Companies that try our cement coated architectural EPS typically keep coming back for more, replacing all the other products in their arsenal. We strongly believe that, with a few exceptions, it is the best architectural product on the market for a variety of uses.
With that in mind, often contractors and architects need that “reason to switch.” They need to understand why they should try EPS before they start using it for all of their builds. Today, let’s address one concern – how the finishes will hold up over time when there is an EPS core and the coating is under direct sun.
Patterson Whittaker’s cement coated EPS profiles have been tested under ASTM G155/G26 using a xenon-arc Weatherometer, and the results after 2500 hours of exposure show no change in product appearance. That’s a strong outcome, and it translates to genuine confidence in how the finish holds up over years of sun exposure on a real building, not just hours in a lab chamber.
About the Xenon-Arc Weatherometer Test
A Weatherometer chamber runs repeating cycles of intense xenon-arc light, controlled heat, and moisture to reproduce the combination of UV exposure, temperature swings, and rain or dew a building material experiences outdoors. It does this to mimic long term sun damage compressed into a fraction of the time.
ASTM G155 governs how the chamber operates, and ASTM G26, its retired predecessor standard, defines an earlier version of the same method still referenced in product testing today. After a set number of hours, the sample gets compared against an unexposed control for color change, chalking, cracking, or loss of gloss.
Coatings and plastics manufacturers across the industry use this exact test to separate formulations that hold up from ones that don’t, and PW’s coating held through 2500 hours without any visible change — a result well ahead of where most coatings start to show wear.
Using the coatings industry’s common rule of thumb, where roughly 2000 hours of xenon-arc exposure tracks with about 5 years of vertical outdoor exposure in a temperate North American climate, 2500 hours works out to somewhere around 6 years of sun exposure before any change was detected in testing. That translation is an industry approximation rather than an exact guarantee, but it’s a strong signal for a finish coating.
Getting the Most Color Life Out of an On-Site Installation
Of course, there are testing limitations, which is why it is so important to make sure that you’re taking into account the factors that may affect color in your local area. Consider the following to get the most out of your product:
- Match Color Intensity To Sun Exposure — Lighter finishes handle south- and west-facing walls, where UV and heat exposure run highest over the course of a day, better than darker ones, since dark pigments absorb more energy and run hotter in direct sun.
- Factor In Regional Climate — Projects in high-altitude or high-UV-index regions, or areas with long, intense summers, get more color life out of lighter or more UV-stable color selections chosen up front.
- Confirm Proper Application — A finish coat that’s applied and cured correctly gets the full benefit of the tested formulation. This is where the tested result and the installed result line up most closely.
Paired with the right color choice for a project’s exposure and a properly executed application, our products show in the research a strong basis for expecting long-term color stability on the finished building. For help choosing a finish color suited to a specific project’s climate and orientation, reach out to the PW Profiles team.
