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What is FlameBlock?LP FlameBlock™ is a structural, fire-rated panel used in both new construction and renovation projects. The panel’s fire-resistive properties are provided by Pyrotite® – a patented, non-hazardous, cementicious coating bonded to oriented strand board. Pyrotite is non-combustible and when exposed to the heat of fire will release molecularly bound water. The water cools the panel’s surface and slows the spread of fire.
Is the FlameBlock product based on proven technology?
Yes. LP FlameBlock is manufactured with proven Pyrotite technology that has been producing structural fire rated sheathing in the US since 1991.
Where are FlameBlock panels used?
LP FlameBlock is most commonly used as:
- a structural roof sheathing in multifamily roof decks along fire walls
- an interior or exterior fire-rated structural wall assembly an ignition-resistant soffit or “overhang” panel
- a roof deck panel in both Class A and C low-slope commercial roof deck assemblies
- a thermal barrier for foam core panels, including structurally insulated panels (SIPs)
The product is specified by architects or engineers, and its code-compliant applications are outlined in ICC ESR-1365.
What is the fire rating of FlameBlock?
LP FlameBlock is rated for flame spread and smoke development as well as burn-through resistance. LP FlameBlock is a Class A (or I) flame and smoke rated panel as determined by the 30-min “extended” ASTM E-84 Flame Spread test. LP FlameBlock meets Class A commercial low slope roof deck assembly requirements under single-ply membranes, exceeds the 15-min. thermal barrier requirement for foam core plastics, and is listed in a variety of 1 and 2-hr load bearing wall assemblies.
Does the coating side face in or out?
The orientation of the coated face of the panel depends on the application, please review the “Application Instructions” document that pertains to your particular use. In general, the coated side is oriented to face the side of the roof deck or wall where protection from fire is required.
How do I treat the panel edges?
LP FlameBlock was tested with the edges untreated. Since building code requires field applications to mimic the way a system was fire tested in a laboratory, no further treatment of the panel edges is required for those applications tested with untreated edges. Be sure to check the relevant Application Instructions to be sure installation in the field is done correctly.
What about roofing nails protruding the surface of the coating?
Protruding roofing nails were shown in fire tests NOT to reduce the fire rating of the panel.
What is the panel strength?
The Pyrotite coating adds structural strength to the panel. The span and strength ratings have been determined by the independent strength testing laboratory Progressive Engineering Inc. (PEI). The minimum strength of each panel is determined by the initial rating of the underlying untreated panel (e.g. 15/32 Category OSB at 32/16). Each panel is individually labeled with span rating references. Span and load tables are available here.
Is FlameBlock available in Structural Rated Panels?
Yes, LP FlameBlock is available in Struc-1 rated panels of varying performance categories and lengths.
Who tests and certifies FlameBlock?
LP FlameBlock has an International Code Council (ICC) Evaluation Services (ES) report, ESR-1365, which lists the code compliant applications. In addition, LP FlameBlock is listed and subject to quarterly quality control inspections with two independent laboratories: Intertek (Omega Point Laboratories) and Underwriters Laboratories (UL). LP FlameBlock is also included as an approved product on the California State Fire Marshall’s Wildland Urban Interface List (WUI) for exterior wall sheathing, under eave applications, and ignition resistant building materials.
What are the key FlameBlock advantages?
LP FlameBlock’s key advantage is that the panel combines fire resistance and structural strength in a single panel. Meaning that in the right applications, LP FlameBlock can reduce the time and cost associated with installing double-layers of gypsum, or a combination of gypsum and structural sheathing.
Single panel applications can provide considerable savings in terms of dimensional space. Architects and designers report that using a single panel saves reconfiguring window and door frames to accommodate thicker walls or roofs.
What are the dimensions of FlameBlock panels?
LP FlameBlock panels can be made in all standard OSB performance categories in 4’ x 8’, 4’x9’ and 4’x10’ lengths. LP OSB Sheathing panels are sized to 3’ 11-7/8” x 7’ 11-7/8” dimensions (reduced 1/8” from 4’ x 8’ to allow for proper spacing during installation). Panels are available in performance categories ranging from 3/8 to 1-1/8. Extended length and oversized panels are subject to availability.
What are performance categories?
Performance category replaces the fractional nominal thickness used in U.S. Voluntary Product Standard PS2. The Performance Category is consistent with the panel thickness used in the U.S. model building codes.
How much do FlameBlock panels weigh?
The Pyrotite coating itself adds approximately .7 (seven-tenths) of a pound per square foot to a board. Thus, a 4’ x 8’, 15/32 Category LP FlameBlock panel weighs approximately 66 pounds. As a comparison, the combined weight of a layer of a 4’ x 8’ 5/8” gypsum board plus a 4’ x 8’ 15/32 sheathing panel can easily be 120 pounds.
How do you install FlameBlock panels?
Installation is similar to standard sheathing. LP FlameBlock can be cut and installed with standard carpentry tools. LP FlameBlock has been shown in relevant testing not to corrode nails, so standard nails, screws, and fastening patterns may be used. Carbide tipped saw blades are recommended and they may have to be sharpened 20% more often than if cutting untreated boards only.
Is the dust from cutting FlameBlock dangerous?
The dust from cutting LP FlameBlock has been shown to be no more hazardous than cutting untreated boards.
How do you treat the edges of FlameBlock panels?
LP FlameBlock has passed required fire tests with untreated edges, so you do not need to apply special edge treatment or use special techniques to treat panel edges. LP FlameBlock may be finished in the same way other sheathing is finished.
Can I cover FlameBlock with any type of siding?
Local code officials have jurisdiction over what types of sidings and coverings can be attached to fire-rated walls and roofs. You will want to discuss approved siding options with your local code official.
Does FlameBlock reduce sound transmission?
Testing is currently underway to provide sound transmission coefficients for wall assemblies utilizing LP FlameBlock.
Where can I buy FlameBlock?
LP FlameBlock will be distributed by most building material suppliers that carry other LP branded products. Please contact your LP representative to locate a dealer near you.
What does FlameBlock cost?
LP FlameBlock panel costs vary based on panel size, dimension, geography and volume. LP FlameBlock is priced competitively to other alternatives. In addition, using LP FlameBlock will save the builder time and money overall, as well as provide the best performing and safest fire-resistant sheathing technology available. For pricing on any specific order of LP FlameBlock, please contact your local LP representative or email us.
Has FlameBlock or Pyrotite® technology ever experienced any issues associated with their use?
The use of Pyrotite technology as a structural wood based panel has been remarkably trouble-free. When used as a roof deck material, however, it is important that the attic space below the panel be ventilated at least to building code standards. The build-up of humidity in a poorly ventilated attic space, coupled with temperature fluctuations in northern environments, may cause condensation to form on the surface of LP FlameBlock.
Span Tables |
ESR-1365 |
Evaluation Report |
WUI Website |
Contact Us