Paints and finishes — suitability of stucco paints Stucco (textured) paints are generally suitable for which types of masonry substrates?

Introduction / Context:
Stucco paints (often acrylic or cement-based textured coatings) are specified to provide decorative texture, hide substrate irregularities, and enhance weather resistance. Selecting appropriate substrates ensures bond and durability.

Given Data / Assumptions:

• Common masonry substrates include stone and brick.
• Stucco paints can be applied to mineral surfaces after proper preparation.
• Moisture movement and surface soundness influence performance.

Concept / Approach:
Mineral-based substrates like stone and brick provide adequate key for textured coatings. After cleaning, repairing joints, and priming if required, stucco paints adhere well and provide a durable, textured finish. They are not restricted to one masonry type.

Step-by-Step Solution:
Identify compatible substrates: mineral, porous, sound → stone and brick qualify.Account for preparation: remove dust, efflorescence; ensure dry and stable background.Confirm suitability: manufacturers list stone and brick among approved substrates.Therefore, both (a) and (b) are suitable.

Verification / Alternative check:
Technical datasheets for textured coatings show application to brick, block, and stone with appropriate primers and curing times.

Why Other Options Are Wrong:
Limiting to stone or brick alone is unnecessarily restrictive; “neither” contradicts practice; timber needs different coating systems and preparation.

Common Pitfalls:
Applying over damp/unsound masonry; failing to treat cracks and movement joints; inadequate curing leading to crazing or debonding.

Final Answer:
Both (a) and (b)