In
a previous piece, I focused more on the substrate, which is critical to
the stucco performance. Let me emphasize, thin
structural wood panels (OSB or plywood) are the killer of a good stucco
assembly, especially when not installed correctly, in my humble opinion.
Flimsy, unstable sheathing is not good
for stucco but good for the builder’s cost. I’ve been a
contractor for 25 years and one thing against my principles is applying
stucco over OSB of any size or plywood less than 5/8-inch. Why? Because
of experience—and when it cracks, I get the call.