One-coat, or synthetic, stucco installed over backerboard can perform well, but only with a well-detailed drainage plane behind it.

Cementitious backerboard provides a more durable substrate for synthetic stucco than foam insulation board. The backerboard must be installed over mesh furring strips to provide a drainage gap so that any water that gets through the stucco is directed to weep areas at windows and wall skirts.
Cementitious backerboard provides a more durable substrate for synthetic stucco than foam insulation board. The backerboard must be installed over mesh furring strips to provide a drainage gap so that any water that gets through the stucco is directed to weep areas at windows and wall skirts.

In addition, all stucco types need a range of control joints to prevent cracking. For details on these and other critical details for ensuring a durable stucco job, visit the JLC Field Guide.