I have been asked to build a clear polycarbonate gable roof over a patio. One end will extend over the bottom of an existing shingled gable roof and gutter. Normally I would simply build it free standing with posts, but the owner doesn't want posts close to the house (as they would be in the wrong place). Instead she wants that end of the roof to be supported by posts on the existing shingled pitched roof. I'm thinking I will have to attach them to the exterior wall and go up through the roof and then find a way to flash around them. They will be fairly well protected by the new roof, but I'm still a little concerned they may be hard to make watertight. Does anyone know of the best way to flash around the posts, or a better way to support the new roof that doesn't involve cutting in to the roof?
Someone here once told me about using steel pipe for vertical structure that passed through a roof.
I don't remember exactly how he said they did it; but basically it was galvanized pipe, (1 1/2"? 2"?) threaded into a fitting (or was it welded?) that was attached somehow to the interior framing. It got a roof jack where it passed through the roof. Then some bracket or something was threaded or welded on at the top to support the exterior framing above.
The beauty of it was the standard round vent pipe roof jack made sealing it easy.
Alternatively, they do make square roof jacks, like these: http://www.bestmaterials.com/detail.aspx?ID=16449 (those particular ones are split, or retrofit ones). Those work over square tubing (or possibly even wood posts, although the seasonal swelling and shrinking of the wood would really stress it).
wow that pipe idea is great ,never thought of that .
Not my idea at all, just passing it on. I'll try to dig around for the old thread for better info.
You do have to have a way of attaching it to the framing (interior and exterior), and you also have to deal with lateral loads somehow, so it's not completely easy, but I thought it was a pretty cool idea too.
"I'm late to the party on this one and for the life of me, I can't find the pics, but in a similar situation, for a structure that needed to cantilever over the roof. We had some custom brackets made up that bolted down onto the top plate of the exterior wall. 3" galv. pipe was welded to the steel plate. This allowed us to just use a roof jack for sealing up the roof pentetration. After the roof was patched up, Simp CC's were welded to the top of the pipe.
It worked out real well and looked clean. This was about 20 years ago and I'm not sure that it would fly with the building departments today in CA. Though I'm sure that something similar with engineering could still work."
Not that I doubt you have been doing it for some time as well, very few of these things are singular strokes of inspiration, that's the beauty of these forums.