Building a deck over a shed roof
When I considered the problem over building a deck over a shed roof over the years in theory only, I figured I could do it no problem. Now confronted with the task I find that there are a few things I’m unsure of or at least would like to test my thinking with the other forum members.
I’ll describe the roof first. The job is on a 3 story brick row house. In the back there is a el section, one story. In the past year the el was extended about five feet out the back to incorporate a kitchen remodel. The el plus the addition is about 14 X 14. Front of the house is north. The shed roof is a single layer modified bitumen with a 2/12 slope and is pitched east / west, side to side. The west wall, the low part of the slope, is solid brick construction, the last 5 feet being 2X6, with the rafter seats bearing on top.
The east side of the deck will attach to a brick wall (the neighbor to the east has an original two story el) via all thread and epoxy (SS). At first I was considering using treated wood post bearing on the brick / 2X6 wall for the west side. This, of course requires cutting a hole in the roof and patching after. The potential for water infiltration around or even through the wood after time worried me so I then considered having three 4X6 tubular steel posts made up with connection flanges at the bottom, a welded cap made of plate steel to seal at the top, and flat metal tongues for connection to the header. I figured I could torch the membrane onto the metal for a good seal.
Another option that came to me is to span the entire fourteen with with LVL and completely wrap the LVL in copper. The header would set in from the brick wall because of a need to create a beam pocket in from the edge of the building
I was also going to stress having another layer of bitumen added.
To top it all off the people want a pergola over the southern half of the deck. Again I can attach to the neighbors (Actually the wall is half my clients) but the logistics of planting a post toward the western end concerns me. It has to bear on the header. The header in the post scenario will be over the brick wall, but the LVL scenario will have to be back from the corner because I will have to create a beam pocket on then north brick wall at least a foot from the edge.
To add to the pergola the people want to use the Trex Brasilia for decking, rail, posts. I can get the whole way up to the canopy of the pergola with Brasilia stock material, but any thoughts on composing something that would work for the canopy? I was trying to do something with a scroll. intensive. I was thinking taking two layers of 5/4 cutting a scroll on them and then taking some 1x and cutting the same pattern only recessing it 3/4 of and inch or so to add some architectural detail. A little labor intensive buy at least to my limited knowledge of composites viable.
Thanks in advance