Roofing underlayment is a necessary piece for any roofing installation project. It lays between the shingles and your roof sheathing

The underlayment adds extra protection from the elements. Some types of underlayment are water-resistant. Others help insulate your home from heat or snow. 

But before installing, you need to know the correct roofing underlayment type for your roof. We’re here to help guide you through it. In this article, we’ll be covering:

What is a Roofing Underlayment?

Roofing underlayments are typically made up of synthetic fiber or felt that sits on top of your roof deck (boards fastened onto trusses to give structure to your roof). 

Throughout the years, your underlayments protect your home against the elements. That means it isn’t a permanent solution. The good news is experienced contractors can easily replace it. 

Back then, you’d find only one type of underlayment—asphalt-saturated felt. However, as technology improved, several types of roofing underlayment were developed. 

Types of Roofing Underlayment

You’d often find three main types of roofing underlayment that can be used on most standard roof decks. These are asphalt-saturated felt, synthetic underlayment, and rubberized asphalt. 

Each type is best suited for specific kinds of shingles and use cases. Here’s a quick rundown of the underlayment’s characteristics and what they’re best used for. 

Asphalt-Saturated Felt

Asphalt-saturated felt has been the go-to roofing underlayment type for years until synthetic types were made. It’s still used today. But, like everything, it does come with pros and cons.



With all things considered, asphalt-saturated felt is best used for inexpensive roof repairs and standard slate or tile shingles. Be mindful of the weight (typically 15 or 30 pounds).

Synthetic Underlayment

Most roofing professionals recommend using synthetic underlayment for your roofing. That’s because it’s lightweight, has better water and tear resistance, and has improved stability. 

It’s also made with saturated asphalt, but fiberglass is added. The result is a more vital underlayment effective against harsh weather conditions and moisture buildup. 



Synthetic underlayment is best if you want something tear-resistant, durable, and mold/water-resistant. 

Rubberized Asphalt

Rubberized asphalt is the most expensive underlayment, and for good reason. With the highest percentage of asphalt and rubber polymers, rubberized asphalts are waterproof, not just water resistant. 

Before installation, rubberized asphalt strips come with sticky protective membranes on the back. Once the membrane is removed, it creates a waterproof seal between the underlayment and your roof deck. 

Just ensure that the roof deck is clean before installation. This covers any potential water damage or leaks following storms or heavy rains. Here are some of its pros and cons:



How to Choose the Right Roofing Underlayment?

We’ve already learned the main types of roofing underlayment. Now, which one is the best fit for your home? Before investing in an underlayment, consider these critical factors:


Climate plays a huge role in the material you can get. For example, asphalt-saturated roofs are good options if you’re situated in an area with low weather fluctuations. Regions with harsh, seasonal weather changes might be better off with rubberized or synthetic underlayment. 

Type of Roof

Different roof types work best with specific roofing underlayment. Here’s a quick checklist to help you identify what underlayment works best for your roof type:


You want an underlayment that lasts long, requires little maintenance, and needs minimal repairs. If you want something durable and tear-resistant, invest in a synthetic roof. But, if your area is prone to rain or storms, you might want rubberized asphalt instead.


Asphalt-saturated felt underlayment is the most affordable. But, also consider where your home is located. It might be cheap now, but roof repairs and maintenance can quickly stack up. 

Like any other roofing material, underlayment is quoted per square foot or roofing square (100 square feet). Here’s a quick rundown of estimated costs (not including labor)

Final Thoughts

Roofing underlayment is essential in any roofing installation. It adds extra layers of protection and insulation and can waterproof your home with the proper underlayment material. If you’re planning on installing or repairing roofing underlayment, consider the following:

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