Journal of Forestry Research

, Volume 29, Issue 3, pp 859–867 | Cite as

Water-repellent efficiency of thermally modified wood as affected by its permeability

  • Asghar Tarmian
  • Akbar Mastouri
Original Paper


This study shows how the air permeability of thermally modified wood contributes to its water-repellent efficiency. For this purpose, freshly cut boards of hornbeam (Carpinus betulus), poplar (Populus nigra), and heartwood of oak (Quercus castanifolia) were modified at a steam temperature of 180 °C for 3 h inside a ThermoWood kiln. The porous structure, permeability, and water uptake of wood were affected differently by thermal modification, depending on the wood species. The creation of micro-cracks in the cell walls, due to collapsing of fiber cells, resulted in a noticeable increase in the permeability of hornbeam. Despite checking in the poplar wood structure, its permeability was negatively affected by thermal modification. In contrast to oak and poplar, a negative water-repellent efficiency was observed for the modified hornbeam, caused by an increase in the permeability.


Air permeability Thermally modified wood Water-repellent efficiency 



The authors are grateful to Prof. Ingo Burgert, Prof. Emil Engelund Thybring, Ms. Vivian Merk and Ms. Stéphane Croptier in the Wood Materials Science Group at the Institute for Building Materials at ETH Zurich.


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Copyright information

© Northeast Forestry University and Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  1. 1.Department of Wood and Paper Science and Technology, Faculty of Natural Resources, College of Agriculture and Natural ResourcesUniversity of TehranKarajIslamic Republic of Iran

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