Westlake Royal Building Products™ Introduces 5/8” Lap Siding Profile for TruExterior® Siding & Trim

Key Terms

lap siding technical

Lap siding is exterior cladding made of long, horizontal boards or panels that overlap each other like the scales on a fish, commonly made from wood, vinyl, fiber cement, or metal. For investors, the choice and condition of lap siding matters because it affects a building’s durability, maintenance costs, weather resistance, energy performance and curb appeal—much like a car’s paint and bodywork indicate future repair needs and resale value.

fly ash technical

Fly ash is the fine, powdery residue left when coal is burned in power plants and captured from the smokestack; it contains minerals similar to sand and clay and sometimes trace metals. Investors care because fly ash can be sold as a low-cost, recycled ingredient for concrete and cement—like swapping part of a recipe to save money and reduce emissions—while its availability, regulation, and potential contamination risks can affect construction costs, company revenues, cleanup liabilities and environmental reputations.

TruExterior 5/8” Lap Siding Named Best of IBS™ Finalist in “Best Outdoor Product” and “Most Innovative Building Material Product” Categories

HOUSTON--(BUSINESS WIRE)-- Westlake Royal Building Products^™ (“Westlake Royal”), a Westlake company (NYSE: WLK), is expanding its line of TruExterior^® Siding & Trim with the addition of a 5/8” Lap Siding profile. The new profile combines the coveted appearance and shadow lines of traditional lap siding with the high-performance attributes of TruExterior’s poly-ash material. It has a true 5/8” butt and a sought-after aesthetic that mimics real cedar.

“Not only does TruExterior Lap Siding meet demand for a popular, timeless style, it also emulates the thickness and shadow lines of cedar in a way few other manmade products are able to accomplish,” said Steve Booz, vice president of marketing at Westlake Royal Building Products. “The result is remarkable authenticity and enduring beauty alongside low maintenance and long-term durability.”

Like all TruExterior Siding & Trim profiles, 5/8” Lap Siding is made of poly-ash, a proprietary blend of polymers and fly ash that provides for a high level of dimensional stability and resistance to warping, cracking and splitting. As a result, the siding requires no sealing of ends or cuts in the field, it can be used for ground-contact applications, and it can be painted any color, including dark hues.

TruExterior offers workability similar to wood and does not require special tools for cutting. Installers can fasten TruExterior close to the edge, eliminating the need to worry about mushrooming and pre-drilling.

As a result of its authentic look and advanced material engineering, the TruExterior 5/8” Lap Siding profile has been selected as a finalist for the 2026 Best of IBS™ Awards in two categories: “Best Outdoor Product” and “Most Innovative Building Material.” Hosted annually by the NAHB International Builders’ Show^® (IBS), the Best of IBS Awards recognize the most outstanding building products across the residential construction industry.

To learn more about TruExterior Siding & Trim, please visit the Westlake Royal Building Products website.

About Westlake Royal Building Products

Westlake Royal Building Products USA Inc., a Westlake company (NYSE: WLK), is a leader throughout North America in the innovation, design, and production of a broad and diverse range of exterior and interior building products, including Siding and Accessories, Trim and Mouldings, Roofing, Stone, Windows and Outdoor Living. Westlake Royal Building Products manufactures high quality, low maintenance products to meet the specifications and needs of building professionals, homeowners, architects, engineers and distributors, while providing stunning curb appeal with an unmatched array of colors, styles, and accessories.

For more information, please visit WestlakeRoyalBuildingProducts.com. Follow us on LinkedIn and Instagram and “Like” us on Facebook.

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Media Contact:

Kriss Swint

Westlake Royal Building Products

Kswint@Westlake.com

Source: Westlake Royal Building Products