Ready-Mix Concrete Volume Calculator & 2026 Pricing Guide
C20/25 concrete — also widely known in the UK as GEN3 concrete under the BS 8500 designated mix system — is the standard specification for domestic strip foundations, trench fill foundations, blinding layers, oversite concrete, and lightly loaded ground floor slabs throughout the United Kingdom. The designation C20/25 refers to the characteristic compressive strength of the concrete: 20 N/mm² when tested on a cylindrical specimen and 25 N/mm² when tested on a cube specimen at 28 days — the two standard test geometries used in European and UK practice respectively.
In 2026, the price of C20/25 concrete per cubic metre in the UK ranges from approximately £125 to £160 per m³ for standard ready-mix delivered by a full transit mixer truck. Regional variation, delivery distance, order volume, and supplier account type all influence the final price. Understanding the full cost picture — including delivery charges, short load surcharges, pump hire, and finishing costs — is essential for accurate project budgeting. This guide covers everything you need to know about C20/25 concrete pricing, specification, and ordering in the UK in 2026.
C20/25 concrete is a standard-strength structural concrete suitable for a wide range of non-aggressive, below-ground domestic construction applications. Under the BS 8500-1 designated mix system, it is sold as GEN3 by most UK ready-mix suppliers — a designation that specifies not just the strength class but also the minimum cement content, maximum water-cement ratio, aggregate size, and workability appropriate for the intended use. The GEN3 designation is accepted by building control for the vast majority of standard domestic strip and trench fill foundations, oversite concrete slabs under beam and block floors, garage floor slabs, and garden outbuilding bases.
Common applications for C20/25 / GEN3 concrete in UK residential construction include: strip foundations for single and two-storey domestic extensions; trench fill foundations where the trench is filled with concrete from the base to within 150mm of finished ground level; oversite concrete (the 100mm blinding slab poured over the compacted sub-base beneath a beam and block or suspended timber floor); concrete garage floor slabs (typically 100mm thick, reinforced with A193 or A252 mesh); paths and external hardstandings where the loading is limited to domestic vehicles and foot traffic; and garden retaining walls and steps where the structural loading is light. For applications subject to de-icing salts, heavy vehicle loading, or aggressive chemical conditions, a stronger and more durable concrete designation is required.
The price of C20/25 ready-mix concrete in the UK in 2026 varies by delivery method, volume, location, and supplier. The following prices represent typical May 2026 pricing for trade customers with established accounts at major UK ready-mix suppliers including Hanson, Aggregate Industries, Tarmac, and CEMEX:
Full transit mixer (6–8m³ minimum order): £125–£160 per m³ for standard GEN3 / C20/25 concrete. The majority of domestic construction pours fall into this category. Most suppliers require a minimum order of 6m³ — smaller orders are subject to a short load charge. Delivery charges are typically included within the per-m³ price up to a certain distance (usually 20–30km from the batching plant), with additional mileage charges applying beyond that radius.
Mini-mix (under 3m³): £175–£250 per m³. Mini-mix suppliers use smaller drum trucks that can access tighter residential sites and deliver volumes as small as 0.25m³. The higher per-m³ cost reflects the smaller vehicle, more frequent deliveries, and generally higher operating costs of the mini-mix model. Mini-mix is the appropriate choice for small garden walls, post foundations, step bases, and other low-volume domestic pours where a full transit mixer would deliver far more than needed.
Volumetric / on-site mix truck: £145–£185 per m³. Volumetric concrete trucks carry dry aggregate, cement, and water separately and mix the concrete on site to order. The advantage is that you only pay for what you use — there is no minimum order and no short load charge. The disadvantage is a slightly higher per-m³ price than full transit mixer concrete and the need to have the truck on site for the full duration of the pour. Volumetric is increasingly popular for residential projects of 2–5m³ where a mini-mix would be too expensive per m³ but a full transit load would generate significant unused concrete.
