Roofing underlayment, or felt, is an essential part of every residential roofing system. It serves as the barrier between the outer roofing layer and the roof deck. As one of the roofing and gutter companies who install complete roofing systems, Sentry Exteriors takes a closer look at this important roofing component.
A typical residential roofing system consists of three layers. The innermost part is the decking, made of plywood or OSB (oriented strand board). The outermost part is the outer roofing material, which could be made of asphalt shingles, shake, or metal, or even heavy materials like slate or tile. Between these two layers is the underlayment.
Having a waterproofing barrier on a roofing system is important. Most roofing systems feature an outer layer built from hundreds of pieces that rely on gravity to push rainwater down to the gutters. If rainwater gets pushed back up through the gaps, or if one or more pieces get removed, the roof deck would be easily damaged by water intrusion. The right underlayment, installed by capable roofing contractors like Sentry Exteriors, can help ensure that no amount of moisture will get in contact with the roof deck.
Types of Underlayment
Every roofing manufacturer sells various types of underlayment under different names, but these products can be classified under three different types: asphalt-saturated felt, synthetic and rubberized asphalt. Asphalt-saturated felt is commonly known as “felt paper” because it is basically paper (cellulose) that’s coated with asphalt or tar. Rubberized asphalt contains asphalt and rubber polymers and is attached to the roof deck using adhesives for superior wind and leak protection.
Non-bitumen synthetic underlayment, or simply synthetic underlayment, is today’s most popular underlayment type, made with fiberglass and reinforcing material. Unlike tarpaulin, underlayment can remain exposed to the elements for as long as six months, making it ideal for prolonged or delayed installations, without compromising the installation quality.
To learn more about underlayment or other roofing accessories such as gutter guards, call Sentry Exteriors today at (434) 333-7753. You can also fill out our contact form to schedule a free estimate. We serve Lynchburg, VA, and surrounding areas.