Do you have a picture of your floor system @Woodsplitter67 ?
When you wrap and unwrap is going to depend on your local weather pattern too. My typical weather is mild gentle scattered rains in May, sunny and dry June 1 to July 4th. Sometime between July 5 and August 10 the rains start, and keep on coming, and in September the rain turns to snow.
What worked for me this year was to leave the sides open right up until the rain came in July, then close the sides and wait for cool weather.
Here is a picture of the wood racks that i used. Got them from home depot and used 2x4 as the bottom shown in the picture but i put pavers under the wood rack to get it up to allow air to go through the entire bottom