How to Make a Fake Rock Wall

Measure the dimensions of the wall you'd like to cover in fake rock. Visit your local home supply store and get several pieces of plywood that together will fill those dimensions. The plywood should be 1/2 inch thick.

Nail the plywood into your existing wall by hammering a nail to all four corners or drilling in a screw into each corner. Paint the plywood any shade of gray that you like. You will be creating a wall that resembles sandstone, and sandstone walls generally have dark gray to light gray cement between the stones.

Break the sheets of Styrofoam into large chunks 10 to 13 inches wide. Don't strive to make the pieces look regular. They should all be uniquely shaped, like naturally occurring chunks of sandstone.

Hot glue them to the wall in rows starting at the top of the wall. The pieces of Styrofoam should have 1/4 to 1/2 inch of space between them. Continue in this fashion until you have covered the wall.

Fill plastic containers with various colors of acrylic paint: light gray, dark gray, light cream, dark cream, tan, light bronze, silver, copper and other colors. For the sandstone to look realistic, paint the rocks a range of slightly different colors. Apply one layer of paint to each "rock" and then add a second and third layer of paint in different colors. The less uniform the colors, the more realistic the fake rock wall will look and it will give the surface of each Styrofoam rock an uneven appearance, masking its flatness.