Here are some 2D images of 3d models of the dome design that I've refined over the course of a few years. I'm very excited about the design improvements that have taken place over this time. I've thrown out a lot of ideas! The dome combines the advantage of a circle and a octagon. The dome/octagon hybrid has a 185 sq. ft of living area. It measures 15'4" from one end to the other and 9'8" tall with a 2' knee wall on the sides. It is constructed out of 1" or 2" rigid Styrofoam and parged (covered in thin layer) with either an acrylic modified surface bonding cement or grancrete with fibers added. Creating a very strong, well insulated and very affordable shelter.
Erecting the open dome:
Building the dome would be very easy and could be done with minimal tools and supplies. A standard saw or common drywall saw that can puncture the foam easily would be required to cut the sheet goods into the usable sizes. The design has been optimized for standard 4x8 or 2x8 sheets. Using the saw each piece would be cut to size and correct angle. After cutting all 56 Styrofoam pieces a good quality tape like duct tape would be used to adhere the edges together creating a seamless dome. Starting from the bottom the 8 2' knee wall pieces would be taped together. After this each section going up horizontal would be added until the dome is completely assembled.
At this stage the dome could be stayed in for a bit if nessicery however covering with a tarp or parging before the sun degrades the Styrofoam. The door frame made out of Styrofoam would be traced onto dome face and the outline cut into dome. The frame then installed. Windows then would be cut out where needed.
Window options:
1. Car windows with a length or width less the 2' would be prefered however i bet you could be creative 2. Single glass panes windows , used both inside and out to create a double paned window 3. Wine glass could be used to bring interesting light patterns into the living area 4. Glass bowls like punch bowls could be especially useful as the main skylight
Trace and cut out the windows (make sure to give yourself a good inch to the inside of hole) or make the puncture holes for the wine bottles. If you want strong mount points such as a hanging bed or plant hangers now would also be a good time to run bolts through shell. Ways to adhere the glass to the shell would variety as shapes would dictate. Using tape should meet most shapes and sizes. A fast acting construction adhesive might also do the trick.
Covering the insulated shell
We now have our dome basically how we want it to look. It's time to use either surface bonding cement with an acrylic modifier (the modifier will resist cracking and damaged caused by the sun) or grancrete which is a fairly new magnesium based cement like material which doesn't have the same UV problems as Portland cement but as of now harder to find locally.
Tools required:
1. a trowel ( using rubber gloves, would be possible in order to save or give different texture) 2. a mixing container 3. a hoe of sorts (could be mixed other ways )
Working your way from the bottom to the top making sure to coat the corners good as this is where the stress load ends up. I believe an 1/8 could be done however most likely a bit thicker . If you only had money enough for an 1/8th this step could be done in stages. Now you can either leave it grey or stain it. Painting would work but would degrade faster.
Platform for dome:
The dome could be erected on a multitude of foundations or platforms.
1. A simple rubble trench below the foam. A plastic 6 mil vapor barrier would go on the floor of the ground and covered by a rug. This would prove the most affordable and would give you a very nice floor. This method was used in Mike Olehers $500 dollar underground house and is the most easy and cost effective of the options 2. A wooden deck upon concrete piers. This would be the best in environments where flat or easy level able ground would be an issue but would cost more. 3. A poured concrete slab that could be coupled with a simple radiant floor heat to provide a very nice floor. This would not have to very thick as the weight of the dome is not very much. 1" should be sufficient depending of frost conditions 4. A rammed earth or poured earth floor. This would be better in dryer conditions 5. Any other creative floor that a person could come up with.
Making the door:
The door could be made either using the same materials as the dome or could be fashioned out of salvaged or purchased wood. Use your imagination here!
Finishing the inside: The inside could simply be painted after filling in the gaps with caulk to provide a pleasant immediate interior wall or could be parged with surface bonding cement or grancrete to make a stronger interior coating. Before finishing with concrete or grancrete, use scraps from the Styrofoam panels to create some shelf using the same techniques of taping or Lacquer thinner ( which bonds Styrofoam together ) then finish with concrete/grancrete.
There you have it your dome is done with minimal tools and minimal cash outlay. I have run estimates or 3-6 dollars a sq ft depending on finish quality. This is using common items in any home improvement store.
Goals of my design: A really neat shelter Affordable Strong Efficient Built with minimal tools Built with minimal experience Built using standard easily obtainable materials Hackability
The reason so many of the goals have been able to be met lies in it's shape. With out the proper shape then a lot of these goal are not possible. Let me try to explain the reason I've landed on the sphere/octagonal shape.
The basic shape of a sphere is known to be the strongest possible shapes. It deflects pressure evenly to all directions and has no point of weaknesses it's stress is distribute. This allows a single material to be used for both the roof and the walls very easily which will save you money and time. Money in the materials you have to buy and the tools you need. The octagon part of it was adapted b/c of the compromise to conform to the preference of square items that people and the building industry has. The windows, the tables, the couches, the Styrofoam. If we used a perfect sphere non of these items would fit with out being made custom which takes additional time and money. By using an octagon/dome vs. a geodesic dome you gain predictability and symmetry. Each side is exactly the same you know that a door can fit anywhere, that the window will fit facing any direction. I would also wager a guess that on a small structure like this giving the compromises a geodesic dome would have to make to phsyicate a door and windows that it would also be stronger! The 2' knee wall extends the amount of walking space you have leaving the rest in the edges for other purposes. I'm very proud of all the criteria I've been able to meet for such a low price and easy of building. My hope is that by sharing this design I can empower people to take it upon them self to go there own way. I can say that personally I don't have a lot of money and you see a lot of great things but they are never made for the people b/c a simple smart design doesn't do much for a business model. To be able to give someone a chance to build this structure, to be able to build there own lives in someway is pretty powerful
I hope that by standardizing on the exact dimensions that people might have the option to share a successful pieces or make a business out of selling it.
That being said once I create the first prototype this year I will be able to verify the exact dimensions of each piece so that I can come up with an open dome instruction pdf. If you are interested I will sell the exact Styrofoam pieces needed to build the open dome as can anyone else who wants too.
Jeff
Orange Dome Picture 5
If your intrested in ordering a precut kit let me know. I am creating a list of intrested people. Price is not final but should be in the 500-600 dollar range thanks
