B A C K

A fresh look at colorants for pressure treated lumber

You don’t have to look too far back to capture the history of coloring pressure treated lumber. It’s a market innovation that Eco Chemical played a critical role in getting started a little more than two decades ago.

The trend originated in the West where harder species of wood, such as Douglas fir, are used for framing lumber. That required breaking of bundles and special processing of each piece of wood prior to treatment. Once the bundle was broken into individual boards, it was easy to insert a machine staining step that made the finished product much more attractive to the consumer.

Softer species of wood, such as southern yellow pine, are used for framing on the East Coast. That means there is no need to break bundles before pressure treating, making it less economical to do single board staining. As a result, the common process is to add colorants to treating solution when color is required.

In either case, the evolution of chemistry, colorants, techniques, and processes for coloring treated wood has been rapid and steady, getting better over time to keep pace with growing consumer preference and demand for higher quality and greater color variety.

With machine staining, the lumber is stained one piece at a time, either before or after pressure treating, carried by conveyor through a spray stain or flood coating step. This so-called pre- or post-treatment staining process provides more flexibility for the manufacturer in planning how much lumber they want to make of one particular color. Typically, machine staining provides better control over quality and a richer color on the wood.

The in-tank method involves fewer steps, which means it’s a more efficient and economical approach to staining. The job is done in one step by simply adding colorant to the pressure treating chemicals. In spite of the economics, several East Coast treaters have recently explored making the change to staining by machine. It provides consumers with a higher quality color product, while also giving pressure treaters the flexibility to accommodate different accounts that require specialized “brand” colors.

Better color quality and flexibility offer the industry several benefits. With increased color demand around the world, there’s greater market penetration opportunity, more sales, higher profit margins, and happier customers in the long run.