Bagged dry-mix concrete: £220–£320 per m³ equivalent. Bagged concrete is the most expensive per-m³ option but requires no delivery planning, is available from builders merchants and DIY stores on demand, and is appropriate for very small pours of under 0.5m³. In 2026, a standard 25kg bag of general purpose concrete dry mix costs approximately £5.50–£7.50 and makes approximately 12.5 litres of concrete — equivalent to approximately £440–£600 per m³ for the smallest bags. Larger 40kg bags offer slightly better value at approximately £350–£480 per m³ equivalent.
Ready-Mix Suppliers 2026: Hanson Concrete UK | Aggregate Industries | Tarmac Ready Mix | CEMEX UK | Technical standards at BSI Group
The price of C20/25 concrete per m³ is not fixed — several factors cause the price you pay to vary significantly from the national average. Understanding these factors helps you get the best price and avoid unexpected costs:
Distance from batching plant: Ready-mix concrete has a maximum transport time of approximately 90 minutes from leaving the plant to placement on site. Suppliers charge additional mileage fees — typically £1.50–£3.50 per km beyond their standard delivery radius — making location relative to the nearest plant a significant cost variable. Checking which plant will supply your site and the mileage surcharge before ordering can save a meaningful amount on large pours.
Order volume: The minimum order for a full transit mixer is typically 6m³. Orders below this minimum attract a short load surcharge of £50–£120 per load in 2026. For very small orders — under 2m³ — the short load surcharge on a transit mixer often makes mini-mix or volumetric concrete more economical despite their higher per-m³ price. Always calculate the total delivered cost, not just the per-m³ price, when comparing options.
Admixtures and special requirements: Standard GEN3 / C20/25 concrete is supplied at a standard slump (workability). Requesting a higher slump for pump-placed concrete, adding a plasticiser for improved flow, specifying retarded concrete to extend the working time in hot weather, or adding accelerator for cold weather pouring — all add to the per-m³ price, typically £5–£25 per m³ depending on the admixture type and dosage.
Regional pricing variation: Ready-mix concrete prices vary by 15–25% across the UK. London and the South East are consistently the most expensive regions — expect to pay £145–£165 per m³ for GEN3 in London versus £115–£140 per m³ in the North East and Scotland. The South West and Wales fall in the middle range at approximately £130–£150 per m³. Local competition between suppliers also affects prices significantly — always obtain at least two quotes.
Fuel surcharges and cement price fluctuations: Ready-mix concrete prices in 2026 continue to reflect the elevated energy costs that have affected the construction materials sector since 2021. Cement — the primary cost driver in concrete — is energy-intensive to manufacture, and its price is closely linked to gas and electricity costs. Most suppliers apply a fuel surcharge that is reviewed quarterly — in 2026 this adds approximately £5–£12 per m³ to base concrete prices compared to pre-2020 levels.
A typical C20/25 / GEN3 concrete mix design for domestic applications contains the following proportions per cubic metre of finished concrete: approximately 240–280 kg of Portland cement (CEM I) or a blended cement; 150–175 litres of water; 1,750–1,850 kg of combined aggregate (typically 30–40% fine aggregate / sharp sand and 60–70% coarse aggregate / 20mm crushed stone or gravel); and a small quantity of plasticiser or air-entraining admixture as required for workability and durability. The water-cement ratio — the key variable controlling concrete strength — is typically 0.60–0.65 for standard GEN3 concrete.
The total density of freshly mixed C20/25 concrete is approximately 2,350–2,400 kg/m³ — meaning that each cubic metre of concrete weighs approximately 2.35–2.40 tonnes. This is important for structural calculations (to determine the dead load of a concrete element) and for site logistics — a fully loaded 6m³ transit mixer carries approximately 14–15 tonnes of concrete, requiring suitable site access and ground bearing capacity. The transit mixer itself weighs approximately 12–14 tonnes unladen, giving a gross vehicle weight of 26–29 tonnes for a standard 6m³ load.
