Olympia · Lacey · Tumwater, WAYour independent deck planning guide
Call about your deck(360) 526-0891 · project voicemail

Real wood, a different specification

Thermally modified & acetylated wood decks

Modified wood includes different processes intended to change wood’s outdoor performance. Thermally modified wood and acetylated wood are separate families; neither is simply a new name for pressure-treated lumber.

Plan this project Explore decking materials
AI-generated concept of a modified-wood-style garden deck
AI-generated design inspiration

Natural-wood design inspiration; this is not a product or species sample.

01

Understand the process being offered

Thermal modification uses heat as part of the manufacturing process. Acetylated products use a different modification process. Get the manufacturer, product line and intended-use documentation instead of relying on the broad label “modified wood.”

02

Keep surface and structure separate

A decking product is not automatically approved as a structural framing member. Ask the designer to specify the frame separately and confirm the board support, fasteners and installation details for the actual surface product.

03

Plan appearance and care

Some modified woods are selected to weather naturally; maintaining a particular tone can still require care. Ask for the manufacturer’s cleaning and finish guidance, sample the surface, and confirm local supply and installer familiarity before committing.

Questions worth asking

Is modified wood maintenance-free?

No outdoor deck is free of care. Cleaning and the appearance you want to maintain still matter.

Can modified deck boards replace structural lumber?

Do not assume so. Structural suitability must be documented for the exact product and use.

Go to the source

Official resources and manufacturer guidance used for this guide. Confirm current requirements for your project and exact product.

Thermory installation and care

Your next chapter outside

Start with a good plan.

Tell us about your space, what you want to change, and the way you want to live outside.

Plan my deck project