Thanks to its aesthetics and overall durability, wood has become a favorite home construction material through the years. Unsurprisingly, several products have been developed to care for it and extend its life, such as wood preservers.
Timber has three mortal enemies, namely, fungi, wood-boring insects, and termites. Fortunately, there are various types of natural wood preservatives and synthetic wood treatments available today.
Types of Wood Preservatives
Chromate Copper Arsenate
Chromate copper arsenate (CCA) is a pesticide that protects wood against termites, fungi and other pests that can erode it. It has been a popular wood-preserving pesticide since the 1940s. The United States’ Environment Protection Agency is concerned, however, that arsenic may leak out and cause health risks to 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. 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 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 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. 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 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. Ammoniacal copper zinc arsenate and copper citrate are two very popular types of water-based wood preservers that you can find n the market these days.
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.
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.