Vent Pipe Flashings

Vent Pipe Flashing importance and common issues

Importance of Pipe Flashings:

Weathertight Seal: Pipe flashings create a seal around vent pipes, preventing water from entering the roof system.
Structural Protection: They protect the integrity of the roof and prevent water damage to the structure.
Accommodate Roof Angles: Pipe flashings must accommodate the different angles or pitches of the roof to maintain a proper seal.
Weather Resistance: They withstand wind-driven rain, snow, icing, and ice damming, ensuring long-term durability.
UV and Thermal Resistance: Pipe flashings endure the harsh effects of UV radiation and temperature fluctuations without degradation.

Common Issues and Failures:

Undersized Flashing Plate: Poorly designed flashings may have undersized metal or plastic plates, compromising the seal.
Cheap Materials: Commercially available flashings are often made from cheap materials, leading to premature failure.
Thin Elastomer Seals: Contractor-grade flashings may feature thin elastomer seals that lose their compression over time, resulting in leaks.
Egg-Shaped Holes: Round holes in flashings can become distorted when placed at an angle, causing leaks.
One Size Fits All: Flashings designed to fit various pipe sizes may overstretch or tear, leading to seal failure.
Slow Leaks: Slow leaks from pipe flashings can go unnoticed, causing moisture damage, rot, mold, and attracting pests.

Addressing these issues requires using high-quality flashings with properly sized plates, durable seals, and design features that accommodate roof angles. Regular inspection and maintenance can help detect and prevent leaks before they cause significant damage to the roof and the underlying structure.

How to Install Vent Pipe Flashing on an Existing Roof

Once you’ve collected the tools and materials you’ll need to install the flashing, it’s time to get to work. Here’s a step-by-step guide to see how it’s done whether you want to do it yourself or get a better idea of what your roofing expert is going to do. Let’s begin!

Step 1: Loosen the shingles. Pry back the shingles that are above and on both sides of the vent pipe using a pry bar. You don’t need to bend back the shingle that’s beneath the pipe. You can bend them back by working a putty knife under the bottom of each tab and slipping it through the adhesive to break the seal.
Step 2: Place the new flashing over the vent and into the correct position. The flashing should be installed under the top and side shingles, but it should be laid above the shingles that are below the vent pipe. To make the installation easier, you can turn the flashing as you lower it in place. The neck of the flashing should fit snugly around the pipe.
Step 3: Hammer the nails into the top and sides of the flashing. Before you do so, make sure the top and side shingles are bent back, so you don’t accidentally nail through the shingles. Use roofing cement to seal the nail heads.
Step 4: Hammer nails into the bottom edge of the flashing. When you hammer the roofing nails into the flashing’s bottom edge, you’ll have to make sure the flashing is on top of the shingle that’s below the vent pipe. After that, seal the heads of the nails using roofing cement.
Step 5: Use roofing cement to seal around the flashing’s edges.