How to Build Concrete Forms

A worker putting down concrete forms for a sidewalk.
  • 2-10 hours
  • Beginner
  • 50-500
What You'll Need
Tape measure
Circular saw
Eye protection

Building concrete forms is a very simple job that virtually any DIY-minded individual can accomplish. Concrete forms can be used for foundations for nearly any type of structure. Whether you are needing a form for a playhouse, shed, or gazebo, this is a great way to pour and level your foundation with ease. This article will break down the process of creating this form step by step to make it quick and easy for everybody.

Step 1 - Mark the Dimensions

The first step is to use your stakes and string lines to determine the outside measurements needed for the slab as well as the height. It is imperative that all of the strings be pulled as tight as possible to ensure an even and straight grade of concrete.

Step 2 - Choose Wood for Floorboard

Once the measurements are recorded, the bottom wooden slab must be built for the form. Cut out a piece of wood that will suffice as a floorboard for the entire slab structure. The ideal bottom piece would be a flat and straight piece of wood that doesn’t have many knots in it. This makes the process of forming the slab a great deal easier because you won’t have to worry about any imperfections in the lumber disfiguring the concrete.

Step 3 - Add More Stakes

Now, it’s time to cut some wood and to create more stakes for the corners. Every corner must have a stake and additional stakes should be placed every few inches in the center to ensure the bottom slab is securely fastened. Remember, slabs that will be very thick must have a higher density of stakes in order to properly support the form.

Step 4 - Match Center Stakes to the String Line

The next step is an extremely important one, so pay attention! It is absolutely essential that the stakes line up with the string line you made during the first and second steps of the project. Without this matchup, your form will be uneven and unstable. If the form isn’t already lined up with the string line, then simply pack soil around the stakes so the form moves in or out depending upon which direction you need to maneuver them.

Step 5 - Reinforce Form

Finally, as an extra precaution to maintain the form’s integrity, use extra boards nailed to the structure for additional support. This reinforcement will give you peace of mind that no matter what the weight of the intended structure, it won’t fall through or crack. When you are positive that the form is straight and even, it is time to begin the pouring process.

Step 6 - Pour Cement

Simply pour the concrete into the form slowly and steadily. For a project such as this, it is best to steer clear of quick-drying cement formulas. A quick-drying formula can end up causing more work for you later since you need to take time to pour and even out the cement. Make sure you watch to see the falling concrete hasn’t moved the strings. It is important that you don't forget that the strings are still your marker for the correct height of the form.

Now you know how to build a concrete form on your own!