RexBoard is a structural fire rated sheathing that is factory coated with RexShield to meet the Alberta Fire Code (5.6.1.2) Protection of Adjacent Buildings.
When exposed to flames, RexBoard will produce a dense layer of protective char that insulates the panel surface significantly reducing the ability of fire to start and spread.
We tested RexBoard vs. uncoated OSB to demonstrate the difference between the two when exposed to an open fire. We gave a head start to the uncoated OSB and began burning RexBoard 20 seconds + before igniting the torch for the uncoated OSB.
You can see that only after a few seconds the uncoated OSB begins to burn and the RexBoard is not holding a flame.
The uncoated OSB burns through around the 6:11 minutes mark. RexBoard is still protecting the OSB.
While the uncoated OSB continued to burn the OSB after 6 minutes, RexBoard continues to protect the OSB and the demonstration is finalized. RexBoard fire rated board performs as intended.
Products are certified for flame spread and smoke developed ratings on the coated side only. All REXBoards must be labeled with the applicable test standard.
