Over the past few years, residential builders keep running into the same requirement: a structural garage slab designed by an engineer. A slab that used to be poured by rule of thumb now comes with signed and sealed plans.
Why the requirement has spread
Residential developers are writing it into their specifications more and more often, and municipalities ask for it before issuing permits. The Garantie de construction résidentielle (GCR) may also check compliance during its new-home inspections. A non-compliant slab can then lead to costly corrections and delay acceptance of the building.
A poorly designed garage slab can crack, settle or heave, especially under frost if the soil and drainage weren't taken into account. An engineer's plan reduces that risk and documents the design in writing.
What the plans include
An engineer's garage slab design covers much more than the thickness of the concrete:
- reinforcement (mesh or bars), sized for the expected loads: vehicles, equipment, surcharges;
- slab thickness and concrete quality;
- control joints to manage cracking;
- the bearing soil, the fill and the drainage;
- frost protection, where the configuration requires it.
The plans are sealed by an OIQ engineer and ready for the permit application and the GCR inspection.
Bring the engineer in early
The best time to involve the engineer is before the pour, ideally at the plan stage. The slab, fill and drainage are then designed together, which avoids rework and surprises at inspection.
We work with contractors in Lévis, on the South Shore and across the Quebec City area. See our foundation and structural slab design service, which meets GCR requirements.
For your sealed plans, contact us.
This article is provided for general information. The applicable requirements (GCR, municipal, Quebec Construction Code) vary by project and should be confirmed for your situation.