During his 25 years as a professional roofer, Jim learned that one of the most common causes of leaky roofs is a deteriorated pipe flange. Roofs have one to four vent pipes usually located above homes kitchens and bathrooms. Most roofers charge $300 to replace one pipe flange and $750 to replace all four. In addition, roofers have to remove the shingles surrounding the flange to replace it. If the shingles are undamaged, roofers can reinstall them.

