Traditionally, thick elastomeric coatings were not permeable and were mainly used on roofs. Modern elastomeric coatings “breathe,” which lets moisture vapor escape. Rhino Shield’s ceramic elastomeric formula passes wind-driven rain tests and is still fully permeable, allowing the substrate to breathe.

AmCoat’s Director of Products and Applications, Mike Moore, stressed the importance permeability in today’s coatings. “The resin technology we employ allows for a thick, protective elastomeric coating that is fully permeable,” said Moore. “This is super important for wood and stucco. The coating must release moisture vapors to be able to prevent moisture retention which can lead to bubbling and peeling.”

Even though Rhino Shield has employs heavy mil application thickness of between 12 mm and 20 mm, its elastomeric permeability rating is high. AmCoat’s commitment to regularly testing and upgrading its formulas is a testament to its superior performance in the field for more than 25 years. 

“We test this as a system regularly — how the primer and the top coat work together to create a water resistant but breathable coating,” said Moore. “Rhino Shield passed the wind-driven rain test with flying colors and retained a high perm rate for a ceramic elastomeric coating.”

A home’s coating is just one component of the housing envelope. Every part of the home should be contributing to a healthy house that repels water and breathes. 

“Today’s coatings must repel water but still be breathable,” said Moore. “This is particularly important in residential historic homes, many of which have no vapor barrier or insulation. These homes must breathe and the big challenge is the coating.”

Why permeability is so important:

• Impermeable coatings can fail – blister and peel
• Moisture vapors that can’t escape increase the chances of bio-growth – mold and mildew
• Trapped moisture can cause the substrate to fail

“Even with Rhino Shield, your home must have adequate venting,” said Moore. “Our dealers are trained to look for issues that could compromise a good coating and they prioritize breathability. They look at the whole home so that our coatings can perform like they are designed to.”