This changes the cell structure of the wood and minimises the absorption and release of water so that the dimensional stability and durability of the wood is significantly improved.

Dekker Hout - longtime partner of Sikkens Wood Coatings - uses Accoya for a number of its products including facade cladding, windows and doors and for garden products such as decking or fences. It is naturally pale in colour like Pine, but it greys naturally over time so to preserve the natural colour, Dekker Hout uses a semi-transparent coating developed in partnership with AkzoNobel. Accoya is guaranteed to last 25 years with ground contact and 50 years above ground level.

Combining Thermo modification and coatings

As well as the benefits of Accoya, Thomas also talked about thermo modified woods like Thermo Radiata Pine, Thermo Ayous/Obeche and Thermo Fraké/Limba. By coating these woods, whose cell structure is altered through thermal modification, with semi-transparent wood coating, Dekker Hout can significantly improve the product’s durability. In some cases, it can offer a warranty of up to 10 years for the coating and a 30-year guarantee against wood rot for woods that would ordinarily only last five.

Thermal modification minimises the absorption and release of water and thereby reduces the likelihood of fungus and the deformation or curvature of wooden facades. It means that woods with low natural durability, which might typically be restricted for usage within indoor applications, become durable enough to be used outdoors. Ayous/Obeche was one of the examples given by Thomas, which is popular for saunas but after thermal modification can also be successfully used for external facades.

Thermo Pine, which Dekker Hout sources from Germany and Scandinavia, is readily available, affordable and a popular choice due to its warm rustic charm. Thermo Pine is highly durable and dimensionally stable, and after being coated in a semi-transparent coating from Sikkens Wood Coatings, comes with a 10-year warranty.

The African Obeche wood is also easily available and is FSC certified for its sustainability. The darker colour of Thermo Ayous, which originates from the thermal modification process, quickly turns to its naturally brighter hue. When used outdoors, it will turn grey if not properly coated.

Like Thermo Pine, with thermal modification and semi-transparent coating, Dekkers Obeche wood products have a warranty of 10 years for the coating and 30-year guarantee against wood rot.

The only disadvantage of the thermal treatment, Thomas cautions, is that woods may become a little softer than the normal untreated woods. However, the dimensional stability and durability of woods are of much higher importance for facades than their grade of hardness.

Trends

When it comes to trends in cladding, Thomas and his team at Dekker Hout have seen the barcode profile become ever more popular, both in vertical or horizontal applications and using different types of species. The most popular colours currently, particularly in outdoor applications, are grey, black and a natural colour coating.

Regardless of trends, what customers want is for the timber to retain its colour for as long as possible without having to invest in constant maintenance. Acetylation, thermal modification, and innovative coatings with full or semi-transparent coverage from Sikkens Wood Coatings help protect the wood and achieve durable, stable colours regardless of the weather conditions so that Dekker can guarantee that its timber will look beautiful for 10 years or more.