Figuring Out Buildings
Thanks to its aesthetics and overall durability, wood has become a favorite home construction material through the years. No wonder everything is being done to care for it and prolong its life, such as wood preservers
Termites, fungi and wood-boring insects are timber’s three worst enemies. Fortunately, there are various types of natural wood preservatives and synthetic wood treatments available today.
Types of Wood Preservatives
Chromate Copper Arsenate
Chromium copper arsenate is a pesticide that strengthens wood against fungi, termites and other pests. It has been used as a wood-preserving pesticide since way back the 1940s. One concern raised by the United States’ Environment Protection Agency, however, is that arsenic may leak out over time and endanger the health of those who are exposed to it.
To mitigate the risks that come with wood treatment in general, all treated wood should be sold with a Consumer Information Sheet that details all handling and disposal precautions that must be taken. Many manufacturers, however, prefer to provide Material Safety Data Sheets over CIS. There is a never-ending debate on this practice of distributing information regarding treated wood, but the more important point is that the consumer is fully aware of the product.
Oil-Borne Wood Preservers
Two very common oil-borne preservatives today are creosote and pentachlorophenol. Creosote has been widely used in history as a treatment for railroad ties, bridgework and other outdoor applications. In this method, the timber is placed in a sealed chamber, and a vacuum sucks out the air and moisture out of the wood. Then the creosote is applied by way of pressure treatment. Acting like a pesticide and a disinfectant in one is pentachlorophenol, an organochlorine compound. It may be brushed or applied by pressure, or the wood can be dipped or soaked in the liquid.
Water-Borne Wood Preservers
Water-based preservatives are some of the cheapest you’ll find in the market, but because of their water content, they tend to cause wood to swell or warp. Two examples of water-based wood preservatives are alkaline copper quaternary compounds and copper.
A popular trend in the wood preservation industry today is the development of more environment-friendly alternatives, such as heat treatments and acetylation. Heating timber to extreme temperatures without oxygen changes its chemical composition and renders it useless to microbes and insects.
Instead of infusing water-based preservatives into wood through pressure, acetylation chemically changes wood by reducing moisture in its cell wall enough that fungal degradation becomes impossible. This makes the wood not just stronger but termite-resistant too, being harder and drier than its unmodified counterpart.