I had a squirrel problem. Why I did was cut it open to clean out the junk and replace the insulation. I left as much of the tarp up as I could and stapled it back up. Went to a sign shop and got a 4x8 sheet of coroplast for about $15 some large washers and screws along with silicone and clear gorilla tape. I cut the coroplast to fit so it would wedge underneath the frame as much as possible put a big washer on with a screw covered in silicone and screwed it up. Big washer was so it would not pop through the plastic. I took the clear gorilla tape and coverd all the screws and also ran it around the perimeter to seal it up. Worked pretty good.