We have stucco buildings in Florida, they are about 25 years old and are experiencing many cracks in the walls which we have been caulking but cannot keep up with as these cracks lead to water intrusion in our units. Will elastomeric paint solve this problem?
Elastomeric paint can solve your problem as long as the cracks are fairly tight and not moving. Large cracks that expand or contract indicates possible structural problems. No paint can fix structural defects.
If the cracks are non structural in nature then 2 coats of a good elastomeric paint will effectively seal your buildings from water intrusion. It is important that cracks larger than 1/16th of an inch be pre-filled with an elastomeric patching compound. Very large cracks will require repairing the stucco before painting. Usually, caulking alone isn't enough for medium too large cracks.
The exact repair and patching procedures depends on the brand of elastomeric paint. Consult with the paint manufacture for recommendations.
Know the Characteristics of Elastomeric Paint
Elastomeric coating is a great product in the right application, but it is important to know that the characteristics that make it waterproof also give it a low permeability rating. Therefore moisture from within a structure cannot pass out. Possible negative outcomes that I have encountered are interior rot and bubbling of the elastomeric coating where you will find pouches of delaminated paint actually containing water. The same condition can occur if elastomeric is applied to the underside of a horizontal surface. An elastomeric coating called Ceramic Insulcoat has the highest perm rating I have encountered in this type of product.