Some 24 years of refinishing and repairing redwood, cedar, ipe, pressure-treated wood, and other types of decking has taught me that most decay starts at the cut ends of boards, particularly where they are butted together. Raw end grain absorbs water like a sponge, and once decay starts there, it is almost impossible to stop. Most builders know this, yet my experience tells me that most don’t do anything to prevent it.

Since we see the problems this causes over and over again, we always treat cut ends—in new construction and when we do repairs. When we’re working with one of the tropical hardwoods or redwood, cedar, or fir, we keep a quart can of Anchorseal Green Wood Sealer (888.363.2628, on hand. It’s a waxy coating that’s typically used to prevent checking and cracking in freshly sawn logs, but it does a nice job of sealing the end grain of dimensional lumber too, and is easy to apply with a paint pad (photo, below left).

When we’re working with PT decking or framing, we treat all of our cuts with Green Product’s Copper-Green Brown Wood Preservative (510.235.9667,, a solvent-based copper-naphthenate solution designed to protect against termites, fungus, and mold. This treatment is available in quarts and gallons, but we buy the aerosol version. The low-pressure spray comes out in a thick stream and really saturates the surface, so there’s no need to brush (photo, below right). It’s convenient to keep a can in the work area, grab it when it’s needed, and just spray it on. These simple steps don’t take much time, and can prevent thousands of dollars in damage.

Jim Grant is the proprietor of Jim The Deck Guy, in San Diego, Calif.

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