more expensive than GEN or basic FND2 mixes due to higher cementitious content and specialist cements.
- Order only from certified suppliers (QSRMC or BSI Kitemark) and verify the exact designation on the delivery ticket.
- For very aggressive variants or reinforced work, additional protective measures (APMs) like surface protection or enhanced quality may be needed.
- Discuss additives, flow, or aggregate size with the supplier for site-specific placement.
Exact requirements can vary with updates to BS 8500, site conditions, or intended working life (50 vs 100 years). For your project, share ground investigation details or consult a structural/geotechnical engineer and concrete supplier for precise recommendations
(From: C35 DC-3 Concrete)
Yes — a full ground investigation with soil and groundwater sampling/analysis is required to establish the ACEC class and resulting DC class. Key factors tested include sulfate content, pH, magnesium, groundwater mobility, and site history (e.g., brownfield). Without testing, some guidelines conservatively default toward FND2 or higher for safety, but using the wrong class risks premature failure or over-specification/cost. Engage a geotechnical engineer and follow BRE Special Digest 1 for accurate classification.
(From: C35 DC-3 Concrete)
FND3 is mainly intended for unreinforced (plain/mass) foundations. For reinforced foundations in DC-3 ground, many specifiers use FND3 with additional checks (e.g., cover, crack control) or opt for a designed concrete (such as RC30 or equivalent) that satisfies both structural strength and chemical resistance requirements. Reinforcement increases the need for low permeability and proper placement. Consult the structural engineer, as BS 8500 guidance may recommend designed mixes in some reinforced cases.
(From: C35 DC-3 Concrete)
- DC-2 / FND2: Moderately aggressive ground (lower sulfate risk) → Lower minimum cement content (often ~300–320 kg/m³) and higher maximum w/c ratio (e.g., 0.55).
- DC-3 / FND3: More aggressive conditions (higher sulfate, wetter, or more reactive soils) → Higher cement content, lower w/c ratio (better impermeability), and stricter cement type requirements for greater sulfate resistance. Both often have similar nominal strength (~30 N/mm²), but FND3 provides upgraded durability. Variants like FND3Z exist for specific mobility or magnesium issues. Higher DC classes generally demand richer, denser mixes or additional protective measures (APMs).
(From: C35 DC-3 Concrete)
FND3 is primarily for unreinforced foundations in moderately aggressive sulfate-bearing or chemically reactive ground, including:
- Strip footings, trench-fill, mass concrete bases on clays or soils with higher sulfate concentrations, wetter conditions, or increased reactivity.
- Sites where ground testing shows DC-3 conditions (e.g., certain brownfield, pyritic, or sulfate-rich natural soils). It offers enhanced protection compared to FND2 but is not for the most severe cases (those use FND4). Always base the specification on a professional ground investigation report.
(From: C35 DC-3 Concrete)
FND3 is typically a C25/30 or C28/35 strength class (25–35 N/mm² compressive strength at 28 days; often described as ~30 N/mm²). Key limiting values include:
- Minimum cement content: Around 320–340 kg/m³ (higher than many FND2 variants).
- Maximum water/cement ratio: Often 0.50 (tighter than DC-2 for reduced permeability).
- Sulfate-resisting cement combinations, such as CEM III/A or III/B with high slag content plus SR (sulfate-resisting) options, or other approved blends that provide enhanced chemical resistance.
- Default consistence (workability): S3 (target slump around 100–120 mm), suitable for trench fill and pumping. It is a certified designated mix supplied by ready-mixed plants.
(From: C35 DC-3 Concrete)
DC-3 stands for Design Chemical Class 3. It classifies the ground as moderately to highly aggressive to concrete, mainly due to elevated sulfate levels (typically higher than DC-2), lower pH, or more reactive/wetter conditions. This class comes from site-specific ground investigation results that determine the Aggressive Chemical Environment for Concrete (ACEC) class, which is then converted to a DC class. DC-3 requires concrete with greater sulfate resistance than DC-2 to prevent chemical attack, expansion, and long-term deterioration. The corresponding designated concrete is usually FND3 (Foundation concrete for DC-3).
