There are several important components that play a role in the typical roof and its ability to protect structures, and knowing about these is helpful for many home and building owners. One great example here that’s less well-known than certain other roofing components is known as roofing underlayment.
At The Roof Doctor, we’re happy to help with a wide variety of roof installation and repair services for shingled roofs, slate roofs, shake roofs and many other types for clients in Salt Lake City and West Jordan. What exactly is roofing underlayment, which types of underlayment are out there today, and what important roles does underlayment play in maintaining your roof’s quality? Here are some basics.
Roofing Underlayment and Deck Basics
To fully understand how roofing underlayments work, you also have to know about roof decks and their role. The roof deck, also sometimes referred to as roof sheathing, is made from plywood, OSB, wood planks, or skip sheathing, and involves boards fastened onto rafters or trusses to form the surface for roofing products and materials.
Roof underlayment is installed over the roof deck, typically above a layer of self-adhering membrane located at the eaves. It offers secondary protection from several elements, such as ice damming and wind-driven rain.
Specific Purposes of Underlayment
While your roof’s shingles are its primary defense against things like the sun’s rays, precipitation, wind, ice and more, the underlayment is a secondary form of protection here as well. It serves a few important roles:
- Safety in case of shingle blow-off: In cases where severe weather may tear off shingles, the underlayment is an additional layer of protection against water intrusion. This is vital if the shingles are not quickly repaired or replaced following a severe storm.
- Moisture protection: The underlayment helps to protect your roof deck in case of any moisture that may leak through the shingle layer – it prevents water from saturating and damaging the plywood and other underlying materials.
- Ice dam prevention: During the winter, ice dams can form on roofs and cause water to back up onto the deck. This is where underlayment helps once again. It adds another layer of protection to help prevent damage from ice buildup on your roof.
- Assistance with shingle installation: Since underlayments are applied before shingles during roof installations, they help protect the entire roof deck while the shingle materials are being installed making shingle installation much easier.
Types of Underlayment
Today, there are several types of underlayments that each have their own specific benefits in terms of protection, cost and ease-of-installation. Here are some of the top options:
- Felt underlayment: The oldest and perhaps most well-known type of underlayment among homeowners is felt paper. It’s made from layers of either organic or fiberglass material and can offer a good level of protection against moisture. This type is also sometimes known as “tar paper” and comes in a couple different weight options. It’s commonly found on shingle, slate or wood shingles, though its use may depend on the region and the weather.
- Self-adhered underlayment: If you’re looking for an underlayment with great water resistance, self-adhered options come with high levels of asphalt and rubber polymers. This type of underlayment is also known as “ice and water shield”. And as its name suggests, this type has a sticky back and can be easily applied to any roof. It’s commonly used in high-leak-risk areas like valleys, eaves, dormers and rakes.
- Synthetic underlayment: Synthetic materials are gaining traction in the roofing industry due to their superior resistance to water, as well as their light weight and easy installation. They’re also designed for better breathability than felt or self-adhered options, which helps with ventilation during hot summer. They’re resistant to mold and mildew growth, as well as punctures and tears in cases of strong winds.
Protecting Your Underlayment
While roof underlayment typically won’t need much maintenance, there may be times when it’s necessary to inspect or repair any sections that have been damaged by debris, weather or other elements. It is important to remember to follow all safety guidelines while inspecting and maintaining your roof underlayment, such as using a safety harness and ladder.
One particular concern is if you notice missing shingles that have exposed your underlayment. In these cases, be sure to check if the underlying material is still intact and not showing signs of damage from water intrusion. If this is the case, it’s a good idea to replace any shingles as soon as possible to prevent further damage or potential leaks in the future.
By understanding roof underlayment and its many benefits, you can ensure that your roof is well-protected and able to withstand any weather conditions. For more here, or to learn about any of our roofing installations or other services for SLC and West Jordan clients, speak to our team at The Roof Doctor today.