Concrete Slab Thickness Guide: How Thick Do You Actually Need?

Slab thickness is the single most important decision on a concrete project. Get it wrong and the slab cracks, settles, or fails years before it should. Get it right and you've got a pour that'll outlast the building on top of it.

4 inches — patios, sidewalks, light residential

Foot traffic, patio furniture, light residential use. Plenty of strength for what it's going to see. Always with rebar on a grid — never just mesh.

5 inches — driveways, RV pads, standard shops

Our default for residential driveways and most shop floors. Handles passenger vehicles, half-ton trucks, light trailers, and storage with no problem. #4 rebar on 18" centers.

6 inches — heavy shops, equipment storage, dually parking

When you're running a lift, parking a dually full-time, or storing tractors and skid steers. We thicken the edges and run a tighter rebar grid. Costs a little more — saves you a slab replacement in 10 years.

Why we don't just pour everything at 4"

Because the difference in cost between 4" and 5" on a 1,200 sq ft shop is small. The difference in lifespan is decades. We spec what the slab will actually see and pour accordingly.