(From: C35 DC-3 Concrete)
DC4 Concrete FAQs
DC4 concrete is a high-strength designated concrete suitable for foundations, slabs, and driveways that demand extra durability and load capacity. It bridges the gap between simpler DC mixes and fully engineered structural concrete, making it a popular choice for domestic and light commercial construction in the UK
DC4 may be preferred because it is:
- Simpler to specify under BS 8500
- Widely accepted by Building Control for many projects
- Consistent and standardised
- Often more cost-effective for domestic works
- Adequate where full structural design is not required
If reinforcement design, exposure class optimisation, or precise load calculations are needed, C‑class designed concrete is the better choice.
Yes. DC4 concrete is well suited for outdoor use, including:
- Exposure to rain and frost
- Driveways and access roads
- External slabs and paving bases
Correct curing, joint detailing, and drainage are still essential to prevent cracking and surface defects.
| Feature | DC3 | DC4 |
| Typical strength | ~20 N/mm² | ~25 N/mm² |
| Durability | Good | Higher |
| Foundation use | Domestic | Domestic & light commercial |
| Driveways | Light traffic | Heavier traffic |
| Cost | Lower | Slightly higher |
DC4 is chosen when extra strength, stiffness, or durability is required compared to DC3.
Yes — to a limited extent.
DC4 is suitable for:
- Simple load-bearing elements such as strip and trench foundations
- Ground-bearing slabs with modest reinforcement
However, it is not suitable for:
- Highly reinforced structural elements
- Beams, columns, suspended slabs
- Complex structural designs
For those applications, a designed concrete (e.g. C30/37) should be specified by an engineer.
DC4 concrete is commonly used for:
- Domestic and low-rise commercial foundations
- Industrial floor bases
- Driveways (including light commercial traffic)
- Garage and workshop slabs
- Oversite concrete with higher load expectations
- Heavier-duty external paving
It is often specified where Building Control requires higher performance but a fully designed mix is not necessary.
DC4 concrete has an approximate compressive strength of 25 N/mm² at 28 days.
This makes it:
- Similar in strength to C25/30 in some domestic situations
- Significantly stronger than DC3
- Suitable for heavier-duty domestic and light commercial applications
DC4 concrete is a designated concrete mix defined under BS 8500.
It is the highest-strength option within the DC (Designated Concrete) range, intended for applications requiring greater strength and durability than DC1–DC3, while still being simpler to specify than designed (C‑class) concretes.
Concrete Screed FAQs
Sand and cement screed is a traditional floor screed made from a mixture of sharp sand, cement, and water. It is used to create a smooth, level surface before installing floor finishes such as tiles, vinyl, carpet, or wood.
(From: Screed Concrete)
It is typically used for leveling floors, covering underfloor heating systems, forming a durable base for floor finishes, and providing a strong, stable substrate in both residential and commercial buildings.
(From: Screed Concrete)
A common mix ratio is 1 part cement to 4 or 5 parts sharp sand. The mix should be semi-dry, holding together when squeezed but not overly wet.
(From: Screed Concrete)
Traditional screed is usually laid between 50–75 mm. Thinner sections may require reinforcement or alternative screed types.
(From: Screed Concrete)
Traditional screed dries at approximately 1 mm per day under ideal conditions. Full drying may take several weeks depending on thickness, temperature, and ventilation.
(From: Screed Concrete)
Yes. Adding polypropylene fibres can improve screed strength, reduce cracking, and increase durability.
(From: Screed Concrete)
Yes. It is commonly used with underfloor heating systems, ensuring good heat transfer when properly installed and cured.
(From: Screed Concrete)
Yes, screed is essential for covering and protecting underfloor heating pipes while providing even heat distribution.
(From: Screed Concrete)
Yes, screed can be pumped, making it easier to apply in areas with limited access or large floor spaces.
