Should I Replace Flashings on Parts of my Roof?
Customer: I am going to repair part of my tile roof. The section in which is being repaired has a couple of pipes with sheet metal flashings around the bases of them. My contractor will be removing, replacing and re-installing the base flashings. Should I have him do the rest of the flashings on the areas of the roof which are not being redone?
Raneri and Long: Good question! My answer is categorically no! Do not replace flashings unless you are reroofing the entire structureI Why?
The answer follows:
Think about standing with a running water hose, on the top of your driveway. Now imagine the action of the water, as it runs downhill. Note how it does not follow a straight line, but instead will follow its own path seeking the lowest point. This is the same action which occurs on your roof.
In other words, water can leak into the roof and under the tile, from somewhere up above.The water then runs downhill, under the flashing, to the hole in the sheeting which was cut for the pipe itself, potentially causing a leak where no leak was before. So, by disturbing the flashings, you may be doing more harm than good!
Voila! A leak!
So, what happens next? The roofer or handyman comes out to repair the leak, thinking it is that same offending flashing. He smears some mortar or mastic around the flashing, collects his payment, then goes on his way. Next rain, the same leak recurs. You call the repairman back. He looks, sees it is showing up in the area he already “repaired,” then tells you that, uh oh, must be coming from somewhere else. Not my responsibility, starting the process all over again.
The bottomline is that leaks often are not super simple to diagnose. They can come from almost anywhere. That is why replacing flashings haphazardly, while not doing the entire roof, is simply not recommended by any reliable contractor. Kinda like throwing money away!
When you want answers, place your trust in Raneri and Long. We’ll always tell you the truth!