Thickness and sub-base
A standard single or double garage base is 100–150mm of concrete on 100–150mm of well-compacted MOT Type 1. The thicker end of that range is better if you'll be parking vehicles inside.
Excavate to the combined depth of the sub-base and slab, plus a little extra for compaction. Get the levels right before the sub-base goes down.
Reinforcement and mix
A layer of steel mesh in the middle of the slab will help control cracking. For a domestic garage, a C25 or C30 mix is typical. If the base will take heavier vehicles, C30 is the safer choice.
With volumetric concrete, the mix is batched on site so you get exactly the grade you need — and you only pay for what you pour.
Size and quantity
A single garage base of roughly 3m × 6m at 125mm thick is about 2.25m³ — easily within a single volumetric wagon. A double garage of 5m × 6m at 125mm is about 3.75m³.
Add a 5–10% wastage allowance. Use our concrete calculator to get your estimate, then call us to book the pour.
Related services
Need concrete for your project? We supply volumetric concrete across South Wales, mixed fresh on site to the exact quantity you need. Request a quote or call 01495 820164.