The characteristic compressive strength of C20/25 concrete at 28 days — 25 N/mm² cube strength — is confirmed by quality control testing at the batching plant. Reputable ready-mix suppliers will provide a delivery ticket (docket) with each load confirming the mix design, water-cement ratio, slump, and plant test data. For structural applications, always retain the delivery tickets and request a concrete conformity certificate from your supplier confirming compliance with BS 8500-1 and the relevant exposure class.
Ordering ready-mix concrete for the first time can be confusing — the terminology, ordering process, and site logistics are unfamiliar to many self-builders and small contractors. The following guide covers the key steps for a successful C20/25 concrete pour in the UK in 2026:
Calculate your volume accurately before contacting suppliers. Use the calculator at the top of this page to calculate net volume and add 10% wastage. For odd shapes, break the pour into rectangles and add the volumes. Always round up — running out of concrete mid-pour is a serious problem that can compromise the structural integrity of the pour and requires either stopping and forming a cold joint (a potential weakness) or emergency delivery at premium cost.
Book in advance — most UK ready-mix suppliers require at least 24–48 hours notice for standard deliveries, and popular booking slots (Monday to Friday morning deliveries) can fill up several days ahead during the busy spring and summer season. For large commercial pours, booking 5–10 working days ahead is advisable. Have a contingency plan in case of delivery delays — bad weather, mechanical breakdown, or traffic can delay a truck and your concrete team should be briefed on what to do if the truck is late.
Prepare the pour area thoroughly before the truck arrives. All formwork must be in place, properly braced, and checked for level. Sub-base must be compacted, the DPM laid (for floor slabs), and any reinforcement positioned at the correct cover depth on spacers. Have sufficient labour — typically one person per m³ per hour as a rough guide — to spread, compact, and finish the concrete before it begins to stiffen. For large pours, a concrete pump is the most efficient way to distribute concrete from the truck to the pour location.
Specify the correct workability (slump) when ordering. Standard GEN3 concrete for foundations is typically supplied at S2 slump (50–90mm) — pourable but not self-levelling. For pump placement, S3 or S4 slump (100–160mm) is usually required. For self-levelling floor screeds, even higher slump or a self-compacting concrete (SCC) designation may be needed. Discuss the specific requirements of your pour with your concrete supplier when ordering — they will advise on the correct slump class for your application and whether a plasticiser is needed.
C20/25 concrete is appropriate for the majority of standard domestic below-ground and lightly loaded applications, but there are several situations where a stronger concrete designation is required. Understanding when to upgrade from C20/25 to C25/30, C30/37, or higher is important for both structural performance and Building Regulations compliance.
Upgrade to C25/30 (FND2) or stronger when: ground investigation reveals sulfate aggressivity class AC-2 or above (requiring FND2–FND4 concrete with SRPC or blended cement); the concrete will be permanently exposed to freezing and thawing in a wet condition (external steps, retaining wall copings, exposed floor slabs); the concrete is to be used in a car park or road subject to de-icing salt application; or the structural engineer has specified a higher strength class for a specific structural reason. In 2026, C25/30 ready-mix costs approximately £135–£175 per m³, a modest premium over C20/25 that is easily justified where the application demands it.
Upgrade to C30/37 or higher for: exposed concrete in aggressive environments (coastal, industrial, high traffic); structural elements carrying significant loads such as columns, deep beams, and bridge elements; concrete subject to abrasion from vehicle or foot traffic (factory floors, loading bays); and any application where a structural engineer has specified higher strength. In 2026, C30/37 costs approximately £145–£185 per m³ ready-mix, and C35/45 costs approximately £160–£210 per m³.
For larger C20/25 concrete pours where the transit mixer cannot discharge directly into the pour area — due to site access, distance from the road, or the need to distribute concrete across a wide area — a concrete pump is used to convey the concrete from the truck to the pour location through a pipe or boom. In 2026, a standard boom pump (on its own truck, with a 24–32m reach) costs approximately £650–£1,100 per day to hire including the operator. A line pump (trailer-mounted, pumping through flexible rubber hose) costs approximately £350–£600 per day. Pump hire is generally only economical for pours of 5m³ or more — for smaller volumes, the pump mobilisation cost per m³ of concrete is prohibitive.