(From: Screed Concrete)
Screed typically dries within 24–48 hours for light foot traffic, but full curing can take up to 28 days.
(From: Screed Concrete)
Most domestic screed applications require a thickness of between 50mm and 75mm, depending on the floor type and usage.
(From: Screed Concrete)
Concrete is a structural material used for load-bearing surfaces, while screed is a finishing layer applied on top to create a smooth, level surface.
(From: Screed Concrete)
Screed concrete is used to create a smooth, level surface over a structural concrete base. It is typically applied before final floor finishes such as tiles, laminate, or carpet and is essential for achieving a flat, durable floor.
(From: Screed Concrete)
Dry Lean Concrete FAQs
Yes. Dry lean concrete is often used in domestic foundations, extensions, garages and patios as a base layer. It is a cost‑effective solution that improves ground stability and helps ensure accurate placement of the final structural concrete.
(From: Dry Lean Concrete)
Dry lean concrete is delivered in a semi‑dry condition, spread to level, and then compacted using mechanical rollers or vibrating plates. Proper compaction is essential to achieve a dense and durable base layer.
(From: Dry Lean Concrete)
No, dry lean concrete is not normally reinforced. Because it is used as a base layer rather than a load‑bearing element, reinforcement such as steel mesh is usually unnecessary.
(From: Dry Lean Concrete)
Dry lean concrete is not structural, but it is ideal as a blinding or support layer beneath foundations. It creates a stable and level base so that reinforcement and structural concrete can be placed accurately and safely.
(From: Dry Lean Concrete)
Unlike standard concrete, dry lean concrete contains less cement and very little water, giving it a stiff, almost zero‑slump consistency. It is compacted rather than poured and does not achieve the strength needed for structural elements.
(From: Dry Lean Concrete)
It is commonly used beneath foundations, ground‑bearing slabs, road pavements and hardstandings. Its main role is to stabilize the ground, prevent contamination of structural concrete by the subsoil, and provide an even working platform.
(From: Dry Lean Concrete)
Dry lean concrete is a low‑cement, low‑water concrete mix used mainly as a non‑structural base or sub‑base. It provides a clean, firm and level surface beneath foundations, slabs or pavements but is not designed to carry structural loads.
(From: Dry Lean Concrete)
No Fine Concrete FAQs
It is often more economical than standard concrete due to reduced cement and aggregate use. Costs vary by region, project scale, and application but tend to be lower for materials. Installation may require specialised knowledge. Get local quotes, as sub-base prep and any coatings add to the total.
No-fines concrete excels in sustainable drainage and lightweight applications but is not a one-size-fits-all replacement for dense concrete. For specific projects, consult a structural engineer or experienced contractor, as performance depends heavily on local climate, soil, and design. Factors like permeability testing or strength requirements should guide decisions.
(From: No Fine Concrete)
Bond strength is low, so reinforcement is rarely used or requires special considerations. Additives like air-entraining agents improve freeze-thaw durability. Supplementary cementitious materials can enhance properties in research/modern mixes.
(From: No Fines Concrete)
- Permeable uses: Regularly sweep or pressure wash (low pressure) to clear debris, sediment, or vegetation from voids to preserve drainage.
- Walls: Apply external plaster, render, or coatings for weatherproofing and aesthetics.
- Avoid heavy chemicals or de-icers that could damage the structure.
- Inspect for clogging or erosion periodically. Maintenance is generally low but focuses on keeping permeability intact where required.
(From: No Fines Concrete)
Like all concrete, it can crack from shrinkage, settlement, or thermal changes, though shrinkage is typically lower. Prevention includes:
- Proper mix design and ratios.
- Adequate sub-base preparation.
- Control joints where needed.
- Air-entraining agents for freeze-thaw areas. Minor cracking is often less critical in drainage applications, but structural uses require engineering oversight.
(From: No Fines Concrete)
- Prepare a stable sub-base.
- Mix carefully (coarse aggregate coated with cement paste; avoid excess water to prevent paste drainage).
