One of the more common questions we field during exterior estimates is whether a home should get elastomeric paint or a standard acrylic. The distinction matters more in Florida than in most of the country, because our combination of stucco construction, thermal cycling, and intense UV exposure plays directly to the strengths and weaknesses of each product type.
The short answer: both are good options, but they solve different problems. Here’s how to think about which one your home needs.
What elastomeric paint is
Elastomeric paint is a thick, rubber-like coating with exceptional flexibility. It’s applied at a much higher mil thickness than standard paint — typically 10–20 mils dry film thickness versus 3–5 mils for a conventional exterior acrylic. That thickness gives it two properties that are particularly relevant in Florida: it can bridge hairline cracks in stucco, and it forms a highly waterproof membrane over the substrate.
It’s designed specifically for masonry — concrete block, stucco, EIFS — not for wood or trim. You’ll see it specified on commercial buildings and multi-family construction throughout South Florida, and it’s a legitimate option for residential CBS homes as well.
What standard acrylic exterior paint is
Premium 100% acrylic exterior paints like Sherwin-Williams Emerald Exterior or Duration Exterior are flexible, breathable coatings that adhere well to properly prepared surfaces. “Breathable” is the operative word — a quality acrylic allows moisture vapor to escape from the substrate rather than trapping it behind the paint film. This matters a lot in Florida’s humidity, where moisture vapor is constantly trying to move through wall assemblies.
Acrylics are the right choice for wood siding, trim, doors, and most standard applications. They also work well on stucco that’s in good condition with no active cracking issues.
The key tradeoffs
Crack bridging. This is where elastomeric has a clear advantage. Hairline cracks in stucco — the fine spider-web cracking that appears as CBS homes age and thermal cycling works on the substrate — can be bridged by an elastomeric coating. A quality acrylic will follow the crack; it won’t bridge it. If your stucco has significant hairline cracking, elastomeric is worth considering.
That said, elastomeric crack bridging has limits. It handles hairline cracks (under 1/32”) well. Larger cracks — anything you can insert a credit card into — need to be filled before any coating goes on. Elastomeric is not a substitute for proper crack remediation.
Vapor permeability. This is where the decision gets nuanced. Elastomeric coatings are much less vapor-permeable than quality acrylics. In a dry climate, that’s fine. In South Florida, where masonry walls absorb moisture and that moisture needs to escape, trapping it behind a low-perm coating can cause problems: blistering, delamination, and in serious cases, stucco damage.
Elastomeric is most appropriate when the substrate is in good condition and there are no active moisture intrusion issues. If there’s any sign of water getting into the wall assembly — efflorescence, interior staining, soft spots — those need to be diagnosed and fixed before an elastomeric coating goes on. Sealing an active moisture problem behind a waterproof membrane makes it worse.
Film thickness and application. Elastomeric requires careful application to achieve the specified mil thickness. It’s typically applied in two coats by experienced applicators using the correct roller nap and technique. Under-applying elastomeric defeats its purpose. This is one reason we’re cautious about it as a DIY product in the Florida market — the application requirements are less forgiving than a standard acrylic.
Cost. Elastomeric products cost more per gallon than standard exterior acrylics, and they require more material to achieve the correct film build. On a typical South Florida CBS home, expect elastomeric to add $1–3 per square foot compared to a quality acrylic job, depending on the specific product and the number of coats specified.
When we recommend elastomeric
- Stucco that has significant hairline cracking across large surfaces (not just isolated spots that can be filled)
- Homes that have had recurring minor stucco cracking issues after previous paint jobs
- Certain EIFS (synthetic stucco) applications where the manufacturer specifies an elastomeric coating
When we recommend quality acrylic
- Most standard CBS homes with stucco in good condition
- Any wood siding, trim, doors, or fascia (never use elastomeric on wood)
- Homes where the previous elastomeric coating is failing and needs to be stripped — elastomeric over failed elastomeric is not a solution
- Budget-conscious projects where the substrate doesn’t have significant cracking
Our default specification
For the majority of residential exterior jobs we do on the Treasure Coast and in South Florida, our default is Sherwin-Williams Emerald Exterior — a 100% acrylic with excellent flexibility, a built-in mildewcide, and strong UV resistance. For homes with significant hairline cracking, we specify Sherwin-Williams Loxon Elastomeric or Elastomeric Coating as a topcoat system over appropriate primer.
We don’t have a one-size-fits-all spec. The product selection happens after we’ve looked at the substrate, checked the paint history, and assessed the condition — which is why the estimate walkthrough is more than just a measurement.
For more on what makes a paint job last in this climate, see our post on how often stucco homes in South Florida need repainting.
Ready to get a proper assessment?
Understanding which product is right for your home starts with seeing the substrate in person. Our exterior painting estimates are free, written, and include product recommendations specific to your home’s condition.
KB Painting & Refinishing is a family-owned and operated Sherwin-Williams preferred contractor, founded in 2019, with a crew bringing 25+ years of combined hands-on Florida experience. Our own crew on every job.
