How to Form a Foundation for Concrete Slabs
- 1). Using a tape measure, find the length and width of the area where you intend to pour your slab. Be sure to get the correctly sized lumber for your frame.
- 2). Clean up the area where you are planning to pour your slab--you will build your pour frame foundation there. Remove any plants, grass and other items so that the area is just bare soil.
- 3). Lay out one of the longer boards. Measure exactly 1 foot in from one end of the board, and mark this with a pencil. Repeat this, measuring exactly 1 foot in from the other end of the board and marking this place, as well.
- 4). Pick up one of the shorter boards, and line up one of the end edges against the first mark that you made. Make sure that the edge is perpendicular to the flat side of the long board. Clamp this board into place. Repeat this step with the second shorter board, lining it up against the second mark that you make on the long board and clamping it into place.
- 5). Use a hammer to nail a vertical line of three to four nails through the broad backside of the long board into the edge of each shorter board so that they are secure. Release the clamps.
- 6). Lay out the second long board, and mark 1 foot in from each end as you did with the first long board. Turn this board up onto its long edge, and place it against the ends of the short boards lengthwise, parallel to the first long board. Position the board so that the ends of the short boards are against the 1 foot marks, then clamp this board into place. Nail it to the short boards as you did the other long board.
- 7). Around the exterior of the frame, push a 2-by-2-inch wooden stop pin into the ground approximately every 2 feet. Make sure the pins are placed tightly against the frame. Go back with your hammer and hammer each pin until it is sunk into the ground halfway. Once all of the pins are secure, cut off the top of each one with a manual saw so that it is level with the top of the frame.
- 8). With a shovel, dig a narrow trench 4 inches deep along the inside of each edge of the frame. This will make the cement heavier here so that the slab is stronger.
- 9). Dampen the soil inside of the frame with a garden hose so that it is malleable. Using a long-handled tamp, tamp down the soil until it is packed and consistently even.
- 10
Pour the concrete for your slab as directed.
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