4x4 PT deck post: crack?
Hi, all. I'm rebuilding our side deck (12' x 5', 40" floor height), and am well along in the process -- just starting on the stairs -- but I've noticed something disconcerting: two of the three (brand new) 4x4 PT posts have developed vertical cracks almost along their whole length. The support structure I've chosen is a 'sandwich' of two 2x10 beams on either side of the 4x4 posts, bolted in place.
I'm pretty new at this stuff, but have done a lot of research. I just don't know whether I should be especially concerned about this or just chalk it up to shifting and/or the wood drying out naturally. If the worst-case scenario arises and I have to replace them, I believe I can do so with some appropriate jacks.. but as you can imagine I would rather not.
Thanks in advance for any feedback or suggestions!
N.B. I turned this photo on its side to get the largest image.