Spotting a bad roof is easy for most veteran roofing contractors. Curled or missing shingle tabs often tell the story. However, there can be wild cards, both in terms of what you find on the roof and in terms of the people who call for the inspection. The first question that Mark David, vice president of sales for Joseph David Roofing in Linden, N.J., asks those who call for repairs is: “How old is the roof?” He follows with: “But you must have a warranty.” To which, he says, the homeowner usually responds by saying the roofer's number was disconnected or they don't want the guy on the property because they don't trust him. David then schedules a roof inspection.

INSPECTOR NEGLECT Alan Archuletta of Full Systems in Salt Lake City says many contractors in his market don't inspect roofs. Archuletta finds inspections an indirect and cost-effective route to a replacement job. Though he walks the roof and inspects carefully, Archuletta finds the top problems in his market easy to see: curled shingles or missing shingles sometimes attributable to the substrate.

In San Jose, Calif., David Cameron, owner of Certified Roofing, also does inspections — he gets calls from mortgage companies, realtors, and prospective homeowners alike. But, unlike Archuletta, he charges for inspections. Cameron sees lots of roofs requiring ventilation and attic insulation, and has added attic insulation to his roofing services because of this.

GRAINS GONE “My number-one signal that a roof is bad,” says ace roofer Brett Hall of Joe Hall Roofing in Arlington, Texas, “is when I can see the fiberglass from worn shingle tabs reflecting in the sun.” He calls this phenomenon “granular loss,” adding, “it's difficult to spot, and the sun has to be right, but you can see it. A roof like that has one or two years left on it.”

For David, grains in the gutter are a dead giveaway. So is shingle discoloration, and the presence of mold or algae. When he arrives, “from the curb to the door, I'm doing a visual inspection. I can tell whether it's an obvious culprit like flashing details around the chimney or something added at a later date, such as a satellite dish. So I have an idea before I make my way up to the attic. The attic inspection,” he adds, “is mandatory.”

Now the question comes down to whether to replace or repair. With a bad roof, a repair job can be “like a trip to Atlantic City,” David says. A roll of the dice. “I give homeowners choices and tell them what I would do if it were my home,” he points out. —Mark Clement is a freelance writer and former contractor based in Ambler, Pa.