Elastomeric or rubberized paint is a specialized exterior coating known for its elasticity and waterproofing abilities. Unlike regular exterior paints, elastomeric paint can stretch and flex along with the surface as it expands and contracts due to temperature changes. This flexibility makes it highly durable and weather resistant. The elastomeric resins in the paint also provide excellent waterproofing, allowing it to seal out rain and moisture effectively.
While the benefits are significant, it is also important to understand elastomeric paint’s potential drawbacks and disadvantages. There are certain limitations in how and where it can be used. The product also comes with higher costs compared to regular paint. The application requires specific skills and techniques for the best results. Knowing these factors will allow you to decide whether elastomeric paint is the most suitable for your exterior coating project.
What is elastomeric paint? What are its common uses and benefits?
- Elastomeric paint is a flexible exterior coating that contains elastomeric resins or rubber-like polymers as binders. The elastomeric resins allow the dry paint film to expand and contract flexibly with the surface underneath.
- Its key uses are as an exterior coating for surfaces like stucco, concrete, masonry and wood. It protects from weathering and waterproofing.
- Key benefits are durability, crack resistance, waterproofing and weather resistance. The paint film can bridge cracks and move with the surface, preventing damage.
- Elastomeric paints often have a thicker consistency than regular paints to provide a protective coating over the surface. Two or three coats are usually applied for best performance.
One of the biggest potential disadvantages of using elastomeric paint is its high cost compared to regular exterior paints. Here are some factors that contribute to the higher price point:
High Upfront Cost
- Elastomeric paint is more expensive than regular exterior latex or acrylic paints. The elastomeric resins make the paint more complex to manufacture.
- Expect to pay 50% to 100% more compared to the cost of regular exterior paint. For example, a gallon of quality elastomeric paint can cost $70 to $100, while regular exterior paints cost $30 to $50 per gallon.
- The high solids content and thicker consistency means more raw materials are used per gallon than regular paint. This further drives up production costs.
- Being a specialty product for specific exterior applications, it is produced by fewer manufacturers. The niche market leads to higher pricing.
Additional Expenses for Professional Application
- While it is possible to apply elastomeric paint as a DIY project, hiring professional painters for the best results is highly advisable. Improper application by an amateur can lead to early paint failure.
- Professional application adds significant cost in the form of labor. Complex areas like multi-story exteriors take more time to prep and paint correctly.
- Professionals have the right tools, like commercial airless sprayers, to apply the thick paint efficiently. Spray application is faster compared to rolling by brush.
- Consider additional expenses for surface repairs, caulking, extensive prep work and primer that a painting pro may recommend as part of their service.
- Professional painting services can add $3 to $7 per square foot on top of the paint costs. The total project cost for elastomeric painting will be substantially higher than regular paint jobs.
Applying elastomeric paint correctly is an intricate process that presents challenges even for experienced painters. Here are some key difficulties to be prepared for:
Requires Experienced Painters
- Elastomeric paint is not well-suited for DIY application by amateurs. The application techniques required differ significantly from applying regular latex paint.
- Each coat must be applied at the proper wet film thickness (WFT) to achieve the right dry film thickness (DFT) for protection. This requires skill.
- Professionals use specialized tools to measure WFT and ensure proper coverage. Amateurs may end up with areas that are too thin.
- Paint preparation, spraying techniques, back-rolling and recoat times require training and experience for a successful application.
Complexity in Application Process
- Surface preparation is vital and involves thoroughly power washing, repairing cracks and caulking joints. The use of proper primer may be required.
- Paint needs to be mixed correctly before spraying or rolling. This includes proper dilution if required by the manufacturer.
- The application process involves careful spraying or rolling using vertical passes and crosshatch techniques. Each coat must go on at the right thickness.
- Optimal spray tips, sprayer pressure settings and spraying motions take experience to master. Each coat must also be back-rolled.
- Proper drying and curing times between coats is critical. Rushing the job leads to weak inter-coat adhesion and paint failure.
- Environmental factors like temperature, humidity and wind must be monitored throughout the application process.
Does elastomeric paint require a primer?
- Using a compatible primer provides an improved surface for the elastomeric paint to adhere to. However, some products are formulated as self-priming.
- A primer may not be necessary for previously painted surfaces in sound condition. Always check manufacturer guidelines.
- On new surfaces like stucco, concrete and masonry, an alkali-resistant primer helps protect the elastomer binders in the paint from alkalinity damage.
- Primers also help seal porous surfaces and improve coverage, though some elastomeric paints contain extra resins to help wet such surfaces.
