Well, it depends. Wood is a natural product and all wood has its own characteristics, so natural variations in grain, color, checking and defects are to be expected. A "Check" is a long crack that appears as the sap wood of a timber shrinks around the heart wood over time. Checking is typically not a structural problem, and usually occurs only on one or two sides of a beam. However, if you notice any blatant cracks large enough to fit a quarter inside, then you may have a problem and you should contact your local dealer for replacement. At that point the structural integrity of your play set may be in jeopardy. Please keep in mind if you are the original owner, these parts will more than likely be under warranty.