Cut only from the blister at the best layer of roofing; don't cut the roof substrate, or maybe the fiberboard beneath the rubber or asphalt.[nine] X Research resource Inspect locations the place surfaces join, which include in a chimney or valley. Search for gaps in caulk, sealant, or aluminum flashing https://roofingsupplies47232.blogchaat.com/33786843/reroofing-for-dummies