Pressure-treated wood has been around for nearly 70 years, yet most of us still know very little about this popular outdoor building material. And because these new wood treatments are especially corrosive to aluminum, it’s best to use vinyl or copper flashing, or to wrap the wood in a protective rubberized membrane. Even though it is new pt wood it should be cleaned (lightly pressure washed) using an oxalic acid wash to remove mill glaze. Only specially ordered ‘kiln dried after treatment’ treated lumber has a controlled mositure content of between 12-15 and little if any treated lumber on the shelf in any lumber yard is kiln dried after treatement. Lowes/HD don’t always carry the best products. Pressure treated wood is a must for many outdoor projects, but it requires different handling than untreated woods. Pressure treating is a process that forces a chemical preservative deep into the wood. Always let the salesman know the eventual location of the PT lumber. Above, on or below grade. So that you can make the best purchase!.
Just because you used pressure-treated lumber doesn’t mean your outdoor project has to stay green. Kiln-dried after treatment: Dry treated wood is ideal because you can confidently stain it right away with either oil- or water-based exterior stains. The pressure-treating process leaves wood fairly saturated with preservative. Over several months, pressure-treated Southern Pine lumber will weather naturally to an appealing silver-gray color. Most paint manufacturers recommend two coats of a good-quality acrylic latex paint for best results on treated Southern Pine.
All measures that are taken to ensure a long life of wood fall under the definition wood preservation (timber treatment). Commercial pressure treatment began in the latter half of the 19th century with the protection of railroad crossties using creosote. Wood that has been industrially pressure-treated with approved preservative products poses a limited risk to the public, and should be disposed of properly. Although the practice of distributing MSDS instead of CIS is widespread there is an ongoing debate regarding the practice and how best to best communicate potential hazards and hazard mitigation to the end-user. Pressure treated wood is the ideal option for outdoor projects like fencing panels. Wood that is pressure treated goes through a process that involves placing it into a large vacuum. How to Seal and Stain Pressure Treated Wood Decking. The best method for applying the material is with a brush or a paint pad on a long handle, available at any hardware store.
Can You Stain Pressure-treated Wood?
Note that for a time-sensitive project, it may be wise to choose pressure-treated wood marked as having been kiln-dried after treatment (KDAT). The timeline for painting KDAT wood is considerably more condensed. You loved your pressure treated (PT) wooden deck when it was new and looked like this:. See step 7 in Eight Tips for Maintaining Your Mahogany Deck. Q: I have a deck built of pressure-treated lumber that absorbs rainwater like a blotter. A: Some owners of pressure-treated structures assume the wood needs no protective treatment, and this view at one time was encouraged by manufacturers of the wood. If do-it-yourself treatment and correcting moisture-causing conditions doesn’t eliminate the ants, it’s best to call in a pest-exterminator. In the past, people waited 6 months or so before finishing projects that use pressure treated wood. That’s no longer the case with newer treatments like the micronized copper preservatives used to treat YellaWood brand products. Weather wreaks havoc on unprotected wood, even pressure-treated pine, tropical hardwoods, cedar, redwood, and others that are resistant to rot and insect damage. Referred to variously as sealers, coatings, protectors, and stains, finishes penetrate the wood’s surface to slow down its ability to absorb moisture, prolonging the life of the decking and maintaining its appearance. If the wood in your deck is pressure-treated with CCA, the EPA recommends using a semi-transparent stain, which tends to penetrate wood and seal in the arsenic, preventing it from leaching out. The best opaque treatments tend to last the longest.
Pressure-treated wood may not be the best choice for exterior trim, since most pressure-treated wood is southern yellow pine, a species that is not particularly good at holding paint. Is this because pressure-treated lumber is so wet, or do the chemicals used to treat the wood cause the paint to come off?. Pressure treatment is a process that forces chemical preservatives into the wood. Wood is placed inside a closed cylinder, then vacuum and pressure are applied to force the preservatives into the wood. If your deck was built prior to 2004, the best deck treatment is a semi-transparent stain. This is because prior to 2004, pressure treated woods frequently contained arsenic to help repel insects. Pressure treating slows wood rot and can deter insect attack. It does not stop black mold or algae or the greying caused by sun and water. If you are only doing one penetrating stain coat then Mountain XT is the best deck stain.
For those unfamiliar with the pressure treatment process, watch this brief YouTube video for clarification:. Assuming the best wood available (see above) has been chosen for the job, take care to install a proper drainage system for your structure and treat the wood with additional preservatives. Pressure-treated lumber is nearly impervious to rot and insects but is not maintenance-free. But it is still sold for agricultural and highway applications, and several other alternative pressure treatments have been developed. For deck floors, pigmented water repellent or semitransparent stain is the best option. During the pressure treating process, wood is saturated with the chemical solution carried in water. The wood takes several months to dry and there may be some shrinkage and warping as a result. Pressure treated wood is 30 to 40 cheaper and last twice as long as redwood. Alternative Treatments – By far the best alternative pressure treatment seems to be Alkaline Copper Quaternary, or Quat for short. Economical and reliable pressure treated wood crossties, switch ties and lumber are the foundation of Koppers railroad products and services. Koppers wood treatment plants produce high quality creosote treated crossties, switch ties and lumber.