Always discuss pump requirements with your concrete supplier when ordering — they can advise whether the concrete specification needs to be adjusted (typically to a higher slump with plasticiser) for pump placement, and can often arrange pump hire through their own network. Pump lines and boom sections must be primed with a cement slurry before the concrete pour begins — this slurry (typically 0.1–0.2m³) must be discarded and must not be included in the structural pour. Factor this into your concrete volume order.
| Delivery Method | Min. Order | Price per m³ (2026) | Delivery Charge | Short Load Surcharge | Best For |
|---|---|---|---|---|---|
| Ready-mix transit mixer | 6m³ (typical) | £125–£160/m³ | Included up to ~25km | £50–£120 if under 6m³ | Foundations, slabs, large pours (>6m³) |
| Mini-mix (small truck) | 0.25m³ | £175–£250/m³ | £25–£55 fixed charge | None | Small domestic pours 0.25–3m³ |
| Volumetric / on-site mix | None | £145–£185/m³ | £30–£75 mobilisation | None — pay per m³ used | Awkward volumes 1–8m³, no waste |
| Bagged dry-mix (25kg) | 1 bag | £440–£600/m³ equiv. | Free (from merchant) | None | Tiny pours <0.2m³, post holes, repairs |
| Bagged dry-mix (40kg) | 1 bag | £350–£480/m³ equiv. | Free (from merchant) | None | DIY pours <0.5m³ |
| Pump + ready-mix combined | 6m³ concrete | £125–£160/m³ + pump | Pump: £350–£1,100/day | As per transit mixer | Pours >5m³ with access issues |
Prices correct as of May 2026. Regional variation of ±15–25% expected. London and South East are consistently 10–20% above the national average. Always obtain at least two quotes from local suppliers.
| Region | C20/25 / GEN3 Price per m³ | C25/30 Price per m³ | C30/37 Price per m³ | Notes |
|---|---|---|---|---|
| London | £145–£165 | £158–£180 | £175–£205 | Highest in UK — access surcharges common |
| South East England | £138–£160 | £150–£175 | £165–£195 | High demand, competitive market |
| South West England | £132–£152 | £145–£168 | £158–£188 | Rural areas may attract mileage surcharges |
| East Anglia | £128–£150 | £140–£165 | £155–£182 | Good plant coverage in most areas |
| Midlands | £125–£148 | £138–£162 | £150–£178 | Well-served by major suppliers |
| North West England | £122–£145 | £135–£158 | £148–£175 | Competitive market — multiple suppliers |
| Yorkshire & Humber | £120–£143 | £132–£156 | £145–£172 | Good availability, competitive pricing |
| North East England | £118–£140 | £130–£154 | £142–£168 | Lowest prices in England |
| Wales | £125–£150 | £138–£164 | £150–£180 | Rural areas can attract significant surcharges |
| Scotland (Central) | £122–£148 | £135–£162 | £148–£178 | Good supply in Central Belt |
| Scotland (Highland / Islands) | £145–£195 | £160–£215 | £175–£235 | Remote surcharges apply — consider site-mix |
| Northern Ireland | £120–£145 | £132–£158 | £144–£172 | Competitive local market |
Prices are indicative May 2026 estimates based on trade account pricing. Cash / retail prices are typically 10–18% higher. Volume discounts apply on orders above 20m³. Always request quotes from at least two local suppliers before ordering.
