Find reclaimed or salvaged wood. Salvaged wood comes from various sources, but typically comes from old homes, buildings and barns. Once the building falls down or the owner tears it down, the wood is left behind. You can find salvaged wood from demolished buildings in your area or purchase it from a company that sells the wood.
Measure the size of the frame and determine the size of wood needed to cover the frame. Hold a measuring tape against the frame and measure both the width and height. Transfer those measurements onto the reclaimed wood. You generally want 4-by-8-foot boards with a width of 11/16 inch.
Wear protective goggles and lay the reclaimed wood on sawhorses so the wood sits flat. Carefully cut through the wood with a circular saw. Cut the wood down until it's the size needed for the building’s frame.
Attach a coarse-grit sanding disc onto an orbital sander. Sand one side of the reclaimed wood, turn the piece over and sand the back side. Switch the disc for a fine-grit sanding disc and sand both sides again, making the wood feel smooth to the touch.
Place the wood flat against the frame. Press a nail gun flat against the top corner of the board and pull the trigger, which shoots a nail through the wood and into the frame. Work your way around the edges of the reclaimed wood, attaching it to the frame.