Modified bitumen roofing is a type of durable, layered asphalt roofing often used on low-slope roofs, while ridge vents are ventilation systems installed along the roof peak to allow hot air to escape. Leaks around ridge vents in modified bitumen roofs commonly happen due to poor flashing installation, damaged or improperly sealed seams, or debris buildup causing water to pool and infiltrate vulnerable areas. Over time, the roof’s flexible asphalt layers can crack from temperature changes or sun exposure, making it easier for water to seep in around the ridge vent. To diagnose a leak, look for water stains inside the attic near the ridge vent or dampness directly below on the ceiling and walls. Checking for loose or missing granules on the modified bitumen surface or visible cracks in the flashing around the ridge vent are useful DIY steps. It’s important to approach these checks carefully—avoid walking on the ridge vent itself and use binoculars or a ladder for a closer look from a safe position.
If you spot signs of damage or suspect a leak but are unsure about the source, calling a professional roofer is a smart move, especially because modified bitumen roofing requires skillful seam repairs and proper flashing techniques to maintain warranty coverage. When speaking to a contractor, ask if they have experience working specifically with modified bitumen roofs and ridge vent systems, and how they plan to ensure the repaired seams and flashings are fully sealed and weatherproof. You may also want to inquire if they perform infrared or moisture detection scans to find hidden leaks without damaging the roof surface. Proper repair typically involves resealing or replacing flashing around the ridge vent and carefully patching or restoring the modified bitumen membranes to prevent future water intrusion.