- Place with minimal compaction (rodding or light tamping — it cannot be vibrated heavily as it may cause segregation of paste).
- It can be dropped from height without segregation.
- Cure properly. Professional installation is recommended for best results, especially for structural or paved uses.
(From: No Fines Concrete)
With proper design, installation, and maintenance, it can last 20–40+ years in pavement or drainage applications, similar to or better than some conventional options due to reduced erosion from water. In walls, historical examples have endured decades. Lifespan depends on exposure (freeze-thaw cycles reduce it without protection), traffic loads, and sealing/coating where needed. Regular cleaning of voids helps maintain permeability.
(From: No Fines Concrete)
Pros:
- Excellent drainage and permeability — reduces surface runoff, flooding, and ponding.
- Lower material costs (less cement, no sand needed).
- Lightweight — easier handling and reduced foundation loads.
- Lower drying shrinkage.
- Better thermal insulation.
- Environmentally friendlier in some ways (conserves aggregates, aids stormwater management).
Cons:
- Lower compressive, flexural, and bond strength — limits structural use.
- High permeability can allow water ingress (not weathertight without coatings/plaster).
- Poor freeze-thaw resistance without air-entraining admixtures.
- Lower workability and requires careful placement.
- Not ideal for reinforcement due to low bond strength.
(From: No Fines Concrete)
- Load-bearing or non-load-bearing cast-in-place walls for single- and multi-story housing (historically popular in Europe/UK since the 1930s).
- Small retaining walls.
- Drainage layers or sub-bases under floors/slabs (damp-proofing).
- Pervious pavements, parking lots, driveways, footpaths, and low-traffic roads (reduces runoff and recharges groundwater).
- Landscaping, stabilization, or as lightweight fill.
- Acoustic/thermal insulation panels in some modern uses.
It is not suitable for heavy structural elements or high-traffic/high-load areas without engineering design.
(From: No Fines Concrete)
Common mix ratios:
- Aggregate-to-cement: 6:1 to 10:1 (by volume or mass, often 8:1 or higher).
- Water-to-cement: 0.38–0.60 (lower ratios for stiffer mixes).
Key properties:
- Density: Lower than normal concrete (lightweight).
- Compressive strength: Typically 1.4–14 MPa (200–2000 psi), much lower than standard concrete.
- Permeability: High — water drains freely through the voids.
- Shrinkage: About half that of conventional concrete.
- Thermal insulation: Better due to air voids.
- Workability: Stiffer mix; compaction is usually by rodding rather than vibration.
(From: No Fines Concrete)
- Vs. standard concrete: Standard mixes include fine aggregates for density and higher strength. No-fines lacks them, making it lighter, more permeable, with lower shrinkage but reduced strength and higher permeability.
- Vs. pervious concrete: The terms overlap significantly. Pervious (or permeable) concrete is often synonymous with no-fines concrete, both designed for drainage. Some distinctions note pervious concrete may have slight variations in void structure or additives, but they function similarly for stormwater management.
(From: No Fines Concrete)
No-fines concrete is a special concrete mix that omits fine aggregates (sand or fines) entirely. It uses only coarse aggregate (typically single-sized 10–20 mm crushed rock or gravel), Portland cement, and water. The cement forms a thin coating around the aggregate particles, leaving large voids (around 20–40% porosity). This results in a lightweight, permeable material unlike standard dense concrete.
(From: No Fines Concrete)
Ready Mix Concrete FAQs
To place an order, you have two options, by phone, or online.
To order by phone you can call Mix It on 0207 538 2266 with:
- Project address and access details
- Concrete type or strength required
- Quantity in cubic metres
- Preferred delivery date and time
Or you can use our concrete calculators to work out how much you need and order it online
We will handle the rest and guide you through the process.
Many suppliers offer lower‑carbon or eco‑concrete options, using recycled aggregates or reduced cement content. Ordering the correct amount also helps minimise waste and environmental impact.
- Too little: You may need a second delivery, which can be costly and affect finish quality
- Too much: Excess concrete may incur disposal charges
Accurate measurement and advice from your supplier can help avoid this.
