splitting posts

[HotBacon]

Last summer I built a double deck (bottom ~26' x 20', top ~15' x 10'). The top deck is supported by 3 - 6"x6" posts that run through the bottom deck. I noticed over the weekend that the middle post has developed a few rather significant splits (one approximately 1/8" - 1/4" wide) running lengthwise down the post. It doesn't appear as if the split goes the entire way through the post.

I would expect some splitting as the PT dried out, but is this size of a split something that I should be concerned with? Is there anything I can do to stop the split from getting worse?

[chandler]

It is called "checking", and for the most part it is normal with pressure treated wood (or most any wood as it dries in the atmosphere). There is not much you can do about it, and once the check appears, it will probably not grow any, and certainly won't heal itself. Keep an eye on it and should it seem to lengthen or enlarge, then replacement is in order, but I doubt it will ever get to that point. Don't fill it, as the expansion and contraction of exposed wood will pop it out and make it even uglier.