Asphalt shingles are commonly used as roofing material because they are very durable. They come in many different colors and styles, and they are fairly easy to install. But, just like any part of your home, they won’t last forever. Shingles will eventually begin to curl, curve, and take in a cup-like shape over time.
Lack of Ventilation
You may not notice it happening right away, but if given enough time your roof will begin to look wavy and distorted. There are a number of reasons why this may happen. Lack of venting is one reason. Under your shingles, there is going to be a deck made of plywood or chipboard as well as one or more layers of roofing felt or other material suitable for an underlayment. These layers are important and are what gives the roof durability, but they can also be a heat and moisture trap. Heat and moisture are bad for shingles and will cause them to cup or curl. It is important to vent the attic in a way that complies with the current building codes so that moisture can escape.
There could also be a manufacturing fault, and it could be that there is a lack of asphalt-based binder that was applied to the backing of the shingles. This binding helps to keep the granules on the shingles which helps to protect your roof from UV damage and from the weather. If there isn’t enough binder, the granules will wash away and leave the backing exposed and prone to crumple and curl. If you suspect that this is the case you can contact the manufacturer and they will likely re-roof your home or repair your roof.
Storage of the shingles before they were used to cover your roof can also affect how they hold up. If shingles are not stored in a cool, dry place or if they were sitting out in the rain or direct sun, they will most likely begin to curl and cup over quickly after being installed.
New Shingles Installed Over Old Ones
Sometimes you will run into problems when new shingles are installed over old ones. This is a bad idea but it still sometimes happens. That’s because it is pretty much impossible to line up new shingles with the ones that are already in place. This causes gaps, and that means that you are more likely to see leaks. Shingles will also come off more easily if it gets windy and they will probably curl.
Hot or Cold—You Decide
Asphalt shingles are quite durable and can handle extreme heat and cold, but you need to decide whether you need shingles that will hold up best in the heat or in the cold. Shingles are not designed to do both. It is one extreme or the other.
If your shingles are cupping or curling you need to get a professional installer to come and look at your roof. They will be able to access what needs to be done and will most likely replace your roof with a new one.