Wood Preservative
A chemical substance applied to wood to protect it from decay, fungal attack, and insect damage through pressure treatment, dipping, brushing, or spraying.
In-Depth Explanation
Wood preservatives fall into three main categories: waterborne preservatives like ACQ and copper azole for residential construction, oil-borne preservatives like creosote for utility poles and railroad ties, and light organic solvent preservatives for millwork and joinery. The most effective application method is pressure treatment, which forces preservative deep into the wood cells. Surface-applied preservatives like borate solutions and copper naphthenate offer additional protection for field cuts and exposed end grain. The EPA regulates wood preservative chemicals in the United States, and treated wood must carry a label indicating preservative type, retention level, and approved uses. Choosing the correct preservative and retention level is critical for adequate protection.
Usage Example
After cutting the pressure-treated post to length, I brushed copper naphthenate wood preservative on the exposed end grain.