The pipes of a plumbing fixture need a pressure relief point in order for water to drain without creating a suction. This is achieved with a simple open-ended pipe, usually directly above the fixture. The open end of the pipe is extended to protrude through the roofing surface. The reason for that is because the pipe will occasionally burb noxious gases, especially over toilets. It would be unpleasant to have these gases trapped in the attic space. This brings us to our present issue of how best to ‘flash’ these pipes to the roof system.
The four main options for flashing a plumbing pipe
The first and cheapest option is a black plastic flashing, sometimes referred to as an Auto-Caulk. One costs about eight bucks. Unfortunately they have a tendency to warp and dry-rot when exposed to the Texas elements. They usually last about ten years. When they fail, water can run directly into the structure. You can see the seal failure in the first two pictures. In the third pic you’ll see the wood rot which is caused by a failure.
The next type of pipe flashing is sometimes referred to as a “3 in 1”. It’s a slight step up from an Auto-caulk, and costs about $15. The higher quality feature is the solid metal base. The part that seals to the pipe is a rubber gasket. The rubber will resist dry-rot for 10 to 20 years. When it fails, it’s made to be easily replaced. We don’t use these because Square Roofing doesn’t believe in using material that’s built to fail.
Next we have lead pipe flashings (or lead boots). The first two pics show lead boots which were poorly installed. The third pic shows how Square installs a lead boot. The cost of a lead is around $22, depending on the size. Traditionally lead boots have been the highest quality option. However, some contractors argue that the beauty factor of a “3 in 1” (if painted) is greater than a lead boot. The longevity is certainly more dependable with lead than with rubber. Based on the first two pics, it’s easy to see why folks might argue against the lead. If Square Roofing installs a lead boot, it always gets a ‘Steel Squirrel Sleeve’ added. This feature is a Square Roofing specialty. You can see an example of these in the third picture. One adds about $7 to the cost. However, it ensures long lasting beauty and worry-free protection.
Finally, we have the GAF Pivot Pipe. It’s a bit more expensive at around $55 each. We feel that this is money well spent. The pvc plumbing pipe is completely encased in the all-metal design. Even with the price jump, our bid using the ‘Flagship’ GAF system (including the Pivot Pipes) is often lower than what’s expected. Also, if we install the Armor Shield, then we definitely want to use the Pivot Pipes. They’ll last the roof life and stay looking sharp the whole time!
