Thermory Thermo-Ash Cladding

Why choose Thermo-Ash cladding?

• Highly durable — a dense hardwood, thermally modified for a long exterior service life.
• Dimensionally stable — resists movement, cupping and warping through the seasons.
• Premium finish — rich brown tone and fine grain for a high-end elevation.
• Chemical-free & sustainable — heat and steam only; 100% natural.

How Thermo-Ash weathers

Left untreated, Thermo-Ash silvers to a refined grey over time, with no loss of durability. To keep its rich brown colour, apply a UV-protection oil e.g. Osmo UV oil on installation and maintain it periodically.

Profiles & fixing

We stock Thermo-Ash in secret-fix profiles for a clean, fixing-free face. As a dense hardwood, fix with stainless steel on battens with a ventilation gap behind; pre-drilling may be needed. Matched stainless fixings available.

Thermo-Ash cost per m²**

As a premium thermally modified hardwood, Thermo-Ash sits at the upper end — from around £115.92m². See the boards above for live pricing. For a lighter, lower-cost thermally modified option, see Thermo Ayous or Thermowood pine cladding. The same timber is also available as Thermo-Ash décor tiles for interior feature walls.