Length
Width
Thickness
Colour Tone
Profile
Material
Fire Rating
Range
Species
Wood Type
Warranty
Moisture Content
Thermowood Cladding
Thermowood cladding is timber made durable by heat, not chemicals. We stock Thermo Ayous triple slatted boards (140×21 mm) and Thermo Spruce boards (140×26 mm). Both are Durability Class 1, very stable, and brown all the way through, and every board is stocked in our warehouse for delivery across Ireland.
Sort by
Showing 1-2 of 2 results
Thermowood Cladding for Sale in Ireland
Thermowood is timber that has been made more durable with heat instead of chemicals. We stock it in two species, Thermo Ayous and Thermo Spruce, both machined for exterior cladding, stocked in our warehouse and delivered across Ireland.
What Is Thermowood?
The boards are heated to 180 to 215 °C in a low oxygen kiln. That permanently changes the cell structure of the wood, so it takes up far less moisture. The result:
- Durability Class 1: the top rating, with a service life of 25 years and beyond on an exterior wall.
- Very stable: little swelling or shrinking with the seasons, so joints stay tight and the facade stays straight.
- No chemical preservative: nothing leaches out into the ground or the garden.
- Colour right through: a rich, even brown in every cut, so trimmed ends and chamfers don’t show pale timber.
- Clean to work: most of the resin is driven out, so it cuts and finishes cleanly.
Thermowood Cladding Boards We Stock
Both species come as triple slatted boards, so choose the species by the look and the section, then the length by the wall on the product page: longer boards mean fewer joints on long runs, and a length that suits the wall cuts waste.
Thermo Ayous Triple Slatted Cladding
Ayous is a light, fine grained timber that takes thermal modification very evenly. Each 140×21 mm board is machined to show three narrow slats, which gives a contemporary, linear facade.
Thermo Spruce Triple Slatted Cladding
Thermo spruce is a heavier, more rustic board with visible grain and knots, also machined to show three slats. At 140×26 mm it is the thicker of the two, and it is well suited to large elevations, where long boards mean fewer joints on the wall.
Thermowood vs Cedar and Larch
All three are durable enough for exterior cladding without preservative. Cedar cladding is lighter and has a natural colour variation. Larch cladding is denser and more characterful. Thermowood gives you the most even colour and the least movement, which suits crisp, modern designs.
Installing Thermowood Cladding
- Fix to treated battens over a breather membrane, with a ventilated gap of at least 20 mm behind the boards.
- Heat treatment makes the timber a little more brittle than ordinary softwood, so pre-drill every fixing point.
- Use A2 stainless steel fixings, or A4 near the coast.
- Seal the ends you cut with oil to keep them matching the face.
Oiling Thermowood Cladding
Thermowood doesn’t need a preservative to last, but UV turns the brown to silver grey within the first year or two. Most people oil it to keep the rich brown. Use a UV protective oil made for thermally modified timber, oil it every year for the first couple of years, then every two or three years. See our wood oils and stains for the right finish.
For every species and profile we stock, browse all our timber cladding.
Frequently Asked Questions About Thermowood Cladding
What is Thermowood?
Thermowood is timber that has been heat-treated instead of chemically treated. It is heated to 180 to 215°C in a low-oxygen environment, which permanently changes its cell structure. The result absorbs much less moisture and resists rot, insects and fungal decay, with no preservative.
What are the benefits of Thermowood cladding?
Our Thermowood Ayous boards are very stable and move very little as humidity changes through the year. They have a uniform rich brown colour that runs right through the board, so cut ends do not show pale wood, and a service life of 25 years and beyond.
Does Thermowood need treating?
It doesn’t need a preservative to last, but UV turns the brown to silver grey within the first year or two. Most people oil it to keep the rich brown, using a UV protective oil made for thermally modified timber: every year for the first couple of years, then every two or three years. See our wood oils and stains.
How much Thermowood cladding do I need?
Measure each wall, take off large windows and doors, then enter your area in the calculator on the product page. It works out how many you need, and the cart adds the fixings and extras. Thermo Ayous boards are 140×21 mm and Thermo Spruce boards are 140×26 mm, and you choose the length on each product page.
How do I install Thermowood cladding?
Heat treatment makes the timber slightly more brittle than untreated softwood, so pre-drill every fixing point and use A2 or A4 stainless steel fixings. Most of the resin is removed during treatment, so it cuts and finishes very cleanly.
Thermowood or cedar cladding: which is better?
Neither needs chemical treatment. Cedar is naturally durable (Durability Class 2) and very light. Thermowood gets its durability from heat treatment and gives you a uniform brown colour all the way through and very little seasonal movement. Choose on the colour and the look you want.