Hey folks, I just want to point out a product that seems to be overlooked in winter preparations. Commonly called “house wrap”, or “TyPar”, it’s a construction paper that is typically used on a new home on the outside plywood walls beneath siding. It is water and mold resistant, it breaths, isn’t totally opaque, and has good UV resistance (for a winter, easily). It’s easy to work with, all you need is a box cutter and some duct tape (or that red plastic tape).
Since it isn’t damaged by water, you can have a small roll handy just in case you think your run might get inundated with snow (I’m not putting any up until I see that too much snow is actually getting into my run, but if that happens, I can throw it up in a few minutes to prevent even more getting in.) I really don't like the idea of "sealing" the sides of a run as it could prevent good air movement.
It’s not as pretty as a Lexan solution, but it’s a heck of a lot cheaper.
Cheers,
Russ