Pressure Treated WoodAlso called Pressure Treated Timber, Pressure Treated Lumber, PT Timber or PT Lumber. Pressure Treated Lumber is wood treated with preservative solutions to protect it from being destroyed by insects, fungus, or exposure to moisture.
For the construction of my cabin, I used PT lumber for those areas that would be in contact, or in close proximity, with the ground or concrete. Regular cabin building lumber (i.e. spruce) will degrade faster from contact with ground moisture, fungi and insects.
Pressure treated wood products are manufactured by forcing preservative solutions into the wood cells using vacuum/pressure and thermal processes.
All wood preservatives and processes are subject to strict governmental regulation and environmental/safety controls.
Types of Wood Preserving TreatmentsChromated copper arsenate, type C (CCA-C), was until recently the industry’s standard wood preservative, but alternative treatments such as alkaline copper quaternary (ACQ) and copper azole (CA), have replaced CCA-C in products destined for most exterior residential applications. CCA-C is no longer being produced for residential or general consumer use.
In addition to these two newer preservatives, sodium borate (SBX) treated lumber is now used for many interior applications. The formulation of Alkaline Copper Quaternary and Copper Azole includes copper as the primary protection against termites and fungal decay. It also provides supplemental protection against copper-tolerant fungi.