How the local climate wears a Union roof down
New Jersey gives a roof no easy season. Summer here is hot and humid, and the heat that builds in an unvented Union attic bakes asphalt shingles from below while the sun cooks them from above. Then come the storms. The afternoon thunderstorms that roll across Union County in July and August drive rain sideways into anything that is not flashed tight, and the nor'easters that arrive later in the year pile wind on top of heavy, sustained rain. A roof that has been quietly aging through the summer suddenly has to shed a serious volume of water under real wind pressure, and that is when the weak points give way.
Winter brings the slowest and most destructive force of all. When snow sits on a Union roof and the attic below is warm, the snow melts, runs down to the cold eave, and refreezes into an ice dam that backs water up under the shingles. The same freeze-thaw cycle that creates ice dams also works on every small crack and gap, expanding and prying it open a little more with each cold snap. The leak that shows up in February was often created by a brittle flashing detail the previous August. This is why we are so insistent on inspecting before the cold sets in, while there is still time to seal up the vulnerable spots before water and ice ever find them.