Synthetic Roof Underlayment

Explore our synthetic roof underlayment products and their protective benefits.
GAF certified roofing contractor installing a synthetic underlayment on a roof.

Why choose a GAF synthetic roofing underlayment?

As North America’s largest roofing and waterproofing manufacturer, we engineer each product in our extensive underlayment portfolio to function as vital components of complete roofing systems. Our underlayments meet unique project-specific needs, including resistance to rain, snow, ice, fire spread, wind uplift, and more.
Read article

Parts of a GAF roofing system

Residential warranties
A pictorial representation of the layers of a GAF roofing system, highlighting the ridge cap shingles, the finishing touch that helps defend against leaks at the hips and ridges.

Ridge cap shingles

The finishing touch that helps defend against leaks at the hips and ridges.
View products
A pictorial representation of the layers of a GAF roofing system, highlighting the ridge vent layer, which helps to reduce attic moisture and heat.

Attic ventilation

Helps to reduce attic moisture and heat.
See products
A pictorial representation of the layers of a GAF roofing system, highlighting the rooftop accessories component, designed to enhance the performance of your roof system.

Rooftop accessories

Specialty roofing accessories designed to enhance the performance of your roofing system.
See products
A pictorial representation of the layers of a GAF roofing system, highlighting the starter strip shingles, which help guard against shingle blow off.

Starter strip shingles

Helps to guard against shingle blow-offs.
See products
A pictorial representation of the layers of a GAF roofing system, highlighting the roof underlayment layer, which helps shield the roof deck from moisture infiltration.

Roof deck protection

Helps shield the roof deck from moisture infiltration.
See products
A pictorial representation of the layers of a GAF roofing system, highlighting the leak barrier layer, which helps prevent leaks caused by wind-driven rain and ice dams.

Leak barrier

Helps prevent leaks caused by wind-driven rain and ice dams.
See products

Looking for support?

Thumbs Up Icon

Ready to order?

Find a GAF distributor today with the Distributor Locator.
Distributor locator
Roofing contractor icon

CARE Training

Offering experts educational programs to roofing professionals like you.
Find a class
Arrow Icon

Contact your local rep

Need help finding a Territory Manager near you? Our TM Locator is here to help.
Find a TM
Person with question icon

Customer support

All inquiries regarding product order placement, product availability, shipment tracking, and jobsite deliveries
Contact GAF

Synthetic roof underlayment FAQs

Synthetic underlayments use polymers such as polypropylene and polyethylene to create a weather-resistant barrier against the elements.
Synthetic underlayments are engineered to create a barrier against moisture when installed properly.
While most underlayments are rolled over roof decks horizontally, nailed in place, and overlapping, it’s important to note that each type of underlayment is different, therefore may call for slightly different installation procedures. It’s important to follow applicable instructions closely.
Several GAF roof underlayments are engineered to meet the rigorous demands of a UL 790 Class A rating. Look for that rating information on product packaging, or speak with your GAF representative for more information on rated products.