A GUIDE TO THE HANDLING AND INSTALLATION OF KDAT TREATED WOOD
Kiln Dried after Treatment or DKAT pressure treated lumber, has certain advantages that will help to preserve the “new look” of your deck or other construction project. KDAT provides better nail holding power, less shrinkage and fewer checks after installation, and enables you to apply a stain or sealer soon after construction is complete.
A few simple precautions must be taken with KDAT lumber to insure you get the best possbile result from outdoor construction project.
KDAT lumber is re-dried after treatment to a moisture content of 19% or less. As it sits on our yard, or at a construction site, it will begin to equalize with the environment it is exposed to, and may pick up moisture from humidity or rain. Some pieces may pick more than others, so when the material is dropped off at the construction site, and prior to installation, it should be stored in a covered area and if possible, the boards should be separated. This will allow air to circulate around the boards and cause them to acclimate to their surroundings. Every piece will dry at a different rate, but after a few days the boards moisture content will equalize. This equalization helps to prevent shrinkage after the material is installed. Deck boards should be spaced approximately 1/8” apart, or the width of an 8 penny nail and with the growth rings up.
The use of deck screw is strongly recommended. The use of pneumatic nailers is strongly discouraged. Guns can overdrive nails into wood greatly reducing the nails holding power. To minimize splitting, pre-drill the screw holes when two boards are butted up end to end.
Ventilation is a critical factor to consider when building a wood deck. If a deck is boxed in, there is no place for the buildup of heat or moisture to escape. Extreme heat or moisture can lead to excessive and uneven shrinking or swelling of deck boards. Lattice panels may be used as an option to provide ventilation. If a deck is boxed in, louvered vents between joist is mandatory. Decks that are less than two feet above ground should have black six mil poly covering the ground under the deck, with gravel sprinkled on it to hold it down. This wil effectively seal off moisture from the ground.
As soon as the deck construction is finished and the exposed decking and railing is dry to the touch, a stain or sealer made specifically for outdoor wood should be applied. Use a finish that has a UV inhibitor as well as a water-repellent. This should be done as soon as possible to reduce checks or small splits, cupping, and raised grain. Try to pick a day to apply the coating with a couple of dry days in the forecast. KDAT lumber will absorb a lot of stain, so a second application may be needed. If water does not bead up on the decking, apply another coat. Be sure to follow the finish manufacturer’s instructions for application.
Taking these simple precautions can help you get the best result for your construction project. A little extra time will insure that you benefit from all of the advantages that KDAT treat lumber offers.
HOOVER TREATED WOOD PRODUCTS, INC. – 154 WIRE ROAD NW, THOMSON, GA.
1800-TEC-WOOD
|