In Part 1 we clarified the difference between cracks and checks and established the fact that checks are not indications of stability problems but are actually healthy for your large timbers. The “bad news” that you really can’t prevent these checks is something that some have attempted to change, but there are reasons we don’t recommend any means of preventing checks.
The Kerfing Approach
In order to avoid the appearance of checks, some throughout history have cut saw kerfs into timber to provide a release point. Not only does this achieve the same purpose as the checking would, but it also allows you to choose the side of the timber that displays an imperfection. Perhaps you will position it toward a wall or at least away from the main living space of a room.
While this approach certainly minimizes checks from timbers, it may not entirely eliminate them. More problematic is the fact that a kerf must be cut before the timber begins the drying process. Since most lumber suppliers can’t get their hands on lumber quite so early in the process — in fact, large timbers are often kiln dried or air dried for some time before you place your order — even if kerfing were requested, we simply couldn’t accommodate such a request.
The Reality of Checks
While we certainly take measures to prevent unnecessary checking, we cannot entirely prevent it. We do seal the ends of our timbers (which matters because so much of wood movement is tangential in nature. We also store our timbers in the shade, preventing any unnecessary moisture level fluctuation.
If you want to prevent large amounts of checking, you can try to use your timbers where they won’t be subjected to direct sunlight. After installation, though, they will continue to absorb and shed moisture over time and with seasonal shifts. It’s usually not until after installation that checking occurs anyway. Customers may mention hearing popping and cracking of posts while sitting on their decks. Owners of timber frame homes may hear loud cracking sounds years after it’s been built.
The Importance of Communication
Uninformed customers tend to become frustrated, thinking that the natural checking indicates that their timbers are defective. Worse, they could try to solve the problem themselves by filling what they think to be cracks with epoxy or other products. Such filling can cause structural problems later on, as the timbers continue to move, naturally causing the checks to open and close throughout the yearly moisture level shifts.
If you take the time to educate your customers about what to expect from their large timbers, they will be free to embrace the natural beauty of their home and appreciate your expert workmanship, as well.
Learn More About Lumber
J. Gibson McIlvain Company
Since 1798, when Hugh McIlvain established a lumber business near Philadelphia, the McIlvain family has been immersed in the premium import and domestic lumber industry. With its headquarters located just outside of Baltimore, the J. Gibson McIlvain Company (www.mcilvain.com) is one of the largest U.S. importers of exotic woods.
As an active supporter of sustainable lumber practices, the J. Gibson McIlvain Company has provided fine lumber for notable projects throughout the world, including the White House, Capitol building, Supreme Court, and the Smithsonian museums.
Contact a representative at J. Gibson McIlvain today by calling (800) 638-9100.