NCPTT Partners with GSA to Study Alternative Treatments for Terrazzo Flooring
No, we're not talking about ancient linoleum. But even for historic masonry flooring, it turns out that there are some interesting alternatives to the usual waxing and stripping cycles commonly used today.
Government buildings from the early 1900's are already becoming recognized for their historic importance. These buildings often have unique aspects of construction requiring special means of preservation. Recognizing the extensive usage of terrazzo flooring in buildings of this time period, the General Services Administration (GSA) has partnered with NCPTT to study the suitability of vitrification as an alternative floor treatment.
According to Melissa Schmidt, historic preservation specialist at GSA, the study outcome will guide GSA preservation policy both regionally and nationally, and will potentially set an industry-wide standard for preservation policy on the vitrification process.
"Previously, historic terrazzo floors have traditionally undergone repeated cycles of stripping, waxing, and buffing," Schmidt said. "Many of these floors are showing serious signs of wear and the question of alternative treatments has come up once again."
Vitrification is an alternative method using a chemical buffing technique to change the character of the top microlayer to make it harder, stronger, and more resistant to water damage. However, there have been questions about the suitability of this kind of treatment for historic terrazzo flooring. Schmidt says they are interested in this method, but has three main concerns regarding vitrification as a treatment for historic terrazzo.
"The first area of concern is whether the vitrification treatment is truly reversible or not," she said. "Good conservation practices require reversibility so that any needed future treatments might be applied without complication. Another concern is that vitrification may affect the ability of moisture to move through the terrazzo. The final concern is that the mirror-like appearance of vitrified terrazzo might not be appropriate for a historic floor."
NCPTT and GSA designed and implemented a comparative study to objectively determine the actual impact of these issues. The research compared terrazzo patterned after flooring in the Milwaukee Federal Building but with three different treatments: raw (sealed), waxed, and vitrified. The study examined physical characteristics, water transport characteristics, glossiness and surface chemistry of the sample types.
NCPTT researchers have discovered that compared to standard wax, vitrification allows for somewhat greater moisture transport through the terrazzo, that color saturation does increase, and that surface chemistry changes permanently only for the top microlayer. Researchers also determined vitrification increases terrazzo's resistance to surface impact and that it produces a surface at the upper limit of both allowable glossiness and slip by government standards.