I receive a fair number of inquiries regarding synthetic stone water intrusion problems, or what the industry now refers to as adhered manufactured stone masonry veneer (AMSMV). In my job site visits I’ve seen a number of installs that have resulted in failure. Failures range from the OSB rotting and the stone buckling to water intrusion and mushrooms in the wall cavity.
Overall, AMSMV is a good material, but care must be taken during its installation. The goal of any cladding system and weather-resistive barrier (WRB) is to prevent water from reaching the OSB and the interior of walls. The 2006 IRC requires a weather-resistive barrier behind all claddings for good reason. All claddings can develop leaks over the life of the home. It’s not a matter of if it will leak, it’s a matter of when.