When we mention roofing, most homeowners picture a layer of asphalt shingles for removal and replacement with a fresh layer. A complete system has asphalt shingles, trusses, sheathing, and the ceiling material that covers the trusses. Above the sheathing is a layer of asphalt called the underlayment, which plays a great role in keeping your home moisture-free.
The way asphalt shingle layers build the system ensure water cannot get inside the attic. But, when strong winds blow shingles upwards, moisture with the wind can infiltrate the attic. The underlayment protects the attic from moisture by acting as a second protective layer when the asphalt shingle gets compromised. Without the underlayment, the sheathing gets exposed to rainwater, gets soaked, and lets moisture infiltrate the attic.
Underlayment installation looks similar to asphalt shingles, except you'll install asphalt sheets above it. Most use industrial-grade adhesive that sticks on the sheathing, but you may also install it with roofing nails or special roofing staples. Quality roofers ensure they use the right nails or staples to keep your roof in place.
There are different types of roof underlayment materials available. Learn more about each of them from this post by Johnson Roofing.
Today, metal roofing is more attractive and durable than ever before in the history of it. This is due to the fact that there have been numerous innovations not only in the metal roof materials, but also in the other components that are necessary for a quality installation. One such component is the underlayment material. Since there are different types of underlayment, you must choose the right one to ensure that your metal roof is as durable as possible. When you fail to do so, you leave the roof at risk of exposure to damaging elements such as moisture, chemicals and resins. We share further facts in the following to help you make an educated decision.
What Is the Purpose of Underlayment?
An underlayment separates the sheathing and other structural roof components from the surface roofing material. Its purpose is to provide protection to all of the structural components from potentially dangerous substances including moisture, resins and chemicals. This ensures that the roof’s support system last for as long as it should for the house or building.
The Different Types of Underlayment
1. Felt underlayment is probably the most well-known and affordable underlayment on the market at present. It is made from asphalt-soaked felt and can be of natural materials such as wood cellulose or synthetic ones such as fibreglass. This underlayment does not offer high-quality resistance to moisture migration or incoming air. As a result, it needs to be installed on roofs with a suitable pitch that will not suffer significant moisture loads. However, it is ideal to use with ice dam protection at certain critical points on the roof in cold environments.
2. Synthetic underlayment is made of polyolefin, polypropylene or polyethylene usually and ranges in thickness from eight to 30 mils. In comparison to felt underlayment, synthetic underlayment is at less risk of wind damage and lies suitably flat after installation. Similar to the felt underlayment, it is an affordable option. Also, is it suitable for cold weather installation and as a moisture barrier? It does not qualify as an air barrier, though, for your roof.
3. Self-adhering membrane underlayment is a polyethylene sheet with a butyl-based or rubberized-asphalt based adhesive on it. Roofers install this product by peeling off the backing and sticking it to the roof deck or sheathing. It is extremely effective protection for standing-seam style metal roofs where ice dam protection is a must in various areas of the roof. This style of underlayment can be installed in environments that reach temperatures as high as 115-degrees Celsius. On top of all of this, this underlayment qualifies as both an air and a moisture barrier. (Continue reading here to learn more)
Need quality roofing repairs, maintenance, and installation? Count on Roper Roofing & Solar to provide top-notch solutions that keep your home ready for any weather event. We also offer quality solar panel and shingle installations. Call us today to get started.
