1. Inadequate ventilation
A roof ventilation system works by pulling in outside air from intake soffit vents placed on the lower part of the under side fascia overhangs. Has natural winds hit your home the air that is taken in is displaced through higher parts of your roof. The result of inadequate venting is moisture and heat being trapped in your attic because it has nowhere to exhaust to.
Additional heat on the bottom side of roof decking can cause the shingles to wear prematurely, fade and curl. It’s important to have proper ventilation, which regulates the intake and exhaust of air in your attic and keeps your shingles at an ideal temperature lessening the chance of curling.
2. Improper installation
Roofing manufacturers have strict regulations regarding how their shingles are to be installed on roofs. This can include things like the number of nails per shingle, length of the nails, soffit venting and ridge venting calculations. Because of this, we strongly recommended that homeowners work with a reputable roofing company that is familiar with the type of roof they are wanting installed on their home.
Failure to adhere to these specifications can cause your shingles to curl and can also void your warranty. We have seen many new roofs over the years being installed wrong. In fact just recently right here in Cary, NC we witnessed a local roofing company installing a brand new roof incorrectly. We couldn’t believe it and even stopped to take pictures. We literally see it all the time!
3. Defective products
From time to time we see a manufacture release a bad batch of shingles that can cause issues with the roof not sealing properly. But this would result in a warranty claim with the shingle manufacture. However this is usually not the case.
4. Installing new shingles over old ones
There are several reasons as to why installing a second layer of shingles over a first layer is a terrible idea. Regardless of the local building codes and restrictions, it is very likely that the new shingles will line up with the existing ones.
This will prevent the new shingles from sealing properly and as a result, they may come off more easily during high winds. That being said it is likely that the shingles can move and twist ripping out from the nails that might just be fastened to the shingles below. If the nails are not long enough than the shingles will blow off easily.
You really have to know what you are looking for too. As it is common practice for the edges of the first layer to be cut back so the first layer is not visible from the edges of the roof. You can have your roof inspected to see if you do in fact have two layers.
5. The shingle has reached the end of its life expectancy
While the life of your new roof may vary by material and roofing manufacturer, all shingles are similar in the fact that once they begin to curl, it’s time to start thinking about a new roof. Usually the first signs of a failing roof is that the granules come off and fill up your gutters. Than the fiberglass reinforced asphalt matting is exposed to the elements like the sun and dry out. Next the shingles will start to curl and the seals underneath break and tabs become loose. Than finally the tabs will blow off in high winds exposing the nails and causing roof failures.