| Elastomeric Coating |
Note: available in smooth and textured finishes.
 After water seal, elastomeric coating, trim painting, and deck coating. |
Elastomeric coating is a 100% acrylic resin polymer for use on residential and commercial exteriors. It is formulated for wood, masonry, and stucco surfaces and resists cracking and water damage. Available in smooth and textured.
One of the newest types of coatings is formulated for use on one the oldest types of building materials. You may already be familiar with elastomeric, but it's much more than "just another paint." Elastomeric coatings are specifically intended for application on masonry substrates, stucco, and wood. Special steps must be taken to ensure their optimum performance.
Elastomeric coatings are relatively new to the American architectural coatings industry, having only been introduced in the United States in the mid 1980s. They were first developed after World War II, to help rehabilitate damaged masonry buildings. They address a common problem of masonry and stucco construction - water penetrable cracks. These unsightly cracks can make even the soundest construction job appear flawed, and may also eventually lead to the deterioration of the structural integrity of the building.
Elastomeric wall coatings are uniquely formulated to stretch and bridge cracks that may form due to movement that can occur, despite the hardness and strength of the substrate. When the wall contacts as temperatures drop and the cracks expand, the elastomeric wall coating stretches and resists cracking itself. When the temperature rises and the cracks become smaller, the coating returns to its original shape without wrinkling or leaving ridges. This crack bridging capability results in a long lasting, uniform finish.
 Before water seal, elastomeric coating, trim painting, and deck coating. |
To achieve the special balance of properties required to make a top quality Stretchguard elastomeric wall coating, manufacturers use acrylic binders that are designed specifically for this use. Using these all acrylic binders provides the coating with a high degree of flexibility and elasticity, while exhibiting appropriate tensile strength, and superior alkali resistance and dirt resistance, which are important considerations. These top quality Stretchguard elastomeric wall coatings cure to a smooth, non tacky, high dirt resistant finish which will resist cracking and wrinkling.
In addition, coating elastomeric wall coatings strike a careful balance between water resistance properties on the one hand, and vapor transmission rate, or permeability on the other. Water resistance is important for holding liquid water, e.g., wind driven rain; water vapor permeability is essential to allow moisture from within the substrate, or in the building itself, to escape through evaporation.
Surface preparation
 Before stucco repair, carpentry, water sealing, elastomeric coating, and trim painting |
Good surface preparation is important before any paint or coating job. With masonry, certain aspects need special attention, such as alkalinity, porosity, and the tendency to form efflorescence. Experts at the the Paint Quality Institute advise that first be certain that the masonry substrate is clean and sound, so that the coating can adhere properly to the surface. At the minimum, this requires using a bristle brush to remove any dust dirt, flaking paint or other loose material. If the substrate is extremely dirty or exhibits efflorescence, vigorous wire brushing and possibly power washing or even sand blasting will be necessary.
If the surface was previously painted, mildew or mold may be present. These contaminants should be removed with a common bleach solution (three parts water to one part household bleach). In all cases after performing any surface preparation procedures, the surface should be rinsed well with clean water. Once the surface is clean, cracks greater than 1/16 inch should be sealed with a top quality water based all acrylic or siliconized acrylic caulk or sealant. Furthermore, if the surface remains somewhat chalky or is porous, apply a water based or solvent based masonry sealer before applying coating. If the surface tends to form efflorescence, or is new and highly alkaline, a masonry sealer or primer will help to protect the textured coating elastomeric topcoat.
New, cast masonry surfaces, including tilt up construction, must be thoroughly cleaned. Often forms used for casting masonry are coated with a release agent to keep the concrete from sticking to the form. The release agent may be oily in nature, and thus interfere with the adhesion of the coating, resulting in a non uniform appearance, or even gross adhesion failure. To ensue that the surface is completely free of form release agents, power washing, followed by a through rinsing, is recommended.
Application
 After stucco repair, carpentry, water sealing, elastomeric coating, and trim painting |
Elastomeric wall coatings will perform well only when applied in thick films. The Paint Quality Institute suggests that a total dry film thickness of 12 to 18 mils will provide the best crack bridging capability. The achieve this thickness, two heavy coats are normally applied. The typical application procedure is to use either an airless spray followed by back rolling, or a long nap roller. A 1-½" or 4" brush works well for smaller areas.
Properly formulated elastomeric wall coatings have a satin finish. They can generally be tinted and while white is most popular, soft pastels and subtle earth tones are often chosen as decorative options. As elastomeric wall coatings become more commonplace, questions will arise about repainting substrates that already have a elastomeric finish. When considering repainting or elastomeric coatings, there are a few basic principles to remember.
Ideally, once a coating elastomeric coating is applied, it should be allowed to weather for at least one year before a non elastomeric coating is applied over it. Even then, surfaces with elastomeric coatings should be repainted only with a water based topcoat, since oil based coatings are much less flexible, and can crack severely if applied over the elastomeric coating.
Quality pays when it comes to elastomeric wall coatings, just as it does with other types of exterior finishes. For many residential and commercial masonry buildings, a durable attractive appearance can be achieved by choosing a top quality elastomeric coating. Elastomeric coatings are available in smooth and textured finishes. Custom colors are also available.
 Before stucco repair, carpentry, new garage door, new column, water sealing, elastomeric coating, trim painting. |
 After stucco repair, carpentry, new garage door, new column, water sealing, elastomeric coating, trim painting. |