We recommend you use our free concrete calculators to see how much you need.
Yes. Ready mix concrete is ideal for DIY projects, particularly where quality, speed and ease of use are important. It eliminates guesswork and reduces physical effort compared with hand mixing.
Yes we offer same‑day or next‑day deliveries, subject to availability and order cut‑off times. Early booking is recommended, especially during busy periods.
Ready mix concrete is generally more consistent and reliable than site‑mixed concrete because it is produced under controlled conditions. This makes it especially suitable for structural and load‑bearing applications.
Yes. Before delivery, you should ensure:
- Foundations, formwork and excavation are ready
- Access is clear for delivery vehicles or pumps
- Adequate labour and tools are in place
Good preparation helps avoid delays, wasted concrete and additional costs.
Yes, but weather conditions matter:
- In hot weather, concrete may set faster and need extra care
- In cold weather, setting slows and frost protection may be required
Suppliers can adjust mixes using admixtures to suit seasonal conditions.
Readymix concrete normally begins to set within 1.5 to 2 hours, depending on weather conditions and the mix design. Concrete should be placed, levelled and finished as soon as possible after delivery for best results.
Readymix concrete is typically delivered by:
- Drum mixer lorries, which discharge concrete directly
- Concrete pump, used when access is restricted or distances are long
You’ll need safe access for the vehicle and a clear plan for placing the concrete quickly on arrival.
Yes. We supply small load deliveries, which are ideal for domestic projects such as shed bases, garden paths or small patios. This avoids the cost and effort of mixing concrete yourself.
Concrete is measured in cubic metres (m³). To calculate the amount required, multiply: Length × Width × Depth (in metres)
It’s usually recommended to allow 5–10% extra for wastage and uneven ground. Suppliers can also help calculate volumes if you provide your dimensions.
The correct concrete depends on load requirements, exposure conditions and the application. For example:
- DC2 / DC3 for gardens, patios and paths
- C25 / C30 for foundations and slabs
- C35 / C40 for driveways or heavier loads
If you’re unsure, a concrete supplier can help you select the most suitable mix for your project.
Readymix concrete is suitable for a wide range of domestic and commercial applications, including:
- Driveways
- Foundations and footings
- House extensions
- Garage and shed bases
- Patios and garden paths
- Floors and slabs
Different concrete strengths and types are available depending on the use.
Readymix concrete is concrete that is batched at a concrete plant and delivered to site ready to use. It is mixed to specific proportions of cement, aggregates, water and, where required, admixtures, ensuring consistent quality and saving time on site compared with mixing by hand.
Power Float Concrete FAQs
Yes. Common repairs include:
- Crack filling
- Grinding and re‑sealing
- Resurfacing or overlays
Early maintenance helps avoid costly repairs later.
(From: Power Float Concrete)
For an average slab, power floating is completed the same day as the pour. Large or complex areas may require multiple passes over several hours.
(From: Power Float Concrete)
Costs are generally moderate and competitive due to reduced labour time. Pricing depends on:
- Floor size
- Thickness
- Access
- Finish specification
- Location
It is often more cost‑effective than alternative industrial floor finishes.
(From: Power Float Concrete)
Yes. Colour options include:
- Integral coloured concrete
- Surface hardeners
- Dyes and stains (applied after curing)
(From: Power Float Concrete)
Power floating itself does not cause cracking, but improper timing, rapid drying, lack of control joints, or poor curing can contribute to cracks. Correct planning and professional workmanship minimise this risk.
(From: Power Float Concrete)
- Light foot traffic: 24–48 hours
- Vehicle traffic: 7–14 days
- Full cure: ~28 days
Curing compounds or coverings are often used to control moisture loss.
(From: Power Float Concrete)
Yes. A power floated slab is an excellent base for polished concrete. Proper curing and sealing help achieve the best results.
