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Stack Flashings

Have you looked at your stack flashings? Does your roof leak? Roof leaks can originate from many locations and for various reasons. Sometimes shingles are missing or damaged which then allow moisture intrusion. In other cases, the flashings are to blame. Flashings include chimney flashings, wall flashings, roof vent flashings, drip edge flashings, flue vent flashings, and soil stack flashings. Other flashings exist but the flashings listed above pretty much sum them up. In this post, we are going to cover soil stack flashings.

Soil stack flashing
Soil Stack Flashing

What is a Stack Flashing?

A stack flashing refers to a flashing that covers a vent stack. A vent stack is a plumbing vent that projects above the roofline. This vent serves an an exhaust for sewer gases and also aids the plumbing system in operation. They are typically made of PVC in newer homes and many older homes have cast iron stack vents. A pipe protruding through the roof creates an opportunity for the roof to leak. So, contractors may apply sealant to the outside of the pipe where the pipe and shingles intersect. The proper way to seal this intersection however is by using a flashing. The flashing above is made out of lead. This flashing has been compromised at the top which can allow water to enter into the building. This should be corrected by a qualified licensed roofing contractor.

How was the Flashing Damaged?

In the flashing above you can see the deterioration at the top. Typically you can also see grinding marks near the openings. This is due to squirrels grinding their teeth on the flashings. While this may help the squirrels it can cause leaks into your home. See the photo below:

Damaged stack flashing
Damaged Vent Flashing

Here we see a rubber flashing that has split open on a PVC vent stack. The rubber flashings can be damaged by animals as well. In the photo above, the rubber has split due to aging and heat. This rubber flashing sits on top of a hot roof in the baking sun throughout the years. Temperatures on roof shingles get well above outside ambient temperatures. In fact, the roof surface may reach above 150 degrees F. When this happens, the rubber flashings simply dry out, crack, and split. Can you slap a bunch of tar around this and seal the leak? Sure you can. The proper way to fix this though is to replace the flashing.

Stack Flashings and Home Inspections

So, if your stack flashings are damaged they should be fixed. When you are buying a home then a home inspection can find these concerns. Oatey is one company that makes replacement vent flashings. Many homebuyers should elect to have a professional replace the vent flashing for proper installation and safety. Additionally, some buyers forego inspections in a sellers market. Lask Inspection Group, LLC highly advised buyers to do their due diligence on a major purchase such as a home. Most home inspections range from $300-$500, depending on size and age of the home as well as any ancillary services. This equates to .003% to .005% on the purchase price of a $100,000 home. Commercial inspections will often have stack flashings as well. We serve Rockford, IL and other Illinois cities such as Loves Park, Machesney Park, Chicago, Naperville, Aurora, Geneva, Dekalb, Sycamore, Elgin, Lake Zurich, Arlington Heights, Crystal Lake, and other Chicago suburbs. In conclusion, if you are considering buying a home or in need of a home inspection, call our office at 815-978-7785 or book the appointment here.