Introduction
Proper vent pipe flashing is one of the most critical — and most commonly mishandled — details on a roof. When flashing is installed incorrectly, even a relatively new roof can develop persistent leaks.
We covered a similar flashing failure in this related case study. In this example, a homeowner contacted us after discovering a roof leak that appeared only one month after a roofing contractor installed new vent pipe flashing.
What we found highlights why accurate diagnosis and proper flashing methods matter far more than temporary sealants or shortcuts.
The Problem: Recently Installed Flashing That Still Leaks
The homeowner had recently hired a contractor to replace vent pipe flashing, expecting the leak to be resolved. However, despite the recent work, water continued entering the home.
Upon inspection, it was clear that the flashing had not been installed correctly. Excessive caulk had been used in an attempt to seal gaps instead of using a properly engineered flashing system. While caulk may slow water temporarily, it fails quickly under weather exposure and movement.
Why Improper Vent Pipe Flashing Causes Leaks
Vent pipe flashing must create a watertight seal that allows for roof movement, temperature changes, and long-term exposure to weather. When flashing is poorly fitted or relies on sealant alone, water can migrate beneath shingles and into the roof system.
Common consequences of improper flashing include:
- Recurring roof leaks after recent repairs
- Water damage to the roof decking and insulation
- Hidden moisture that worsens over time
- False assumptions that the roof itself has failed
The Solution: Proper Vent Pipe Flashing Installation
To permanently resolve the leak, we removed the improperly installed flashing and replaced it with a professionally engineered vent pipe flashing system designed to remain watertight for the life of the shingle roof.
Unlike temporary caulk-based fixes, this system accommodates expansion, contraction, and weather exposure while maintaining a secure seal around the vent pipe.
Results: A Guaranteed Leak-Free Roof
After the flashing was properly installed, the leak was eliminated completely. The homeowner now has peace of mind knowing the repair is designed to last and does not rely on short-term sealants.
This case reinforces an important point: when roof leaks persist after recent work, the issue is often improper installation — not the roof itself.
Why Proper Diagnosis Matters
Vent pipe leaks are frequently misdiagnosed or “patched” without addressing the real cause. Accurate inspection and correct flashing methods prevent repeat leaks and unnecessary repairs.
If you suspect a roof leak around vent pipes or that recently completed roof work hasn’t solved the problem,
contact us for a proper leak inspection and diagnosis.
Jon transitioned into custom residential home construction with an opportunity to become a working partner with Mike Evangelist. Since roofing had been a large part of my past work experience, it was a natural fit. Finding and detecting hard-to-track roof leaks is our specialty.
- Roof Leak Repair Case Study: Garage Ceiling Leak Caused by Missing House Wrap - January 28, 2025
- Kick-Out Flashing Repair: Solving a Bathroom Leak During Heavy Rain - November 29, 2023
- Proper Vent Pipe Flashing: The Key to a Leak-Free Roof - October 31, 2023