STEEL DOME SHELLS & FRAMES
Steel domes are an answer to the needs of many areas that encounter natural dangers such as Hurricanes and Earthquakes. They also offer Security protection.
Steel Domes are much more expensive than wood domes. The price of steel varies but you might calculate by the factor of 38 cents per pound of steel. A 5' x 12' x 3/16" steel sheet is about $250.00. Prices vary with location and shipping is also a major factor.
Small steel domes such as the 12' & 19.25' can be built from flatbar strips. In these small domes the flatbar is welded linearly to produce an angle iron that is slightly less than 90 degrees. The ends then must be cut on an electric metal cutting band saw at particular angles and welded together to form a wedge shaped triangle. the triangles then receive inner braces and can be drilled and bolted together to form the dome frame.
The shell is made of triangles of steel from 1/16" to 1/4". They must be cut by a torch or other means and then placed and clamped into position and welded along the seams. The process is much like building a steel boat hull upside down. Extreme accuracy is necessary in every step to assure the finished welded seam does not leak. The outer shell can then be sanded or water sand blasted and painted any color. It is possible to use very thin material as a skin if your welding talents are up to par using a MIG or TIG welder.
The flatbar method is fine but if you want a dome that is really strong the method changes to a fabricated I-BEAM method. This method uses 4 flatbars welded linearly along the edge of a 3/16" x 9" x 10' plate to form a beam with the proper angles. Hubs made from pentagonal and hexagonal stock and are cut in the beams thickness and drilled and tapped ,3 holes on each face. Brackets are then made in a jig and drilled to link each beam to the hub. This requires many 1/2" bolts and is labor intensive without the use of a robotic track welder. In any case the job is on that produces a shell worth around $250,000.00 in a 50' diameter model.
If you have welding and machine shop experience this might be for you. I estimated the materials for a 50' dome produced by this method in the neighborhood of $75,000.00. You can add to that an equal amount of labor then transportation to the site and the actual assembly that may require a rented crane. As you can see a large dome in steel is a serious project.
A 12' Dome for storing a motorcycle you don't want stolen or to be used in the event of natural disaster is a good project. The strut triangles are only2.5' long and can be made as lightweight as you see fit. Sheet metal gauge domes are possible and can even be bent on a brake when you master the art of calculating the angles and lengths. I have listed the 12' steel dome plans for $150.00 so experimenters can study them and then build what they need or can afford. not a bad winter study or summer project.
50'-77' PIZZA RESTAURANT FLOOR PLAN
50'-77' DOCTOR'S OFFICE FLOOR PLAN
THESE PLANS CAN ALSO BE BUILT IN WOOD FRAME KITS WITH ARCHITECTURAL SHINGLES