Pouring a slab is well within reach for a determined DIYer on a small project — a shed floor, a patio, an equipment pad. Here's the full sequence so you know what you're signing up for before the truck arrives.
1. Plan and calculate
Decide dimensions and thickness, then work out how much concrete you'll need — the slab calculator gives cubic yards, bags, and a waste allowance. Order a little extra; coming up short mid-pour is the worst outcome.
2. Excavate, grade, and form
Strip sod and topsoil, grade for drainage, and build level forms (2×4 or 2×6 lumber staked firmly) to your slab outline. Check for square and a slight slope away from structures.
3. Base and reinforcement
Add and compact 4 inches of gravel base for drainage and stability. Lay rebar or wire mesh on chairs so it ends up in the middle of the slab, not on the dirt — see our guide on whether concrete needs rebar.
4. Pour, screed, and finish
Pour and spread the concrete, then screed (drag a straight board across the forms) to level it. Float to bring up the cream, edge the perimeter, cut control joints, and finish the surface — a broom finish gives outdoor slabs grip. Work fast; concrete won't wait.
5. Cure
Keep the slab damp and protected for several days. Curing — not just hardening — is what builds strength; see how long concrete takes to cure.
Common questions
Can I pour a concrete slab myself?
Small slabs, yes, with prep and a couple of helpers. Large pours move fast and are easier with experienced hands or a contractor.
Do I need gravel under a concrete slab?
Yes — a compacted gravel base improves drainage and prevents settling and cracking. Four inches is typical.
How much concrete will I need?
Use the slab calculator with your length, width, and thickness for cubic yards and bag counts with a waste allowance.