Wood as been a favorite home construction material over the years, thanks to its beauty and overall 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 product that fights wood erosion due to an infestation of termites, fungi 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. Several manufacturers though opt to provide Material Safety Data Sheets rather than CIS. There seem to be endless arguments on this practice of disseminating information, but the most important thing is that the consumer is aware.
Oil-Borne Wood Preservers
Two very common oil-borne preservatives today are creosote and pentachlorophenol. Creosote has been a common figure in the history of protecting outdoor wood structures like bridges and railroad ties. 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. It can be applied to wood by spraying, dipping or brushing, by soaking the wood in the liquid, or by pressure.
Water-Borne Wood Preservers
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. Two examples of water-based wood preservatives are alkaline copper quaternary compounds and copper.
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 makes the wood not just stronger but termite-resistant too, being harder and drier than its unmodified counterpart.