Instead of crunching the numbers as he did one just needs to walk by one in a hallway during the middle of summer to know it isn t insulated.
Air sealing details for attic hatch.
If your hatch rests directly on the moldings add 2 1 2 inch wide stops around the opening.
The standard air sealing recommendation is to install a compression bulb weatherstrip.
Cut 1 3 boards to fit the perimeter of the opening and nail them on with 6d finish nails.
This can also be beefed up to a sealing gasket like the one on your refrigerator door.
Air seal the hatch perimeter the plywood hatch rests on a small wood strip lip.
The stops provide a wider surface for attaching the weatherstrip and a space to mount hook and eye fasteners.
Apply self adhesive foam weatherstrip tape to the top edge of the stop.
Weatherstrip the attic access hatch or door.
Sealing the attic hatch or door finish up by sealing the access hatch with self sticking weather stripping.