Actually for shade in the summer we don't use tarps, we use rolls of landscape fabric. Yep, landscape fabric! One of us stands on each side and we toss the roll over, wind it around metal laths that we got at Lowes, and then secure that to the run. On really hot days we can roll it up on the shady side like window shades. Each roll is about the same width as the cattle panels. They lasted all summer without ripping, too. If you put landscape fabric down, then pour water on it, watch what happens.....the water will roll with the creases and only some of it seeps through the holes in the landscape fabric. Same thing with using it to cover the run. Because it's permeable, breezes go through it without it ballooning like a sail (or a tarp) does. Rainwater mostly runs off, and only a little bit seeps down into the run. Since I'm using deep litter out there, I need a little moisture in the litter without soaking it, so it's the best of both worlds.
Just before winter, we bought more vinyl lattice and arched it over the top of the cattle panels. I love how that looks, so it will stay up all summer now, too. But it kept the greenhouse plastic we put up for winter protection from coming into direct contact with all of the wire ties where the chicken wire was attached to the panels - the plastic was touching the lattice but not the metal of the run itself. Boy, did that work slick! No ripping, even when the winds howled and the snow pressed it down. That lattice acted like a buffer.
This is how it looks with the lattice covering and the plastic put over that.

Just before winter, we bought more vinyl lattice and arched it over the top of the cattle panels. I love how that looks, so it will stay up all summer now, too. But it kept the greenhouse plastic we put up for winter protection from coming into direct contact with all of the wire ties where the chicken wire was attached to the panels - the plastic was touching the lattice but not the metal of the run itself. Boy, did that work slick! No ripping, even when the winds howled and the snow pressed it down. That lattice acted like a buffer.
This is how it looks with the lattice covering and the plastic put over that.