Within the past decades, new wood modification technologies have been investigated in order to improve certain wood characteristics and enable the use of timber products for outdoor applications. Some of these non-biocidal technologies have been developed and commercialized recently. Thus, various material properties were studied intensively and shown to be improved. To a great extent, previous research was focused on the resistance of modified wood against fungal decay (basidiomycete monocultures, TMC) and confirmed the ability of biocide-free wood modification to significantly improve biological durability. Since wood modification technologies were developed and commercialized in countries of the northern hemisphere where termite infestation poses little to no risk, much less investigations were conducted and do report on the resistance against attack by insects, especially subterranean termites. Hence, the overall aim of this study was to review recent internal research activities with respect to termite resistance of eight distinct wood modification technologies (heat treatment, acetylation, furfurylation, DMDHEU, phenol formaldehyde, melamine, wax and siloxane treatment). Laboratory and field studies were conducted with termite species Mastotermes darwiniensis Froggatt, Coptotermes acinaciformis Froggatt, Reticulitermes banyulensis Clément and Reticulitermes flavipes Kollar. In general, a termite-species- and wood-species-dependent resistance against attack by subterranean termites was concluded by durability rating according to EN 117 (2013) as well as recorded mass losses. Compared to untreated feeder specimens, significantly increased termite mortality was detected for modified wood during laboratory testing. Contrary to chemical modification technologies, physical modification methods (heat treatment) revealed minor potential to inhibit attack by termites. Even though strong termite attack of modified material was partly detected under no-choice testing conditions, certain termite species exhibited significant avoidance towards modified material at choice feeding conditions. This was shown before as well as after an accelerated ageing procedure (EN 84 1997). Thus, regarding practical application and if there is a choice of feeding, some new modification technologies unveiled a real opportunity of their use under outdoor conditions as alternative, preventive treatments with improved termite resistance.

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