Westlake Royal Building Products™ introduces roof mastic for modified asphalt underlayments

Image of a bucket of Westlake Royal Building Products’ roof mastic for modified asphalt underlayments

August 27, 2025 at 6:00 a.m.

By Westlake Royal Building Products.

Announcing the launch of Westlake Royal™ Roof Mastic, an advanced rubberized flashing cement designed for modified asphalt underlayments, to Florida markets.

Westlake Royal Roof Mastic is formulated to provide ultimate adhesion and waterproofing to polyester-faced underlayments. It is flexible, even at low temperatures, and it will not shrink or crack. In addition, Westlake Royal Roof Mastic offers easy application and is resistant to flow (sag) at high temperatures.

“Today’s roof envelopes require reliable performance from every component in the system to ensure optimal protection against air and moisture intrusion,” said Eric Miller, vice president of sales for Westlake Royal Building Products’ stone and roofing solutions brands. “With superior adhesion, flexibility and long-term dependability, Westlake Royal Roof Mastic helps contractors deliver high-performance roof systems that stand the test of time.”

Westlake Royal Roof Mastic works with Westlake Royal TileSeal™ HT, Westlake Royal™ MetalSeal HT and similar polyester-faced underlayments. The product meets ASTM D4586 Type I Class I & Class II, D3409 and SS-C-153 Type I and is Miami-Dade County approved.

To learn more about Westlake Royal Roof Mastic and explore the company’s full suite of components and concrete, composite, clay and steel roofing options, visit Westlake Royal Roofing Solutions.

Learn more about Westlake Royal Building Products/Roofing Solutions in their Coffee Shop Directory or visit www.westlakeroyalroofing.com.

About Westlake Royal Roofing LLC

Westlake Royal Roofing Solutions is a recognized, national leader in durable and sustainable clay, concrete, and steel roof systems and components. The company’s offerings include: US Tile® products, a legacy line of premium, stunning clay tile solutions manufactured to the highest standard of sustainability and craftsmanship; Newpoint™ Concrete Tile Roofing, the enduring line of concrete tile known for its superior strength, Class A fire rating and long-lasting beauty; Unified Steel™ Stone Coated Roofing, the ultra-lightweight roofing system which benefits from the structural strength of steel; and Westlake Royal™ Roofing Components, a full line of integrated roof components designed to deliver a higher standard of roof installation and performance.