Clement Custom Fencing​

You may see what appears to be a vertical split or crack in your new wood fence posts, particularly cedar post & rail or locust split-rail posts. Actually called wood "checking," the split or crack that you may see is a perfectly natural occurrence and does not weaken or otherwise affect the strength or stability of the post.

According to the U.S. Depart of Agriculture Forest Products Laboratory, which has done considerable research on the subject, the exterior surfaces of a post (sapwood) shrink faster than the inner wood (heartwood) as the wood dries. As a result, something has to give—or "check."

And while that "check" may look like a split or crack in the post, it's simply the result of natural seasoning (drying out) and, based on both laboratory and field tests, does not materially affect the strength of the post.

Wood "Checking" (Splits/Cracks)