Wood has been a favorite material for home building projects through the years, owing to its beauty and general durability. Unsurprisingly, several products have been developed to care for it and extend 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 a popular wood-preserving pesticide since 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. While there is an ongoing debate about the practice of distributing information about treated wood, what’s important is that the consumer is aware.
Oil-Borne Wood Preservatives
Creosote and pentachlorophenol are two of the mos common types of oil-borne preservatives. Creosote has been widely used in history as a treatment for railroad ties, bridgework and other outdoor applications. This technique calls for timber being placed in a sealed chamber, where air and moisture is removed from it through a vacuum. Then the creosote is applied by way of pressure treatment. Pentacholorphenol, an organochlorine compound, is both a pesticide and a disinfectant rolled into one. The substance can be applied through pressure or brushed into the wood, or the wood may be soaked or dipped in it.
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. Copper HDO and ammoniacal copper zinc arsenate are just two of the various types of water-based wood preservers available today.
A popular trend in the wood preservation industry today is the development of more environment-friendly alternatives, such as heat treatments and acetylation. The chemical composition of timber, when heated at peak temperatures in the absence of oxygen, makes it inedible to insects and microorganisms.
Rather than being applied to wood by way of pressure, acetylation chemically changes wood by sucking the moisture out of the cell wall until there isn’t enough for fungi to grow and proliferate, leading to wood degradation. This makes the wood not just stronger but termite-resistant too, being harder and drier than its unmodified counterpart.