Wood as been a favorite home construction material over the years, thanks to its beauty and overall durability. It’s not surprising that various products have been created to preserve and care for it, such as wood preservers.
Timber has three mortal enemies, namely, fungi, wood-boring insects, and termites. Fortunately, there are now several options of natural wood preservatives and synthetic wood treatments that can provide protection.
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 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.
As a way to control risks associated with wood treatment in general, the American Wood Protection Association recommends that all treated wood come with a Consumer Information Sheet that provides guidelines on safe handling and disposal. However, a lot of manufacturers choose to provide Material Safety Data Sheets instead. 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 a whole history of being used to prevent rot for outdoor applications, such as in railroad ties and bridges. This technique calls for timber being placed in a sealed chamber, where air and moisture is removed from it through a vacuum. The creosote is then impregnated into the timber through pressure treatment. Acting like a pesticide and a disinfectant in one is pentachlorophenol, an organochlorine compound. It can be applied to wood by spraying, dipping or brushing, by soaking the wood in the liquid, or by pressure.
Water-Borne Wood Preservatives
Usually the cheapest wood preservatives in the market are those that are water-based, but because of their high water content, they have the tendency to make wood swell or warp. 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. When subjected to extremely high temperatures in the absence of oxygen, timber becomes inedible to insects and microorganisms due to the resuling alterations in its chemical makeup.
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. The wood then becomes stronger and more termite-resistant because it is now harder and drier than before.