Definition
Slab-on-grade is a concrete foundation system where the floor slab sits directly on compacted earth with perimeter footings below frost line. Slabs are cost-effective and provide good insect protection, though repairs to embedded utilities can be expensive.
Not sure where this fits?
Answer a few questions and we’ll open the path that fits, at the right step.
Find my pathAbout this term
Slab-on-grade involves excavating, compacting subgrade, installing perimeter footings below frost line, laying gravel base, installing rebar, and pouring a concrete slab 4-6 inches thick. Plumbing and HVAC ducts may be embedded in the slab (advantages and disadvantages). Slabs are cost-effective, provide no crawl space, and offer good insect protection. Repairs to embedded utilities can be expensive. This system is standard in warm regions with minimal frost concerns.
Pro Tip
Slab-on-grade homes offer lower initial costs but may have higher plumbing repair expenses if buried lines fail.
Example
A home in Texas uses a slab-on-grade foundation with the floor slab poured over a prepared base with embedded plumbing lines and electrical conduits.