I am attempting to place a frame and door
at the bottom of my cellar stairs leading
outside to insulate from the cold.The opening is 4 ft Wide was thinking of building a hollow frame to fill with insulation to further keep the cold out.
The framing will be pressure treated 2x8
nailed to the concrete walls.door frame would be 2x4 and using exterior plywood
with a 80/20 split. Any suggestion on a better idea.