Hi, Jim Coshow here from Dunn Lumber. Welcome to the Dunn Solutions podcast, where we’re committed to providing cutting-edge industry knowledge for the building contractor and trade professional. 

Today we’ll hear from our good friend Gary Katz. Gary’s been part of the Dunn Lumber family for years now. Dunn Lumber is proud to have hosted one of Gary’s first Katz Roadshow events back in 2003, which are still going strong today—and continue to feature Gary's carpentry clinics. Whether through his publication THISisCarpentry, one of his articles in Fine Homebuilding, or a presentation at a JLC LIVE show, Gary always delivers enthusiastic and experienced insight to our industry. We’ve been fortunate to learn from his decades of experience as a general contractor and finish carpenter through his educational contributions to our Dunn Solutions blog.

In this podcast, Gary will discuss methods for creating better miter joints, best practices for installing tongue-and-groove materials, and the tried-and-true method for properly installing a prehung door. He’ll also discuss wood moisture content and how to use a moisture meter, which I found particularly helpful. 

Here are my two big takeaways when it comes to moisture content: 

gary katz

Pay Attention to Wood Moisture Content

For every 4 percent change in moisture content, wood will move 1 percent. It might seem basic, but storing your wood properly is imperative when it comes to a successful project. If you store it in one environment, the wood may expand; if you store it in another, it may contract. When you store it in one and install it in another, that means your finished product—say, hardwood flooring—could expand and buckle (or contract and leave gaps).

Of course, each wood has different properties and will respond differently to moisture content. And, moisture content is completely dependent on the humidity in the air. On the interior of a home across the country where the humidity is around 50 percent, the equilibrium moisture content of wood is going to land around 8-10 percent. The average equilibrium moisture content on the exterior of a home is around 14 percent. Charts can tell you what the moisture content will be at various times of the year to help with installation.

Moisture content is one of the most important things a finish carpenter or framer needs to know (wood starts to rot at 19 percent), so pay attention.

Use a Moisture Meter

The best way to gauge the moisture of your material is with a moisture meter. Scott Wells, a Katz Roadshow presenter, calls it his “crystal ball.” Stick it straight into the material—not into the end grain—in several places to get an accurate reading. Most of the trim you’ll use, as mentioned previously, will probably be around 10 percent. If something has been sitting in a dry space for a longer period of time, you’ll likely get a reading closer to 6 percent.

It's always good to brush up on the basics. I hope everything Gary shares in this podcast will help you expand your knowledge, identify best practices, and grow your skill set—and business.

For more information on attending future educational events, feel free to email me at jimc@dunnlumber.com.

gary katz on moisture content and more