M4-Fire Restrictive Barrier

Structural Fire rated Wall assemblies OSB/Plywood
Ease of installation, light panel, simply scores and snap

  • ASTM E119 (1 hour)
  • ASTM E84 Extended
  • ASTM E 136
  • ASTM E331
  • ASTM E96
  • ASTM C665-12
  • ASTM D1037-99
  • ASTM D3273-12

The M4 Fire Restrictive Barrier 1/8 in. (M4 FRB) is an innovative building panel which is ASTM proven as a Water Restrictive Barrier and can boost most structural wood framed exterior wall assemblies to a 1-hour fire-rating.


How to use
Simply install a single layer of the M4 FRB boards to the exterior facing of any 7/16 in. sheathing of DOC PS1 or DOC PS2 third party approved OSB or Plywood. The M4 FRB is installed Off set to the 7/16 in. sheathing joints


What is the M4 FRB?

M4 FRB is composed of a proprietary cement slurry bound with multiple layers of high strength, premium and alkali-resistant fiberglass mesh.  Only those raw materials with the highest purity and quality are selected.  Each batch goes through extensive QC testing before entering the marketplace.  Our rigorous R&D and extensive third party testing has made us a leading producer of non-combustible building products.  M4 FRB is lightweight, off-white in color and has a hard and durable surface.


Fire Rated:

Wood studs – ASTM E119-20 1 hour Fire Rated, load bearing construction

1 hour fire exposure from either side in fire-rated structural exterior wall assemblies to be used in Type II, III and V construction. (Allowable Axial load of 2,374 lbs/ft /34.65 kN/m specified by the 2018 NDS).

as Fig 1.below.


Water Restrictive Barrier

M4 FRB is factory sealed for exterior applications and tested to WRB standards ASTM E 331 and ASTM E 96.  Board Seams and Joints must be sealed with liquid flashing or flashing tape fulfilling IBC as per AAMA 711 and installed per supplier instruction.

M4 FRB Other testing:

Moisture resistant

The M4 FRB board is vapor permeable with less than 0.15% movement with changes in moisture per ASTM D1037-99.  This means M4 FRB can absorb and release moisture an unlimited number of times without affecting performance, strength or properties.


Resistant to Mold and Termites

M4 FRB will not contribute to mold growth.  On a scale of 0-10 with 10 being the best possible result, M4 FRB produced a 10 per the ASTM D3273 test standard for mold growth.  M4 FRB also contains no food value for termites, making M4 FRB a safe and reliable choice for the long-term performance of your wall assembly.


Corrosion Resistance to Metal

The M4-FRB is 100% Chloride ion free eliminating any risk of corrosion due to leaching chloride as seen with other chloride-based mgo boards in the market.  To prove this, M4 FRB was subjected to ASTM C665-12 corrosiveness testing and passed both standard duration of 96 hours, as well extended 720 hour duration proving no added corrosion risk when in contact with steel, copper and aluminum.


Technical specifications

Size  4’ x 8’ x 1/8” packing 180 pcs per pallet

Size 4’ x 8’ x 1/8” packing 180 pcs per pallet