Is there a difference between frost resistant versus frost proof?
We don’t know of any tile that claims to be frost proof. While there may be such on the market, we don’t know what criteria they are using to separate themselves from frost-resistant tile.
If the tile is sitting in water due to poor drainage conditions or typical winter icing, will these frost resistant/frost proof tiles perform adequately?
It is very common for frost resistant tiles (including tiles that can cycle more than 2000 times through freeze/thaw conditions) to be damaged by water and ice that sits on the tile when the water can get in the grout joints or in voids left in the setting bed.
Will tiles meeting ASTM C-1026 and ASTM C-373 standards perform adequately on exteriors?
Generally yes, so long as the tile is installed according to industry-accepted methods and the manufacturer rates the tile for exterior applications. Many manufacturers apply more stringent requirements to their internal tests before they recommend a tile for exterior applications.
Foreign standards reference EN-202 to define frost resistance. Is this an equal test to the ASTM tests?
No, it is not the same test, although most tiles perform similarly in the EN test and the ASTM test.