by Bob Mamerow
There are many signs a roof needs to be replaced. Some are obvious, such as leaking during rainstorms. But there are many other things that indicate your home needs a new roof.
One of the not-so-obvious signs is shingle granules in the gutter, which point to advanced roof wear. Dark spots are another indication the roof is losing granules. Without granules to protect the asphalt in the shingle, it will be broken down by the sun, become brittle, and won’t prevent water from getting into your house.
Dark spots on the north side of the roof are a sign of algae or contaminants. The algae feed on the limestone filler used to give the shingles weight. Over time, the granules will begin to loosen and wash off, and as above, leave your shingle unprotected. The new generation of shingles now has algaecide in them so that does not happen.
Often seen on the west side of the house, which gets the brunt of hot sun, are curled shingles. The sun has slowly broken down the asphalt layers in the shingle, causing it to shrink on itself and curl up. That makes the shingle vulnerable to wind, flying off your roof, and leaving an open spot for water to get in.
There are other reasons why shingles fail. Ventilation is one of them. Nine out of 10 houses don’t have proper ventilation in the attic, a problem both in summer and winter. Roof manufacturers recommend attics be within 10 degrees of outside temperature year round. Without ventilation, when it’s 90 degrees outside, the attic can heat up to 130 degrees. That heat not only hurts the shingles, but if you have a second story, you will have a hard time cooling it. Proper ventilation means there is positive air flow from the soffit vent to the ridge vent.
In the winter, if you don’t have enough insulation and ventilation, you will lose heat to the attic. An insulated attic will not only help with your energy bills, but will prevent roof problems such as ice dams and condensation. Hand-in-hand with this is ventilation. When warm air is stored in the attic without a ridge vent to let the air escape, the stored heat will melt the ice and snow. The melt hits unheated soffits, refreezes, and creates an ice dam. In extreme cases, the roof decking will mold and mildew because of trapped moisture.
Also contributing to moisture in the attic are improperly vented kitchen and bathroom fans. Many times we see the coil tubing running into the soffit or just laying on top of the insulation, pumping moisture into the attic. Venting should run up through the roof as straight as possible.
Another sign of moisture in the attic, especially with wood homes, is paint blistering and peeling on the gables and soffits.
An obvious indication that a roof needs to be replaced is missing or blown-off shingles, which usually are the result of improper installation. Some installers use only three or four nails per shingle, which isn’t the best protection from wind damage. Callen’s preferred method is six nails per shingle, which ups the wind warranty from 80 to 130 miles per hour. That gives the shingles more stability and keeps the home protected.
Faulty underlayments (the material underneath the shingles) can also be a source of leaks. A common underlayment is tarpaper and that is not recommended. An underlayment should also have ice and watershield to protect the roof.
Proper roof installation can be the subject of another blog, but I will say that even though it’s allowed by code, we don’t recommend putting a second layer of roof on. A second layer is a band-aid, but doesn’t treat the cause of the problem. And by putting that second layer on, you are cutting the life of that layer by 30 or 40 percent. There is more weight on the roof and when it’s hot, the shingles will cook. If there is any movement underneath with the original shingles, it’s going to telegraph through. If there are curled shingles underneath and you put a layer over it, you are going to have an uneven look. Plus, with a complete tear-off, we can examine the roof decking, diagnose any problem, and take care of the situation.
Roofing is not just throwing shingles on. It’s the underlayments, how they are put on, and proper ventilation and insulation.
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