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  • Writer's pictureMatt Weber

Coat your Cuts when Building Outdoors

Treating end-cuts in pressure-treated lumber is not just a good idea, it’s now a

requirement for warranty coverage.

New American Wood Protection Association (AWPA) Standards for preserving end-cuts are being referenced by the International Building Code and International Residential Code. This means building codes are changing.

If your local municipality has not already adopted the new end-cut application as a requirement to meet building code, then they may do so in the near future. When you make a cut in a piece of pressure-treated lumber, you expose the interior wood fiber to water, fungus and insects that the pressure treatment would otherwise protect against. Sealing the end cuts with an approved liquid preservative becomes an important way to protect your investment.

The liquid treatment can be applied to dry wood by sprayer, roller or brush. Back-

brushing will help work the product into the wood grain. Allow the treatment to dry,

then apply a second coat.

Sealing the exposed ends is a simple process that exhibits quality workmanship, but

that’s not the only reason to do it. You may not realize that treated-lumber manufacturers back their warranty if the builder follows the best practices for handling and installation, and “best practices” now include treating the field cuts with an approved preservative. Check your product warranty and don’t be surprised if you find indications that read: “Surfaces that have been cut or trimmed and other holes or damage should be treated with a wood preservative end-cut solution in accordance with the label’s directions. Acceptable wood preservatives contain a minimum of 0.675 percent copper as oxine copper (copper-8 or copper-8-quinolinolate) or 1 percent copper as copper naphthenate.”

In other words, if you don’t coat your end cuts with a preservative—and use the correct preservative—then your treated-lumber structure may not be covered by the manufacturer’s warranty.


Outlast Q8 Log Oil

Are you waiting months for your pressure-treated deck to dry before staining? That's common practice when building with lumber still damp from the treatment plant. The average wait time between the installation of your wooden structure and the application of ordinary stains and sealers is 6 months. Outlast Q8 Log Oil eliminates the wait. When you use Q8, you can build and stain and provide a pressure-treated wood sealer all on the same day.

Furthermore, did you know that the International Residential Code (IRC) now mandates

during construction that you “heal” any drilled holes, abrasion, or end cuts on pressure-treated lumber? Either 1% Copper Naphthenate or .675% Copper 8 quinolinolate (aka Oxine Copper) will satisfy the new requirements. But Outlast Q8 Log Oil with .675%

copper is the only warranty-required product that addresses the wait time and the new code. Build, stain and seal in the same day with no wait time. In fact, Outlast Q8 Log Oil is spelled out by name by many pressure-treaters themselves. Learn more at

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