I used the Dodger and Bimini frames as rafters. I secured lengths 3/4 PVC to them with zip ties which act like roofing purlins. I bought 28"x96" corrugated plastic sheets from Lowes as the decking.
(In the roofing section next to the corrugated metal roofing)
Secured sheets to purlins by drilling and using zip ties. The plastic sheets keep the water from pooling in the spaces between the rafters.
I made the cover in two pieces from TopNotch 9 fabric from Sailrite. Took about 15yds. Added a one foot skirt at the bottom and used e-z lacing material Sailrite # 103696 at the bottom. Laced line through it and tied at various places to stanchions, etc. It just withstood the 30+ mph winds this week with no problems.
Joe
NS26C #156 1985
SEA HORSE