How to Pour a Concrete Foundation for a Basement

Pouring The Footings

• 1

  Drive wooden stakes in each corner of the foundation perimeter. Tie a string to one stake and run the string around the remaining stakes before tying the end to the last stake. This will be the perimeter, or boundary, of your foundation.

  Make sure the boundary of your foundation is square. The string sides at each corner should form a 90 degree angle.

• 2

  Begin digging a trench 2 feet wide within the perimeter of the string boundary. The outer edge of this trench should not go past the string sides tied to your corner stakes.

• 3

  Build forms for the footings with 2-inch by 10-inch boards, hammer, and nails. Footings are the bottommost part of a foundation wall, with a course of concrete wider than the base of the wall.

  The boards will be placed in the trench, pressed up against the sides to act as a cement mold. The length of the boards you'll need depends on the dimensions of your foundation's perimeter. The tops of the footings should be level all the way around.

  The height of the footings' sides --- and, by proxy --- the depth of the trench between the footing boards, depends on the type of structure you're building and local building codes. As an example, some one-story buildings require 8-inch-deep footings, while some two-story buildings require 10-inch-deep footings. Check with your local code officials to make sure you know how high the footers need to be where you're building.

• 4

  Lay steel rebar inside the footer trenches, all the way around. The rebar is needed to reinforce the poured concrete so that it can adequately support the weight of the structure.

• 5

  Pour concrete from the cement mixer into the footing trenches and fill the trenches until they are level with the top of the form. Use a shovel to push the concrete into all areas of the trenches. Run a straight 2-inch by 4-inch board along the top of concrete to ensure that the concrete is flat and level.

  When the concrete inside the footings has dried, remove the boards surrounding them.

Pouring The Slab

• 6

  Place an even layer of sand or gravel on the ground within your new foundation perimeter and install a vapor barrier over this layer of sand or gravel. The vapor barrier will prevent moisture from entering the foundation and causing cracks. Over the top of this vapor barrier, place a layer of wire mesh for reinforcement.

• 7

  Pour concrete onto the ground within the perimeter of the footings, and use a shovel to push the concrete as evenly as possible into all areas of the inside of the footing perimeter.

• 8

  Begin flattening and leveling the wet slab floor with a long 2-inch by 4-inch board (wearing your rubber boots), slowly raking it along the wet concrete to smooth out bumps and irregularities. Rake from one end of the foundation to the opposite end.

• 9

  Allow the concrete slab floor to harden before adding height to the basement walls with layers of cinder blocks.