Hello, This is my first post, and I am excited to find these forums.
I am building a 20 foot dome on top of a 6 foot high deck in my
yard, as a fun house for my daughter and wife, and storage underneath for myself.
I live in Bozeman, MT, in the middle of town, so codes really limit what I can do, and I'm pretty sure I've maximized my fun capabilities within code.
Anyway, my plan is to sink 12 foot posts into
concrete, with 8 feet sticking out (frost line is 2 feet). At the six foot height, I plan to build a deck, with a two foot railing/knee-wall. On the railing/knee-wall, I want to set up a 20 foot 3v dome on top of foam, secured to each post with pipe straps. It will be 1" electrical conduit. This will then be sheathed in white vinyl plastic on the lower 3/4 of the dome, and clear polycarbonate on the upper 1/4. Eventually, as we have
enough money, I want to wall-up the lower portion of the deck, with plywood, and traditional siding, and a patio
door. Once we have walls up, I want to build a
rocket mass heater, and use the lower portion as a
workshop, and garden shed. I will store long lengths of boards and pipe in between the deck joists.
So I came here with the purpose of receiving tips and advice on my plan. My main area of concern is how to make the bottom of a 3v dome flat? I want to steer clear of a 4v dome as it requires more pipe, and more types of cuts. Also, would a galvanized 8" pipe, buried in sand, and run into a seating area around the perimeter of the building be adequate enough for heat? I am not looking to make this a livable space, but I want it to be comfortable. Also, I am expecting this to be be a 3 season fun house. Would this kind of heating be ok for use in fall and spring in zone 4/5 with temps from 32-80 degrees? How big
should my posts be if I am looking to support a deck, dome and at most 10
people? I was thinking that I could use a 4" x 12' post because I will have a post around each corner of the outside of the dome, meaning roughly 15 posts. The inner part would also be supported by another ring of posts because of the 20' span. The center would be a stairwell going up to the deck. I was thinking of using brick pavers as the floor (I have a lot of these materials I accumulated over time, so I would like to use them), and some free composite decking I found on CL for the deck.
Any tips for the following things would be MUCH appreciated:
-Venting
-How to attach the pipe to the deck railing at the posts
-How to make a 3v dome flat along its equator 9I saw the Russian site which can calculate this, but I don't speak Russian)
-Rocket mass heating tips (length width of a max-run underneath a seating area, and if I can use sand as a thermal mass)
-How big my posts need to be to support 20 foot circle of decking (composite), 10 people, some furniture, and a dome weighing ~300 pounds.
Any other critiques and advice would be great! Thanks for a great forum! Mike in MT.