Sorry. Your right my mistake. I understand that the girls don't shrink in length but the post do. So if you had for example 8 post that were 12x12 green they would probably shrink about a 1/2" each this would add up to approximately 4" overall. If the joints didn't separate at all wouldn't the wall shorten up by 4". And if you stick framed the outer wall that wall wouldn't move. Or the joints at each post would separate approximately by 1/4" on each side. Any thoughts