10-25-2013, 04:51 AM
We found that modified thinset over cement board (e.g., Hardibacker) is an excellent exterior finish that is easy to apply if you've done any drywall coating at all. The thinset at the right consistency applies very much like wallboard compound and goes on quickly. We used two coats, the less expensive, coarser type as first coat, then the white, finer consistency type as the topcoat. Then we used HD's mortar and stucco paint as the finish. The paint was really thick stuff and went on as a single coat. Pretty much zero cracks after eight years. The underlying construction was either Protec SIPs or metal studs with a Tyvek layer under the panels.