built a couple of 6x6 blinds a few years back. after all the work etc I regret not making the 8×8. would have cost slightly more but the extra room would be nice if hunting with others. my neighbor has a large blind overlooking his massive wooded food plot. opening day he stomps in around 1 am, lies down takes a knap, wakes up 600 am and around 720 I usually hear the distinctive roar of his 300 win mag I used 2x4 ( or whatever they are now shaved down) in the walls and 2×6 floor. save the headache, anything exterior get pressure treated.