Integral & attached garages
Screed for Garage Conversions
The floor is the single biggest Building Regs risk in a garage conversion. We get it right first time — DPM, insulation and screed to the right build-up.
Building Control almost always asks the same question on a garage conversion: what's the build-up under the finished floor? Get it wrong and the room fails on U-value or damp.
We work to a compliant build-up — usually 100mm PIR on DPM with 50–60mm of liquid screed — that lands at the same level as the adjoining hallway.
Typical compliant build-up
| Layer | Detail |
|---|---|
| Existing slab | Levelled & primed where needed |
| DPM | 1200-gauge, lapped and taped up walls |
| Insulation | 100mm PIR — U-value ≤ 0.15 W/m²K |
| UFH | Optional wet or electric — pressure tested |
| Screed | 50–60mm Cemfloor or anhydrite |
Common garage-conversion pitfalls
- Slab poured without a DPM — dampness later
- Not enough insulation — fails Building Regs U-value
- Screed too thin over UFH — cold spots or pipe shadowing
- FFL not tied to the hall — trip hazard at threshold
Frequently asked
Converting your garage?
Send the drawings and the intended finished floor. We'll spec a compliant build-up and quote the pour.