| Grade | BS 8500 Name | Cube Strength | Price per m³ (2026) | Typical Application | Min. Cement |
|---|---|---|---|---|---|
| C8/10 | GEN0 | 10 N/mm² | £95–£120/m³ | Blinding, non-structural fill | 180 kg/m³ |
| C12/15 | GEN1 | 15 N/mm² | £100–£128/m³ | Mass concrete fill, kerb bedding | 200 kg/m³ |
| C16/20 | GEN2 | 20 N/mm² | £110–£135/m³ | Oversite, drainage bedding | 220 kg/m³ |
| C20/25 ★ | GEN3 | 25 N/mm² | £125–£160/m³ | Strip foundations, floor slabs, garages | 240 kg/m³ |
| C25/30 | RC25 / FND2 | 30 N/mm² | £135–£175/m³ | Reinforced slabs, aggressive ground | 280 kg/m³ |
| C28/35 | RC28 / FND3 | 35 N/mm² | £142–£182/m³ | Moderately aggressive sulfate ground | 320 kg/m³ |
| C30/37 | RC30 | 37 N/mm² | £145–£185/m³ | Exposed slabs, car parks, roads | 300 kg/m³ |
| C32/40 | RC32 / FND4 | 40 N/mm² | £155–£200/m³ | Highly aggressive ground, heavy loading | 340 kg/m³ |
| C35/45 | RC35 | 45 N/mm² | £160–£210/m³ | Structural columns, bridge decks | 360 kg/m³ |
| C40/50 | RC40 | 50 N/mm² | £175–£230/m³ | High-rise, precast, post-tensioned | 380 kg/m³ |
★ C20/25 / GEN3 is the focus of this page. All prices are 2026 UK trade account ready-mix estimates. Confirm current pricing with your local supplier. Prices exclude pump hire and any admixture surcharges.
| Constituent | Quantity per m³ | Notes |
|---|---|---|
| Portland Cement (CEM I 42.5) | 240–280 kg | Or blended cement (CEM II/B-V with PFA, or CEM III with GGBS) |
| Water | 150–175 litres | Free water — water in aggregate not included in this figure |
| Fine aggregate (sharp sand) | 640–720 kg | Zone 2 or Zone 3 BS EN 12620 grading |
| Coarse aggregate (20mm gravel / crushed stone) | 1,100–1,200 kg | 20mm nominal maximum aggregate size (NMS) |
| Plasticiser / water reducer | 0.5–1.5 litres | Optional — improves workability without increasing w/c ratio |
| Water-cement ratio (w/c) | 0.60–0.65 | Key strength parameter — lower = stronger |
| Total fresh density | ~2,350–2,400 kg/m³ | ~2.375 tonnes per m³ average |
| 28-day cube strength | ≥25 N/mm² | Characteristic strength — 95% of cubes must exceed this |
| Standard slump (foundation) | S2: 50–90mm | S3 (100–150mm) for pumped concrete |
C20/25 concrete achieves a characteristic compressive cube strength of 25 N/mm² at 28 days — the "25" in the designation. The "20" refers to the cylinder strength used in European Eurocode design calculations.
In the UK BS 8500 designated mix system, C20/25 is sold as GEN3 by ready-mix suppliers. GEN3 is the most widely specified concrete grade for domestic strip foundations and floor slabs in England and Wales.
Standard ready-mix GEN3 / C20/25 costs £125–£160 per m³ in 2026, depending on region and supplier. London prices are consistently 10–20% above the national average. Always get at least two quotes.
Fresh C20/25 concrete weighs approximately 2,350–2,400 kg/m³ — meaning a standard 6m³ transit mixer load weighs approximately 14.3 tonnes. Critical for site access planning and structural dead load calculations.
Most UK ready-mix suppliers require a minimum 6m³ order for a standard transit mixer delivery. Orders below this minimum attract a short load surcharge of £50–£120. Consider mini-mix or volumetric for smaller volumes.
Ready-mix concrete must be discharged from the truck within 90 minutes of leaving the batching plant, or 300 drum revolutions — whichever occurs first. Plan site access and labour to ensure the truck can be unloaded promptly.
All C20/25 / GEN3 concrete supplied in the UK must comply with BS 8500-1 (Method of specifying and guidance for the specifier). Always request a conformity certificate from your supplier for any structural pour.
The water-cement ratio of GEN3 concrete is typically 0.60–0.65 — the primary variable controlling concrete strength. Never add extra water on site to improve workability; this weakens the concrete and invalidates BS 8500 compliance.
C20/25 / GEN3 is not suitable for ground with sulfate class AC-2 or above, exposure to de-icing salts, or heavy vehicle abrasion. Upgrade to FND2–FND4 (C25/30–C32/40) for these conditions — confirm ground aggressivity from soil analysis.
