Everything You Need to Know About Tile Roof Underlayment

by | Feb 14, 2023 | tile roof companies

The benefits of tile roofing extend beyond aesthetics. Tile is one of the strongest, most durable roofing materials. The texture of some versatile types of tiles can be tweaked to mimic the appearance of wood shakes, chipped stone, and single-style slate. Tiles create an airtight barrier and can help reduce energy costs by 20%.

Like every other type of roofing material, tile is susceptible to water damage. To protect your tile roof from water damage, install tile roof underlayment.

What is Tile Roof Underlayment?

The underlayment for a tile roof is the membrane installed between it and the exterior layer of roofing tiles. Tile roof underlayment creates a water-resistant barrier that protects tile roofs from water damage in the event that water makes its way under roof tiles. Tile roof underlayment also helps to insulate roofs.

Should I change my underlayment regularly? This is One of the most common questions that homeowners ask tile roofing contractors near them. When installed properly, roof underlayment can last up to 20 years.

How long your underlayment will last depends on what it is made of and the type of weather conditions it is exposed to. Underlayment typically has a shorter lifespan than the tiles themselves. If your underlayment takes a lot of punishment every day or infested with pests, it may fail sooner than you expected.

The Importance of Tile Roof Underlayment Installation

In addition to preventing water damage, tile roof underlayment helps create a slip-resistant surface. If it rains during roof installation, the underlayment can protect your roof from moisture. When installed correctly, it can also absorb ambient noise, helping create a calm and peaceful home environment.

Most tile roofs have shingles that overlap each other. This overlapping structure and tile roof layout make sealing all corners of a tile roof impossible. Without underlayment, some corners and edges of your tile roof may not be protected from the damaging effects of the elements. Tile roof underlayment can seal gaps around roof protrusions, roof valleys and edges that are usually not covered by traditional roofing materials.

Different Types of Tile Roof Underlayment

Traditionally, underlayment was only available in one type known as asphalt-saturated felt. Over the years, tile roof manufacturers have come up with different types of underlayment. Here are some of the most popular types of roof underlayment available on the market.

Asphalt-saturated felt

Asphalt-saturated felt Is similar to tar paper. The only difference is that it uses asphalt, instead of tar. This type of underlayment has been used by roofing companies for decades to create a moisture barrier. Though effective, asphalt-saturated felt does not hold a candle to other underlayment types on this list when it comes to flexibility and durability.

Asphalt-saturated felt is the most affordable type of underlayment and remains a popular choice. It protects roofs against impact damage from airborne debris such as tree branches. There are two types of asphalt-saturated felt-

  • 15 felt- a uniform flexible felt that weighs 15 pounds per 100 sq. ft, and
  • 30 felt- a felt that weighs 30 pounds per 100 sq. ft

When choosing between the two types, consider your needs and the nature of your project. If you want to finish the roof of your shed or detached garage, it’s best to use no. 15 felt. No. 30 felt offers comprehensive protection against moisture and is typically used for projects that involve roofing or re-roofing the entire house.


Synthetics are usually made from woven or spun polyethylene or polypropylene. Synthetic underlayment is more tear resistant and durable than asphalt-saturated felt underlayment. Synthetics repel water and can help prevent mold growth. Thanks to the anti-slip properties of synthetics, roofs with synthetic underlayment are easier and safer to walk on.

Synthetic underlayment expands and contracts with temperature changes while being able to resist damage caused by temperature fluctuations. Their rolls are usually lighter than other underlayment options and come with clear lines for ease of installation.

Rubberized Asphalt

Rubberized asphalt is composed of asphalt and rubber polymers. The exact composition can vary from product to product. Manufacturers tweak the composition of their products to enhance their waterproofing or sound absorption properties. Rubberized asphalt can be installed around leak-prone areas such as vents, chimneys, valleys, eaves and skylights to prevent water damage.

Leaks in rubberized asphalt can be patched. Before repairing your underlayment, partially remove the outer roofing layer to gain access to the area. Rubberized asphalt is the most expensive type, so homeowners who are working on a tight budget, will want to consider other options.

Rubberized asphalt comes with an adhesive backing that sticks directly to the roof deck, and is hence, also known as self-adhering underlayment. The adhesive helps to create a waterproof seal between the underlayment and the deck, preventing moisture penetration. The composition of rubberized asphalt allows it to contract and expand with temperature changes without breaking or cracking.

Choosing the Right Underlayment for Your Roof

When choosing an underlayment for your roof, some important factors to consider are top roof layer material, the local climate, and underlayment durability and cost.

Roofing contractors recommend using asphalt-saturated roof underlayment for homes located in areas that experience relatively constant temperatures. For homes located in areas that experience temperature fluctuations throughout the year, rubberized asphalt and synthetic underlayment are the best choices.

Homeowners who want to improve the durability and tear resistance of their roof should opt for synthetic roof underlayment. If you want to improve your roof’s ability to resist water damage, go for rubberized asphalt.

Roof Tile Custom Specialists Inc. is a leading tile roofing contractor serving Antioch. Our roofing experts bring years of experience to the table. They are able to come up with cost-effective solutions to roofing problems. To learn more, call (925) 634-8700.