Originally Posted By: Larry L Leesch This post was automatically imported from our archived forum.
More info would have been helpful but I’ll take a stab at it. I am guessing that the pipe goes into a common roof jack that has about 16" of vertical stack on it. Because of the pitch of the roof, the hot gases are being blown back into the roof jack around the vent pipe and the dark you see in the picture is scorched wood. Exterior vent stacks have the same relation to the roof deck as does a chimney. And if my guess is wrong, it won’t be the first time.
Originally Posted By: dvalley This post was automatically imported from our archived forum.
John,
More detailed pics would be great. But I can tell you right now, there's an issue with clearance to combustibles. Is that top vent connector a B-vent (double walled)? It should be!
Also, that charred OSB is definitely yelling for help. The vent connectors are either getting extemely too hot because of the "horizontal" installation
(that you described) or the pipe that is penetrating the sheathing to the exterior is not installed to the 3-2-10 rule, and is causing the exhaust fumes to be blown right back into this area.
What is this vent connector exhausting?
This chimney definitely needs attention!
Originally Posted By: Guest This post was automatically imported from our archived forum.
It looks to me like the b vent is leaking at the adjustable length band style connector. The flue gases would readily rise and condense on the cold roof surface. The reason that there’s no soot on the pipe is since it’s leaking, the entire air insulated portion is probably at or near interior flue temps and has become too hot for the flue gases to condense on.