chimneyflashingroofsealing
Looking to seal a gap between my furnace's vent pipe & the flashing on the roof, specifically here:
I'll have to check if there's a missing storm collar too, but should I use High-temp silicone, or go with the Big Box's recommendation of roofing asphalt (sounds burny).
That's at the PEAK of a shed roof, true? If that's the case, what you have amounts to a ridge cap, but nobody I know of manufactures premade ridge caps for shed roofs (too many different possibilities, not enough market), so the builder used "drip edge" or flat flashing (bent around the peak) to function as a ridge cap.
There really aren't very many good alternatives to that situation, so what they did is actually pretty common on the peaks of shed roofs. They really SHOULD have tarred over the nail heads, though.
Asbestos. (lgam.info/asbestos-cement-pipe)
You'd need cast couplings: (ebay, Smith Blair Industrial Ad)
Best Answer
I'd recommend Not using any petroleum-based sealant on any surface subject to heat (it will soften and melt). For a positive and weatherproof seal use any 100% silicone caulking (Dap, Owen-Corning, etc.). For an even better and longer lasting seal against water go with any exterior Urethane caulking. Well worth the slight cost increase, but is U.V resistant and stays pliable indefinetly. And there is no need for a high temperature rated sealer. Unless the area you are sealing is in close proximity to the heat source. Than you will need some type of refractory-type caulking.