The influence of the type of coating on thermally modified wood and the resulting durability of the surface treatment on a facade

• Published in: Journal of Building Engineering 2024-08, Vol.91, p.109629, Article 109629
• Main Authors: Sarvašová Kvietková, M., Dvořák, O., Kalábová, M., Šimůnková, K., Štěrbová, I., Pastierovič, F., Lin, C-f, Jones, D.
• Format: Article
• Language: English
• Subjects: Cost-benefit analysis (CBA); Durability; Exterior; Thermowood; Träteknik; Wood Science and Engineering; Wood-façade
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2024.109629

Many architects choose wooden façades to clad modern buildings, and Thermowood® is a popular choice for such applications. This study focuses on methods to prolong the “fresh” appearance of Thermowood® façades, specifically Thermo-ash (Fraxinus excelsior L.), Thermo-spruce (Picea abies (L.) Karst.) and Thermo-pine (Pinus silvestris L.). The study involves exposing three groups to natural weathering: one reference untreated group, one group with a thin-layer alkyd coating, and another with a thick-layer acrylate coating. The results indicated that a thick-layer acrylate coating was the most suitable treatment for Thermowood® surfaces, as this coating retained a better appearance and demonstrated superior coating durability. Furthermore, cost-benefit analysis (CBA) suggested a thick-layer acrylate coating proved to be the most suitable and cost-effective choice, based on architects’ desires, to maintain a “fresh/original” appearance. •The surface of thermally treated wood as a facade material quickly degrades - the so-called “grey".•Pine thermally treated wood had the best color fastness compared to thermal spruce and thermal ash.•Thick-layer acrylic coating shows the best protection of the stability of the surface of thermally modified wood.•The biggest color changes were observed on thermally treated ash wood surfaces.•Economic point of view, it seems optimal to treat the surface of thermally treated pine wood with a thick layer of acryl.