It's almost like gluing a finish coat to the surface. Although blocks and bricks have their own texture, you aren't stuck with what's there. If you want to add more texture to an exterior surface, you can apply a variety of coatings designed to do just that. Some of these are trowel-applied and already colored, so you don't have to paint over them. With the introduction of elastomeric coating systems, the task of coating masonry surfaces became easier.
Elastomeric coatings are flexible, of course.
Their primary benefit is bridging the cracks that are seemingly inevitable in masonry walls, and which typically develop in the mortar joints much more frequently than in the blocks or bricks, Mike Gist said. While stretchable, these coatings have limits. Even though elastomerics solve some problems, you still have to look at the building in general and the substrate in particular to determine how sound it is, what problems exist, and what problems likely will develop. For example, when moisture is present, you still have to determine its cause, which may be anything from cracked caulking to leaking gutters. And then you have to stop it.