Fire Retardant Plywood (Class 3)

Fire retardant plywood treated using chemicals that make it unable to oxidize. This what makes it hard to burn. Where applied, the FRT plywood will char when on fire but will not burn. Thus, it can significantly reduce the progress of a fire.

What is fire retardant plywood

Fire retardant plywood specially treated with chemicals that act as a physical barrier to fire. The sheet material works by utilizing two mechanisms. One of them is reducing the flammability of fire-resistant plywood by lowering the rate at which flames travel and subsequently slowing down combustion.

The second mechanism involves the chemicals reducing the rate at which heat is released from the fire-treated plywood when there’s a fire. By altering the vapours released in the combustion process, it can make the flames less volatile.

Features of fire-retardant plywood

• When the panels are pressure impregnated, they are not just getting a top coat, which can burn off, exposing the ply. They become permanently protected.
• In the event of exposure to flames, the FRT plywood releases a non -combustible gas and water vapour, ensuring that a layer forms, creates char, and essentially kills fire on the surfaces with the treated panels.
• The nature of the panels is reason enough to claim low-risk and save money on insurance costs.

If you pick type A FRT plywood, you can use it where the relative humidity is 95% or less and not exposed to the weather or water sources—type B fire-retardant plywood best used in areas where the humidity is below 75%.

You can also get fire rated plywood that is perfect for exterior applications and places where the humidity can reach 95% or higher. For example, you could get FRT plywood that prevents water from leaching the ply grain’s fire-retardant substance, depending on the type.

When purchasing fire-resistant plywood, ensure that you check it for:

• Product name and species
• Whether the wood was made flameproof and to what degree
• The drying method 
• The name of the approval agency
• Flame spread specifications
• Smoke developed number

Common uses of fire-retardant plywood

Fire retardant plywood is used in commercial and residential applications worldwide. When constructing a new structure, fire-rated plywood infused into interior elements like:

• Framing
• Stairwells
• Trusses
• Roof panels
• Sidewall sheathing

FRT plywood is also suitable for exterior applications, except for where there’s contact with the ground, as that would cause it to degrade due to resistance.

Fire-resistant plywood is also excellent for uses where retrofitting, or remodelling is taking place. Using the fireproof ply, one can fortify existing structural elements or replace them if they do not have the same properties as FRT plywood.

In Conclusion

Caution must be observed when working with FRT plywood and lumber because some modifications outside the usual sawing and fastening may modify the burning characteristics. However, the chemicals used in treating the fire retardant wood are not considered hazardous. Therefore, with standard safety procedures, those working with the wood protected.