How to Glue Foam Insulation to Metal

Measure the metal installation area using a tape measure to determine how large to cut the foam insulation.

Lay a piece of foam insulation board on a table, and using a tape measure, locate the proper cut mark following the measurements you took in Step 1. Draw a pencil line on the foam at that point. Place a straight edge on the line, and hold it firmly in place. Pull the blade of a utility knife along the entire straight edge one or two times to score the foam.

Slide the scored area of the foam over the table edge until it hangs freely, and then snap it downward swiftly to break if off.

Hold the foam board up on the wall to ensure it fits properly. If needed, trim additional material off using the utility knife.

Lay the cut foam insulation panel on the work table, and install a tube of silicone adhesive or subfloor adhesive into a caulk gun. Tighten the gun fully, then snip off the tip of the tube nozzle by a quarter-inch. Insert a screwdriver shaft into the center of the nozzle hole to puncture the inner seal.

Apply a 1/4-inch wide strip of adhesive around the entire perimeter of the foam board, approximately a half-inch from the edge. Apply more adhesive over the entire inside area of the board using a zig-zag pattern.

Lift the foam insulation panel up, and turn the glue toward the metal you are attaching it to. Firmly press the foam board into place with your hands, and hold it for five to 10 seconds.

Proceed to cut and glue all remaining foam board panels in the same manner.