(From: Power Float Concrete)
Sealing is highly recommended. A sealer:
- Reduces dust
- Improves stain resistance
- Enhances appearance
- Extends floor lifespan
Common options include acrylic, polyurethane, epoxy, or lithium-based sealers.
(From: Power Float Concrete)
It can be if left with a high-gloss finish, especially when wet. Slip resistance can be improved by:
- Using a matte or pan finish
- Applying anti-slip sealers
- Lightly texturing the surface
(From: Power Float Concrete)
- Bull floating: Done early to level the surface and remove imperfections
- Power floating: Done later to compact, smooth, and finish the surface
They are complementary steps in the finishing process.
Concrete is ready when it has stiffened enough to support the weight of the machine without sinking, but is still workable. This timing is critical and depends on weather, mix design, and thickness.
(From: Power Float Concrete)
Yes, but it is more common in garages, basements, and open‑plan modern interiors. For living spaces, additional sealing or polishing is usually required for aesthetics and stain resistance.
(From: Power Float Concrete)
- Warehouses and factories
- Garages and workshops
- Retail and commercial units
- Basements
- Agricultural buildings
- Some modern residential floors
(From: Power Float Concrete)
Yes. Power floating compacts the surface, increasing density and abrasion resistance. This makes it more durable, especially in high‑traffic or industrial environments.
(From: Power Float Concrete)
- Smooth and level finish
- Increased surface strength and durability
- Reduced surface dusting
- Faster finishing compared to hand trowelling
- Ideal base for coatings, resins, or floor coverings
(From: Power Float Concrete)
A power float is a petrol or electric-powered machine fitted with rotating blades or a pan. It smooths and compacts the surface of freshly laid concrete much faster and more evenly than hand trowelling.
(From: Power Float Concrete)
Power floated concrete is a concrete floor finish created by using a mechanical power trowel (also called a power float) to smooth and densify the surface after the concrete has been poured and partially set. The process produces a hard‑wearing, level, and professional finish.
(From: Power Float Concrete)
Imprint Concrete FAQs
It is possible but challenging and not recommended for beginners. Timing is critical (concrete sets quickly), multiple stamps/tools are needed, and mistakes (e.g., stamping too early/late) are hard or impossible to fix without removal. Professional crews with experience deliver better, longer-lasting results.
For specific projects, consult local contractors, as climate, soil, and regulations vary. Always verify warranties and request references. If you’re planning a project, factors like site drainage, expected traffic, and local weather should guide your choices.
- Vs. regular concrete: More expensive and decorative but similar durability. Requires more upkeep for colour protection.
- Vs. pavers/block paving: Cheaper and lower maintenance (no weeds between joints, no shifting), but pavers are easier to repair individually and more permeable. Imprinted concrete is a seamless monolithic pour.
Imprinted concrete offers a good balance for many homeowners seeking looks without the ongoing work of individual units.
Hundreds of options exist: stone (e.g., Ashlar, flagstone), brick, cobblestone, wood, slate, and custom combinations. Colours use integral mixes, dry-shake hardeners, or stains for base and accent hues. Designs are highly customisable. There is an extra costs for colour pigment and a lead time needs to be considered for ordering this.
Like all concrete, it can crack from settlement, temperature changes, or heavy loads. Prevention includes:
- Proper sub-base preparation and compaction.
- Control/expansion joints.
- Correct concrete mix and curing.
- Avoiding installation in extreme weather.
Minor cracking is common and sometimes considered normal; severe issues usually stem from installation errors.
It can be, especially when wet or freshly sealed, compared to a broom-finished surface. Textured stamps improve traction, and anti-slip additives are available for sealers. It’s often suitable for patios and driveways but may need extra consideration for pool decks or high-traffic wet areas.
- Indoors: Yes, thinner stamped overlays or specialised mixes work for floors or walls, but ensure proper ventilation and consider slip resistance.
- Over existing concrete: Direct stamping into hardened concrete isn’t possible. Instead, use a stamped concrete overlay (a thin layer of specialised mix applied on top) for resurfacing. Success depends on the condition of the old slab—proper preparation is essential.
