To help with your peace of mind, we are happy to offer custom fire treating to our Western Red Cedar or Douglas Fir products through our partner, CHEMCO. CHEMCO was one of the early pioneers in fire retardant technologies and became the only producer of fire-resistant wood roofing allowed for sale in California. CHEMCO uses Thermex-FR, a safe and environmentally friendly fire treatment formula that renders wood resistant to fire.
Products treated using CHEMCO’s proprietary fire retardant system have passed strict fire and weathering tests and comply with all building codes. However, we recommend checking with your building department to ensure compliance with your local regulations. The effectiveness of this fire retardant is proven by an independent laboratory and quality-control testing and verified by real-world stories in which it was subjected to both structural and wild fire scenarios.
The process of fire retarding is done by using a vacuum-pressure impregnation to remove moisture and air from the wood cells and replace it with Thermex-FR. Next, the wood is cured in a kiln to lock the fire retardant into the cells. This process significantly increases fire protection for residential and commercial buildings without sacrificing the natural beauty of the wood.
To sustain fire, you need three main ingredients ~ Fuel, Heat, and Oxygen. THERMEX-FR suppresses all three elements
1) Fuel: An intumescing foam is produced to protect the surface of the wood.
2) Heat: Intumescing foam insulates the wood, absorbing heat endothermically and surface
temperature drops below what is required for combustion.
3) Oxygen: A non-combustible gas is generated to dilute the amount of oxygen in the air around the flame.
Q: What is the difference between “fire-resistant” and “fireproof”?
A: All materials are vulnerable to fire damage, so the term “fireproof” is technically incorrect for any product. Nevertheless, engineers and fire technicians have developed tests to compare the fire-resistant properties of different materials. Products treated with Thermex-FR have proven themselves consistently on all such tests.
Q: What makes fire-resistant wood treatment last?
A: The patented fire-resistant formula bonds to the interior structure of the wood during a vacuum-impregnated treatment process. The result is fire protection that lasts for the useful life of the wood product itself.
Q: Are fire-resistant products hazardous to the environment?
A: No. Fire-treated wood products are composed of all-natural elements, and they are not toxic to the environment.
Q: Will my fire retardant-treated wood products have to be re-treated?
A: No. Fire retardant products never need to be re-treated. The unique formula that is used during processing at the facility is thermally cured in dry kilns. Upon reaching the right temperature, the treatment is bonded to the wood and is no longer water-soluble.
Q: What are the typical applications for fire retardant treated lumber and plywood products?
A: Lumber and plywood that have been treated with fire retardant are intended for above-ground exterior use. These include exterior decks and balconies, stairways, covered walkways, siding, molding and trim, soffits and fascia, open-air roof systems, stables, scaffolding, and construction staging.
Q: What wood species and sizes are available to have fire treated?
A: Douglas Fir, Southern Yellow Pine, and Western Red Cedar. All common sizes and most
construction species of lumber and plywood can be treated by Thermex-FR, including Shingles and Shakes, Exterior Siding, Soffit, Fascia, Decking, Timbers and Beams, Trim, and Interior Paneling.
Q: Does the fire treatment meet building codes?
A: Yes. These products meet the performance requirements of most local building codes. However, we suggest checking with your local agency to ensure compliance.
Q: Is there any reduction in strength compared to untreated wood?
A: Yes. The treating and drying processes may cause a slight reduction in strength that varies according to treatment, wood species, specific properties, and applications.
Q: Can these fire retardant products be used in ground contact?
A: Fire retardant treated Western Red Cedar and/or Douglas Fir is intended for exterior, above-ground uses only.
Q: Is it okay to cut wood that has been treated with fire retardant?
A: Yes. Cutting lengths, drilling holes, and light sanding are all permissible. It is not necessary to field-treat cut ends in order to maintain the flame spread rating.
Q: What types of fasteners should be used with fire-treated products?
A: Hot-dipped galvanized or stainless steel hardware is recommended, as the FRX wood treatment could increase the corrosion of bare steel.
Q: Why should I put fire-resistant shakes on my roof when I live in a relatively wet
A: No matter where you live, there always exists the danger of an errant firework or a flying ember from the burn pile of a neighboring home. When it comes to protecting your home, there is no such thing as playing too safe.
Care & Maintenance of Building Materials that have been Fire Treated
Fire-retardant lumber and plywood can be coated with a paint or stain, but caution should be taken in choosing the right product, as not all products will adhere to the unique finish. Shakes and shingles that have been treated with fire retardants should not have any additional coatings applied.
For warranty and other important information, including MSDS Sheets, please visit the Chemco website by clicking HERE
Before your next project, be sure to visit us!
We Ship Nationwide!
950 B Fountain Street, Burlington, WA