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.
Roof leaking around vent boot.
Here are four common problems that can cause water to leak around vent pipes.
When this happens the water can seep into the house along the pipe.
Remove debris make sure your roof valleys are clear of debris re shingle valleys valleys may need to be reshingled with new ice and water shield put in place.
If the rubber boot is cracked rotted away or torn.
If your shingles are still in relatively good condition chances are that water seeps around a plumbing vent that goes through the roof.
Recaulk the corner flashing if any areas have hardened caulk.
Rusty and cracked collars around the vent pipe can allow rainwater to pool and eventually drip into.
Roof vent pipes from plumbing or exhaust vents penetrate the roof and are usually sealed using a collar style flashing made out of a flexible material like epdm rubber or flexible pvc.
Metal flashing and vent boots work together to prevent water.
When the roof vent is leaking the actual cause must be identified first.
Roof vent pipes are common areas for roof leaks.
If any of these issues are present water will be able to enter your roof along the pipe.
Dig out any cracked or dry caulking that isn t properly sealing adjoining surfaces and replace with silicone caulk.
Sun exposure and heat especially during the summer can cause the rubber boot to crack creating the space for water to leak in.
A plumbing vent pipe is a common culprit for leaks.
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.