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
There are three major threats to timber – termites, fungi and wood-boring insects. Fortunately, protection is possible through various types of natural and synthetic wood preservatives and treatments 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. Several manufacturers though opt to provide Material Safety Data Sheets rather than 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 of the most popular types of oil-borne preservatives are creosote and pentachlorophenol. Creosote has been a common figure in the history of protecting outdoor wood structures like bridges and railroad ties. This method involves putting timber in a sealed chamber and removing air and moisture using a vacuum. Then the creosote is applied by way of pressure treatment. Acting like a pesticide and a disinfectant in one is pentachlorophenol, an organochlorine compound. 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 Preservatives
Water-based preservatives are typically the least expensive, but their disadvantage is that they tend to cause swelling or warping because of the water that they contain. Copper HDO and ammoniacal copper zinc arsenate are just two of the various types of water-based wood preservers available today.
A rising trend in the industry of wood preservation is the creation of alternative methods that are more environment-friendly, such as acetylation and heat treatments. The chemical composition of timber, when heated at peak temperatures in the absence of oxygen, makes it inedible to insects and microorganisms.
Acetylation does not involve pressurized treatments but instead protects wood by reducing moisture in the cell wall until nothing is left for fungi to thrive. This doesn’t only make the wood stronger but also termite-resistant since it has become harder and drier than wood in its original state.