The underlayment might not be as visible from the ground as the shingles, gutters and flashings around dormers and vents, but it is an important part of a roofing system. But what exactly does it do?
How Roofing Underlayment Works
Between the roof deck and the outer roofing material – which may be asphalt shingles, sheet metal, or wood shakes – is a sheet of material known as the underlayment. The primary function of the underlayment, which comes in a variety of types, is to keep the roof deck dry in the event that the outer roofing is punctured or blown off. The underlayment can stop water from entering the roof deck in the event of shingle damage, but it is not intended to serve as a “second” roof; you still need to have the outer roofing layer repaired.
Why Your Roof Needs Underlayment
- Weather protection. Shingles resist wind, protect against ultraviolet (UV) rays and repel water. However, because they overlap, shingles can be blown off by violent winds and are vulnerable to water intrusion if they are not correctly fitted. Also, if a powerful wind blows off your shingles, your underlayment will keep precipitation from intruding the roof deck and attic. It provides protection until the damaged shingles are repaired or replaced.
- Moisture protection. Rainwater that penetrates through the shingles can cause leaks, decay, mold and mold on both the attic and your home interiors. All of these can be avoided with the underlayment installed.
- Fire safety. The Class A fire rating cannot be achieved with just roof shingles. Certain underlayment materials can help your roof adhere to industry requirements and offer sufficient fire resistance to prevent damage to your house.
At Punum Roofing of Houston, Inc., you can expect quality repairs done by experienced, professional roofers. We have worked on thousands of roofs throughout the years, delivering superior workmanship for every project we handle. Call us at (713) 466-4447, or fill out this contact form for a no-cost estimate.