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How to Install Concrete Form Panels

When pouring a concrete slab for a garage, deck, shed or other outdoor building project, you need to install concrete forms that do not bow out or warp before the concrete can dry. You can purchase special concrete form kits from hardware stores, but you can just as easily build them yourself out of plywood. The key to building a strong concrete form is to build enough braces so the plywood stays firmly in place.

Things You'll Need

  • 2-by-12-inch lumber
  • Measuring tape
  • Circular saw
  • Nails
  • Hammer or nail gun
  • 2-by-4-inch lumber
  • Rubber mallet
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Instructions

    • 1

      Cut the 2-by-12-inch form panels down to the appropriate size based on the dimensions of your project. Cut the two side panels about 3 inches longer than the actual dimensions needed -- this gives you room to nail the front and back panels to them.

    • 2

      Secure seams together using cleats. This is only necessary if you need to use multiple pieces of lumber to form a single side of the form. Cut a 4-foot length of 2-by-12-inch lumber and nail it over the seam -- check that the seam is perfectly lined up before driving the nails.

    • 3

      Secure the four form pieces together by nailing through the side panels into the front and back panels. This creates the form, which you can set down on the build site.

    • 4

      Check that the form is level once you set it down on the build site. As long as the form was level when you built it, you can tap it down into the ground with a rubber mallet to make adjustments until it is level.

    • 5

      Drive stakes made of 2-by-4-inch lumber into the ground so they are right up against the form panels. Cut the stakes long enough so that the tops end up just below the tops of the form when the stakes are driven 8 to 12 inches into the ground. Place one stake every 2 feet along all four sides of the forms.

    • 6

      Install footers made of 2-by-4-inch lumber against the stakes. Place the footers at a 45-degree angle against the stakes, then nail the tops of the footers to the tops of the stakes. This prevents the tops of the forms from bowing out when you pour the concrete.

    • 7

      Spread form oil all over the insides of the concrete form panels. Alternatively, cooking oil and motor oil may be used as substitutes. This prevents the concrete from sticking to the form as it dries.