I know I'm a dog diggin up old threads, however for anyone looking for a good answer. I am currently building my chicken run out of pvc. I am going to put a pvc door. You can get thick PVC and its still lighter then heavy thick wood and will hold up to most large predators, but also don't forget the smaller ones also. you want a tight fit so cats and other slinky things can't get in there. what I am going to do is measure and prebuild my door to make sure of a snug fit. you can do slip tees, IE if using 1" pvc, get 1" to 1 1/4" tees to allow for easier movement. once you have made your door you need to mount it. I have thought this through during endless nights of worrying over non existent chickens that I now have. you can do this a few different ways by either placing more slip tees and building a brace... or you can do it my way. I am going to measure how tall my door will be and then measure the width between the hoop. I will cut and drill a hole through the brace and the hoop. I will place the brace on the outside of the hoop post... I find this to have less bend and easier to fit. you take your zip ties or wire and you go through the holes and get that brace nice and tight and then zip tie your outter square of the door to the brace. ... now you have a working door you just need to put a latch you like on it.
I find wood to be great, however in this situation if you are going PVC, go PVC. if you are concerned about the flexibility of it, get a thick kind for the brace and the door itself since you do not need it flex. just because you built the hoops from 1/2" you can build the door from 1", 1 1/2" or even 2".
Hope this helps. sorry if my description is not the best... I am great at showing, not telling.
