Seeing this, I'm inspired to argue for a lightweight geodesic structure to go over the earth oven. I reckon we can make one with pallet timber, and cover it with either tarpaulin or timber shingles (or even wattle and daub). This link shows the initial dome construction: then go here to see the bales and adobe going on: http://www.youtube.com/watch?v=T2NvnhLPBVM&feature=related
PS, can anyone show this to Chris? Simon? Keith?