Pressuretreated

Pressure-treated wood is timber that has been infused with chemical preservatives under high pressure to improve resistance to rot, decay, and insect damage. The treatment process saturates the wood with waterborne or oilborne preservatives, enabling deeper and more uniform penetration than surface coatings. It is commonly applied to softwoods such as pine, fir, and spruce for outdoor use.

Preservatives: Historically, chromated copper arsenate (CCA) was widely used, but concerns about arsenic led to its phase-out for residential use. Modern residential products typically rely on copper-based formulations such as alkaline copper quat (ACQ) or copper azole, sometimes with micronized copper. Oilborne options include creosote or pentachlorophenol in restricted applications. The choice of preservative affects performance, color, and environmental considerations.

Applications and safety: Pressure-treated wood is used for decks, fences, retaining walls, garden beds, and other outdoor structures, as well as structural timbers in damp or soil-contact conditions. When cutting or sanding, wear protective equipment and wash hands after handling, since preservatives can be present in dust. Do not burn treated wood, and dispose of scraps per local regulations. Avoid contact with edible crops unless the wood is properly protected or separated by barriers.

Maintenance: Treated wood resists decay longer than untreated wood but can still degrade with moisture, sun, or damage. It may change color over time and often benefits from staining or sealing to reduce surface deterioration and prolong life. Regular inspections can help identify warping, cracks, or hardware corrosion and guide timely repairs.