Source: MASONRY CONSTRUCTION MAGAZINE
Publication date: May 1, 2007
By Lorella Angelini
High-build coatings are much more than paint over concrete block or other concrete surfaces. They are high-tech products characterized by properties such as resistance to wind-driven rain, chalking and checking after weathering, high ultimate (breaking) elongation, elongation recovery and crack bridging capability, and water vapor permeability.
This article focuses on the benefits in using high-build coatings as surface treatments over concrete, points out their unique performance properties, and explains applicable ASTM test methods.Coatings vs. paints
| Graph illustrates the relationship between temperature and thickness, with the thin elastomeric coating breaking at the maximum crack extension in cold temperatures. |
At a glance, acrylic high-build coatings are often mistaken for ordinary paints. They come in a pail, are applied on the wall by roll or spray, and are available in a variety of colors, either directly from the factory or tinted at the local distributor. However, the similarities end here.
High-build coatings are generally applied in one or two coats to a total dry film of 10 mils to 15 mils, while ordinary paints have average thicknesses from 3 mils to 5 mils. The difference in thickness is directly related to the viscosity of the two materials and their percent of solids. High-build coatings contain about 50% solids by volume, versus 30% for ordinary products.
Click here to read full article from Masonry Construction