I am getting ready to start building my stick lumber cabin in Wasilla off Church Rd at the end of May. I am wondering how deep I should go with my 6" x 6" support posts that I will have inside what is called "Post Protector II" (basically a sleeve that protects the PT post from rotting prematurely)? I want my cabin raised about 18" off the ground from the bottom of the floor joist to the ground. I will install some sort of siding with a insulated panel around base to keep animals and wind from blowing under the cabin. I will use R30 insulation in the floor. How deep should I bore my holes for the posts? Cabin will be a 16' x 24' with a small loft sitting on 12 of the 6" x 6" PT Posts.