Do PVC terrariums need silicone?

[Kensa]

I've heard this a bunch of times. But I'm confused as to where this information comes from. AP's own website states that their cages and racks are made with cdpvc, not HDPE. Further more if they were made from HDPE they would weigh an absolute ton. I hade a 3/4" 4x8' sheet of HDPE in my shop a few months ago. It must have been close to 175 lbs.

Gio was referring to the Pro-Line cages when he said they were made with HDPE, not the AP cages.