20.500.12556/DiRROS-28806 Fire performance of thin intumescent coatings material characterisation and application to mass timber structures This study investigates the thermal behaviour of two opaque and one transparent thin intumescent coating at material level (coating only) and system level (coating applied at real scale on timber), and their effects on timber in fire. Micro-scale tests were conducted to examine the underlying mechanisms of intumescence and degradation for each coating individually, while bench-scale tests demonstrated how these behaviours translate to larger scales. Critical temperature and heat flux thresholds were identified at which the coatings begin to insulate the timber through the formation of the intumescent char layer, as well as those marking degradation of the layer and the reduction of its insulating efficacy. The findings highlight that coating type and thickness, heating conditions and exposure duration influence mass retention, swelling pattern, and the integrity of the intumescent char layer. Overall, the transparent coating exhibited lower durability than the opaque ones. It was also shown that, due to the similar temperature ranges of timber pyrolysis and coating swelling, timber degradation occurs close to the coated surface during the transient swelling process, resulting in a heated region of 15- 20 mm with negligible mechanical properties by the end of swelling. Therefore, intumescent coatings provide insulation progressively rather than immediately. mass timber thin intumescent coatings swelling fire testing charring fire safety masivni les tanki intumescentni premazi nabrekanje preskusi odpornosti proti ognju ožganje požarna varnost true false true Elsevier Angleški jezik Slovenski jezik © 2026 The Authors Neznano 2026-04-08 10:37:27 2026-04-08 10:40:42 2026-04-09 03:51:17 0000-00-00 00:00:00 2026 0 0 This special issue is based on the selection of works presented at the 15th International Symposium on Fire Safety Science (IAFSS 2026); str. 1-13 [article no.] 104711 Vol. 162 Jul. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2026-03-12 62 1873-7226 10.1016/j.firesaf.2026.104711 273029379 https://www.sciencedirect.com/science/article/pii/S0379711226000792 1 2f1372fc-3326-11f1-b941-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=42908 RAZ_Wiesner_Felix_2026.pdf RAZ_Wiesner_Felix_2026.pdf 1 F7912FBFB610FC3CFF768F41B56B8586 7c33ffc4b4747107f869205ff837e4ef98906ec31db06b334ed1710c7655cfad 99fd4a85-3326-11f1-b941-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=42909 Zavod za gradbeništvo Slovenije 0 0 0