
At Coppice & Crown, we celebrate the authentic beauty and resilience of British-grown timber. Thermally Modified Ash, otherwise known as Thermo Wood stands out as an exceptional material for sauna construction, offering both aesthetic appeal and functional benefits.
Why Choose Thermo Wood for Your Sauna?
Enhanced Durability and Stability
Through a natural heat treatment process, thermo wood gains superior resistance to moisture, decay, and temperature fluctuations—ideal for the demanding environment of a sauna.
Chemical-Free and Eco-Conscious
The modification process involves only heat and steam, eliminating the need for chemicals. This aligns with our commitment to sustainability and ensures a safe, toxin-free environment for relaxation.
Rich, Warm Aesthetics
The thermal treatment deepens the wood’s natural hues, resulting in a rich, inviting appearance that enhances the tranquil ambiance of your sauna.
Comfortable to the Touch
Thermally modified ash remains smooth and splinter-free, providing a comfortable surface even at high temperatures—perfect for sauna benches and walls.

Building Your Sauna with Coppice & Crown
Our thermally modified ash is sourced exclusively from British woodlands, ensuring full traceability and adherence to sustainable practices. Each piece is crafted with care, reflecting our dedication to traditional craftsmanship and environmental responsibility.
Whether you’re envisioning a home sauna retreat or a commercial wellness space, our team is here to provide bespoke solutions tailored to your needs. Contact us to explore how our thermally modified ash can bring natural beauty and enduring quality to your wellness space.