On the rear roof of a house, the highly flexible rubbery seal and flashing around the plumbing-drainage vent pipe are generally replaced when the roof is replaced. However, this seal will dry out, crack, fall apart, and leak before the roof needs replacing. I always have my guy at roof repair in Manhattan NY look at my place first. It’s the best way to make sure that my roof doesn’t have any issues before the issues show themselves. Never let a roof problem go for too long or otherwise you’ll have serious problems. One way to prevent this leakage without replacing the surrounding roof shingles is to double-up on the vent seal itself. The sooner this job is done, the better this leak protection is.
Most bathrooms have drainage vent pipes running up through the house walls, attics, and roofs to offset the pressure fluctuations caused by flushing the toilets. These pressure-equalizing vents prevent wastewater backup and other problems. A one-bathroom house will have one vent pipe. A multiple-bathroom house will have several, depending on where the bathrooms are located. By looking at the roof of the house itself, these vents normally appear as uncovered 1-to-4-inch-diameter pipes protruding vertically through the roof by six inches or more. The flashing and seals are located at their shingle-level bases.
Vent-pipe flashing is a rectangular piece of sheeting having a raised oval-shaped crown at its center with a circular rubbery seal and pipe-hole centered atop the crown. This flashing is fitted down over these pipes before the roofing is laid over its base. Most of this flashing is made from thin aluminum or hard-plastic sheeting. The flexible rubbery seal on top of the crown fits tightly around the pipe by squeeze-gripping it. This seal prevents any rain water from leaking downward around these pipes.