How to Install a Concrete Slab
Concrete slabs are useful for many things. A slab can be poured for a cook out area, mounting heavy equipment or creatively adding to the landscape. Concrete slabs are also used as the base for building structures, rather than pouring an entire foundation.
- To guard against future cracking, start with a well-prepared base. Remove the old dirt and lay down a bed of crushed gravel about three inches deep.
- Use a two by four board to pack the gravel down and smooth it out. Check your work by placing a level on top of the board. This makes it easier to set the forms, as well as making the slab more uniform.
- Most slabs are either six or eight inches thick, depending upon the weight they will be expected to carry.
- Place two by six or two by ten boards on the edge all around the perimeter. Nail the boards around the outside edge of where your slab will be.
- After this wooden box is in place, measure from corner to corner to make sure it is perfectly square. It should measure the same from each of these points.
- Drive wooden stakes in each corner to hold the box square. For larger slabs, drive stakes every sixteen inches along the boards. This will enable the box to retain its shape against the weight of the concrete.
- Backfill with gravel, so the box will not slip when the concrete is poured.
- Depending upon the size of the slab, hand mix the concrete or have it delivered pre-mixed and ready to pour.
- Start pouring the concrete from the furthest section away from where you are mixing it. Place a two by four across the top of the cement and pull it end to end to smooth it out.
- Lay plastic over the concrete for ten days to trap moisture and prevent it from drying too rapidly. The slab will cure in three weeks.
- After the concrete has setup, remove the plastic cover and wooden forms from around the outside edge of the slab.