How to Keep Pressure Treated Pine From Shrinking
- 1). Dry the pressure treated lumber prior to installation. This will help prevent shrinkage. Locate an area outdoors that is undercover. This is an ideal place for drying lumber. The area must be covered in case it rains.
- 2). Lay out small scrap pieces of 1-by-2 lumber, called stickers, on the ground. Lay the stickers vertically every 12 inches and set the pressure treated lumber horizontally on top. Set another row of stickers running vertically on top of these boards, and lay more lumber horizontally on top of those stickers. Continue up in the same pattern until all of the lumber is stacked.
- 3). Place cement blocks on the ends of the lumber at the top of the stack to flatten it out. Stack two blocks on each end. Stick an electronic moisture meter into a piece of lumber after it has dried for two weeks. Check to if the moisture content has fallen to 20 percent or lower before using the lumber. Wait longer, if necessary, to achieve the desired moisture content.
- 4). Install the boards you will be using for your deck or other application so they are firmly against one another. Butt them together during installation and ensure the joists, posts and all other pressure treated boards you are installing your boards on have been properly dried just like your pressure treated lumber. Boards installed underneath can cause cupping if they have not been properly dried.
- 5). Seal the surface of the boards. This will prevent shrinkage in the boards and help protect the boards from the sun. Seal your deck or other area where you are using the pressure-treated lumber. Repeat this sealing process every two years.
