In the world of wellness design, few materials carry the sensory depth and natural beauty of wood. From the subtle scent of timber warming in gentle heat to the soft touch of a finely crafted bench, sauna wood defines the experience. But not all woods are created equal — and when it comes to creating a sauna that’s beautiful, stable, and sustainable, thermally modified British ash stands in a class of its own.
At Coppice & Crown, we’re proud to craft with British-grown timber — always fully traceable, always sustainably sourced, and always worked with care. And increasingly, we’re seeing thermally modified ash emerge as one of the most exceptional choices for sauna wood in contemporary wellness architecture.
What Makes Great Sauna Wood?
A sauna is a challenging environment for timber. Constant cycles of heat and humidity test every grain and joint. The ideal sauna wood needs to:
Resist warping and swelling through high heat and moisture changes.
Remain smooth and cool to the touch for comfortable seating and wall panelling.
Avoid resin or sap bleed, which can be unpleasant under heat.
Offer natural durability without chemical treatments.
Look and feel beautiful, enhancing the calm atmosphere a sauna deserves.
Traditionally, Scandinavian species such as aspen and alder have been the go-to choices. But with the growing movement toward sustainable, locally sourced materials, British-grown hardwoods are finding their place in this ancient craft — especially when thermally modified for performance.
The Power of Thermal Modification
Thermal modification transforms British hardwoods through controlled heat treatment — typically between 160°C and 220°C — in an oxygen-free chamber. This natural process permanently changes the wood’s structure, enhancing both stability and durability without introducing any chemicals or coatings.
For saunas, the benefits are significant:
Improved dimensional stability – thermally modified wood doesn’t shrink, swell or twist when exposed to fluctuating heat and humidity.
Enhanced resistance to decay – ideal for the naturally humid conditions of a sauna.
Beautiful rich tones – the process deepens the wood’s colour, creating warm, chocolate-brown hues that complement a wellness setting.
Completely non-toxic – safe for high-temperature use and skin contact.
A Sustainable Alternative to Imported Sauna Wood
Imported sauna timber — typically cedar, hemlock, or Scandinavian softwoods — travels thousands of miles before reaching a wellness project in Britain. Beyond the carbon footprint, there’s also the issue of traceability and long-term supply.
By choosing thermally modified British ash, you’re choosing:
Local provenance — supporting British forestry and craftsmanship.
Lower environmental impact — fewer transport miles, no chemical preservatives.
Grown in Britain certification — full traceability from forest to finished sauna.
For architects, designers and homeowners seeking to align their wellness spaces with sustainability principles, locally sourced sauna wood offers both ecological and emotional resonance — connecting people to the landscapes that nurture them.
In Summary
If you’re searching for the best sauna wood that combines natural performance, refined beauty, and local sustainability, thermally modified British ash offers a truly exceptional solution.
With Coppice & Crown’s craftsmanship and commitment to traceable British timber, you can build a sauna that not only looks and feels exquisite — but tells a story of place, purpose, and enduring quality.
