C30 Concrete Supply in Birmingham
Step-up durability: 30-newton concrete for external slabs and hard-working floors — and, air-entrained, the mix a Birmingham driveway actually needs. From £115 per m³ +VAT.
What C30 Is
Concrete that lives outside has a harder life than concrete under a roof: rain, frost, thaw, repeat. C30 is where that starts to matter. The name is the cube-strength way of saying the C25/30 class — 30 N/mm² cube strength at 28 days, "30-newton concrete" on site. (Yes, it's the same family C25 orders land in; one name is the cylinder half of the designation, the other the cube half. The trade is like that.)
What earns C30 its own page is where it goes: external slabs, harder-working ground-floor slabs and hardstanding — and, in its air-entrained form, the strength class behind proper driveway concrete. When a job says "C30", it's usually a slab that has to face the weather, not just hold a load.
From £115 per m³, +VAT — guide price, confirmed when you book. 0.5m³ minimum, no part-load penalty, billed on the metered volume poured.
Driveways: The Air Matters More Than the Newtons
Here's the bit most price lists skip. A driveway mix — what the designated-mix book calls PAV1 — is air-entrained C25/30 at S2 consistence. "Air-entrained" means the mix carries a minimum of 4.5% microscopic air bubbles (at 20mm aggregate). When water in the surface freezes, it expands into those bubbles instead of blowing the top off the slab. No air, and you get scaling: the flaky, pockmarked surface you see on driveways that were poured with plain C20 to save a few pounds.
We batch an equivalent air-entrained C25/30 designed mix to BS 8500 / BS EN 206 — the designated PAV names belong to certified producers, so we sell it as what it is. Two practical notes: driveways want around 150mm of depth, and air-entrained concrete must not be power-floated.
If the surface will see de-icing salts or heavy traffic — a shared access, a working yard — the step up is an air-entrained C32/40 (PAV2-equivalent) at S3. That's C40 territory.
When Can You Use It?
Strength takes time. Light foot traffic is fine after 24–48 hours; cars should stay off for about a week to be safe (Tarmac's published guidance); heavy vehicles wait the full 28 days — the age at which design strength is measured. At seven days the slab is typically at about 70% of its design strength, which is why patience with an external slab pays.
Curing is the other half of durability. Keep young concrete covered and damp — polythene sheeting or damp hessian — for at least 3–4 days, ideally a week. The first 24 hours matter most: industry guidance is blunt that poorly cured slabs can lose up to half their surface durability, and on external work the surface is the whole point.
Sizing up? Length × width × depth in metres — the concrete calculator does it in seconds — and add 5–10%. Because we batch on site, the spare costs nothing unless it's poured. Not sure between grades? Start at the concrete grades guide, or step up to C35 for reinforced and structural floors.
C30 Concrete FAQs
What is C30 concrete used for?
C30 — 30-newton concrete, the C25/30 strength class quoted by its cube figure — is the step up for work that faces the weather or takes a harder pounding: external slabs, hard-working floors, and (in its air-entrained form) the mix behind proper driveway concrete. Indoors and unreinforced? C20 is usually enough. Reinforced and structural? That's ordered as C25 or above.
Is C30 the same as C25/30?
Yes. A strength class carries two numbers — cylinder first, cube second — and C25/30 is 25 N/mm² cylinder, 30 N/mm² cube at 28 days. The UK trade quotes the cube number, so C25/30 gets shortened to C30 on site. Same family that C25 orders land in; what changes is the durability detail we batch into it for outdoor work.
What makes a driveway mix different from ordinary C30?
Air entrainment. A driveway mix (PAV1-equivalent) is air-entrained C25/30 at S2 consistence, with a minimum 4.5% of microscopic air bubbles at 20mm aggregate. When water in the surface freezes, it expands into those bubbles instead of scaling the top off your drive. It's why plain C20 driveways fail in frost. One caveat: air-entrained concrete must not be power-floated.
How much does C30 concrete cost in Birmingham?
Our C30 guide price is from £115 per m³ +VAT, confirmed when you book. We batch on site, so it's a 0.5m³ minimum, no part-load penalty, and you're billed on the metered volume actually poured.
How long before I can drive on a new C30 slab?
Light foot traffic after 24–48 hours; cars about a week to be safe (that's Tarmac's published guidance); heavy vehicles wait the full 28 days, which is when design strength is measured. Curing matters as much as strength — keep the slab covered and damp for at least 3–4 days, ideally a week, because poorly cured slabs can lose a big share of their surface durability.
Planning an Outdoor Slab or Driveway?
Tell us what it's for and we'll batch the right mix — air-entrained where it matters. C30 from £115/m³ +VAT, from 0.5m³, same-day slots often available.