LP® FlameBlock® Fire-Rated OSB Sheathing offers you the best of both worlds—impressive structural strength and remarkable burn-through fire resistance. Created by applying a proprietary non-combustible, fiberglass-reinforced Pyrotite® layer to LP® OSB panels, LP FlameBlock Sheathing is an ICC certified (ESR-1365), structural fire-rated sheathing with a Class A Flame Spread Rating. It provides extended burn-through resistance, delivering a 15-minute thermal barrier (UBC-26-2). It’s durable on the job site, easy to work with, and is Exposure-1 rated to withstand weather during normal construction delays. LP FlameBlock Sheathing is cost competitive and is available in a variety of PS2-rated thicknesses and lengths, including Struc-1. Plus it contains no hazardous chemicals. Backed by a 20-Year Transferable Limited Warranty, LP FlameBlock Sheathing is the one to count on when every minute counts.