How to Insulate Door to Attic Steps

Failure to insulate the attic door properly can increase your power bill.

A door that leads to stairs up to the attic should be insulated to keep the cold air where it belongs --- in the attic. Attaching fire-code-approved insulation board on the unseen side of the door, weather stripping around the door jam where the door edges meet the frame and adding a door sweep along the base of the door accomplish this. The job isn't aesthetically appealing for the door, but it won't matter if the attic isn't accessed often.

Things You'll Need

• 1 door-size sheet of fire-code-approved insulation
• Utility knife
• 1 tube of multipurpose construction adhesive
• Caulking gun
• 1 roll of single-side adhesive weather stripping
• Door sweep installation kit with screws
• Screwdriver

Instructions

1. Hold the piece of insulation up against the attic side of the door.

2. Trim away all insulation overlapping the door's edges with the utility knife. The edges of the insulation board should be flush with the outer edges of the door all the way around.

3. Cut a hole out of the board to accommodate the location of the doorknob.

4. Apply adhesive to the door in zigzag patterns with the caulk gun. Apply enough adhesive so that there isn't an open area on the door without adhesive bigger than a baseball. Apply the adhesive all the way around the edges of the door face perimeter.

5. Attach the insulation board to the door by pressing it into the adhesive and holding it there for a few minutes until the adhesive bonds with the board. Slide your hands all over the board pressing it into the door to ensure proper overall adhesion. Wait 12 hours for the bond to set.

6. Apply weather stripping on the inner edge of the door jam where the door edges touch when the door is closed. Pull the paper off the adhesive to get the sticky side to stick. Cut it with the utility knife to fine tightly in the corners. Place a piece across the top, down the sides and across the bottom, if there is a bottom jam.

7. Follow the instructions in the door sweep kit to install the sweep to the door. The sweep will go across the front side bottom edge of the door. Screw the sweep to the door with the screwdriver.

References

• Dover Projects: Insulate An Attic Door
• MGE: How To Insulate Your Attic; Walk-Up Attic Door

Resources

• Oak Ridge National Laboratory: Insulation Rating Calulator