I'm turning my patio into a catio for my kitties and want to install a cat flap in my sliding glass patio door. While I found a premade panel online for around $120, my budget is tight. I plan to buy the cat flap for around $10-$12 and need suggestions for a lightweight, waterproof material that's about 1'x7' that I can easily cut with a jigsaw. I came across 1/4" plywood, but I'd have to paint it. Any ideas on other materials that could work?
2 Answers
Consider getting a 2'x8' piece of 1/4 inch plywood. You can cut it in half and attach a 1/2 inch foam board on both sides. Just slot the plywood into the door and use expanding foam to ensure it fits snugly. A PVC pipe cut long enough to create pressure between the door and plywood will keep it secure. You'll need your cat door, a sheet of foam, and the plywood. Easy peasy!
Have you thought about using Coroplast? It's lightweight and waterproof. You could stack a few layers together and just tape the edges for more rigidity. Plus, it’s super easy to cut. One panel could give you four layers, making it stiff enough for your needs!

Yeah, I initially thought it would be too flimsy too, but layering it sounds like a solid plan. Thanks for the tip!