Thin veneer real stone over rigid EPS foam substrate

[IamTheWalrus]

In a July 2005 issue of JLC, an installation of stone veneer was storied out in text and photos. The stone was either real or faux, I cannot recall which, but it went onto a wall built with ICF blocks.

I am questioning this technique of gluing stone directly onto the EPS substrate with whatever thinset was used. There are some who say it is a bad detail, and that felt paper should go on first, then expanded metal lath, then a scratchcoat of type S mortar. Or is it some other type. Whatever.

Do these thinsets really bond adequately to EPS (expanded polystyrene, think "styrofoam," like the inexpensive molded picnic coolers) well enough and permanently enough to ensure the veneer (2" real stone or faux like Cultured Stone or Eldorado) will be secure?

[James Eggert]

Do these thinsets really bond adequately to EPS

Maybe, BUT you'll never get a manufacturer to approve it! I did 4400Sq. FT of Eldorado Stone and we did the metal lath. I did an article somewhere about it, not on the right computer at this time to bring it up.

I would probably do first level only without mesh, but it all depends on location and mfg input!