When building a trapezium dome, is it better to construct the dome row by row or by first making a vertical arch? Is some form of bracing required?
By constructing the dome row by row you have the opportunity to attach the bottom row to the ground so it becomes secure prior to attaching the rest of the dome.
If the dome is constructed by joining vertical segments, the dome can't be securely attached to the ground until it has been constructed.
Either way, an internal scaffold may be needed to be erected prior to constructing the dome. The scaffold would act as a temporary support during construction.
If constructing by rows, the upper rows will not be self supporting, due to the shallow angles of the upper rows of the dome, until the dome is complete.
If constructing by vertical strips, the dome won't become stable until most of it has been completed.