New Lumber Treatment Process Brings Changes For Poultry House Construction
Farmers managing poultry houses now have additional concerns in the maintenance of their facilities. These concerns stem from changes in the pressure-treated lumber that is now widely sold.As of January 2004, there was a change in the chemical preservative used for pressure-treated lumber available for most uses in the United States, according to Auburn University Extension Engineer Jim Donald. Most of the new pressure-treated lumber is preserved with alkaline copper quaternary (ACQ). This chemical treatment is more corrosive to nails, screws and other metal fasteners or parts that come in contact with the lumber than was the old chromated copper arsenic (CCA) treatment, he said.Most of the fasteners commonly used in the past, whether galvanized or not, are likely to be corroded by the chemicals in ACQ-treated lumber at a higher rate than in CCA-treated lumber. Using the wrong fasteners could affect the structural performance and service life of the building, the Extension System warned.”The corrosiveness of the new chemicals means that much of our commonly used metal siding or other parts or equipment, whether aluminum or steel, are likely to be damaged if they are allowed to come in direct contact with the treated lumber,” Donald said. “No carbon steel or aluminum siding or other metal should be used directly against ACQ-treated lumber. This is a serious issue for poultry housing and for the construction industry in general.”CCA-treated lumber is still manufactured and sold for certain industrial and marine applications, including agricultural posts and poles. Donald reported that some builders prefer CCA-treated lumber for poles and posts, but a considerable amount of ACQ-treated lumber is being used in new poultry houses in Alabama. The new-formula lumber is used for posts and dimensional lumber, including 2x4s and 2x6s. “It is almost certain that no pressure-treated lumber bought today from a lumber yard will be the old CCA-treated lumber,” Donald added.The building industry recommends that fasteners or other metal contacting the lumber either be treated with the heaviest galvanizing possible (Class G-185 for sheet metal), be ceramic coated, or be type 304 or type 316 stainless steel. Galvanized and stainless steel should not be mixed in the same connection. These requirements apply across the board–whether the lumber is used on the ground or not, or in wet or dry conditions. No fasteners should be used unless they are clearly labeled as approved for use with ACQ-treated lumber. “Your local treated lumber supplier should have a list of fasteners that are approved for use with ACQ-treated lumber by brand name and type,” said Donald.Anyone preparing to build or make structural repairs needs to make sure their builder is aware of the importance of using the proper fasteners and taking the other steps needed to ensure the structure will not deteriorate over time. It is the builder’s responsibility to instruct his people or crew on the proper methods of installing and fastening. But farmers must also take responsibility to be sure their poultry houses are being built properly. There should be either an inked stamp on the broad side of the lumber or a plastic tag on one end of the lumber that states the grade and preservative used.”While this news is particularly important to poultry producers building new houses or remodeling existing structures, all farmers need to take note of how this change in the chemical process of available pressure-treated lumber will affect its uses both on the farm and in our homes,” said Jimmy Carlisle, director of the Alabama Farmers Federation’s Commodity Department.Poultry house owners and managers can get more information about this and other issues affecting poultry houses online at www.poultryhouse.com.