Problem: Roofs have two main layers: a layer of sheathing and a layer of shingles. Sometimes rather than removing old shingles to lay new ones, contractors will just put a 2nd or even a 3rd layer of shingles on top of the old one. This is called an overlay and results in zero warranty and cuts the shingle life down to 1/3. This roof was one of those. Overlaying is just poor installation practice but inspectors will pass up to 3 layers in some counties.
Solution: The shingles were in really bad shape and beginning to break and fly off, so we decided to focus providing longevity for the future and giving the homeowner a roof that would last. We tore the entire roof down including the sheathing and installed a performance grade roof.