Wood is a living material with a dimensional stability problem. White spruce wood is a
Canadian non‐permeable wood that is used for siding applications. To improve this property,
white spruce wood was treated with organosilanes sol‐gel treatment with different moisture
content (oven dried, air dried, and green wood). No major morphological changes were observed
after treatment. However, organosilanes were impregnated into the cell wall without densifying
the wood and without modifying the wood structure. Si‐O‐C chemical bonds between
organosilanes and wood and Si‐O‐Si bonds were confirmed by FTIR and NMR, showing the
condensation of organosilanes. The green wood (41% moisture content) showed only 26%
dimensional stability due to the presence of too much water for organosilanes treatment. With a
moisture content of 14%–18% (oven dried or air dried wood), the treatment was adapted to obtain
the best improvement in dimensional stability of 35% and a 25% reduction of water vapor sorption.
Finally, impregnation with organosilanes combined with the appropriate heat treatment improved
the dimensional stability of white spruce wood by up to 35%. This treated Canadian wood could be
an interesting option to validate for siding application in Canada.