Elastomeric paint’s visual appearance and finish may make it unsuitable for surfaces where aesthetics are a priority. Consider these potential issues:
Glossy, Plastic-Like Appearance
- Elastomeric paints provide a thick, rubber-like coating over the exterior surface. This often results in a glossy or semi-gloss appearance.
- The visual effect is sometimes described as looking ‘plastic-y’ or too glossy compared to regular matte paint finishes. This may be viewed negatively from an appearance standpoint.
- If the elastomer paint is not applied perfectly uniformly, noticeable visual irregularities like shiny spots can become apparent as light reflects unevenly off the coating.
Limitations in Color Options
- Elastomeric paint is available in limited colors, often just basic white and tinted colors. Specialty and custom colors are harder to find.
- Tintable options still cannot achieve dark colors. Deep hues are difficult to formulate with the thick resinous paint base.
- Color options are more limited than the vast selection of colors and finishes with standard exterior acrylic latex paints.
Elastomeric paint for exterior walls
- For exterior walls, elastomeric paint can provide great protection. However, the glossy finish and limited color choices may be unsuitable for exterior house walls where aesthetics are important.
- Using elastomeric paint only for susceptible areas and regular paint for general wall areas is a good compromise. Regular acrylic latex exterior paint may be the better overall choice for homes.
Properly preparing surfaces for elastomeric paint application is critical for good results but presents some unique challenges:
Time-Consuming Prep Work
- Elastomeric paint requires extensive surface prep as it will not mask flaws. Any damage or imperfections must be repaired.
- Previously painted surfaces must be pressure washed and scrubbed using chemicals like TSP to remove chalking or loose paint. This is labor intensive.
- New surfaces need proper cleaning, abrasion and profiling for the paint to adhere correctly. This adds time.
- On some jobs, structural improvements or installation of expansion joints must be completed as part of preparation. This further lengthens the project timeline.
Need for Specialized Cleaning Agents
- General prep products like bleach or vinegar are ineffective at cleaning surfaces for elastomeric painting.
- Professional strength chemicals like TSP (trisodium phosphate), Jomax or Krud Kutter are essential to etch and degloss existing painted surfaces properly.
- Paint failure can result if inadequate cleaning leaves behind chalk, grease, oil or other contaminants before applying the elastomer coating.
- Proper safety precautions are required when using hazardous cleaning chemicals, further adding complexity for DIYers.
Elastomeric paint for stucco
- Elastomeric paint works well for new or existing stucco by flexing over hairline cracks. However, thorough initial prep and cleaning is vital to prevent adhesion problems.
- A primer coat designed for stucco improves adhesion and prevents saponification issues. The elastomeric paint topcoats provide lasting protection from moisture ingress.
Not all elastomeric paint products are created equal. Quality and performance can vary significantly between different brands and formulations. Here are some key considerations:
Inconsistent Product Descriptions
- Some manufacturers loosely use ‘elastomeric paint’ to market products that may not contain true elastomer binders.
- Product descriptions do not always provide complete details on resin chemistry and composition. This makes it hard to know you are purchasing a quality elastomeric coating.
- Claims of elongation or flexibility are loosely thrown around without supporting lab test data on a product’s elasticity properties.
- It takes extra diligence for contractors and consumers to cut through vague marketing claims and select a coating backed by performance data.
Importance of Brand Selection
- With an array of elastomeric brands and products, it pays to stick with established manufacturers focusing on coatings.
- Look for products like Sherwin-Williams Loxon XP, Benjamin Moore Elastomeric Plus or PPG PermaCrete Alkali Resistant Primer which major reputable suppliers back.
- Review product data sheets carefully to evaluate elastomeric resin content, elongation ability, permeability ratings and application requirements before purchasing.
- Using quality products helps ensure you will achieve the protective performance and longevity elastomeric paints are known for.
Sherwin-Williams Elastomeric Paint
- Sherwin-Williams Loxon XP masonry coating is a premium elastomeric paint with excellent protection and waterproofing.
- It contains elastomeric acrylic polymers that help the coating bridge minor cracks and expand/contract with the surface.
- Loxon XP has over 240% elongation for flexibility and offers alkali and water vapor permeability.
- For best results, Loxon XP should be applied by skilled professionals in 2 coats at 4-8 mils wet film thickness per coat.
Limitations in Use
While elastomeric paint works well on many exterior surfaces, it does have some inherent limitations that restrict its use in certain applications:
Not Suitable for All Surface Types
- Elastomeric coatings are only designed for use on non-moving exterior surfaces. They should never be applied on joints, doors, windows or mobile surfaces.
