A slow permit process still holds back the reconstruction, but knowing they're approved means I can finish making the rest and gather other materials needed. It also means some attention can be shifted to the design of the roof deck.
Atop the trusses will be 3/4" OSB, a vapor barrier, and large pieces of rubber Matt and I cut from the roof of the bowling alley last fall. These will act as oversize shingles to shed water. Every effort will be made to collect all of the rainwater from the roof.
The occupiable deck needs to be leveled out, so deck joists will be cut to negate the roof slope. These had to be carefully designed so that all the pieces resting directly on the roof are running parallel to the direction of water flow, as to not create barriers/pockets for it. Because a rubber roof has a relatively short lifespan, the deck is also being designed to be easily removed. The framing is constructed in six pieces to be easily removable and reinstallable. Securing anything into a roof becomes very tricky; we don't want to penetrate the waterproof surface anywhere it can be avoided. For that reason, the framing and deck won't mechnically be attached to the roof, but will just be held in by its own weight.
By using pallets for the walking surface, the deck is also modular. These will be attached to the frame to make the entire construction heavy and sturdy enough to hold its place.
Finally, a railing of "historic" character will be installed for obvious safety reasons. A painted wood end cap may be installed where the ends of the pallets are visible from the street.