Image courtesy American Ingenuity
The Lowdown on Geodesic Dome Construction
Not all geodesic domes are alike. The most basic and common dome is based on the aforementioned icosahedron with its 20 faces made up of equilateral triangles. You can make ever larger domes by dividing the face of each triangle into smaller and smaller triangles.
As you view a geodesic dome, you may notice that the lengths of support struts (the individual rods or bars) making up the dome's frame usually aren't identical. In the most basic kind of dome design, there are many different lengths of struts necessary to complete an unbroken sphere.
A one-frequency dome employs struts of one similar length. Likewise, a two-frequency dome uses two distinct strut lengths. Lower frequency domes (those with fewer parts) are easier to put together, but those with greater frequency can be built to bigger sizes. When assembled into triangles, struts are called trusses. The joint where the straight ends of the struts meet is called a node.
Struts must be measured and cut precisely in order for the dome to take proper shape. So for anyone who has to deal with the challenges of the dome's actual physical construction, fewer lines make for fewer struts and much easier assembly.
So although software might be able to calculate enormously intricate domes, in reality, only a few basic designs usually wind up in the real world. More complex plans – that is, those with great frequency -- require struts of many varying lengths, and as such they are more difficult to put together.
Once a dome design is ready to go, builders select the desired materials. Dome struts may be high-strength metal alloys, or more traditional wood members. The nodes, or hubs, that connect struts are often steel.
After the framework is complete, it must be covered. The triangle panels are generally made of plywood, plastics or concrete. The interior of the dome is often lined with insulation and finished with triangular sections of drywall or wood.
With a smart dome plan, there’s no limit as to how high those triangles will go. Keep reading to find out more about how domes are built and how Fuller’s geodesic creations took on gigantic proportions -- and then went up in flames.