How to Make an Insulation Cover for an Attic Door

Open the attic door and climb up onto the stairs so you can easily access the ceiling opening on the attic side. If your attic door has no ladder attached, position a step ladder under the hole for access.

Measure the inside width and length of the opening of the attic door to determine the size of the insulation cover required. Standard drop-down attic doors can use a box that is 52 1/2 inches long, 23 3/4 inches wide and 9 1/2 inches deep. If your attic opening is nonstandard, create a box to your measured width and length with a height of 9 1/2 inches.

Lay a piece of rigid foam board on a work table and use a tape measure and a pencil to draw five boxes on it representing each panel of the cover box. Make box A and B 53 1/2 inches long and 9 inches wide. Make boxes C and D 24 3/4 inches long and 9 inches wide. Make box E 53 1/2 inches long and 24 3/4 inches wide.

Cut out each box from the rigid foam insulation using a sharp utility knife, tracing around each pencil line until the boxes detach.

Lay box E flat on the table and apply a 1/4-inch thick bead of construction adhesive around the entire perimeter. Place box A on one of the long sides and hold it in place for approximately 60 seconds. Repeat the process to attach box B on the other long side.

Attach boxes C and D to either end of box E so that a cube forms. Apply small strips of masking tape around the corners, overlapping the panels to hold them in place while the adhesive dries.

Turn the box with the open side facing downward, once the adhesive dries fully. Remove the tape and insert 1-inch long roofing nails into the corners 1/4 inch from the edges using a hammer. The nails should penetrate through two panels at each corner.

Position the box over the attic door opening and then close the door up into the ceiling.