Tile substrate for Leo helop

I'm a soon to be, and first time reptile owner, and I'm getting a gorgeous super snow from a good breeder. I have a 30x12x12 zilla 20 gallon critter cage and I'm getting some tile as a substrate. I was wondering what kind of glue/putty/bonding agent i should uses to seal the tiles together and not create a sharp edge if they're uneven. Any help would be fantastic! Thank you!

Just get some caulk and apply just enough to have a firm even surface on the bottom make sure you let it dry completely before you place
you're new companion in it. hope this helps