Before a roofing contractor places shingles on a roof, they must first place the underlayment. Asphalt shingles are the first line of defense against the elements. The second line of defense is the underlayment, which protects the wooden structure of a roof from moisture. Even if rainwater does make it past shingle tiles, the underlayment will prevent that water from seeping into the roof.
But when underlayment fails, moisture can enter your roof space and cause mold and rot damage.
Roofing underlayment can fail for several reasons.
1. Wild Animals
Animals like roof rats, possums, and squirrels can all damage roof underlayment if they decide that your attic would make a good place to nest. That's why you need to limit access to your roof by trimming nearby tree branches.
2. Tree Branches
Tree branches also damage underlayment when bad weather causes them to rake over a rooftop. Even if a tree branch only loosens a shingle during a storm, this will be enough to allow wind-driven rain to make its way under the shingles.
If animals, tree branches or bad weather dislodges or damages your shingle roof, swift repair is necessary. Although underlayment works by diverting water away from your roof structure, it will eventually begin to rot if left exposed for too long. This rot will then spread to your roof's wooden supports.
And during rainfall, a rotten underlayment will no longer protect your home from roof leaks.
4. UV Radiation
Another urgent reason to replace missing or damaged shingles quickly is that UV radiation can damage underlayment, especially if that underlayment is comprised of asphalt felt. Asphalt felt deteriorates rapidly when exposed to UV radiation for a prolonged period.
Although synthetic underlayment is more resistant to UV radiation, it too will fail if exposed to direct sunlight for too long.
5. Poor Installation
Sometimes, roofing underlayment fails for no other reason than poor installation. If a roofing contractor damages underlayment during installation, that underlayment will no longer provide sufficient protection against the elements.
This is why it's important that you take the time to choose a roofing service with a good reputation and verifiable roofing work history.
The underlayment is a vital part of your roof. One breach in your underlayment can lead to wood rot and leaks in your attic. If you see signs that your roofing underlayment might be damaged, hire a roofing service to fix it as soon as possible.