What monolithic slab means
A monolithic slab is a slab and its perimeter footing poured as one piece of concrete, common for garages, sheds and houses in warm climates.
Also called slab on grade, thickened edge slab.
Where it matters on a concrete job
One pour saves time and forming, but the edge depth and the frost rules still apply. Check the local frost depth before quoting one in a cold area.
What the model code says
- Concrete slab on ground floors are at least 3 1/2 inches thick. (IRC 2021, Chapter 5)
- Exterior footings go at least 12 inches below the undisturbed ground surface. (IRC 2021, Chapter 4)
Check which code edition your building department enforces for monolithic slab before you quote.
What it costs
Jobs that involve monolithic slab are priced in the concrete slab cost guide: about $5,100 typical, usually $2,800 to $7,350. The guide shows its sources and what moves the price. The concrete slab cost calculator prices a job line by line.
Work it out
- Free calculator: Concrete slab cost calculator
- Cost guide: Concrete slab cost
- Tools, templates and guides: Free concrete resources
Sources: 2021 International Residential Code, Chapter 5, Floors (ICC); 2021 International Residential Code, Chapter 4, Foundations (ICC). Checked October 9, 2026.