What we were called in to fix
This is a classic Kitsilano lane-house: the garage sits at the back of the lot and the family uses its flat roof as an upstairs deck off the second floor. By the time the homeowners called us, two things had gone wrong at once — the head and sill detailing around the upper door had rotted out, and the old torch-down roof membrane over the garage was failing. Water was tracking in behind the stucco and pooling on the roof deck below. The whole assembly needed to come off and be rebuilt as one waterproof system, not patched.
Repairing the door header and rebuilding the roof deck
We stripped the old deck boards, sleeper system and failed membrane back to the original framing, opened up the wall around the upper door, and replaced the rotten header, sill and any soft framing. With the framing sound again, we re-sheathed the garage roof in fresh 5/8" exterior plywood, fastened down to the joists below, and prepared the surface for new waterproofing.
Waterproof membrane and sleeper system
On a deck-over-living-space (which is what a deck over a garage really is — there's habitable use happening underneath) the waterproofing is the deck. The composite boards on top are wear surface only. We bonded a fresh waterproof roof membrane over the whole plywood field, lapped it up the walls behind the new flashing, and then floated a pressure-treated 2× sleeper system over the membrane on protection pads. That gives the composite boards a level, ventilated substrate to fasten to without ever puncturing the waterproofing.
Composite deck with a picture-frame border
Boards went down on the sleepers with hidden fasteners — no screw heads showing on the finished deck. We ran the field boards the long direction of the space and detailed every edge with a contrasting picture-frame border. That border isn't just decoration: it cleans up every cut end, hides the fastener line at the perimeter, and frames the stair opening so the eye reads it as an intentional architectural element rather than a hole in the deck.
Matching composite stair down to grade
We built a new straight-run stair from the deck down to the back lane, clad in the same composite system. Treads were detailed with contrasting fronts to match the deck border, and the stringers were wrapped so no raw framing shows. Result: the stair reads as one continuous material with the deck above, the homeowners get a slip-resistant grippy surface that drains, and there's nothing on the stair that needs to be sanded or restained next year.
The finished deck
Up top the homeowners ended up with a full-size, low-maintenance deck over the garage — properly waterproofed, properly flashed at the door, framed cleanly in a contrasting composite border, and tied back down to the lane with a matching composite stair. The glass guardrail keeps sightlines open across the neighbourhood without competing with the deck pattern, and the new black head flashing over the door means the rot that started this whole project doesn't get to start again.
