The Paint Quality Institute

It your home’s exterior is made of stucco, concrete, cement block or brick, cracks in the masonry surface might already be a familiar and unwelcome sight.

But such cracks can do more than mar the appearance of your home. In extreme cases, wind-driven rain can penetrate the cracks and cause serious damage to the structure of your home or even to your interior walls.

While top quality acrylic latex paints can improve the look of a masonry exterior, there’s an even better alternative when cracks are present: elastomeric wall coatings, sometimes referred to as “EWCs.” These special, thick paints actually bridge cracks in masonry, sealing out moisture and enhancing the beauty of the exterior.

According to experts as the Paint Quality Institute, elastomeric coatings made with 100% acrylic binder literally stretch and contract as temperatures rise and fall, maintaining their flexibility, even in extremely low temperatures.

As temperatures drop, these flexible coatings, which are applied at a film thickness four to five times that of a standard latex exterior paint, “stretch” to span cracks that may develop or expand in your masonry. When temperatures rise again, the coatings contract, returning to their original shape without warping or wrinkling.

Elastomeric coatings are also highly water-resistant, so they help prevent moisture from penetrating cracks and porous stucco. At the same time, these coatings do “breathe, ” so they will tend to allow moisture that is present within the home or the masonry itself to escape to the outdoors as vapor.

Preventative Maintenance

While elastomeric wall coatings have traditionally been used to conceal existing cracks in masonry, they are also a very effective form of preventative maintenance. Applying the coatings to new masonry – whether on a new home or an addition – will help conceal any cracks that may develop in the future.

One thing to keep in mind: According to the experts, it is best to wait at least 30 days before applying an elastomeric wall coating to new masonry. This will reduce the chance that alkalinity in the masonry will damage the elastomeric film, causing the color to fade or the coating to break down. For best results, first apply a latex or solvent-based masonry sealer or primer, particularly if the surface is less than a year old.

Experts at the Paint Quality Institute also advise that you use top quality elastomeric coatings that contain a 100% acrylic binder. This type of coating has better resistance to alkalinity than do lower quality products made with other types of binders.

Practicality and Beauty

While elastomeric wall coatings are usually applied for practical reasons, once they dry, the beauty of the finish is hard to distinguish from that of quality exterior latex paints.

Like conventional paints, top quality elastomeric coatings are available in a broad range of colors, although white, soft pastels and lighter earthtones are the most popular choices. And these colors tend to look good for a long time, since these coatings have excellent resistance to dirt and mildew.