Acceptable Sealing for Vent?

Sorry if this is a dumb question, but is this an acceptable water seal around the vent?

Edit: It seems like there should be flashing over that cut out section instead of just sealant.

Stew Baskin

It’s an acceptable roofing boot flashing for a pipe penetration in a metal roof. However, when properly installed, caulking isn’t required. Caulking could be an indication of improper installation and or leakage. When that caulking cracks, and it will, if there is something wrong with the boot, it will leak.


i see nothing there that would alarm me…


Thank you!

Thank you as well!

Are you talking about the caulking at the pipe? Or the metal?
At least around here, every metal panel roof I come across is done exactly this way. Except for the caulking at the rubber. Perhaps that was just because it is cast iron, and not a smooth surface.
I am not a fan of the indent at the bottom though, that always holds water…

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The pipe. Of course smearing some caulk around it will hold, the question is how long.

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It seems to be standard practice in my area, needed or not. I think our roofers consider it insurance.

They sure do, because they don’t trust the flashing they’ve installed. It’s the new norm.

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Morning, Stewart.
Looks like a ‘No caulk #3 universal snug fit caulk-less main plumbing stack vent flashing.’ There should be a foam backer under the flange.
Roof and plumbing stack flange has been painted.
Crease in the rubber collar acts as a trough to hold water. Should be a spillway in the crease to allow water to escape. Example below.

What is the roof pitch/angle of slope if you don’t mind me asking?

For now, monitor annually for cracks or ware in the rubber.

No. That’s not accurate. You have a split boot pictured which is used to retrofit, around electrical mast for example. That is not a trough for water, it is the seam.

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If you say so.