Shake and Checking in Timber Post & Beams.

Examples of Shake & Checking

Timber is a natural product so natural variations in grain, color, checking, are to be expected. Knots of various sizes are also to be expected, even though some of the samples show below appear to be clear. Great resourses for lumber grading and design values can be found at the Northeast Lumber Manufacturers Association, WWPA Western Lumber Grading Rules, and Hall and Foreman Inc, Engineers.

Shake is the separation of the rings in a piece of wood that occurs as it dries. The wood can also 'peel' off around the rings, similar to the layers of an onion.

Extreme Shake

Checking is the appearance of cracks or splits in wood as the wood dries out over time.

The image to the left shows extreme shake and checking in hemlock

Golden Oak on Fir

Natural Checking in Hand Hewn Pine Timber

This image shows natural checking that is to be expected in timber.

A "Check" is a long crack that appears as the sap wood of a timber shrinks around the heart wood over time.

Checking is not a structural problem, and usually occurs only on one or two sides of a beam. Oak, however, can have surface checks everywhere, which many people feel add to the beautiful rustic appearance of a timber frame.

A Natural Check