LP FlameBlock

Proven To Slow Down The Spread of Flames

Features and Benefits

Resisting Flame Spread

ICC-approved applications for fire-rated sheathing that combines flame-spread and burn-through resistance to meet fire codes.

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.

FlameBlock Board

Product Specifications

  • 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

Product Data Sheet

Flameblock Board

Putting Our Fire-Rated Panels To The Test

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


To create the wood substrate at the core of LP® Structural Solutions products, LP’s Engineered Strand Technology 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 applied to one or both sides to combine flame-spread and burn-through resistance. This creates a product that not only resists fire damage but helps meet code, provides design flexibility, and also offers the strength and structural integrity of an elevated wood substrate core.

Infographic of FlameBlock board

Fire-Resistive Technology

Go to work with a building solution that meets building code requirements for fire-resistant construction without reduced structural ratings. LP® FlameBlock® sheathing is an ICC-ES evaluated component of 1- and 2-hour fire-rated wall assemblies and as an alternate material to fire-retardant-treated wood panels in roof deck applications. LP FlameBlock fire-resistant panels combine flame-spread and burn-through with EST, the elevated wood substrate at the core of all LP® Structural Solutions products, to give your customers peace of mind.

Working Better Together

Architect's Corner

We’re here to help you build your vision that stands the test of time.

Product Catalog

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LP FlameBlock Warranty