How to Build Your Own Home Slab

A house is only as strong and stable as the foundation it is built upon. Building your own home foundation is a simple procedure requiring only a few minor skills. The basic premise of pouring a house slab is making sure the form is constructed properly. If the foundation form boards are straight and level, the home slab will be too.

Things You'll Need

• Tape measure
• 12-inch wood stakes
• Sledge hammer
• Shovel
• String
• 2-by-10 boards
• Circular saw
• Metal stakes
• Double headed nails
• Level
• #4 Rebar
• Rebar tie wire
• Rebar tie tool
• Rebar chairs
• Sand
• Concrete
• Trowels
• Anchor bolts

Instructions

1. Determine where the corners of your home slab will lie and place stakes in each corner. Use a sledge hammer to pound in 12-inch wooden stakes. These stakes outline the exterior of the house.

2. Dig your footing holes 12-inches deep. Use a shovel. This trench will be dug all the way around the perimeter of your home, and will create the exterior walls.

3. Build your footing frames using 2-by-10 boards. Lay the boards out along the exterior house markers. It might be easier to tie string from one corner stake to the next. Lay the boards along the string lines. Use a circular saw to cut the boards to size.

4. Use a level to make sure all the form boards are the same height. Place metal stakes every 4-feet behind the boards. Nail the stakes to the boards using double headed nails--the metal stakes have small nail holes for nailing them to the boards.

5. Repeat the form board procedure for the interior form framing. Measure in the thickness of the foundation wall and build your forms along the same exterior wall pattern. Use the level and make sure the interior frame is level with the exterior.

6. Place #4 reinforcing rebar down the center of the footings. Create a continuous line keeping the rebar at least 2-inches away from any exterior surface. Tie pieces of rebar together by overlapping the ends and wrapping rebar wire around the two bars. Use a rebar tie tool to twist the wire tightly around the ends.

7. Place rebar chairs under the rebar every 12-inches. These seats can be purchased at any hardware store and are used to keep the rebar suspended off the ground before the pour. (Rebar can corrode if it is exposed to dirt or air.)

8. Prepare the inside slab. Pour a 2-inch layer of sand over the ground. Lay out a rebar grid--this will look like a checkerboard when finished. Tie the ends of the rebar together with rebar tie wire for reinforcement. Also tie the rebar at each intersection. Use rebar chairs under the rebar intersections and also every 12-inches.

9. Rent a concrete truck if your house slab is large, or just a line pump if it is small. After the concrete is sufficiently mixed, pour it into the space between the concrete forms. Fill it to the top and use a 2-by-4 piece of scrap to scrape the concrete level and smooth. Place your anchor bolts in the concrete every 12-inches.

10. Continue filling the home slab area with a 2-inch layer of concrete. (This is called a one-pour method.) Use long handled trowels to smooth out the concrete before it cures. Let the concrete cure at least 48 hours before removing the forms.

Tips & Warnings

• Give each step of the home slab building process proper time for drying and evaluation. This will ensure your home slab is structurally sound. When you get to the corner of a footing, either bend the rebar with a rebar bending tool, or cut the rebar with a rebar cutter. Both tools can be rented from a tool supply house.

• Do not permanently embed your ground plumbing and other components in concrete until you are certain they are all placed properly.