I'm renovating a heritage house in Victoria BC and repairing an
exterior stair and deck/landing over an insulated space. The
inspector says I must treat the deck like a roof, with waterproofing
The landing is 4' x 4' covered by a roof overhang. Head room below is
less than 7'.
How about membrane under the deck flooring, then just vent the
insulated space under the deck with holes in the first stair riser,
under the deck lip, through to the space above the insulation, then
out holes under the door threshold? Sorta rules out washing the deck
with a hose, but then you can't wash your soffits with a hose and not
get water up the vents either, right?