Roofing systems are comprised of many different components. An important aspect of a well-designed roofing
system is the underlayment. Underlayment is a membrane that is directly applied to the roof deck before shingles are mounted. When thinking about replacing a roof, many homeowners do not know much about the different types of underlayments. Our team, at First Out Roofing in Denton, Texas will help you choose an underlayment. We will help you decide which option will be best for your home and your pocket book.
Roofing underlayment acts as a water barrier between the top layer of roofing and the roofing deck. It helps prevent precipitation and water vapor from reaching the roof deck. This is important because the roof deck is the foundation for your entire roofing system. It supports the weight of the roof and needs to remain structurally sound. This means that it needs to avoid coming into contact with damaging moisture that could cause rot or decay. The underlayment not only protects the roof deck from moisture, but it also protects from the chemical mixture from the shingles. Overall, the underlayment acts as a secondary barrier. It keeps your roof deck and your home safe from moisture, heat, and noise pollution.
There are three common types of roofing underlayment. It’s a good idea to speak with a professional about what option will work best with the roofing material and style you’ve selected. Keep in mind that the option you select will influence the overall cost of your roof. It’s important to find a balance between quality and affordability when needed. The three common types of underlayment include asphalt saturated felt, rubberized asphalt, and non-bitumen synthetic underlayment. We’ll cover the details about each of these options to provide you with better insight to their advantages and disadvantages.
Asphalt saturated felt is among the most common types of roofing underlayment for residential homes. It is a sheet of material which is permeated with asphalt. This option comes with both organic and inorganic types of felt. The organic felt is typically created from cellulose fiber. The inorganic felt typically uses either fiberglass or polyester. Both options come with an additional thickness option. Most commonly, you’ll find them listed as being either 15 pounds or 30 pounds.
The thickness of the felt reflects the perm rating. The 15 pound paper carries a perm rating of 5. However, this number has been known to increase in humid areas. The 30 pound option is much more resistant to damage during and after installation. It also provides better protection overall.
Asphalt saturated felt is normally attached to the roofing deck using staples. However, in areas that are prone to hurricanes, tornados, or frequent high winds, it is advisable to use plastic wind strips at the edges. You can also use plastic caps to secure the felt as it will provide better wind resistance than staples.
In most residential areas, asphalt saturated felt makes a perfectly acceptable choice for roofing underlayment. However, it is important to know that this material can lose effectiveness over time. This ultimately contributes to its fragility and eventual moisture absorption. This process is sped up if the underlayment is exposed to sunlight as the UV rays will hasten the deterioration process.
Your roofing company may make the suggestion that you use rubberized asphalt as a roofing underlayment. This option is made of crumb rubber from recycled tires along with regular asphalt concrete. Unlike asphalt saturated felt, this option adheres directly to your roofing deck with a peel and stick surface. It also seals around nails, screws, and stables.
Variations of rubberized asphalt have been known to have polymer film or polyethylene bonded to the weather surface to increase weather resistant benefits. Some versions are reinforced with fiberglass. Other options may have a mineral coating on the weather surface. All of these options are designed to increase durability.
Another benefit of rubberized asphalt is that it is impermeable to water vapor. This makes it a great choice for areas that regularly face tropical storms and hurricanes. It’s also very resistant to air pressure due to the fact it fully adheres to the roofing deck and any adjacent sheets.
The third most common option for roofing underlayment is non-bitumen synthetic underlayment. This is a lightweight option made of polypropylene or polyethylene. Despite its lightness, it is very strong. It also has a very high resistance to UV damage and a resistance to fungal growth. This option is normally secured with roofing nails and plastic caps. Staples do not work well with this type of underlayment.
This option is typically more expensive than asphalt saturated felt, however it provides superior protection. Both felt and rubberized asphalt can be challenging to work with and dangerous to walk on during installation. However, due to its non-skid surface, non-bitumen synthetic underlayment is much easier to work with and safer for installation.
All of these roofing underlayment options play an important role in your roof system as a whole. It’s important to consider the benefits of each option and choose which will be the best option for your structure.