It is unlikely that many homeowners sit around counting the days until they get to re-roof their house. The day will come when every house will require a new roof. It may be due to the age of the roof or the result of damage. The key is to determine when a new roof is needed and get it taken care of before additional damage can happen to other parts of the dwelling.
Damage to a roof may not always be apparent to the untrained eye.
Hail, wind, and other elements can victimize a roof without leaving ugly or unsightly marks on a roof that are easy to see from the ground. Unless you use binoculars and have some measure of training or experience in what to look for when inspecting a roof for damage, you will probably not know your roof has sustained damage.
The only really sure way to find some types of damage is to make the trip up to the roof.
When hail hits an asphalt or fiberglass shingle, it can make a small depression. This is someone like the impact crater left by a meteorite when it hits the earth. Obviously, the scale is much much smaller. The dents can be less than one half inch across. However, when there are thousands of these across the surface of the roof, the life of the shingles will be tremendously reduced.
Along with the dents, small cracks can form along the line where the tabs meet the shingle body from the impact of hail or other debris.
While the dents will cause the granules to leave the surface of the shingle, these cracks can cause even worse damage. Eventually, the cracks will worsen and cause the tabs to be in danger of being blown off by the wind. When this happens, the roof will often begin to leak and result in interior damage to the building. At the beginning, these cracks are small enough to missed by all but the most trained eye. Even some insurance adjusters will discount these cracks as just signs of wear.
Even in the absence of hail in strong thunderstorms, damage can occur from the wind.
It is usually assumed that once shingles become sealed to the roof that straight wind will not harm them. This is somewhat true. The reality is that even straight wind can raise a tab here and there. Once shingle tabs are a few years old, a minor flex can cause them to crack and loosen a little. Hot sun, heavy rain, and more wind will work on this tab until it can no longer provide the protection that it is designed to do.
Age will work against your roof.
Many shingled roofs are now guaranteed for between twenty-five and fifty years. The owner of a newly shingled roof will probably feel smug that this may be the last roof he or she will have to have installed on this house. After shingles have reached about half of their projected age, they are much more brittle than new shingles. This means they are more susceptible to damage.
Anyone who owns a house with a roof that is ten or more years old should always have it inspected after any major storm that blows through. Waiting too long for this type of inspection can mean that the insurance company may depreciate your shingles or refuse to pay because the roof was too old.
Barring damage, there are other signs that you need a new roof.
When the shingles begin to lose their color because of the loss of granules, it is a good sign that a new roof is probably needed. Likewise, when the slots between the tabs become worn until they are about twice their original width, it is time to replace the shingles. If your roof is old and has started to leak in more than one spot, call a roofer and get new shingles. If shingles begin to fall off or blow off in light wind, it is only a matter of time until you have major problems if you do not replace the roof quickly.