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Wolmanized Decking |
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Facts you should know |
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Pressure treated or "Wolmanized" wood as commonly known has undergone significant changes. First of all, the term Wolmanized has been used like "Scotch" brand tape or “Formica” brand plastic laminate. Wolmanized is a proprietary name that refers to the process licensed by Arch Chemical Company. Osmose Chemical Company licenses another similar process. These are the two main processes in use. Wolmanized may be more familiar simply due to the fact that it rolls of the tongue easier that "Osomosized" These chemical companies license their process to local pressure treaters. The treating process involves putting wood into large pressure chambers and pumping liquid chemical into the tank under pressure. These chemicals penetrate the wood while it stays under pressure for a predetermined time. The pressure treatment forces the chemicals into the wood fibers throughout the board. Newly treated wood is very wet and also very heavy. With exposure to air, the wetness dries out somewhat, but the chemical treatment stays to preserve the wood from rot, bugs, decay, etc. Depending on the intended usage boards are treated to various degrees of saturation. For dozens of years the chemical process of both chemical companies was "CCA” (Copper Chromated Arsenic.) Over the last 5 or 10 years, the word "arsenic" caught the eyes of many people. Bugs don't like arsenic, and common wisdom says it isn't too good for people either. There was quite a debate as to whether there were any actual medical problems resulting from human contact with CCA treated wood. However, before the EPA could issue a directive, it became a moot point. Due to media and environmental group pressure, chemical manufacturers voluntarily agreed to stop producing CCA wood for common dimensional lumber. As of Jan 1, 2004, with only a few exceptions CCA products are no longer being produced. Treating companies that licensed the process switched their treating plants over to a new, non-arsenic formula. Some small treaters, unable to bear the cost of switching went out of business. While no more CCA is being produced, lumberyards will continue to see stock treated prior to 12/31/2003. Once those supplies are depleted, CCA will cease to be available. CCA and the new products look pretty much the same after exposure to the sun, but the new product is more of a brown than green color. Exceptions to the cessation of CCA treated wood include telephone poles, dock pilings and large structural posts for post frame construction and foundations. These exceptions are approved by the EPA but for the homeowner building a deck, play set, sandbox or other backyard project, only the new formulas of treated wood will be available. You will now hear some different terms describing treated wood. They include ACQ (Alkaline Copper Quat) and CA (Copper Azole). CA is licensed by Arch Chemical and keeps the familiar Wolmanized label for consistency. Another product name used by Arch is "Natural Select". Wolmanized, CA and Natural Select all refer to the same product. ACQ, a product of Osmose Chemical Company uses the product name "Nature Wood". ACQ is the most popular term for this wood. Both chemical formulas depend heavily on copper to prevent rot, bugs and decay and the copper content is higher than the copper content of CCA. The middle C of the older CCA process was "Chromated" a term, which includes a bunch of hard to pronounce chemical words. These chemicals have been eliminated. The chemical soup in "chromated" provided corrosion protection for fasteners, which meant screws in deck boards were not as prone to rust. The added copper content in both new formulas creates an electrolysis type environment. Metal in contact with either of the newer treated wood products is subject to much faster rust than previously experienced. Fastener (nails, screws, bolts) and hardware (hangers, flashing, etc.) failure can be a serious issue and the new treated lumber requires that proper fasteners, hardware, and fastening techniques be used. Chemical companies are recommending hot dipped galvanized fasteners as opposed to stamped electroplated joist hangers previously available. The same is true with screws. Stainless steel for both devices is also suggested, which obviously carries a higher price. Of the two products, ACQ has a higher copper content and is more prone to fastener corrosion, but be aware that both require a different fastener. Regardless which of the two treated products used, look for fasteners and joist hangers that bear a stamp or label indicating, "approved for ACQ and Natural Select.” Although there are alternative products available for the decking, these products are only for the deck surface material. Alternative products such as composites are not suited for structural members of a deck. Posts, joists and beams will continue to be constructed of pressure treated lumber.
How It's UsedUsed almost anywhere...Effective against termites and fungal decay, both above-ground and in-ground, Wolmanized wood ideal for many residential, commercial and agricultural applications. · Decks · Raised beds · Planter boxes · Retaining walls · Walkways · Picnic tables & benches · Fences · Sill plate · Sawn structural members · Permanent Wood Foundations Different applications may require different amounts of preservative protection.
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Pressure treated wood is a safe long lasting building material used in decks, fences, retaining walls, picnic tables, docks, and other places where the wood is exposed to rot, insect attack or other forms of biodeterioration. The basic treating process is simple and highly controlled.
Pressure treated wood is not only workable, it is clean, odorless, non-staining and, used as directed, safe - safe to handle, safe to work with, and non-irritating to humans, domestic animals, wildlife, plants, and the environment. |