When southern pine is treated, it undergoes a process in which it is soaked with a liquid solution of copper azole preservative. This “wet” board is then either shipped out to consumers, or it undergoes a drying process called KDAT, or Kiln Dried After Treatment. KDAT is a method in which lumber is dried in a controlled environment before being sold. The KDAT process takes place in a giant kiln where controlled temperatures, allowing airflow between each board, ensure the lumber is dried uniformly. Traditional decking without this extra step often take 8 months to a year to dry out, making it less desirable as it is exposed to the harsh sun while it is drying. Boards dried in this way are more likely to cup due to the top surface drying out faster than the bottom, and they will often start to grey since they aren’t sealed for protection. It is recommended that KDAT decking is stained immediately after installation to ensure maximum protection.
Below are some of the benefits of using KDAT Treated Lumber:
- It can be pre-stained immediately
- Fast staining reduces twisting, cupping, and warping
- Less shrinkage problems
- Lighter material make it easier to transport and work with
- Environmentally sound; there’s less chance of leaching since re-drying assures maximum fixation within the wood
- Better fastener holding power
