Acoustical Performance Tests Natural Finish

In many existing spaces, sound reverberates off hard surfaces—be it an office, theater, or other enclosed space - thereby diminishing the general enjoyment or compromising the work environment.

Fellert Acoustical Plaster affords architects and designers a softer approach to those areas, creating inviting spaces proven to provide superior acoustical performance. Fellert Acoustical Plaster can be applied to both ceilings and walls, so freedom-of-design can be retained with optimum acoustical control.

Acoustical performance varies depending upon the method of application and thickness of the core material. Special attention should be made to review the performance of the material at the actual frequencies required for the project.

All testing was performed by certified laboratories in Sweden and the USA in accordance with ASTM C423.

Sound Testing

When comparing acoustical data of different products it is important to note how the exposed edges are treated in the test laboratory. The test data reported on the Fellert website is conservative as the edges of the samples were sealed with a wooden frame so there is no edge absorption. Edge absorption artificially inflates a product's acoustical value in the laboratory; this value is not representative of the field-applied material regardless of installation practices. A simple 72sqft test with exposed edges will differ from actual 2,000sqft installation with an air gap as the exposed edges are less of an absorption factor.

It is estimated that acoustical data obtained with a 1/8' air gap is 10% to 20% higher than if the data were obtained with a wooden frame, negating the edge absorption of the test specimen. Printable Version