It is described as plastic but the thickness of heavy  nylon. Should think of it as a glorified pop-up shed. That being said. What do you expect for $200? The next price point was over my head. That being said, it totally serves my purpose, giving me storage space and protecting the stuff that used to take up too much space in my garage. Haven't gotten through the winter for the real test yet, but I'll get back to you in the spring with an update.