Evolution of thermally modified wood properties exposed to natural and artificial weathering and its potential as an element for façades systems

•Response of thermally modified wood after natural and artificial weathering tests.•Study of relevant wood properties for building applications.•Assessment of the flexural modulus including a data correction model.•Thermal stability after weathering by means of thermo-gravimetric measurements.•Modified wood maintained acceptable properties after weathering conditions. Renewable building materials may partially offset the intensive use of materials from finite resources, with the advantage of biodegradability and carbon take-up. Thermally modified wood (TMW) provides an appropriate service life for easily replacing elements of façade systems, which do not require high mechanical strength. In this study, TMW underwent one year of natural weathering conditions and on the other hand, eighty accelerated aging cycles, to determine potential changes of relevant properties of TMW in service. The results showed a positive effect of TMW when exposed to outdoor conditions, with a stable MOE (values mathematically corrected), lower reduction rate of MOR and more constant color parameters than untreated wood. Furthermore, the thermal degradation analysis showed that the mass loss in TMW was not compromised by the weathering tests. These stable properties over time provide favorable perspectives for TMW as potential construction element for outdoor applications.