Rollover sheet for temporary yard cover

[Bald n Grumpy]

We've got an exercise yard/pen on the bulls shed which is next to the covered collecting/ feed area for the dairy cows.Have been toying with the idea of covering the bull pen to cut down on yard run off but when the weather is good ( hopefully we have summer)I don't want it covered so the old boy can still feel the sun on his back.
Had a random thought about having a rollover type sheet like a trailer? The pen is only about 7m X4 m so not huge.
Any thoughts anyone TIA

 

[gmgmgm]

Scaffolding sheet is 4m wide, could easily fit the bill. Very tough (but will degrade eventually).

 

[Ffermer Bach]

have a look at some of the "super" sheds in Australia (super as in superphosphate), they have push on roofs that can be rolled off to tip the super.