Thermowood Cladding

Thermally modified European softwood. Durable, stable and chemical-free - with a service life of 30 years or more.

Style

Contemporary / Traditional

Profiles

Various

Source

Nordic countries

Considerations

Knotty appearance. Relatively brittle.

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What is Thermowood cladding?

Thermowood cladding is made from fast-growing European pine or spruce, thermally modified using heat alone. No chemicals are added. The heat process alters the structure of the wood, reducing its ability to absorb moisture and significantly improving durability and stability.

The result is a cost-effective cladding option that performs well in exposed conditions. When correctly installed and detailed, Thermowood cladding delivers a service life of 30 years or more.

Boards are available in a knotty grade, giving a natural, characterful finish that works across a wide range of building styles – from contemporary new build to traditional rural.

Key features

Made from fast-growing European softwood (pine or spruce)
Cost-effective thermally modified cladding option
Thermally modified using heat alone – no added chemicals
Durable and resistant to decay
Excellent dimensional stability — reduced shrinkage and swelling compared to untreated softwood
Available in a knotty grade
Service life of 30 years or more when correctly installed

Thermowood cladding prices

Thermowood cladding is priced per linear metre, with the total cost per m2 depending on the profile and board width you choose. For current pricing, download our price list or get in touch with the team.

Call us to discuss your timber cladding project

01793853281

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Thermowood cladding specification

Species: Spruce or pine
Certification: Available as PEFC
Grade: BS1186-3 Class 3 / EN942:2007 J50
Finished thickness: Various
Widths: Various
Lengths: 3.6m+
Profiles: Various machined and fine-sawn profiles
Moisture content: 5–8%
Durability: Class 2 (EN350-2)
Finish: None

Characteristics of Thermowood cladding

Appearance
Thermowood has a knotty appearance and a rich, dark colour. Freshly machined surfaces are silky smooth.

Weathering
Thermowood weathers quickly and relatively evenly. The dark colour fades within a few weeks and develops a silver patina within a few months.

Service life
30 years+

Movement
Small movement class

Impact resistance
Low

Workability
Relatively brittle. Always pre-drill before nailing or screwing.

Density
350–400 kg/m³

Extractives
Thermowood contains no extractives.

How to install Thermowood cladding

Fixing method
Hand nail or screw through the face or tongue, depending on profile. For speed and consistency, a second-fix nail gun with two angled 16-gauge brad nails at each batten works well. All fixings must be stainless steel.

Battens
Use Thermowood or treated softwood battens. The primary batten must be a minimum of 40mm thick.

Find out more about our Thermowood batten system

Batten spacing
400–500mm

Nail type
Stainless steel only. For hand nailing: 50mm ring shank nails. For gun fixing: 50mm 16-gauge brad nails suitable for external use.

When to fix
Year round.

Resistance to fixing
Low

Thermowood cladding profiles

Thermowood cladding is available in a range of machined and fine-sawn profiles. We machine boards to the profile of your choice.

View our full range of cladding profiles.

Disclaimer

While the utmost care has been taken to provide accurate information, Vastern Timber shall not be held responsible for any consequences arising from any errors or omissions on this website nor for any damages resulting from the use of the information.