Three Phillipsburg homes in four predate 1960. On roofs that old, the shingles in the middle of a slope often outlast the joints around them: chimney flashing, valleys, vent boots and the metal along a wall. Many have been patched before, sometimes with roofing cement smeared over the metal.
Allamuchy has 44 percent of its homes in attached houses and Independence 29 percent. Where two roofs meet, water can enter on one side and come out on the other. We look at both sides of the seam where we are allowed to, and a repair on an attached house goes through the town's construction office.
In winter the eaves are the usual suspect. Heat from the attic melts snow from below, the water runs to the cold overhang and freezes, and that ridge of ice holds the next melt against the shingles. The stain then turns up near an outside wall.
A stain tells you water got in, not where. We go up when it is safe, follow the water back to the opening, and photograph it before we put a price on the repair.