How to Insulate an Attic Door

If you have an unfinished attic and a simple attic access door, consider insulating the access door. This simple step could help you reduce your heating and cooling costs throughout the year. This process is a bit trickier than other insulation processes and you must work on a ladder so enlist the help of an assistant to make the project go quicker.

Step 1: Open the attic access door and measure the opening in the attic that it conceals using a measuring tape. Add three inches to the dimensions as noted.

Step 2: Cut a piece of foam insulation to fit the dimensions of the attic hatch plus the 3 extra inches. Use a utility blade and a metal straight edge to make a clean cut.

Step 3: Cut strips of insulation that are 8 inches wide and as long as the longest sides of the attic access hatch.

Step 4: Cut strips of insulation that are 8 inches wide and 3 inches shorter than the dimensions of the shorter side of the large piece of foam insulation.

Step 5: Place the foam insulation on the table. Put the 8 inches wide pieces of insulation on the largest piece of insulation. Set the 8 inch pieces on end to create a box with an open top.

Step 6: Glue the pieces together using construction adhesive to create the box. Let the construction adhesive dry thoroughly.

Step 7: Turn over the box and place fiberglass insulation over the top of the box. The insulation should not fit in the box, rather it should sit on the bottom outside of the foam insulation box. Cut the pieces to fit the correct dimensions of the bottom of the box.

Step 8: Glue the fiberglass insulation into place using construction adhesive.

Step 9: Place weatherstripping on the joists surrounding the attic hatch on the side of the joist facing the interior attic ceiling. Make sure the corners butt closely together to prevent leaks.

Step 10: Settle the box into place, setting it on the weatherstripping. The fiberglass insulation should face up towards the interior attic ceiling. Close the attic access door to check for any obstructions and trim the box slightly if necessary.