Top Cast is a water-based, film-forming surface retarder that saves time by eliminating the need for covering the surface even when it rains. The product, available in thirteen depths of etch, is designed for poured-in-place flatwork and the top surface of precast panels.
Top Cast has been used with both integrally colored and color-hardened concrete surfaces to achieve the popular “sand” finish without loss of coloration.
“Its outstanding quality is that it is not only a chemical retarder, but it has polymer in it,” says Dustin Ferch, a contractor from Roseburg, Oregon. “When you apply it, you don’t have to cover it with plastic because it creates its own film.”
The fact that it is available in many subtle gradations of depth — from super-fine sand, to sand, to exposed aggregate — also makes it extremely useful. “If you need to match a pre-existing job, it gives you a lot of range so you can get an exact match,” he says.
His only caution is that you need to be careful about overspray. “Ammonia does clean it up but it takes a lot of elbow grease,” he says. He recommends covering adjacent areas to avoid this problem.
The product is VOC-compliant and easy to apply. It has an excellent coverage rate.