Mataverde Introduces Fire Retardant Treated Hem Fir Wood Siding

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The beauty of vertical grain thermally modified Western Hem Fir siding is undeniable. It closely matches the elegant, natural look of Western Red Cedar siding. The thermal modification process used to create thermally modified hemlock siding makes the finished product more consistent in color, more stable and highly durable. What could be better you ask?  Well, Mataverde Thermally Modified Western Hem Fir siding is now available as a fire retardant treated cladding.

Thermally Modified Hem-Fir siding and fencingMataverde Thermally Modified Hem Fir siding is available with fire retardant treatment


New Code requirements are driving the need for more fire resistant wood siding options

Many of the international building codes, including ICC (International Code Council), IRC and IBC, now require ever more stringent flame resistance performance. The basic difference in the new code rules is that an additional 20 minutes of flame resistance is required in some regions. And now these building codes are being enforced in more areas than ever, especially in WUI (Wildland Urban Interface) zones.

Mataverde ThermaWood FR (Flame Retardant Treated Hem Fir Siding) has been evaluated by the ICC to meet many of these new code requirements. Please refence the document below.

Because the new fire resistance code requirements are being adopted in more areas daily, always check the local requirements with the authority having jurisdiction in your area. State, county, and local building codes and building inspectors are a great resource and a very good place to start.

DOWNLOAD ICC-ES ESR-1159 WUI Evaluation Document for Mataverde Fire Retardant Treated wood

What are my fire retardant treated wood siding options?

Mataverde flame retardant treated thermally modified Hem Fir cladding is offered in several traditional siding profiles.

In Stock Items

Mataverde ThermaWood FR Hem Fir Siding for West Coast clients (including Rocky Mountain states)

Currently available in our West Coast facility we stock Mataverde ThermaWood FR 1x6 633 T&G in a reversible pattern (smooth one side, rough on the other)  and mataverde ThermaWood FR 1x6 T&G "Nickel Gap" Hem Fir Fire Retardant Treated Wood Siding. 

Mataverde Therma Hem Fir 633EE siding profile1 x 6 633 T&G E4E Reversible pattern

1x6 TG Nickel Gap siding profile

The Mataverde ThermaWood FR Hem Fir 1x6 Tongue and Groove Nickel Gap siding profile is available in the following grades, 6' through 20' Random length tallies:

A+ Better Grade Hem Fir 85/15 Vertical Grain/Mixed Grain.



Thermally modified hem fir siding performs exceptionally well all by itself. The vacuum kiln pressurized process allows the wood to become more durable, more stable, and stronger at lower temperatures. And when you take the extra step of flame-retardant treating the Hem Fir siding, you add an extra layer of safety and flame resistance.

Thermally Modified Hem-Fir  siding on mountain home

Mataverde thermally modified Hem Fir fire retardant treated siding is available in many siding profiles

Mataverde flame retardant treated Hem Fir siding is installed and maintained in the same way as standard thermally modified Western Hemlock siding. Oil stains and paints are the preferred method if a finish is needed. This oil finish can be maintained periodically if desired, or the Hem Fir siding can be allowed to eventually weather to a silvery gray patina.



Thermawood Hemlock siding and Thermawood FR Fire retardant treated have the beautiful look and consistent colors of old growth western red cedar. The material is available in A& Better vertical grain and is absolutely stunning. 

Thermawood hemlock soffits



Would you like to see an actual piece of Mataverde Thermawood FR Fire retardant treated decking or siding?

Order a sample today:

Looking for more information about Mataverde ThermaWood Hem Fir Siding? 



If you don't like the appearance of a portion of boards, the solution is to defect-cut out that portion and use the remaining usable portion of the board in your project.

*Pro Tip - Always order extra decking to cover your needs for trimming, fitting, and defect-cutting your boards. This lets you use the best boards and the best portions of each decking board to meet your needs. Any extra materials may be saved and stored on site as 'attic stock'. Keeping a small amount of leftover material is the best insurance policy in case you ever need more later.


For additional information about Mataverde ThermaWood FR decking and siding, please visit our website:

Mataverde ThermaWood FR Fire Retardant Treated Hem-Fir Siding and Decking info

ThermaWood Hem Fir Installation, Care and Maintenance Guidelines

ThermaWood Hem-Fir Siding Project Photo Gallery

Thermally Modified Decking Project Photo Gallery




Thermawood FR Fire Retardant Treated Lumber

Thermally Modified Hem Fir Siding info

Compare Thermally Modified Hem Fir to Western Red Cedar

Looking for more information about rainscreen siding systems?

Download the “Ultimate Guide to Building Green with Wood Rainscreen Siding” today.


Need some design inspiration? Check out some of these award winning rainscreen projects.

Download the Wood Rainscreen Featured Project Portfolio now.


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