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New grow dome going up.

This is a two frequency dome (two lengths of struts) that will have a diameter of 24 feet and a height nearly 11 feet.

There are 65 2x4s involved. These are cut to specific lengths calculated from the material at the Simply Differently Dome site. The 'interior' angles on the pentagonal connections are 72 degrees, and the hexagonal are 60 degrees. These are also cut (these sharp points) on a 9.8 degree slope for fit.

Each piece of wood is repeatedly handled, but other than that, the operation is very straight forward, and each step, once set up, is simple.

Triangles ready to go. Site leveled and ground cloth down.

First three triangles connected. One large B triangle in the middle (from which a door will emerge), and two A triangles all cross connected with A struts to form 5 interconnected triangles that are now form a self supporting structure. So the other triangles remaining (see below) form our base. The rest of the structure will be assembled tomorrow. Doors and three vents will be built. And the whole structure will be covered with 11 mil, clear, UV protected woven poly. In our experience the 20 mil is a 20 year product, and i am expecting a decade at least from the new covering which will be tightly afixed.

By using wood 2x4s and readily avialble 3 inch deck screws i am able to stay with very ubiquitous materials, and thus reduce costs. By NOT using hubs or metal inter-strut ties, i reduce weight, and cost (considerably), but necessarily have to transfer the complexity of the joins directly to wood. The simplest system produces a nice, wood joined hub composed of individual struts with appropriate angles cut into the ends bound by position, and held there by 3 inch coated deck screws. The wood is treated with stain. Excepting the very bottom pieces which are pressure treated 2x4's, all the wood is standard stud grade 2 or better, cut from 8 foot pieces.

This approach to covering the garden area allows for us to use bio-intensive growing techniques for a very reasonable cost. When i looked at locally available or on order greenhouse solutions of this size, the costs were typically over 2 times the cost per square foot. Further, from experience, i know that the dome shape assists in providing optimal growing conditions. And it keeps the radioactive dusts from the Fukushima reactor meltdown from being part of our diet.

This dome will be used to house the permanent plants (olives, fruits, et al) while i build a larger, 3 frequency, wood strut dome to replace the current grow dome (which is mild steel and wood lath- an inadequate solution). This new, larger dome will be 12 meters or larger (tbd).

Here is a link to the joinery technique.

Another excellent resource is ISBN 0-520-23931-8

Geodesic Math and how to use it. Hugh Kenner.