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The Science Behind LP FlameBlock® Fire-Rated OSB Sheathing

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The Science Behind LP FlameBlock® Fire-Rated OSB Sheathing

As the demand for fire-resistant building materials continues to heat up, LP has recently announced the addition of a FlameBlock® Fire-Rated OSB Sheathing line at its facility in Clarke County, Alabama. As the demand for fire-rated building products in single-family, multi-family and light commercial construction markets continues, the expansion of the mill will increase LP’s ability to meet the growing demand for fire-rated products, like LP FlameBlock. 

But just how exactly does LP FlameBlock work to slow the spread of flames?

LP FlameBlock is an ICC-certified structural fire-rated OSB sheathing that combines fire resistance and impressive structural performance in a single panel. The fire-resistant coating bonded to LP® OSB allows for a 15-minute thermal barrier (UBC 26-2) and slows the spread of flame and heat.

Panels manufactured with Pyrotite® contain no less than two quarts of water per 32 square feet of panel. The water is released only during the heat of a fire, so as the temperature rises during a fire, water is gradually released, reducing the spread of flames.

A unique combination of flame-spread resistance and burn-through resistance, LP FlameBlock has a code compliant component of 1-hour and 2-hour fire-rated interior and exterior wall assemblies and roof decks. LP FlameBlock is backed by a 20-Year Transferrable Limited Warranty.*

*See for complete warranty details. 

Read more about LP FlameBlock and watch the video comparing it to both FRT plywood and gypsum.

This information and the websites identified above are provided solely as a convenience to the reader. They are not intended to state or imply that the editors of Engineered Wood or LP Building Products sponsor, recommend, endorse or are affiliated or associated with the companies or products listed.