THERMALLY MODIFIED WOOD SIDING & DECKING

Thermal modification is a process that uses high heat to alter the properties of the wood. As with most things in life, there is a cost benefit analysis to be made in relation to this process and the end use of the product.

During thermal modification the cell structure of the wood is changed and the free movement of water in and out of the cell is inhibited. As a result of this process the wood will decrease in strength and hardness, making it more likely to break or dent. At the same time the process increases the stability and durability of the wood, making it more suitable for exterior uses and decreasing the tendency of the wood to expand and contract with fluctuations in moisture content.

Careful consideration has to be made in regards to the timber being modified, and its intended end use. A lighter wood species such as Pine or Ayous will benefit from the modification process but will lose strength and weight, making the end product useful for a siding application but unusable in a decking application without a second modification to enhance the density and strength - As is done with Rhino wood for example. A medium or heavy density wood, such as Korina or Ash, will retain sufficient strength and hardness to be used for decking applications but may not be suitable for heavy construction. In most cases the benefits of the thermal modification process outweighs the cost, provided the end use is suitable for the final product.