Across the joists lay a.
Roof vent boot leak.
These collars consist of a metal base generally made out of aluminum and a rubber boot integrated into the top of the collar.
The immediate thing to do is to contain dripping water from the leak.
Leakage due to improper installation of the vent pipe boot would present as water stains dark spots and or wet areas on the under side of the roof sheeting.
Recaulk the corner flashing if any areas have hardened caulk.
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This old house general contractor tom silva shows how to create a watertight seal around a vent pipe.
A vent pipe boot can leak either from improper installation or more likely from a split in the rubber where it fits around the pipe.
Find the water entry point.
Dig out any cracked or dry caulking that isn t properly sealing adjoining surfaces and replace with silicone caulk.
Vent pipes are roof maintenance items that should not be overlooked.
Damaged vent pipe collars typically v ent pipe leaks occur at the collar surrounding the base of the vent pipe where it breaks through the surface of the roofing material.
The water entry point may not always the same as where the water drips.
Quick fix from inside contain dripping water.
Replace any missing or rotted siding above the step flashing on dormers.
When the vent pipe boot cracks your roof is open to a water leak.