When you think about a roof, what comes to mind? The shingles and the gutter, right? Well, most people don’t know there is another layer of protection that is under the shingles and plays a pivotal role in the performance of your roof.
It is the second layer of protection under the shingles. It is installed directly to the deck with cap nails and it protects your home from water intrusion!
These two products each have pros and cons. However, most of the time it is going to make more sense to install synthetic underlayment. There are many factors that can determine what is right for your roofing system. These include geographical area, roofing materials used, roof design, and budget.
Felt roofing underlayment is one of the oldest types of roofing underlayment. It’s made by saturating paper or fiberglass mat with asphalt.
Felt roofing underlayment is available in two types: No.15 felt and No. 30 felt. Compared to No. 15 felt, No. 30 felt is typically thicker, and stronger, and may be less prone to tearing or ripping off during installation or weather events.
The main advantage of using felt roofing underlayment is cost. Felt underlayment tends to cost less compared to synthetic underlayment, which is why it’s often the go-to for budget-conscious homeowners.
There are several disadvantages to using felt underlayment on a roof. One disadvantage of traditional felt roofing underlayment is it generally can’t be left exposed for more than a few hours. The material may dry out or leach oils in the heat. This would impact the felt’s ability to protect against moisture.
Other drawbacks of felt underlayment include:
Felt Roofing Underlayment and Warranties
If felt underlayment is installed it may also prevent you from being protected under the manufacturer’s warranty, which may require synthetic underlayment.
For enhanced water resistance and protection from the elements, we are choosing to go the route of synthetic underlayment. These products are usually made from long-lasting polymers, which provide added strength and longevity. This type of underlayment is typically moisture-resistant, and when it’s installed correctly, it offers better protection from the weather compared to felt.
There are four main advantages to installing synthetic roof underlayment rather than felt. Compared to felt.
Synthetic roof underlayment is extremely durable- It typically doesn’t tear and is suitable for extended UV and moisture exposure in some cases, which is especially helpful if there’s a bit of lead time before your roof covering is installed.
Synthetic underlayment also stands up to boot traffic, which is important when your roofing contractor is walking around on its surface as it’s being installed.
Synthetic roofing underlayment also tends to be:
Because it’s made of plastic, synthetic underlayment is typically resistant to mold growth, a definite advantage over felt.
Many synthetics are competitively priced, but when compared to felt, the main drawback of synthetic roofing underlayment is the cost. The upfront investment in higher quality roofing materials, however, could save you money down the road. You can’t put a price on the peace of mind knowing that your roof is sufficiently protected from moisture.