[Sputnik]

I could imagine concrete could be quite dangerous. As moisture can penetrate it, it would be a great haven for bacteria, wouldn't it?

When I first read about James' slate flooring I was quite impressed and a couple of days later I passed a building site and asked the roofers if I could have a few pieces of the old slate that had been taken down.

A good scrub later and they went into all of my large vivs. It really works great! It warms up to a lovely temperature, doesn't get too hot (I have a thermostat anyway), but keeps the temperature for a while after the heater has been switched off. I know James seals his in, which I think I might do eventually, so far I have not had anyone slithering underneath, but my pieces are placed in loosely, so I can take them out and rinse all the soiling off. I also add some soft substrate like recycled paper animal bedding (like catlitter) in one corner on top, larger pellet types are best, so less risk of swallowing, as the snakeys love digging through it.