Pipe Flashing and Bathroom Leaks

One of the most common complaints we get in our office is from homeowners with leaks in their bathroom ceiling. Although there are a variety of reasons a roof can leak, when we are called in to repair a leaking roof in a bathroom, the culprit is almost always a failed pipe flashing.

What Is a Pipe Flashing?

Somewhere in the walls and ceiling of your bathroom, a vent pipe runs from your roof to the sewer line that services your bathroom plumbing fixtures. This line is often called a plumbing stack and exists to vent sewer gases that have accumulated in your lines. Sewer gas, when allowed to build up, can have both explosive and obnoxious consequences. The hole created to place the vent line in your roof must be sealed in order to prevent damage to the interior of your home.

Pipe flashing goes by many different names and may be commonly known as any of the following, depending on where you live:

• Pipe flashing
• Stack boot
• Pipe collar
• Stack cone
• Cone flashing

Regardless of what you call it, pipe flashing is a water-resistant gasket and collar that fits around the stack pipe in your sewer line. This collar is designed to stop water from flowing down the outside of the pipe and into your home. A pipe collar can come in a variety of shapes and styles — all containing the same basic elements.

• Boot: The boot is a rubber ring that is designed and sized to fit tightly around the vent stack. This piece creates a seal that prevents water from running down the pipe and into your ceiling.
• Flange: The flange is the base of the flashing and lies, at least partially, underneath a layer of roofing materials. The flange also holds the boot and the cone, if present, securely in place.
• Cone: On some types of flashing, there is a metal cone that sits over the pipe and the boot. Cones come in a variety of decorative colors, sizes, and shapes and help to protect the rubber seal and provide an attractive silhouette.

Depending on the shape of your roof, the height of your stack, and a variety of other factors, your pipe flashing could look like anything from a black ring attached to a metal board to a foot-tall-tiered wedding cake. However, most of them will be made of aluminum, be partially or completely covered by roofing materials, and have a black rubber boot.

Why Does Pipe Flashing Fail?

Much like any fixture on your home, pipe flashing has a finite life. The most common reason for failure in flashing, however, is the degradation of the rubber boot. Degradation takes place over time — from exposure to the sun, water, and other elements. When a rubber boot fails, it allows water to leak into your ceiling from around the outside of the pipe.

UV radiation plays a major part in the life span of rubber used in outdoor applications. UV radiation put out by the sun, in combination with oxygen, causes what is called photooxidative degradation. Over time, photooxidative degradation breaks down the chemical chains in the rubber, causing it to become brittle and cracked. As it degrades, the rubber shrinks and pulls away from the vent stack. Eventually, the rubber seal is no longer able to hold back water, and you will begin to see the damage inside your home.

UV radiation is not the only reason for a pipe flashing to fail. Although not as common, occasionally rodents such as squirrels will also damage the rubber boot. Although hardly malicious, a dedicated rodent can make short work of most building materials.

Occasionally, though far less likely, damage to other portions of the flashing may cause trouble. Screw gaskets can fail, the roofing material that restricts water from entering under the flange can be knocked loose or high winds, and damage can damage the pipe itself. There is a variety of outlandish but perfectly realistic ways your pipe flashing can fail.

Reasons To Avoid Repairing Rubber Boots

What many homeowners fail to recognize is that a rubber boot does not “expire.” There is no real way to know how long your replacement boot will last. Most professional roofing companies will comfortably estimate the lifetime of a rubber boot to be about five years. Some may last for decades — others for years. The breakdown of polymers caused by UV radiation does not happen over a set period of time, and there is no way to realistically estimate the life span of a replacement boot.

Evolution of Pipe Flashing: Modern Solutions for Lasting Performance

Although modern pipe flashing still utilizes the same basic design, our understanding of polymer degradation has allowed modern manufacturers to adapt old concepts to create lasting, long-term solutions. When properly installed, a modern pipe flashing can last over 50 years.

Modern flashing includes a protective, fitted cone made of high-quality PVC or other UV-resistant materials. A cone shields the rubber boot from harmful UV radiation, greatly extending the lifetime of the gasket. The addition of a compression collar prevents the gasket from relaxing around the pipe and allowing water to flow through. These advances have greatly extended the functional lifetime of pipe flashing in residential homes.

Beyond the technical, modern flashing creates a clean and decorative silhouette — a vast improvement on older pipe flashing. There’s always something to be said for a more attractive product.

The Right Solution for You: Modern Flashing

We encourage all our customers to have modern flashing installed around their vent pipes. It’s a low-cost, effective way of preventing one of the most common roofing issues in residential buildings. Professional installation by BRAX can be handled quickly — in less than an hour for many homes, and your new flashing requires no maintenance. It also comes with a lifetime guarantee for the life of your roof covering. So, even if you are not having your roof repaired, replacing your old pipe collar with a modern, long-life flashing is a low-cost investment that is guaranteed to last you until you do.

Contact BRAX Roofing today for more information on installing long-life pipe flashing in your home.