Assemble the sides of the box with metallic duct tape.
Build attic stair insulation box.
After cleaning and drying the opening of the stairs put the insulation box in place.
An attic insulation box covers the attic ladder with insulation which stops the flow of air into your house and eliminates any drafts around the opening.
The tuff r has an r value of 13 for 2 inches and a foil facing which works great as a radiant heat barrier as well.
With attic insulation we aim for a pretty high standard usually at least r 49 and the coffin insulation should match.
To build the attic stair cover i decided to use two inch thick foil faced foam board by dow tuff r.
Lay the insulated sheathing down on the floor and get a straight edge.
Seal the insulation box by running foil tape along where its outer edges meet the surface of your attic floor.
The box is hinged on one side which makes.
You may add caulk on top of the tape to reinforce your seal.
Take those measurements and create a rectangular box.
Add insulation to the exterior of the plywood box.
Mark out six pieces to create the parts of the box two large top pieces and four shorter side pieces.
Measure the size and height of the stairs from the attic.
Position the box over the stair opening in the attic.
More insulation 6 inches or 8 inches isn t uncommon.
That means that you should glue at least 4 inches of foil faced polyisocyanurate r 26 to the box.