Elastomeric Coatings & Paint Explained
Elastomeric Paint Coatings Pros, Cons & Comparisons
Elastomeric coatings offer thick coverage and often look the same as conventional paint. It also provides the strongest moisture barrier of any exterior coating, but an elastomeric product is much different than household paint and is only ideal in some situations.
Elastomeric technology has been around for nearly 80 years but is often misrepresented by a lack of awareness.
Several things still need to be clarified, even for those familiar with an elastomeric coating.
An Introduction to Elastomeric Paint Coatings
Elastomeric applications are high-build coatings designed to perform in specific applications.
The term elastomeric describes the properties of the coating that allow for elongation to accommodate substantial expansion. Its expansion capabilities enable the coating to stretch without cracking or degrading. A high-grade elastomeric product will allow over 200% substrate expansion without separating the molecules of the coating.
Elastomeric coatings contain acrylic and vinyl polymers having a higher ratio of vinyl polymers by volume and offer 45 – 70% solids.
Even though elastomeric paint contains less acrylic, it will inevitably last longer because it provides substantially thicker milage offsetting oxidation influenced by climate-causing degradation.
The thick elastomeric coating bridges hairline cracks and increases uniformity on textured or uneven surfaces. But elastomeric coatings will cause water damage to areas that require high water permeation.
Comparing Paint, Coatings, & Elastomeric Applications
Since a significant aspect of the elastomeric verbiage is related to thickness, comparing paints and coatings quantitatively is the most definitive way to understand their differences.
Applying multiple layers of paint is not comparable to an elastomeric coating, and here is why.
The number of solids and dry film thicknesses is substantially more for elastomeric coatings. Let’s compare by mils, also known as thickness.
- Elastomeric coatings range from 25 – 40 mils wet thickness.
- Conventional exterior household paint dries less than 5 mils thick.
- When a paint film dries at more than 5 mils thick, it’s considered a coating.
- Elastomeric coatings contain 45-70% solids by volume.
- Exterior paint contains 25-40% solids by volume.
The wet mil thickness rating calculates how thick a semi-solid product applies before completely drying on the surface.
Dry film thickness refers to how thick the raw materials and resins remain after all solvents have evaporated. “Think of it as what you had vs. what remains.”
Consequently, an elastomeric coating will dry thicker and last longer than a paint coating.
Elastomeric paint is good for?
Not all surfaces can sustain a thick coating that doesn’t allow moisture transfer. The need for moisture transfer is where conventional exterior paints prevail, offering enough protection to prevent excessive water vapor entrance while gradually allowing small amounts of moisture to dissipate beneath the surface.
Elastomeric paint is great but has its place and is commonly more appropriate in commercial applications. Although, in instances where water prevention is needed, like interior basement walls, elastomeric paint is an ideal option.
Most notably, elastomeric paint works extremely well on stucco, concrete, brick, and masonry substrates. This thick moisture-prohibiting coating is ideal outdoors on slab-on-grade homes.
Fortified elastomeric coatings will fail outside on concrete substrates and foundations that transfer moisture. But when your foundation walls are properly sealed and ventilated from the inside, an elastomeric coating will last a long time.
Elastomeric Paint & Coating Drawbacks
The surface must be completely dry upon application if your home is primarily wood.
Secondly, if areas are prone to constant water flow, an elastomeric coating will not allow the wood to breathe, leading to wood rot. Coatings that limit water vapor can also lead to structural issues that are often unseen.
Things to consider before starting the process:
- Harder & more calculated applications
- Covers less sqft (between 40-180 sqft)
- Unexperienced painters thinning the paint
- Requires an industrial-grade sprayer
- Requires back rolling
- Visually excessive paint stippling
When considering an elastomeric coating, it’s best to seek the professional option and analysis of a certified or licensed expert that can assess the property and offer recommendations that provide long-lasting results. Otherwise, like any other application error, an ill-advised coating will lead to failure and damage.
Should You Use An Elastomeric Paint on Your House?
Elastomeric Rubberized Roof Coatings
Elastomeric rubberized roofs are monolithic waterproofing systems that last up to 25 years. These systems are offered in water-based, silicone/ acrylic, and urethanes.
Rubberized roofs often come in black and white colors, while white will reflect UV keeping the roof cooler and lowering energy costs. But white often comes in an acrylic formula that can only be applied to sloping roofs.
Behr Elastomeric Paint
Behr’s elastomeric paint is highly sought after by homeowners but doesn’t meet industry standards for industrial applications. So, we cannot recommend or consider it an official elastomeric coating.
Generously enough, our exterior painters loosely refer to Behr’s elastomeric offering as a paint coating, not to be confused with an elastomeric coating.
The key feature of this product is its ability to breathe and withstand hard wind and weather. Behr Elastomeric paint is worth considering if you are looking for thick paint requiring less application expertise.
Sherwin Williams Elastomeric Paint
Sherwin Williams Conflex elastomeric paint is an official industrial-grade coating that doesn’t come with a cheap price tag. Its resistance to wind-driven rain on vertical surfaces makes it stand out in a way few other products do.
Additionally, Conflex provides resistance to ground efflorescence and is easier to apply than other elastomeric coatings.
The limit in sheens deems this product suitable for limited applications. This non-reflective coating reduces surface imperfections and bridges hairline cracks just as good or better than competing brands.
Conclusion
When a concrete wall, flooring, or a roof needs long-term durability from the elements, an industrial coating will enhance and preserve it like no other product.
Be mindful that some offerings combine acrylic and elastomeric properties, so you must read the product details carefully to ensure the paint meets the intent of the purchase.
In terms of application, the most overlooked step is back-rolling surfaces after spraying to provide a uniform finish.
If you are looking for a professional finish, contact us for your next assessment.