Always order 10% more concrete than your calculated net volume. Over-ordering by 10% on a 6m³ pour costs approximately £75–£100 extra; running short and emergency re-ordering can cost £300–£800 in surcharges and wasted labour.
C20/25 concrete achieves approximately 70% of its 28-day strength at 7 days and roughly 50% at 3 days. For lightly loaded domestic foundations, formwork can typically be struck after 24–48 hours, but full structural loading should wait until 28 days.
Do not pour C20/25 concrete when air temperatures are below 2°C or expected to drop below 2°C within 24 hours. Frost during curing permanently damages the concrete matrix and dramatically reduces ultimate strength. Use insulated blankets or frost-protection admixtures in cold conditions.
C20/25 is a European concrete strength class designation defined in BS EN 206 and adopted in the UK through BS 8500. The "C" stands for concrete; the first number (20) is the characteristic compressive strength in N/mm² measured on a 150mm diameter cylinder specimen; the second number (25) is the characteristic compressive strength in N/mm² measured on a 150mm cube specimen — both tested at 28 days after casting. In the UK, the cube strength of 25 N/mm² is the more commonly quoted value because cube testing has historically been the standard UK test method. In everyday ordering from UK ready-mix suppliers, C20/25 concrete is most commonly specified by its BS 8500 designated mix name: GEN3.
In May 2026, standard GEN3 / C20/25 ready-mix concrete costs approximately £125–£160 per m³ delivered by a standard transit mixer truck in most parts of England. London and the South East are at the higher end (£145–£165/m³) while the North East and Scotland are at the lower end (£118–£145/m³). Mini-mix deliveries for small volumes cost £175–£250/m³. Volumetric on-site mixing costs £145–£185/m³. Bagged dry-mix costs the equivalent of £350–£600/m³. Always obtain at least two quotes from local suppliers and compare the total delivered cost including any delivery charges, short load surcharges, and pump hire.
The minimum order for a standard transit mixer delivery from most UK ready-mix suppliers is 6m³. Orders below 6m³ are subject to a short load surcharge of £50–£120 per delivery. For volumes under 3m³, a mini-mix supplier (using a smaller drum truck) is typically more economical despite the higher per-m³ price, as no short load surcharge applies. For volumes between 2m³ and 6m³ where you want to avoid waste, a volumetric concrete truck — which mixes on site and charges only for what you use — is often the best solution.
Yes — C20/25 and GEN3 are the same concrete, just referenced by different naming systems. C20/25 is the Eurocode strength class designation (cube strength 25 N/mm²). GEN3 is the BS 8500 designated mix name used for ordering from UK ready-mix suppliers. When you order GEN3 from a UK ready-mix supplier, you will receive concrete compliant with the C20/25 strength class, with the appropriate minimum cement content (240 kg/m³), maximum water-cement ratio (0.65), and specified aggregate size for the application. Both designations are accepted by building control for standard domestic strip foundation and floor slab applications.
Using standard 25kg bags of dry-mix concrete (which make approximately 12.5 litres of concrete per bag), you need approximately 80 bags per m³. Using 40kg bags (making approximately 20 litres per bag), you need approximately 50 bags per m³. At 2026 prices of £5.50–£7.50 per 25kg bag, the bagged equivalent costs approximately £440–£600 per m³ — roughly three times the price of ready-mix. Bagged concrete is only economical for very small pours of under 0.2m³ (under 16 bags). For anything larger, ready-mix or mini-mix concrete is significantly cheaper and produces more consistent results.
Calculate the volume of concrete required by multiplying length × width × depth in metres to give the volume in cubic metres (m³). Add 10% wastage to this figure to give the volume to order. For example, a garage floor slab 5.0m × 4.0m × 0.100m (100mm thick) requires: 5.0 × 4.0 × 0.100 = 2.0m³ net + 10% = 2.2m³ to order. Use the calculator at the top of this page to automate this calculation. For irregular shapes, break the pour into rectangles and sum the volumes. Always round up to the nearest 0.5m³ when ordering from a ready-mix supplier.
