The county median is 1975, a few years newer than the state. That number hides a wide spread. In Monroe Township 43 percent of homes went up this century, and South Brunswick has a 1987 median. A house from the late 1980s or 1990s may still be on its original roof, and shingles that old are often close to worn out.
Go north toward Raritan Bay and the picture flips. Perth Amboy dates to 1959, Carteret to 1960 and Dunellen to 1955. Roofs there have usually been replaced at least once, and an earlier crew may have laid new shingles on top of old ones. Some of those houses still have plank decking under everything.
The whole county sits in the middle of the Central Zone. Winter storms often come as a mix of rain and snow, and slush in the valleys freezes again overnight. In July a dark roof in full sun gets far hotter than the air. Shingles take both, year after year.
A 1995 roof and a 1959 roof are different jobs, so nobody here gets a price from the curb. We go up, count layers, and look in the attic first.