- 1). Level out the dirt on the basement floor as much as possible with a shovel and a garden rake. Scrape off the surface of high areas and fill in the low areas. Work right up to the edge of the walls for a straight surface.
- 2). Bring in 2 to 4 inches of gravel or sand to top off the dirt, forming a surface that it easier to level. Check with your local building codes to see what the requirements are for your area. Drag a 2-by-4 over the layer to level it out.
- 3). Cover the aggregate with a sheet of the 6mm or thicker polyethylene to form a moisture barrier between the ground and the concrete slab. The sheets must overlap by 6 inches at all the seams and at the edges.
- 4). Space the No. 4 reinforcement bars every 18 inches across the floor to add extra rigidity to the slab and reduce the chance of cracking over time.
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