Concrete Slabs in Kent

A slab pour is one event and it cannot be paused. The concrete arrives already mixed, and it is discharged, spread, levelled and finished in a single working session. Almost everything that decides whether the slab is sound has already happened by then: the excavation, the sub-base, the damp-proof membrane, any insulation, the reinforcement and the levels.

Ready-mix suits slabs for one reason above the others. The whole area goes in at one strength from one batch. A slab mixed on site in a barrow mixer has a different strength in every square metre and a cold joint wherever one batch met the next.

Which concrete mix suits a slab

Concrete is ordered by designation, not by description. Under BS 8500, a shed base, a greenhouse base or a garden building slab is commonly poured in GEN3. A slab that will carry a vehicle usually steps up to PAV1, which is air-entrained so that it resists freeze-thaw damage and de-icing salt. A slab carrying a structure or a designed load takes a reinforced concrete class such as RC25/30 or higher.

Those are the mixes that typically suit those jobs. They are not a specification. Anything structural is the engineer’s call, and where drawings exist the designation printed on the drawings is what gets ordered.

Working out how much concrete a slab needs

Slab volume is length times width times depth, all in metres, which gives cubic metres. A slab 5 metres by 4 metres at 150mm deep is 5 x 4 x 0.15, so 3 cubic metres.

Two things move that figure once you are on site. Dug levels are never exactly as drawn, so the sub-base runs thin in places and the concrete makes up the difference. And a slab poured against an existing structure often needs a thickened edge. It is normal to allow a margin over the calculated figure, and your approved supplier will say what allowance they would order on for the job you describe.

Getting the base right before the concrete arrives

A ground-bearing slab is only as good as what sits under it. In order from the bottom: a compacted sub-base, usually MOT Type 1; a sand blinding so the sub-base cannot puncture what goes over it; a damp-proof membrane, lapped, taped and carried up to meet the damp-proof course; insulation where the slab is inside a heated building; then reinforcement, either mesh on spacers or fibres batched into the mix.

Two conditions stop a pour on the day. Standing water in the excavation dilutes the face of the concrete, and frozen ground robs it of early strength. Both need resolving before the load is batched, not when the lorry is already on the drive.

Access, discharge and how far the chute reaches

A standard mixer discharges down a chute, and that chute has a limited reach. Where the slab sits beyond it, the concrete has to be barrowed, pumped, or brought in on a smaller vehicle.

That decision belongs to the site rather than to the slab. A rear garden reached only through a house, a lane too narrow for a full-size mixer, a soft verge, a low bridge or a weight restriction all change what can be sent. Kent Readymix takes the access detail with the enquiry so that the right vehicle arrives first time, and where a chute will not reach we look at mini-mix delivery or a concrete pump instead.

What your approved supplier confirms

Kent Readymix works with approved concrete suppliers across Kent and Medway. Most of them work on a pay-for-what-you-use basis, and many can deliver next day. Your quotation, delivery and payment are agreed directly with the approved supplier appointed to your pour.

The supplier confirms the delivery window rather than the site guessing at it. Concrete has a genuine working life from batching to discharge, and the window depends on the load in front of yours and the distance from the plant, so it is settled by the people holding both facts.

Booking a slab pour in Kent and Medway

Tell us the slab size, the depth, what will sit on it and how a lorry would reach it. That is enough for an approved supplier to price the load and confirm the mix. Where you have an engineer’s drawing, the designation on it is what we quote against.

We will also say plainly when a pour is better served by a pump or a volumetric mixer than by a standard delivery, because the wrong vehicle on a tight site costs more than the right one.