- Daily/weekly: Sweep or blow off debris; hose down as needed.
- Sealing: Apply a quality concrete sealer every 2–3 years to protect colour, prevent water penetration, and reduce wear. Some recommend waiting 21–28 days after pouring before initial sealing.
- Avoid: De-icing salts in winter (they can damage the surface); harsh chemicals.
- Repairs: Small issues may need patching or overlay; major cracks often require professional attention. Proper sealing significantly extends life and appearance. Without it, the surface is more prone to fading, staining, mold, or freeze-thaw damage.
Costs vary widely by location, project size, complexity, colours/patterns, and labor. It generally costs more than plain concrete, but less than natural stone or high-end pavers. Contact us for a quote, as factors like site preparation and sealer type affect the total.
Pros:
- Aesthetic appeal: Customizable patterns and colours mimic expensive materials like stone or brick at a lower cost.
- Durability: Strong, seamless surface resistant to weeds and subsidence when properly installed.
- Low routine maintenance: Easy to sweep, hose down, or pressure wash.
- Cost-effective alternative to pavers, natural stone, or brick.
- Increased curb appeal and potential home value boost.
Cons:
- Can crack over time due to ground movement, freeze-thaw cycles, or poor sub-base (repairs are often noticeable since it’s a monolithic slab).
- May become slippery when wet or sealed (especially in rain or pool areas).
- Requires periodic resealing (every 2–3 years) to prevent fading, staining, or moisture damage.
- Colouring can fade or appear inconsistent if not maintained.
- Not permeable, so drainage planning is needed.
- Installation is weather-sensitive and demands skilled labor.
With proper installation and maintenance, imprinted concrete can last 20–30 years or more — similar to standard poured concrete. Factors affecting lifespan include climate (freeze-thaw cycles), usage (vehicle traffic vs. foot traffic), sub-base quality, and regular sealing. Poor maintenance or extreme conditions can shorten this.
Installation typically involves:
- Preparing a stable sub-base (compacted gravel or similar).
- Pouring and leveling the concrete.
- Applying colour hardener and release agent.
- Stamping patterns with mats or tools while the concrete is still workable.
- Curing the slab.
- Applying a protective sealer once cured.
The process usually takes 3–7 days for installation, plus additional time for drying/curing. Exact timing depends on weather, project size, and crew. Professional installation is strongly recommended due to the narrow window for proper stamping.
Imprinted concrete is a type of decorative concrete where patterns and textures are stamped or pressed into the surface of wet concrete using mats. Colour hardeners, release agents, and accent colours create realistic looks resembling natural materials. It forms a single, seamless slab unlike individual pavers or blocks.
Flowing Concrete FAQs
In most cases, yes. It’s popular because it saves time, improves finish quality, and simplifies installation. Your concrete supplier or contractor can advise on the best mix for your job.
(From: Flowing Concrete)
Curing is the same as standard concrete. It needs to be protected from drying out too quickly to ensure good strength and finish.
(From: Flowing Concrete)
It actually tends to be cleaner and easier to place than traditional concrete, provided it’s handled by experienced professionals.
(From: Flowing Concrete)
Setting times are similar to normal concrete. Weather, temperature, and mix design can affect this, and setting speed can be adjusted if needed.
(From: Flowing Concrete)
Yes. It pumps very well and is often used on sites where access is limited or concrete needs to be placed at a distance.
(From: Pumping Concrete) (Flowing Concrete)
The concrete itself can cost a little more, but many customers save money overall thanks to:
- Faster installation
- Lower labour costs
- Less finishing work
(From: Flowing Concrete)
Absolutely. Flowing concrete is widely used in residential builds, extensions, and refurbishments because it gives a flatter floor and quicker installation.
(From: Flowing Concrete)
Only if the formwork isn’t sealed properly. Because flowing concrete is more fluid, good, tight formwork is important to prevent leaks.