C20/25 / GEN3 is acceptable for a domestic driveway subject to light vehicle traffic (private cars, light vans) when laid at 100mm thickness on a well-compacted sub-base. However, for driveways subject to heavier vehicles, frequent turning movements, or de-icing salt application in winter, C25/30 or C30/37 is a better specification — the additional strength and lower water-cement ratio significantly improves resistance to surface abrasion, freeze-thaw damage, and salt attack. The price premium between C20/25 and C25/30 is typically only £10–£20 per m³, which is easily justified for the improved durability of an exposed surface.
C20/25 concrete gains strength progressively over time. At normal curing temperatures (15–20°C), it achieves approximately 50% of its 28-day strength at 3 days, 70–75% at 7 days, and its characteristic 25 N/mm² cube strength at 28 days. For domestic strip foundations, the concrete is typically strong enough to allow light brickwork loading after 3–7 days. For floor slabs, foot traffic is generally acceptable after 24–48 hours; vehicle loading should wait until at least 7 days. Full 28-day strength should be achieved before applying heavy structural loads. Cold weather significantly slows strength gain — concrete poured at 5°C may take twice as long to reach the same strength as concrete poured at 20°C.
Slump is the measure of concrete workability — how easily it flows and is placed. For C20/25 / GEN3 concrete, the appropriate slump class depends on how the concrete will be placed: S2 (50–90mm slump) is standard for strip foundations poured direct from the truck chute; S3 (100–150mm) is typically required for pump placement, narrow trenches, or congested reinforcement; S4 (160mm+) for self-levelling applications. Specify the correct slump when ordering — requesting a higher slump on site by adding water is strongly discouraged as it increases the water-cement ratio, reduces strength, and invalidates BS 8500 compliance. Request a plasticiser admixture instead if higher workability is needed without compromising strength.
Light rain during a concrete pour has minimal effect on the finished concrete — the surface water dilutes the surface slightly but the bulk of the concrete is unaffected. Heavy rain during pouring is more problematic — it can wash cement from the surface, weaken the top layer, and make finishing the surface extremely difficult. If heavy rain is forecast during a pour, protect the finished surface with polythene sheeting as soon as the concrete has stiffened enough to accept it without marking. Rain falling directly into the truck drum or the wet concrete before it is placed can significantly increase the water-cement ratio and reduce strength — avoid pouring in heavy rain if possible and never add cement to compensate for rain water entering the mix.
Yes — for any notifiable building work (new builds, extensions, structural alterations), you must notify your building control body when foundation trenches are ready for inspection and wait for their inspection before pouring concrete. Building control surveyors inspect the open trench to confirm depth, width, soil conditions, and any reinforcement before concrete is placed. Pouring without an inspection can result in a requirement to expose the concrete for belated inspection — an extremely costly and disruptive outcome. Most local authority building control offices aim to inspect within 24–48 hours of notification. Use the statutory inspection notice system provided by your building control body and keep records of all notifications and inspection approvals.
C20/25 / GEN3 ready-mix concrete is supplied by all major UK ready-mix producers including Hanson, Aggregate Industries, Tarmac, and CEMEX, as well as hundreds of independent regional suppliers. For small volumes, mini-mix suppliers operate in most urban and suburban areas — search for "mini-mix concrete near me" or ask your local builders merchant for a recommendation. Volumetric concrete suppliers such as Mixamate operate nationally. For bagged dry-mix, all major UK builders merchants including Jewson and Travis Perkins stock a wide range of concrete dry-mix products.
Additional Resources 2026: Ready-mix at Hanson Concrete | Tarmac Ready Mix | CEMEX UK | Standards at BSI Group | Building control at LABC | Technical guidance at The Concrete Centre
© 2026 C20/25 Concrete Price per Cubic Metre UK. All prices are indicative May 2026 estimates. Always obtain quotes from local suppliers and confirm concrete specification with your structural engineer or building control authority before ordering.