Underlayment is a layer of material that covers a roof before you put on shingles or roof tiles. Many types are available, including fiberglass mesh, felt paper, natural rubber, and synthetic rubber underlayment. Where you live and what type of roofing system you use will determine the type of underlayment to choose.

A quality underlayment will keep moisture out of your roof and prevent leakage. It’ll also protect it against fungi, insects, and wood rot caused by exposure to water.

Underlayment sits between your home’s exterior walls and the shingles. It supports the weight of the roof covering and disperses it evenly throughout the structure. Thus, providing increased protection against leaks and structural damage.

How Does it Work?

An underlayment raises the tiles off of the roof deck and provides a space for water runoff. When installed, it keeps your shingles lifted away from the sheathing of your home. This keeps them dry and free to move, expand and contract with seasonal temperature changes.

Types of Underlayment

1. Felt

Roofing felt is made from natural fibers, including cotton, jute, or other cellulose-based materials. It’s comparable to paper towels that you would use around the house. It’s light, strong, absorbent, and resistant to ultraviolet light.

Felt is considered the most efficient underlayment in terms of fire protection and energy efficiency. Remember, it can withstand high temperatures without breaking down or melting.

2. Synthetic

This material offers several advantages over felt, including being flexible enough to support heavy loads. It’s light enough for easy handling when installing and durable enough to remain effective even during extended periods. Moreover, it doesn’t get stiff or hard.

Synthetics are also waterproof and insect-proof, unlike natural fibers like wool or cotton, which absorb water quickly, exposing them to fungal growth. It’s not adversely affected by moisture content either, eliminating the risk for damage because of termite infestation.

3. Rubberized

This variation of felt is lighter, stronger, and more durable than the other choices you have. Compared to naturally-derived materials like cotton or jute, rubberized underlayment is more resistant to bacterial growth.

It’s also easier to install. It doesn’t stretch with ease like felt, requiring special equipment when rolling out onto your roof deck.

Choosing the Right Underlayment for Your Roof

If you’re shopping online, check what type of material is used for the underlayment you’re buying. You should also note that most suppliers don’t list fire resistance ratings unless you specifically ask them for more information.

Visit a local store where you can pick up samples and do some testing on your own with a lighter and heat source. This will give you the best indication of how easy it’ll be to handle while working on site.

If there are no local suppliers in your area, we can help you find them and install them at affordable rates.

Match your underlayment material with the type of roof that you have. For example, if you have an asphalt shingle roof, it makes sense to choose a felt underlayment because they’re compatible materials.

Try to avoid mixing materials, though. This can cause future problems with the roof’s waterproofing covering. It’s not something that will happen immediately, but it could create issues later on down the road.