Water is the ancient enemy of structures everywhere. From the very oldest times, builders have been trying to find ways to keep water from infiltrating their buildings. Today, we have many different ways of doing that—and one of the best is elastomeric paint.
Elastomeric paint, or elastomeric coating, is a paint that’s uniquely strong at repelling water. An elastomer is a polymer that has elastic properties—in layman’s terms, it’s something you can roll on as a coating that will dry as its own elastic, impermeable layer.
What makes elastomeric coatings special?
Regular paint will help you keep rain out, but only for so long. Given enough time or a hard enough rain some will begin to seep through. Elastomeric paint is much more resistant to rain than regular paint.
In addition, the properties that make the elastomeric coating elastic also make it fill in any gaps and cracks. With regular paint, small gaps and cracks will run all the way through to the surface, exposing the interior of the wall to the elements. Elastomeric paint stretches instead of breaking at the crack, making it a great choice for walls that are exposed to the elements. It’s particularly useful for concrete, stucco and EIFS, which are the most commonly used commercial building materials for the outside skin of a building.
For the same reason, elastomeric coatings deal well with thermal fluctuations. When buildings expand and contract, regular paint will expand and contract with it. Elastomeric coating has more flex built in. The elastomers act similarly to shock absorbers, taking the strain and flexing with the temperature changes that will break the waterproofing of regular paint.
Why not use elastomeric coatings for everything?
There are two reasons: cost and color.
Elastomeric coatings are more expensive than regular paints, and not every application needs the extra flex and waterproofing that are their calling card. If you don’t need it, it’s more money for a marginal extra bit of protection.
In addition, elastomeric coatings don’t come in dark colors. Coatings will lighten and “chalk” over time with exposure to the elements too. If you want to put a dark color on the wall, you’ll have to use an exterior acrylic paint.
If you have a structure that needs some extra waterproofing, elastomeric coatings may be the answer. Give JKI a call for any of your structural waterproofing needs, and find out what we can do for you.