LP® FlameBlock® Fire-Rated OSB Sheathing Provides Burn-Through Fire Resistance, Withstands Weather


For many first time homebuyers seeking both beauty and community, condominiums are often the house of choice. With over 40 years of experience, The Dragas Companies knows this well. But multifamily construction carries with it its own set of challenges, especially when it comes to fire codes.

At its most recent development—The Grove at the Arboretum in Chesapeake, Va.—Dragas wanted to not only meet those codes, but sought to deliver on its commitment to quality while preventing weather-related hassles on the jobsite, according to Drew Dewey, the project manager of new construction.


"The code requires us to use a flame-resistant product where the condominium units are joined together," Dewey explained. "In the past, we used fire-resistant plywood to meet these codes."

But according to Dewey, the plywood didn’t measure up. Dragas needed a product that was durable enough to withstand rain while providing the fire resistance necessary to meet code requirements. Enter: LP® FlameBlock® Fire-Rated OSB Sheathing.


LP® FlameBlock® offers structural performance and fire resistance in one panel. Created by applying a proprietary non-combustible, fiberglass-reinforced Pyrotite® treatment to LP OSB Sheathing panels, LP FlameBlock Sheathing is a PS2-rated structural sheathing with a Class A Flame Spread Rating. When used as roof decking in Type III, IV, or V construction, it satisfies IBC code requirements for vertical continuity of fire walls, and is backed by a 20-Year Transferable Limited Warranty.

"Making the switch to FlameBlock from standard fire-rated plywood was an easy decision. We chose it because of its ease-of-use, its outstanding warranty and its weather resistance,"

Dewey explained. "When we've used plywood in the past, it tends to delaminate, soften or bow when it gets wet. FlameBlock doesn't do that. It stays stiff like you expect it to."

That's because LP FlameBlock Sheathing is designed to withstand exposure to moisture during normal construction delays, as evidenced by its Exposure-1 classification. The Grove at the Arboretum is a 112-unit development. Each condominium runs on a 75-day schedule from breaking ground to completion and move-in, so there's no time for products that can't withstand weatherrelated delays.

"FlameBlock also helps us save money in both the short and long term. Unlike plywood, when FlameBlock gets wet we don't have to replace it, so we're saving on both product and labor. Plus FlameBlock cuts like regular OSB and blends seamlessly with the other OSB products that our roofs require."

LP FlameBlock panels are installed with the same tools and fasteners used for installation of other structural sheathing panels. The product is available in a variety of PS2-rated thicknesses and lengths, including Structural 1, and is paintable.


Dragas turned to LP® FlameBlock® Fire-Rated OSB Sheathing, which is backed by a 20-Year Transferable Limited Warranty. According to Drew Dewey, project manager for new construction, the product has been easy to use and weather-resistant. It is now a standard company-wide for any application requiring fire resistance.