But it got me thinking.
When we lived in Europe courtesy of the Army all the roofs were clay tiles. They didn't have a roof deck covered by moisture barrier covered by shing les; the tiles were wired to the battens or rafters (I'm not sure of termin ology) and they could be worked on from underneath. A mechanic would unwir e a section and step through from the attic to fix an antenna, etc., then w ire it back. They never leaked. They did sometimes blow off in a big stor m, or get cracked if something hit them.
Not that I would put a tile roof on a shed.
But you could almost simulate a tile roof just by splitting some plastic pi pe, maybe in the 4 to 6 inch diameter range, and overlapping. Roof tiles a re about 20 inches long normally, but there'd be no reason you couldn't use standard ten foot pipe lengths. Alternate face up and face down, and ther e should be nowhere for water to get in.