Reduced moisture uptake supports more predictable swelling and shrinkage than untreated wood.
Material process & project guidance · Maximo Thermo
Real wood.Permanently transformed.
Thermal modification uses controlled heat and steam to change how real wood responds to moisture. The result is lower moisture uptake, reduced dimensional movement and a deeper tone through the board—with no added synthetic wood preservatives in the Maximo process.

The thermal process
How controlled heat & steam
change real wood.
Thermal modification is a controlled industrial process designed to improve wood stability and durability without adding synthetic wood preservatives.
Heat and steam lower the wood’s moisture content in a managed cycle before the peak treatment stage.
Temperature rises under steam protection. Maximo documents treatment up to 413.6°F (212°C), changing moisture-attracting components of the wood and reducing volatile resins.
The material is cooled and conditioned so it can be machined into the final catalog profiles and prepared for distribution.
The high-temperature process reduces resin and the risk of pitch bleed on finished surfaces.
The process changes performance and color while preserving the material’s wood character.
Review the current Maximo terms, approved applications and exclusions for the selected product.
Drag to compare
Defined profile.
Natural variation.
This visual is illustrative, not a grade sample. Use it to frame the specification conversation: profile, moisture, grain, finish, installation and documented warranty.
Weathering preview
Natural Weathering & Silver Patina Visualizer
Select a species and move the slider to preview a possible shift from the factory brown tone toward silver gray. This is a visual aid, not a timeline or color guarantee.
Reference view of the deeper brown tone produced by high-temperature thermal modification through the board.
No modeled outdoor exposure at this starting point.
Project guidance
From material choice to
installation and care.
Installation & Maintenance Guide for Thermally Modified Wood
Practical guidance for installing and maintaining Maximo thermally modified siding, soffits, decking and trim, including storage, ventilation, fasteners and finish care.
Open guide →Factory Prefinishing vs. Jobsite Finishing for Architectural Wood
Compare controlled factory prefinishing with jobsite finishing for thermally modified wood, including coverage, curing, touch-up and maintenance planning.
Open guide →Durability & Decay Resistance in Thermally Modified Wood
Understand how heat and steam change wood moisture response, dimensional stability and decay resistance—and what proper installation still needs to provide.
Open guide →Fire Performance & Project Code Review
Plan a responsible fire and WUI review for thermally modified wood using product-specific test reports, assembly details and local code approval.
Open guide →Sustainability Documentation & Green Building Submittals
Plan environmental documentation for Maximo thermally modified wood, including sourcing, heat-and-steam processing, carbon reporting and LEED submittals.
Open guide →Explore Maximo Species
Four distinct species.
One coordinated collection.
Thermo Ash
Review material character, documented properties and available catalog profiles.
Explore species →Thermo Ayous
Review material character, documented properties and available catalog profiles.
Explore species →Scandinavian Thermo
Review material character, documented properties and available catalog profiles.
Explore species →Thermo Clear Radiata
Review material character, documented properties and available catalog profiles.
Explore species →Where to buy in Issaquah
Builders FirstSource Issaquah
Catalog available by consultation. Contact the Issaquah team to confirm availability, sample kits, and lead time for your selected Maximo profile.
Issaquah, WA 98029
(425) 391-8000
Monday–Friday, 7:00 AM–4:00 PMDealer information verified August 31, 2026. No in-stock claim is made on this site.
Request a local quote
Put this profile
on your project.
Tell us what you are building. Our team will review your wood selection and contact you to coordinate a Maximo consultation with Builders FirstSource Issaquah.
Frequently Asked Questions
Material &
project questions
What is thermally modified wood?+
Thermally modified wood is real timber treated at high temperature under controlled steam. The process changes moisture-attracting components of the wood, reducing equilibrium moisture content and dimensional movement compared with the same material untreated.
Are chemicals added during thermal modification?+
The thermal modification process uses heat and steam without adding wood-preservative chemicals or plastic resins. Coatings, adhesives and application-specific requirements should still be reviewed as part of the complete assembly.
How long does thermally modified wood last outdoors?+
Service life depends on the exact product, exposure, assembly, finish and maintenance. Maximo’s catalog identifies products with Class 1 or Class 2 durability and includes a 20-year limited warranty; review the current terms for the selected profile.
Does thermally modified wood turn gray?+
Yes. Like other real wood, an uncoated surface changes color under sunlight and weather exposure and can move toward silver gray. A compatible pigmented exterior finish can help retain a brown tone, with maintenance scheduled according to the coating manufacturer and exposure.
Product and process references
