How to Insulate a Fiberglass Roof

Measure the width of the roof with the tape measure. Add 2 inches to the measured length, and then cut a strip of the bubble wrap to match the adjusted measurement using the utility knife.

Lay the bubble wrap parallel to the roof trusses along their tops, between the roof and the trusses. Overlap the bubble wrap two inches over the ends of the trusses and one inch over the edge of the end trusses nearest the walls. Secure the wrap to the ends of each truss with two staggered staples an inch apart. Staple the end pieces of the bubble wrap onto the edge trusses with a staple placed every four inches.

Place the next strip of bubble wrap over the trusses and overlap the edge across the first strip by three inches. Make sure that you position the overlap so that it occurs over one of the trusses. Attach to each truss end through the overlap portion with two staples spaced an inch apart, and then attach with the 6-inch spacing along the truss that the two sheets overlap.

Place a strip of reflective foil tape along the seam to seal the connection. Continue with additional sheets of bubble wrap until you reach the other side of the roof, and then attach the fiberglass roof to the structure.

Repeat the attachment process with a second layer of bubble wrap along the bottom of the roof trusses to create a layer of air between the bubble wrap that helps stabilize interior temperatures along with the air and plastic contained in the bubble wrap material.