Q&A Column

We've always heard that you can't color plaster successfully. Is this true, or has the state of the art changed?

For years, plasterers have struggled to achieve uniform color, batch to batch, in both interior and exterior plaster. Designers and builders have always recognized what an advantage it would be, in the construction industry, to be able to feature the solid strength and durability of plaster together with a permanent color, requiring only minimum maintenance, without the cost and delay of paint or wallcovering. Until recently, these features have not been available as part of a single package, and the answer to the question was always, sadly, no we can't successfully color plaster.

With the advent of acrylic polymer technology, the plastering industry has experienced significant changes in not only the products available to plasterers, but also to time-honored techniques and methods of installation. The industry has taken advantage of additives to improve cure and reduce cracks, plasticizers to improve workability and pumpability, and even acrylic color emulsions which will allow ... yes ... colored plaster walls.

Acrylic emulsions can be very precisely measured and dispensed (similar to a paint tinting system), allowing consistent coloration of known-quantity plaster batches. The technology has not eliminated the need for trained and qualified mechanics, as all measurements and batching must be exact, and the application technique can affect the final color. For the first time, though, because of these improvements in industry capabilities, plastering contractors can offer their clients all the positive features mentioned above.

Recent jobs in the Minnesota market featuring colored walls include First Bank, Mpls.; IBM Hq., Mpls; Kenwood Condos; Hopkins West Jr. High.

Answer submitted by Bruce Pottle, CSI, MN Lath & Plaster Bureau