profile

Build Livable's Owner Notes + Courses for Homeowners

What is Thermally Modified Wood?

Published 7 months ago • 2 min read

Welcome to Owner Notes, a free newsletter for anyone planning on (or dreaming about) building a custom home.

👉 If you enjoy Owner Notes, share this link with pals or read past issues.


Hello friends!

I hope you've been able to spend some time outside this summer. I always look forward to summer evenings on our deck with friends. Speaking of decks, have you heard of thermally modified wood?

What is Thermally Modified Wood?

Build Livable does not advertise or earn income from the products and services we discuss.

In the process of designing our home, I spent time researching decking materials. We live in the Pacific Northwest and need decking that will last through our very wet winters. I looked at Ipe, bamboo, cedar, composite, and more. Every option has pros and cons that often come down to price, beauty, durability, maintenance, and environmental impact.

Note: We devote an entire chapter to deck styles and materials in our Home Construction Navigator course.

In this search, I came across an option that I hadn't seen: thermally modified wood. This process involves heating softwood, like ash, to over 400 degrees(f) without adding chemicals. The heat changes the molecular structure of the wood, which makes it durable and water-repellent. The heat also removes sugars that are attractive to insects.

We choose to use thermally modified wood for our decking and so far it's been impressive. A few things to note:

Price - Decking prices fluctuate constantly. In our case, the decking was priced close to very durable (and relatively expensive) hardwoods like Ipe. Westwood is one of the best-known manufacturers. Others include Thermory and Americana.

Beauty - Thermally modified wood is milled with precision and can be installed without visible fasteners. The boards are consistent and most have a dark brown color. Like any wood, the color will fade or "silver" over time. You can stain or oil the wood on a regular basis to maintain the color. We let our deck silver.

Durability - This decking has "Class 1" durability, which means it should last at least 25 years fully exposed to the elements. The heating process makes the wood resistant to warping and cupping. However, it also becomes more brittle. The brittleness is not a factor when used for decking.

Maintenance - Our goal is to find materials that require little maintenance. Cedar, for example, is a great decking material but requires regular care to increase longevity. Thermally modified wood does not require regular maintenance in the form of staining or protecting the wood. We wash ours with a vinegar and dish soap solution every spring and that's it.

Environmental Impact - I was hoping to find a sustainable decking solution. No exotic hardwoods, no chemical impregnation, no questionable sources. Our decking material is ash that was grown in Pennsylvania and processed in the US. It's 100% wood with no chemical additives.

Overall, I'm happy we discovered thermally modified wood. In fact, we also used it for exterior window and door trim.

That's what I have for now. I'll be in touch again soon! 🌞

Lee LeFever, Build Livable


Build Livable's Owner Notes + Courses for Homeowners

We're homeowners helping homeowners navigate custom home construction via online education. Owner Notes is a weekly email with expert tips and advice for anyone planning (or dreaming about) building a custom home.

Read more from Build Livable's Owner Notes + Courses for Homeowners

Welcome to Owner Notes, a free newsletter for anyone planning on (or dreaming about) building a custom home. 👉 If you enjoy Owner Notes, share this link with pals or read past issues. Hello friends! As those of us in the U.S. prepare for Thanksgiving, I'm to share a connection between Thanksgiving dinner and planning a new home. If you've never hosted Thanksgiving dinner, it may be easy to think, "How hard could it be? It's just putting out some plates and cooking a few dishes. I could do...

5 months ago • 1 min read

Welcome to Owner Notes, a free newsletter for anyone planning on (or dreaming about) building a custom home. 👉 If you enjoy Owner Notes, share this link with pals or read past issues. Hello friends! We offer two comprehensive online courses that prepare homeowners for construction: Home Planning Navigator (normally $99) Home Construction Navigator (normally $99) Starting today, we're offering a Black Friday 2-for-1 discount on these courses. Get BOTH for $99 until November 28th. Get the...

5 months ago • 1 min read

Welcome to Owner Notes, a free newsletter for anyone planning on (or dreaming about) building a custom home. 👉 If you enjoy Owner Notes, share this link with pals or read past issues. Hello friends! There is a gap in the experience needed to build your custom home. The gap causes time and money to be wasted. It creates stress and anxiety for homeowners. It's a missing piece of the house-building puzzle that's been there for too long. What's in the Gap Building a new home may be one of the...

5 months ago • 1 min read
Share this post