LP FlameBlockIWP is pleased to bring LP® FlameBlock® to ten Western states!  As part of LP’s Structural Solutions offering, FlameBlock panels combine flame-spread technology and burn-through resistance to meet fire codes and help protect your home.  Proven to slow the spread of flames, FlameBlock is fire-rated OSB sheathing fortified with a thin layer of Pyrotite®; fiberglass embedded in magnesium oxide cement that is proprietary to LP. In the event of a fire, the water contained in the Pyrotite is released, reducing flames and slowing the threat.

FlameBlock is strengthened by the Pyrotite and the coating is weather-resistant, bringing added value, flexibility, and durability to any project.  FlameBlock eliminates the need for extra layers of Gypsum, providing a quick and lighter installation, and the structural benefits of the panel allow greater design freedom.

FlameBlock Sheathing can be used in a variety of single-family and multi-family projects.  Designed for interior and exterior wall assemblies and roof decks, the panels are manufactured with one-sided or two-sided Pyrotite applications, complying with 1-hour and 2-hour fire-rated code requirements.  LP FlameBlock offers the diversity to handle multiple wall assemblies and the high-performing protection each home deserves.


  • 20 Year Limited Transferable Warranty
  • Code Compliant, Class A Fire rating
  • Non-combustible Pyrotite coating
  • Reduces construction time and labor costs
  • One and two hour fire-rated wall assemblies and roof deck applications
  • Greater design flexibility
  • Negative carbon footprint
LP FlameBlockPieces per Unit
7/16" x 4' x 8' FlameBlock OSB66
7/16" x 4' x 9' FlameBlock OSB70
7/16" x 4' x 10' FlameBlock OSB70
15/32" x 4' x 8' FlameBlock OSB60
15/32" x 4' x 9' FlameBlock OSB64
15/32" x 4' x 10' FlameBlock OSB64
23/32" x 4' x 8' FlameBlock OSB42
15/32" x 4' x 8' 2SD FlameBlock OSB45
15/32" x 4' x 9' 2SD FlameBlock OSB49
15/32" x 4' x 10' 2SD FlameBlock OSB49
Struc 1 FlameBlock available at our Cloverdale, CA location