(From: Flowing Concrete)
It’s ideal for:
- House foundations
- Floor slabs and screeds
- Garages and driveways
- Areas with lots of steel reinforcement
- Underfloor heating systems
(From: Flowing Concrete)
Usually not. Unlike traditional concrete, flowing concrete normally settles itself into place, saving time and reducing noise on site.
(From: Flowing Concrete)
Yes. Flowing concrete is just as strong as traditional concrete. It flows easily because of special additives, not because extra water is added.
(From: Flowing Concrete)
Because it’s:
- Quicker to lay
- Easier to work with
- Smoother once finished
- Less messy and less labour‑intensive
It helps jobs get done faster and often with a better final result.
(From: Flowing Concrete)
Flowing concrete is a type of concrete that spreads easily when poured. It levels itself with very little effort, helping create a smooth, even finish without lots of manual work.
(From: Flowing Concrete)
Coloured Concrete FAQs
Yes. Mix It’s commercial concrete mixes are suitable for reinforced foundations, pads, columns, ground beams and floor slabs. We work closely with contractors and engineers to ensure compliance with structural drawings and specifications.
(From: Coloured Concrete)
Like all concrete, coloured concrete can crack. However, correct installation, control joints, reinforcement, and good curing practices significantly reduce cracking. Importantly, cracks do not typically affect the colour itself.
(From: Coloured Concrete)
Maintenance is simple:
- Regular sweeping and washing
- Resealing every few years (depending on traffic and exposure)
- Avoid harsh chemicals
Proper care helps preserve colour vibrancy and surface protection.
(From: Coloured Concrete)
Absolutely. Coloured concrete is commonly used for:
- Driveways
- Patios
- Pathways
- Pool surrounds
When sealed correctly, it is weather-resistant, durable, and slip-resistant.
(From: Coloured Concrete)
Yes, coloured concrete typically costs more due to:
- Added pigments or decorative treatments
- Extra labour and finishing time
However, it can eliminate the need for additional finishes like paving or tiles, often making it cost-effective overall.
(From: Coloured Concrete)
High-quality coloured concrete is UV-stable and long-lasting, especially when sealed properly. Some minor fading may occur over many years, but sealing and routine maintenance greatly reduce this risk.
(From: Coloured Concrete)
There are three common methods:
- Integral colouring: Pigment is mixed into the concrete before pouring.
- Concrete staining: Acid or water-based stains are applied to cured concrete.
- Dry-shake hardeners: Coloured powders are worked into the surface while the concrete is still fresh.
Each method offers different finishes, durability, and colour depth.
(From: Coloured Concrete)
Coloured concrete is standard concrete that has been enhanced with integral pigments, stains, or surface treatments to achieve a decorative colour. The colour becomes part of the concrete rather than a surface coating like paint.
(From: Coloured Concrete)
Sulphate Resistant Concrete FAQs
Sulphate resistant concrete is a specially designed mix formulated to resist chemical attack from sulphate-rich soils, groundwater, or industrial effluents.
(From: Sulphate Resistant Concrete)
Sulphates can react with cement compounds, causing expansion, cracking, and deterioration. Sulphate resistant concrete prevents structural damage in high-sulphate environments.
(From: Sulphate Resistant Concrete)
The mix typically uses sulphate resistant cement (SRC) or low C3A cement, reduced permeability, well-graded aggregates, and admixtures to improve durability.
(From: Sulphate Resistant Concrete)
Yes, although this will depend on which mix of concrete you order. With appropriate workability agents such as plasticisers or superplasticisers, sulphate resistant concrete can be pumped efficiently.
(From: Sulphate Resistant Concrete)
Setting times are similar to conventional concrete, though slightly slower if low-heat cements or supplementary cementitious materials are used.
(From: Sulphate Resistant Concrete)
It may cost more due to specialised cement types, but it is highly cost-effective in environments where sulphate attack would otherwise cause severe damage and repair costs.
(From: Sulphate Resistant Concrete)
Learn what the different types of concrete are for
What is the difference? How do you use each of them? What are they used for? Find out below.
