Following are questions we hear most often at Follen Wood. If you have others, please contact us.
Pressure treated wood is lumber or plywood that has been impregnated with preservatives that protect the wood from termites and fungal decay. The type of preservative we use for our Wolmanized® Residential Outdoor® wood is next-generation copper azole, which has become the most successful alternative to traditional CCA around the world. It is an effective wood preservative and safe for most indoor and outdoor applications when properly treated and used as directed. Copper-azole treated wood will last for decades in harsh outdoor exposures and comes with a limited lifetime warranty for most residential and agricultural applications.
Wolmanized® Residential Outdoor® wood works like traditional treated wood, but the preservatives used to protect the wood are different.
The patented preservative in Wolmanized® Residential Outdoor® wood is a formulation of copper azole. Copper, derived from recycled sources, is the principal active ingredient, protecting against termites and fungal decay. Protection against copper-tolerant fungi is provided by a carbon based azole that is also used as a fungicide for fruits, peanuts, and other crops.
The formulation renders the wood useless as a food source for termites and fungi while keeping the wood attractive, clean and odorless.
The preservative in Wolmanized® Residential Outdoor® wood is not a “restricted use” pesticide and does not meet the definition of hazardous waste. As a result, fewer environmental restrictions apply. No EPA precautions apply to handling the wood, there is no required Consumer Awareness Program (CAP), and California’s Prop 65 labeling is not required. Treating procedures, warranties, and handling procedures are nearly identical
We purchase dimensional Southern Yellow Pine lumber from local mills and bring it to our plant for treatment. The basic treating process is simple and highly controlled. (1) Lumber, timbers, or plywood is loaded onto small rail or tram cars. The trams are moved into a large, horizontal treating cylinder. (2) The cylinder door is sealed and a vacuum is applied to remove air from the cylinder and the wood cells. (3) Preservative solution is then pumped into the cylinder and (4) the pressure raised to about 150 pounds per square inch, forcing preservative into the wood. Treating time varies depending on species of wood, commodity being treated, and the amount of preservative to be impregnated.(5) At the end of the process, excess treating solution is pumped out of the cylinder and back to a storage tank for later re-use. (6) A final vacuum removes excess preservative from wood cells. The cylinder door is opened and the trams are pulled out. The wood is test for preservative penetration and retention and then stored on an EPA-approved containment pad while a preservative reaction takes place which bonds the preservative components to the wood, making it highly leach-resistant.
Our facility has been constructed to ensure environmental safety. Our concrete treatment pad is sloped to a sump where chemical that drips off the treated wood is collected for re-use. We have a dedicated lift truck that never leaves the pad so that chemicals cannot be transferred to the yard.
We offer dimensional lumber, timbers, and plywood in treated southern pine, and untreated western red cedar fence boards. For a complete list of our products, click here.
Retention is the amount of preservative retained in the outer zone of wood after treatment. It is measured in pounds per cubic foot (pcf) of wood. For example, a .10 pcf retention means that the wood has retained .1 pounds of copper azole in each cubic foot of the assay zone.
For the CA-C formulation that we use at Follen, (dissolved/micro)
- .06/.05 pcf retention is intended for above ground use. (deck boards and fence boards)
- .15/.14 pcf retention is intended for ground or fresh water contact. (deck or fence posts)
- .31/.23 pcf retention is intended for important structural components
No maintenance is needed to renew resistance to fungi and termites. Wolmanized® Residential Outdoor® wood has a lifetime limited warranty against these organisms.However, protection is required to maintain the wood's appearance against weather. Sun and rain cycles cause stresses in lumber and result in swelling, shrinking, warping, and cracking.
- To help protect your project against moisture damage, apply an effective brand of water repellent as soon as the outdoor wood project is finished or, for large projects, as sections are completed. Water repellent should be applied every year or two.
- To revitalize a dingy appearance caused by dirt and mildew, use deck brightener to clean the outdoor wood.
Hot-dipped galvanized fasteners (meeting ASTM A 153) and connectors (ASTM A 653 Class G185 sheet), or better, are recommended for protection against the moisture often present where treated wood is usually used. For Permanent Wood Foundations, use 304 or 316 stainless steel. Check with manufacturer concerning use of Aluminum products.
For indoor applications, while galvanized fasteners are preferable, the use of non-galvanized nails or screws of sizes and types approved by the Model Code is acceptable when attaching joists, studs, or other framing to ® Wolmanized® Residential Outdoor®TM sill plate, provided the wood will remain dry in service, protected from weather and water. Likewise, the use of standard galvanized strapping, anchor plates, or mild steel anchor bolts 1⁄2” diameter and larger is acceptable for fastening ® Wolmanized® Residential Outdoor® wood to foundations, provided that the wood will remain dry in service, protected from the weather and water.
Over the past few years, mold has drawn growing concern. The relationship of mold problems to treated wood is mostly indirect, but the effects of homeowner perception make the issue worth discussion. Indoors and out, molds are present nearly everywhere. There are molds that can grow on wood, paper, carpet, foods, plaster, dirt, and even dynamite. They digest the material, using it as food. Molds reproduce via minute spores, which are the primary cause of health problems. These spores waft through the air continually; when they land on a suitably damp spot with nutrient value, they begin growing.
EPA says, “There is no practical way to eliminate all mold and mold spores in the indoor environment; the way to control mold growth is to control moisture.” Sources of moisture include flooding, leaky roofs and plumbing, sprinkler spray hitting the house, damp basements, humidifiers, and wet clothes drying indoors.
So what does this have to do with copper azole-treated wood? Usually, the scary types of mold-related health problems have little to do with treated wood.
Mold can be found on treated wood just as it can be found on many surfaces and in the air itself. The mold identified on wood has been mostly species that are common and not especially hazardous. Installed outdoors, where humidity fluctuates, spores do not normally reach harmful concentrations. The general attention on mold has heightened concern over mold on treated wood, despite an absence of reported health impacts. Homeowners do not want suspicious discoloration on their wood. Whether that discoloration arises from mold or wood resins or treatment residues or rusty steel bands, it raises doubts and lowers the desirability of the wood.
To minimize the chance of unsightly discoloration from mold, careful lumber treaters, dealers, and contractors try to keep wood dry and rotate their stock to avoid an inventory of wet and old wood. Homeowners should be on the alert for moisture problems and fix them so that conditions do not favor mold growth.
We add moldicide to the specifications recommended by Arch Treatment Technologies* which, when used in a full cell treating cycle, provide protection on wet, stacked lumber for 6 to 9 months. Use of moldicide delays the start and reduces the rate of mold growth in wet packs of treated lumber.
*Arch Treatment Technologies licenses treating companies, such as Follen, to produce Wolmanized® Residential Outdoor® wood. The license agreement requires licensees to inject a specified minimum amount of a particular mold inhibitor, along with the copper azole preservative. This inhibitor, proven over many years of use, restricts mold growth. As part of its quality control program, Follen maintains a record of additive usage to verify that sufficient mold inhibitor is mixed into the treating solution. Furthermore, solution samples are sent weekly to Arch for analysis and confirmation.
At the present time, there are no EPA-approved precautions similar to the Consumer Safety Information Sheet. We recommend following the same guidelines as for CCA, which are essentially the same guidelines that should be followed when handling untreated wood. For example, wear a dust mask to control inhalation of sawdust, wear goggles to protect eyes from flying particles, wash after working with wood and before eating, and do not burn treated wood.
For a complete listing of handling precautions, click here.