Framing & StructuralQuestion 404 of 700
Behind exterior cement plaster (stucco) on a wood-framed wall, the code generally requires how many layers of an approved water-resistive barrier over the sheathing?
a.No barrier is required
b.One-half layer
c.Two layers (equivalent) of water-resistive barrier
d.Four layers
Explanation
Because Portland cement plaster absorbs and holds water, the code generally requires two layers (or an equivalent) of water-resistive barrier behind stucco to protect the sheathing and framing. No barrier or a single half-layer is inadequate, and four layers is more than the code requires.
Law Reference: 2025 CA Residential Code §R703.7.3Practice all 700 questions free — no signup required.
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