LP FlameBlock


  • OSB panels are available in 4 foot nominal widths and 8, 9, or 10 foot lengths
  • Available performance categories: 7/16˝, 15/32˝, and 19/32˝
  • Available on APA Exposure 1 rated OSB
  • Recognized as carbon negative by ASTM in 2023

Features and Benefits

Resisting Flame Spread
Evaluated by ICC-ES, LP® FlameBlock® Fire-Rated Sheathing combines flame-spread and burn-through resistance in applications that meet building code requirements for fire-resistant construction.
Do More with Less
A building solution that provides strength, savings and easy installation – at an affordable price.
Exceed Expectations
Combined flame-spread and burn-through resistance bolster a home’s fire resistance capabilities, improving the homeowner’s peace of mind.
Design Freedom
Structural design values are not limited, providing more flexibility in designing wall openings, frames and bracing.
Carbon Negative
Qualifies as carbon negative, helping you build sustainably by choosing products that store more carbon than is released in their life cycle.
Multifamily building with FlameBlock installed
Sales Tools
Find out how LP® FlameBlock® Fire-Rated Sheathing can benefit your build.

Product Catalog

Architectural Specifications

Assembly Reference Guide

Portfolio Product Guide

FlameBlock panels stacked
Technical Documents
Get the details on LP® FlameBlock® Fire-Rated Sheathing installation.

Installation Instructions


Environmental Product Declaration

Warranty Information

Building with FlameBlock panels installed
Building for Resiliency
LP® FlameBlock® Fire-Rated Sheathing helps meet fire codes.

Guide to Fire Resistance

UL Fire Ratings to Know

Factoring Resiliency into Code Requirements

Carbon Negative Product Portfolio

Putting Our Fire-Rated Panels to the Test

See how LP FlameBlock sheathing performs in a controlled product demonstration compared to untreated OSB.

How It’s Made

To create a standard OSB panel, LP’s innovative manufacturing process combines wood strands oriented in cross-directional layers with waxes and resins. Then, to create LP® FlameBlock® panels, LP’s proprietary non-combustible, fiberglass-reinforced Pyrotite® coating is added, which combines flame-spread and burn-through resistance. This creates a product that not only resists fire damage but meets code, provides design flexibility, and also offers the strength and structural integrity of traditional OSB panels.

Infographic of FlameBlock board

Fire Resistive Technology

Elevate your build with a solution that helps meet building code requirements for fire-resistant construction. Evaluated by ICC-ES, LP® FlameBlock® Fire-Rated Sheathing is a component of 1- and 2-hour fire-rated wall assemblies and for use in roof deck applications. It combines flame-spread and burn-through resistance to give your customers peace of mind.

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