Concrete forms allow a builder to construct a structure to virtually any size and shape. The purpose of the form is to hold the wet concrete in place while it sets. Forms can usually be removed after 24 to 48 hours. Building the form requires some basic carpentry skills and tools, and is usually the hardest part of pouring concrete. The materials used for the form are relatively unimportant as long as the proper shape is maintained and the materials are sturdy enough to support the weight of the concrete.
Cut the plywood to the size and shape of the structure to be erected. Plywood is necessary for structures that will be higher than 5 inches, and for odd shapes such as stairs. Use 2-by-6-inch beams for straight angles on ground structures, such as a walkway or driveway.
Cut 2-by-4-inch wood beams to the same height as the plywood. Nail the 2-by-4-inch beams to the plywood with 2-inch nails hammered. Use 3-inch wood nails for 2-by-6-inch beams. Position a 2-by-4-inch board every 24 inches along the surface of the plywood or 2-by-6-inch beam.
Place the edge of a 2-by-4-inch board flush with the left edge of the form, and a 2-by-4-inch board centered on the right side of the form. The right side needs the 2-by-4-inch board to overlap so an attaching form can be secured to the overlapping board.
Rub motor oil into the surface of the plywood or 2-by-6-inch board using a paintbrush to help prevent the cement from sticking to the wood when you remove the form.
Erect the form. Assemble the walls so the overlapping 2-by-4-inch beams can be nailed to the beams flush with the right edge of each wall. Join each side so the form completely encloses the area.
Drive ground stakes into the ground centered between each 2-by-4-inch beam. Cut one long 2-by-4-inch board for every board that is mounted to the structure for tall structures. Secure the long 2-by-4-inch board to the top of the form at an angle with nails so the beam connects to the ground and the top of the form. Drive in a ground stake pressed against the end of the 2-by-4-inch board to keep it stable.
Things You Will Need
- 3/4-inch plywood
- 2-by-4-inch wood beams
- 2-by-6-inch wood beams
- Ground stakes
- Circular saw
- 2-inch wood nails
- 3-inch wood nails
- Motor oil
- The overlapping 2-by-4-inch board can be on the right side or left side of the form as necessary. The purpose of the overlap is to give a connecting wall something to grab onto. You can use a 2-by-6-inch board instead of a 2-by-4-inch board so the corner of the form is a little more stable when it is fully erected.