Covering the Dome
Most likely, the dome will be covered with Aluminet shade fabric. This knitted fabric can stretch in one direction but not the other because it contains strings, about 1 cm apart, that run through the fabric with the long dimension. I need to decide how to orient these strings.
The shade fabric will be secured along the base of the dome to prevent the cover from being blown off. So, it seems that the best idea is to orient the strings vertically so that many of these strings are attached to the base.
In this diagram, different whole pieces of shade cloth are shown in the same color. The strings of the fabric run in the long direction. I believe that this is the strongest orientation.
An alternative is to run the strings horizontally around the dome instead of more vertically, but this idea seems wrong because the fabric will stretch due to gravity.
I have one more idea for shade-cloth orientation, and it even eliminates two sewn seams, but it runs the strings “from-left-to-right” in these diagrams, and so the cover is stronger in one direction compared to the other. I prefer it to be uniformly strong.
Quantity of Shade Cloth
Aluminet shade cloth comes on 7-foot wide rolls. The pieces of cloth from the top diagram can be cut from a single length of 7-foot wide fabric like this:
The total length of cloth required on this diagram is 167 feet, but I’ll add about 10% to allow for seams and mistakes.
Update . . .
The covering strategy shown in the diagrams above requires this fabric warp (string) orientation. The question is whether the cover will be stable with a 30-degree bias.