Roof asphalt shingles can get damaged – that’s a fact. They get dented by hailstones, cracked by wind-blown debris and heavy foot traffic, blown off by strong winds and pierced by unnecessary rooftop equipment. But what can cause asphalt shingles to curl? 

It’s understandable that homeowners would try to find ways to save on their new roof installation. But some of these methods can actually do more harm than good, which, in turn, leads to even more expenses down the line. One of these questionable methods is a roof layover, which involves nailing the new roofing over the old system. Here’s why this is a bad idea.