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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.

Pacific Northwest modern home built with thermally modified wood cladding
HEAT + STEAMReal wood · modified through its full section
215°CPeak steam temperature
Lower EMCReduced moisture response
Class 1 or 2Product-dependent durability
Heat + SteamNo added wood preservatives

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.

1. Controlled drying

Heat and steam lower the wood’s moisture content in a managed cycle before the peak treatment stage.

2. High-temperature modification

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.

3. Cooling and conditioning

The material is cooled and conditioned so it can be machined into the final catalog profiles and prepared for distribution.

LOWERDimensional movement

Reduced moisture uptake supports more predictable swelling and shrinkage than untreated wood.

LOWER RISKResin and pitch movement

The high-temperature process reduces resin and the risk of pitch bleed on finished surfaces.

REAL WOODNatural grain retained

The process changes performance and color while preserving the material’s wood character.

DOCUMENTED20-year limited warranty

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.

MOISTURE RESPONSEPROFILE CONSISTENCYFINISH PLANMAINTENANCE

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.

Thermo Ash Hardwood Real Wood Texture
Thermo Ash Hardwood Reference
0 Months (Factory Fresh)

Thermo Ash Hardwood

Fraxinus excelsior · Janka: 1,320 lbf (Janka)
Tone: Rich Caramel Dark Amber

Dense cathedral grain patterns with pronounced growth rings and rich chocolate warmth.

Durability: Product-specificWeathering: Exposure-dependentWarranty: 20 Years
Exposure Timeline0 Months Natural Exposure
0m (Factory Fresh)3 Months6 Months12 Months18m+ (Silver Patina)
WOOD SCIENCE

Reference view of the deeper brown tone produced by high-temperature thermal modification through the board.

PROJECT NOTE

No modeled outdoor exposure at this starting point.

Project guidance

From material choice to
installation and care.

Explore Maximo Species

Four distinct species.
One coordinated collection.

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.

5210 E Lake Sammamish Pkwy SE
Issaquah, WA 98029
(425) 391-8000
Monday–Friday, 7:00 AM–4:00 PM
Dealer 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

Maximo 2026 Product Catalog ↗Installation & Maintenance Guide ↗International ThermoWood Handbook ↗