Spray Foam

Spray foam can be soft and easy to put on but deadly when burned, as it does give off a gas. If one is planning to use it only the short period during the pole shift, I wouldn't worry about it just normally giving off gas through age. The pre-fabricated sheets of foam are a good idea. They are not hard to find. You can get them at most lumber supply stores, at least where I live we can because of our cold weather. Soft cell would be good during the pole shift. It won't tolerate much walking around on if you put it in and let the kid's play on it. Tight cell would be more durable and I think it would stay on better. You could use a product called liquid nail to glue it on. I have used this stuff for years and if used on wood and plywood, the wood will break before the glue will give.

I love that idea about the triangle I beams. If this thing is built with that and it tips over, we picked the wrong spot to be in! As far as water seepage goes, spray foam on the outside will prevent most of that, especially under ground. Maybe when it's over, one could box in the I beams and make a second story for growing plants, or put a wind generator on top, or a lookout, or a gravity fed indoor out-house.

Offered by Clip.

I would suggest spraying poly urethane foam on the outside of a container, then bury it. See http://www.monolithicdome.com for details.

Offered by Steve.