We were given the metal frame s to build a geo desic dome on our Permaculture Center in Colombia, ok so I got given it for free, so I built it, great the skeleton of the building is complete, now I have to make a roof for it. I have considered chicken wire as the support between the gaps and then using old clothes dipped in a cement slurry to the do a kind of paper mache roof, but I was advised it would crack and probably super hot, usually we use cob to build walls as the indigenous Indians (Kogi) still do, so now I will attempt to make a cob roof dome and then waterproof it with with a kind of tar based sheet which is flexible.. we have a super long rainy season so always my concern is rain, anybody with experience of geodesic dome roofs in the tropics, would love to hear your comments
The nearly flat top of a geodesic dome really works against any kind of natural materials for roofing in a wet climate. Ferrocement at least for the top third of the dome may be your best bet, and if you can make it to shed over thatch lower on the roof where it is steep enough, that might make the best of it.
Another possibility would be to use the dome as a structural base, and attach lightweight rafters to it to form a fully pitched roof which could then be thatched. This would give a higher peak which could let heat escape better, assuming that is the main temperature concern.