Roofing felt is a sort of felt paper which is soaked in oil. After being soaked in oil, it becomes impervious to water. It is sometimes also called tar paper.
Why bother with roofing felt?
Roofing felt is used because in plenty of cases, shingles aren’t capable of completely waterproofing a roof. For this reason, roofing felt is used to make a second layer in a roof. This second layer acts as a barrier to water. The roofing felt directs any water which manages to drip through the shingles to the gutters.
Are there any downsides to roofing felt?
There are a couple of things that can compromise roofing felt.
- It can be torn and develop holes quite easily while it is being installed.
- Sunlight makes it deteriorate quickly. Ultra-violet radiation from the sun can turn it brown fairly quickly as it degrades the oils. This can happen anywhere between twelve to twenty-four hours.
- If you notice that the roofing felt has turned brown before the shingles have been put in place, then it is a lost cause as it won’t do a good job of protecting the roof.
- Roofing felt can trap moisture underneath it as it doesn’t breathe which can lead to mold and mildew.
Despite these drawbacks, roofing felt is still used extensively. Here’s why.
- It protects the roof while the inner structure of the roof is exposed when the shingles are being removed.
- It is a safer environment for workers as it gives them better traction and helps reduce the chance of them slipping.
- In some roofing systems, it has demonstrated an ability to increase the fire rating.
- It is also cheaper than the alternative which is synthetic.
It is also important to know that the terms “felt paper” and “tar paper” are used synonymously. In reality, they are different. Felt paper is used more commonly and is usually made of recycled paper products which are then impregnated with asphalt. Tar paper is different as it is made of tear-resistant paper or fiberglass matting which is then soaked in tar.
As to the question of whether you need roofing felt or not, it depends on where you live. There are many climates where roofing felt is a necessity and many climates where it isn’t required. However, it is always a good idea to install roofing felt as it is quite inexpensive and can protect your house from damage that could be expensive in the long run.