Thermowood Redwood

Type: Softwood
Source: Scandinavia


Thermowood has a high resistance to moisture and decay which makes it a good option for exterior cladding. Thermowood is a straight grained softwood which offers a more consistent finish. Thermowood density is in-between Cedar and Larch and is darker in colour. Thermowood is thermally modified which increases stability and provides resistance against shrinkage, swelling and distortion. Thermowood is heat treated to a temperature of 180 degrees.

Download Datasheet
Suitability of Profiles

Wide choice of standard profiles.

Profile Cladding Joint Horizontal Diagonal Vertical Thickness
Tongue & Groove Closed Yes Yes Yes 20mm min.
Rectangular Closed No No Yes 16-25mm+
Feather Edge Closed Yes No No 9mm x 16-15mm
Shiplap Closed Yes No Yes 18mm
Parallelogram Open Yes No No 16-25mm+
(up to 50mm)
Ecova Clad Profiles Guide
Desired service life (years)
Natural durability class Need for treatment/modification Occasionally wet Frequently wet
1 (Very durable) Suitable without treatment >60 60
2 (Durable) Suitable without treatment 60 30
3 (Moderately durable) Suitable without treatment except for tall or exposed buildings 30 15 (untreated)
4 (Slightly durable) Treatment required 15-30 years treated 15-30 years treated
5 (Not durable) Treatment required 15-30 years treated 15-30 years treated
Common Name Natural Durability Class BSEN350:2:1994 Sapwood Treatability Movement Strength
Thermowood (European) 2 Resistant Small High
  • Doesn’t necessarily need a surface treatment applied to it, however you can choose to add a finish, stain or paint to their timber to enrich its colour, but if it’s left untreated, the wood will naturally change to a silvery grey (similar to that of cedar or larch)
Cladding Treatment Notes For which species?
Tanalith (Green) High Pressure Treatment – Green Coloured Finish. Once treated, timber can go in the ground Soft Wood Only
Tanalith (Brown) High Pressure Treatment – Brown Coloured Finish. Once treated, timber can go in the ground Soft Wood Only
Vac – Vac (Clear – Yellowish) Low Pressure Treatment – Green Coloured Finish. Can only use above ground Soft Wood Only
Fire Retardant Pressure Treatment All Species
UV Protection Vacuum Applied All Species
Full Range of Stains and Colours All Species
Clear Lacquer Vacuum Applied All Species

If you have decided that Timber Cladding is going to be one of the materials on your project the next step is to create a specification that will meet the criteria and expectations you, and your client have.

We offer installation guidance, detailing guidance based on TRADA documentation, with a wealth of knowledge and information on how different timbers will perform over the life span of your project.

Considerations that should be made when it comes to weather, along with how elevation and design variations can impact timber cladding.