we are building a back yard club house. it is going to be in the air and elavated off the ground but not in a tree. the plan is complex. it is supported by 4 cemented in poles in the ground. it will have a ladder to get in and when you are in if you look up you will see a fairly large hatch in the ceiling. and if you crawl in the hatch you will see the second floor. we want it to be sealed enough that you could actually leave stuff like bean bags in it to hang out. do you think this would work? any suggestions? do you think we could make it like that without the worry of it being instable? this will be greatly appreciated:) thanks-livie