How to Make Styrofoam Cement

Put on safety glasses and long-sleeved clothing.

Set your wheel sander to the lowest setting and turn it on. Touch the edge of the Styrofoam to the sander and Styrofoam chunks will begin to fly.

Continue sanding down Styrofoam chunks until they've all been turned into fine granules.

Sweep the granules into large garbage bags.

Mix a batch of concrete using 1 part water, 2 parts cement and 3 parts Styrofoam granules. Mix the cement with the Styrofoam first and then add in the water at the end. You should have a damp mixture that isn't too wet to form into shapes.

Pour the mixed cement into a form in the shape you want to use in your project. Tap the side of the form while the concrete is setting to pop any air bubbles. Let the cement sit for one to two days before using it in any construction.