How to Build a Form for a Gateway Arch

What You'll Need
Measuring tape

The most famous gateway arch in the world is probably the one that is found in St. Louis. Though this gateway arch is impressive there is no way you are going to build it as an entrance to your garden. A gateway arch can be easily constructed out of various materials such as metal and wood. If you want your gateway arch to stand the test of time then making it out of concrete is the best way to go. In order to do this you will need to first make a form for the concrete to reside in. Think of the form as a mold and once the concrete fills it the shape is created. The concrete dries and you can remove the form being left with a wonderful gateway arch. The article below will show you how to make such a form.

Step 1 – Size

Determine the size of the gateway arch before you begin making any type of form as the size will determine the amount of masonite you need as well as plywood. You also need to decide how thick you want the arch for this will determine how wide the masonite should be. If you can create a form out of two pieces of masonite that is the best-case scenario.

Step 2 – Backing

The plywood will serve as the backing material for the gateway arch form. Lay it down on a flat surface so that you have two pieces going the long way like legs and another piece crossing the top. On the plywood you will begin drawing the outline of the gateway arch. This will serve is a line to follow as you place the masonite. If you make a mistake you can simply redo the lines. Once you are finished drawing the lines; take a step back and look at them from a distance. Make sure they are how you envisioned them to be. When you are certain you add another set of lines parallel with the original set.

Step 3 – Masonite Board

Masonite board is also known as hardboard siding. This material is great for making a gateway arch because it is very flexible. Place the masonite on the plywood on its edge with the bottom lined up with the bottom of the plywood. Place a nail behind the masonite until it is halfway in and place another nail in front of the masonite several inches along the line. Continue placing nails in this fashion in order to secure the first masonite board. Place the second masonite board I n exactly the same way. Use the saw to remove the excess masonite and then nail a piece along the bottom to cap off the form. The form at this point could be used but the nails on the inside of the form will leave gouges in the concrete. Go along the inside of the form and place a nail every six inches on an angle through the masonite and into the plywood. Remove the inside nails.