PAINTING MASONRY: GIVE YOUR HOME A FRESH NEW LOOK

Contrary to what you might think, you CAN paint your brick or stucco home and achieve good looking and long lasting results. Masonry is an excellent candidate for painting, but it requires careful preparation and the use of the proper products to get the best quality paint job.

The experts at The Rohm and Haas Paint Quality Institute recommend that when it comes to painting masonry, take the time to follow these guidelines:

In the Beginning
Surface preparation is key to a quality paint job on masonry surfaces. Start by using a wire brush, power brush or power washer to remove all dirt, unbound sand, efflorescence (a salty calcium deposit), chalk or loose paint. If using a power washer, be sure not to force excess water into mortar joints or other areas. If the surface has mildew or mold, first treat it with a solution of one part household chlorine bleach to three parts water. Be sure to protect yourself during this process by wearing goggles, gloves and a dust mask.

Once the surface has been cleaned, thoroughly rinse it with clean water to eliminate any residual dust or particles.

Before applying a primer or paint, you may want to dampen the masonry. Pre-dampening is helpful if conditions are such that the latex coating would otherwise dry very quickly, resulting in poor film formation. This tends to occur when painting a porous surface that draws water from the paint, a surface that has been heated by the sun or is in direct sunshine, or in very dry or warm breezy weather.

If the masonry has never been painted, it may be extremely porous, especially if it has been exposed to the weather for years. Use a latex masonry primer or sealer to make the surface less absorbent. This will provide a smoother, more uniform, finished paint job. A primer or sealer is especially helpful if the surface has powdery "chalk" that cannot all be removed, or has a tendency to produce efflorescence. (Efflorescence typically results from water that intrudes behind the masonry - try to identify the source and eliminate it if at all possible.) Rough surfaces, such as cinder block, can be smoothed out by applying a latex block filler before painting.

Once the surface preparation is complete, finish the job with a top quality 100 percent acrylic latex exterior paint. These paints are formulated for use on masonry as well as other building materials, and typically provide an excellent appearance for up to 10 years or more over properly prepared surfaces.

Special Rules for Fresh Stucco
Stucco is a challenging surface to paint. One of its most troublesome characteristics is its initial alkalinity. With stucco that is less than a year old, its high alkaline content can "burn" the binder of an ordinary latex paint. This causes the color to fade, or even the paint to crack and peel. But by following the proper surface preparation techniques, and using only a top quality paint, you can achieve good results.

Before beginning any surface preparation, allow fresh stucco to "cure" for at least four weeks. This allows time for shrinkage and reduction in moisture content and surface alkalinity. To help prevent efflorescence from forming, hose down the stucco once or twice a week during the waiting period.

When the stucco is ready for painting, first apply a masonry sealer, such as a latex block filler or an alkali-resistant primer recommended for masonry surfaces. This will help keep paint from absorbing unevenly into stucco's porous surface. It helps the finished paint job look smooth and uniform, and reduces chance of fading. Finally, choose a top quality 100 percent acrylic latex exterior paint for best results.

When painting stucco that is more than a year old, first prepare the surface by removing any traces of efflorescence with a scraper or wire brush. Stubborn efflorescence can be removed with a 6 to 10 percent muriatic acid solution, followed by a thorough rinsing. Then proceed by applying a top quality 100 percent acrylic latex paint. Use a masonry primer if the surface is especially porous.

For Best Results...use an EWC
Elastomeric wall coating (EWC) systems provide the optimum performance for masonry. These coatings stretch, contract and conceal cracks and imperfections that naturally occur in exterior masonry surfaces, so they are a good choice for climates with fluctuating temperatures.

When temperatures drop, EWCs stretch and cover the cracks that naturally develop. When temperatures rise again, EWCs recover their original shape without warping or wrinkling.

These coatings also resist water by covering cracks and protecting the masonry from wind-driven rain and other moisture. They also "breathe" to allow moisture from within the building - or the masonry itself - to escape as vapor.

The experts at The Rohm and Haas Paint Quality Institute recommend having a professional painting contractor apply the EWC system, because it must be applied in a very specific way to achieve its best performance. For best results, the masonry should first be sealed or primed.