- Performance problems arise when elastomeric paint is incorrectly applied onto incompatible materials like flexible rubber membranes, asphalt surfaces, or plastic trim and flashings.
- Adhesion can fail leading to cracking and peeling. Always check manufacturer guidelines on compatible substrate types before applying.
Risk of Peeling and Permeation Issues
- Elastomeric paint needs a completely clean and sound substrate to adhere to. Any glossy or sealed surfaces will lead to peeling or delamination.
- Inadequate surface prep leaves behind contaminants that impede adhesion, causing the paint to peel away prematurely.
- Certain surfaces with varying porosity or high alkalinity can lead to insufficient film build and premature breakdown of the elastomer resins.
Elastomeric Paint for Wood
- Using elastomeric paint on exterior wood surfaces is high risk and typically not recommended. The flexible paint film does not adhere well to dimensional lumber.
- Any moisture trapped behind the elastomer coating cannot escape, leading to peeling and performance problems.
- For wood, breathable acrylic latex primers and paints are a better choice for proper moisture vapor transmission.
Specialized safety precautions are required when working with elastomeric paints. Respiratory protection is a must to mitigate exposure to solvent fumes:
Fumes and Ventilation
- Most elastomeric paints contain volatile organic compounds (VOCs) as solvents that keep the paint workable for spray application.
- The solvents evaporate as the coating dries, creating strong and potentially harmful fumes. This makes ventilation critical.
- Breathing solvent vapors can cause headaches, dizziness, nausea and other health effects. Appropriate respirators must be worn.
- Fans and air scrubbers may be needed to exchange air and remove fumes for interior applications. Open exterior areas still require respirators.
Is Elastomeric Paint Breathable?
- Elastomeric paint forms a thick, protective barrier that can inhibit vapor transmission. This makes ventilation and breathability important concerns.
- 100% elastomeric paints are considered vapor retarders, not vapor permeable. If applied as a singular barrier coating, they can trap moisture inside the wall assembly.
- Elastomeric paint should only be applied as a topcoat over vapor-permeable acrylic primer and paint layers to maintain breathability. This provides a breathable system.
Alternatives and Comparisons
While elastomeric paint has benefits in certain applications, it is not the only option. Here are some other coating types to consider:
Other Exterior Paint Options
- Acrylic latex paint is more affordable and provides good durability and color options. It lacks the elastomeric properties but breathes well.
- Epoxy paint resists abrasion and chemicals. It adheres very well but is prone to chalking and lacks flexibility.
- Polyurethane paint provides a clear glossy finish for accent areas. Requires more prep work and recoat time.
- Silicone-modified paint enhances water resistance while maintaining vapor permeability. It has limited color selection.
What is the Alternative to Elastomeric Paint?
- For concrete and masonry, acrylic latex paint provides decent protection. While not as elastic, it breathes better than elastomer coatings.
- On stucco, a silicone-modified paint provides good water resistance and enhanced breathability compared to elastomerics.
- For wood exteriors, use a 100% acrylic or oil-based alkyd paint. Their permeability allows moisture to escape, reducing peeling risks.
The long-term performance of an elastomeric paint job depends on several factors:
- With proper maintenance, elastomeric coatings can last 8-12 years or longer before needing major reapplication. Regular upkeep is essential.
- Every 2-3 years, a fresh coat of elastomeric paint should be applied over problem areas that receive greater exposure to maintain full waterproofing ability.
- Catching and repairing any damage, cracks or breaches in the coating as they occur will improve longevity and prevent moisture issues.
What is the Life Expectancy of Elastomeric Paint?
- On average, a properly applied elastomeric coating system can last 10-15 years before requiring a full re-application.
- Life expectancy depends heavily on substrate condition, application quality, weathering exposure levels and regular maintenance.
- With minor touch up coats applied every 3-5 years, elastomeric paint can last 15-20 years.
Elastomeric paint can provide excellent protection for exterior surfaces when applied correctly. However, the product does come with higher costs, preparation requirements, limitations on usage and potential drawbacks that should be carefully weighed. Key points to remember include:
Summary of Key Disadvantages
- Higher material costs compared to regular exterior paint
- Complex application process requiring professional painters
- Extensive surface preparation needs
- Potential adhesion and aesthetic issues
- Greater environmental impact from solvent fumes
- Only use elastomeric paint where its protective strengths are required and worth the higher costs
- Carefully evaluate if it is the best choice for your particular exterior, considering the alternatives
- For DIYers, acrylic latex paints provide an easier and more accessible option
Elastomeric coatings are important in protecting exterior surfaces from water and weather damage. But understanding the potential disadvantages allows you to make the most informed choice for your coating project.