Understanding the Different Types of Wood Preservatives
Thanks to its aesthetics and overall durability, wood has become a favorite home construction material through the years. 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
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 preservative for over 50 years. 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. 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 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. Then the creosote is applied by way of pressure treatment. Pentachlorophenol is an organochlorine compound that works as a pesticide and as a disinfectant at the same time. It may be brushed or applied by pressure, or the wood can be dipped or soaked in the liquid.
Water-Borne Wood Preservers
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. 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. Heating timber to extreme temperatures without oxygen changes its chemical composition and renders it useless to microbes and insects.
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 doesn’t only make the wood stronger but also termite-resistant since it has become harder and drier than wood in its original state.
