Quote Originally Posted by Lord Sorril View Post
To further complicate things: There are different grades of PVC and HDPE.

HDPE is a semi-crystalline thermoplastic. I'm told it is harder to work with during fabrication.

I have PVC cages--they work fine. If you offered me both a PVC and a HDPE enclosure of the same design--I would buy the cheaper one. If I planned on modding it--I would go with the PVC.
To simplify it its really simple every single cage manufacturer for cages use either expanded foam board pvc or CPVC so that makes it easy. I can sum it up like this Foam board pvc is used for signs and outdoor exterior uses. So its good for reptiles because it can handle water without rotting and its easy to work with. And HDPE is harder to work with but if your purchasing a HDPE enclosure the only thing you would be doing is using a electric drill to screw stuff in so no worries there. And for HDPE the only type you need to know about is just stress relieved HDPE anything else is not relevant for our uses since the other HDPE is used for specialized uses.