The roof is a vital component of any home's structure, providing protection from the elements and ensuring that everything below it stays dry and safe. However, the roof itself is not enough to keep a home fully protected. The material between the roof and the structural decking is called underlayment, and it plays a crucial role in protecting your home from top to bottom. In this article, we will discuss the importance of roof underlayment, the different types available, and how to ensure that it is properly installed.

Understanding Roof Underlayment

Roof underlayment is a layer of material that sits between the roof's shingles and the roof's decking. Its primary purpose is to act as a secondary barrier against water penetration. If the shingles fail, the underlayment provides an extra layer of protection, preventing water from seeping into the interior of your home.

The Importance of Roof Underlayment

Roof Underlayment

Without proper roof underlayment, your home is vulnerable to water damage. This can lead to a variety of problems, including mold growth, structural damage, and decreased indoor air quality. In addition, roof underlayment can also help to improve the energy efficiency of your home, by providing an extra layer of insulation.

Types of Roof Underlayment

There are several different types of roof underlayment available, each with its unique benefits.

Felt Underlayment

Felt underlayment, also known as asphalt felt, is the most commonly used type of underlayment. It is made from a combination of cellulose, polyester, bitumen, and asphalt, and is available in a range of weights and thicknesses.

Synthetic Underlayment

Synthetic underlayment is made from a variety of materials, including polyethylene, polypropylene, and polyester. It is lightweight, easy to install, and can provide superior protection against water infiltration.

Rubberized Asphalt Underlayment

Rubberized asphalt underlayment is made from a combination of asphalt and synthetic rubber. It is an ideal choice for roofs with low slopes or areas with high wind resistance, as it provides excellent adhesion and flexibility.

Installation Tips

Proper underlayment installation is crucial for ensuring that your roof underlayment provides maximum protection. Here are some tips to keep in mind:

Start with a Clean Surface

Before installing your underlayment, make sure that the surface is clean and free from debris. This will help to ensure that the underlayment adheres properly and provides an effective barrier against water.

Use the Right Fasteners

The type of fasteners used to secure the underlayment will depend on the type of roof you have. Be sure to use the appropriate fasteners to ensure that the underlayment stays in place, even in high winds.

Overlap the Seams

When installing underlayment, it is important to overlap the seams to prevent water from seeping through. The amount of overlap will depend on the type of underlayment being used.

Pay Attention to the Edges

The edges of the roof are particularly vulnerable to water infiltration. Be sure to pay close attention to these areas, and ensure that the underlayment extends at least 2 inches beyond the eaves and rake edges.


Roof underlayment is an essential component of any roofing system. Without it, your home is vulnerable to water damage, mold growth, and other problems. By understanding the different types of underlayment available and following proper installation techniques, you can ensure that your home is fully protected from the top down.

importance of roof underlayment


How long does roof underlayment last?

Roof underlayment can last anywhere from 15 to 30 years, depending on the type of underlayment and the climate conditions in your area. It is important to inspect your underlayment regularly and replace it if it shows signs of wear or damage.

Can I install the roof underlayment myself?

While it is possible to install roof underlayment yourself, it is recommended that you hire a professional roofing contractor to ensure that it is properly installed. Improper installation can result in water infiltration and other problems.

Do I need underlayment if I have a metal roof?

Yes, underlayment is still necessary even if you have a metal roof. Metal roofs can still experience water infiltration, and underlayment provides an extra layer of protection.

How does roof underlayment improve energy efficiency?

Roof underlayment can help to improve energy efficiency by providing an extra layer of insulation. This can help to reduce heat transfer between your home and the outside, leading to lower energy bills and improved comfort.

Can I use multiple types of underlayment on my roof?

While it is possible to use multiple types of underlayment on your roof, it is generally not recommended. Different types of underlayment may not work well together and can lead to problems with water infiltration and other issues. It is best to stick with one type of underlayment for your entire roof.

For hassle-free Roof Underlayment done right at Dallas TX, call Moore Construction Co.

at (972) 820 5950.