If your stucco has a web of fine cracks, elastomeric paint is worth considering. Its flexible film can bridge small cracks and help keep wind-driven rain out. Before choosing it, though, you need to know what condition the wall is in beneath the paint.
A dry wall with surface cracking is one situation. A wall with recurring bubbles, damp patches, or a crack that keeps reopening is another. They shouldn't automatically get the same treatment.
What the coating can do
Elastomeric masonry coatings form a thicker, more flexible film than conventional exterior paint. They're designed to accommodate limited movement and bridge cracks within the product's stated limits. That can make them useful on sound stucco exposed to driving rain.
The word "elastomeric" doesn't tell you everything, however. Products differ in how much cracking they can bridge, how they handle water vapor, and how they must be applied. Ask for the actual product name before deciding whether the recommendation makes sense for your house.
Check the moisture problem first
A thick coating doesn't necessarily stop a wall from drying. Some elastomeric products allow water vapor to pass through the film while resisting rain. Behr's elastomeric masonry paint, for example, is described by the manufacturer as breathable. Check the properties of the proposed product rather than assuming they're all the same.
That doesn't make it a repair for a leak. If paint is lifting, stains keep returning, or white salt deposits appear on the stucco, investigate the cause before covering it. Check nearby joints, roof details, and any irrigation spraying the wall. Those observations help identify where a closer inspection is needed; they don't establish the cause on their own.
Recurring salt deposits deserve particular attention. Sherwin-Williams advises delaying painting when efflorescence continues, repairing the moisture entry points, and allowing the wall to dry.
Cracks and prep still need a plan
A coating's ability to bridge fine cracks doesn't mean every crack can be painted over. Wider cracks, cracks that are growing, and failed previous repairs need assessment before the finish is chosen. The repair method should suit the damage and the coating system; opening up every hairline crack isn't a universal requirement.
Loose paint, dirt, chalk, and mildew also have to be dealt with. Priming depends on the surface and product. Some masonry coatings can go directly onto suitable masonry, while others require primer on bare, patched, or chalky areas. "We'll wash it and paint it" leaves too much unanswered.
Thickness is part of the job
An elastomeric coating has to be applied at the manufacturer's specified coverage and film thickness. Stretching a gallon farther to save material can undermine the performance you're paying for. The estimate should name the coating and describe the application, including any repairs and primer.
For stucco with isolated cracks and an otherwise sound finish, repairs followed by a compatible exterior acrylic paint may be enough. A wall with widespread fine cracking may justify a different system. We explain the work involved on our stucco repair and painting page. To have your walls assessed, request a free written estimate.