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Improving durability of cross laminated timber (CLT) with borate treatment


Sajad Bagheri
Mona Alinejad
Mojgan Nejad



Publication type:

Scientific Journal (JRNL)

Primary Station(s):

Forest Products Laboratory


Journal of Wood Science


Borate solution was used to treat two sets of Douglas-fr wood samples, one by spraying cross-laminated timbers (CLT) and another set by dip-treating wood in solutions at different retentions. A novel model was developed to explain and predict borate uptake based on dip-treatment parameters. Small-scale CLT samples were prepared using commercial emulsion polymer isocyanate (EPI) and polyurethane (PU) adhesive with dip-treated wood. The effect of adhesive and borate retention on CLT samples were evaluated through adhesion, fire, termite, and decay tests. The adhesion strength of wood was statistically unaffected by borate treatment. Statistical analysis showed that both spray- and dip-treated samples had significantly higher termite and decay resistance and fire performance than the untreated boards. Untreated CLT samples bonded with PU showed a considerably higher inherent decay and termite resistance than untreated specimens bonded with EPI adhesive.


Bagheri, Sajad; Alinejad, Mona; Ohno, Katie; Hasburgh, Laura; Arango, Rachel; Nejad, Mojgan. 2022. Improving durability of cross laminated timber (CLT) with borate treatment. Journal of Wood Science. 68(34): 110.


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