P-T wood is notorious for warping. Unfortunately, there is not much that can be done about it once it warps.
P-T wood is pressure-saturated with liquid chemical in a treating tube, and then allowed to "drip dry" with a very high moisture content. It air drys slowly, depending on the moisture in the air wherever it has been shipped. If it dries out too fast, it tends to warp.
That isn't comforting, but the only thing that you can do is salvage pieces of it that haven't warped and hope to use that somewhere else.
Mike

 

Make sure you do this!!!!!!

When doing any repairs, make sure that the grain on the end of the boards is curved down. At least it will warp down and not up. I don't know of anyway to stop warping.

 

When doing any repairs, make sure that the grain on the end of the boards is curved down. At least it will warp down and not up. I don't know of anyway to stop warping.

Boards usually warp the opposite way. The growth rings will try to flatten themselves out. So if the growth rings in the end of the board are "frowning", the board will tend to cup upwards (like a smile) as it dries.

 

You may try to remove the boards if possible and flip them over in otherwords.

 

I have found that the best thing to do is select the straightest PT lumber you can find (which will be in the center of the bundle because it hasn't dried much yet) and make sure you use it the same day you buy it. The quicker you get it nailed, screwed or bolted in place the better.