ACOUSTIC CEILING RESTORATION CANADA

Combating challenges with coatings for acoustic ceilings

 

Product testing
Since the ceiling’s ability to perform as stated is crucial, the kingpin in the restoration process is ensuring the selected acoustical coating will perform as expected. Independent laboratories should document six major performance characteristics of an acoustical coating to be considered by the architect. Without hard test data to support claims made in product literature, promises about performance can be suspicious.

 

Not only should the product be tested in the following areas, but procedures must also be conducted in accordance with specific ASTM or industry standard tests. From an architect’s perspective, if a restoration product manufacturer cannot provide independent testing data in each of these six areas, there is an unnecessary risk in accepting verbal claims.

 

Acoustics
The application of a restoration coating should not negatively affect the tile’s ability to absorb sound. In accordance with ASTM C423, Standard Test Method for Sound Absorption and Sound Absorption Co-efficients by the Reverberation Room Method, and ASTM E795, Standard Practices for Mounting Test Specimens During Sound Absorption Tests, one coating manufacturer reports an improvement of a 0.55 NRC tile to 0.60 has been reported.

 

While the exactness of these tests can be questioned because every test has levels of accuracy, there is a slight improvement generally attributed to the softer composition of an acoustical coating, rather than a harder conventional paint. Regardless of whether there is a slight improvement to the NRC, however, most restoration products see no decrease or negative effect, which is preferable to the alternative.

 

Fire retardancy
The rate at which a flame is delayed from spreading across a ceiling surface is measured by the Steiner Tunnel Test—ASTM E84, Standard Test Method for Surface Burning Characteristics of Building Materials. In this test, ‘0’ represents the rate at which flame spreads using cinder block as a substrate and ‘100’ when using white oak. (The closer the number is to zero, the better the results.) Class A is defined as a flame spread between ‘0’ and ‘25,’ Class B between ‘26’ and ‘50,’ and so on. The Steiner Tunnel Test also measures the amount of smoke developed by the coating material’s burning. (Again, the lower the number, the better.)

 

Lightreflectance
The coating’s ability to disperse light is important from an energy standpoint. The better the light dispersion, the less dependency on artificial electrical sources (and, as such, less energy use). When the coatings were developed, this was measured by ASTM C523-68, Test Method for Light Reflectance of Acoustical Materials by the Integrating Sphere Reflectometre.

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Combustion toxicity
Since fires are always a possibility, it is important to know whether the burning of the coating material itself gives off a gas dangerous to occupants. In place of an ASTM test, the industry standard is The Protocol of the University of Pittsburgh for the Evaluation of Acute Toxicity of Thermal Combustion Products.

 

Aging
A common question when considering options other than replacement with new materials, is about the restoration’s longevity. The assimilated time exposure test of ASTM E313, Standard Practice for Calculating Yellowness and Whiteness Indices from Instrumentally Measured Colour Co-ordinates, demonstrates how long the restoration coating will last by comparing samples exposed to the same conditions.

 

In this case, the coated surface of a new tile and a restored one can be tested simultaneously and the whiteness index of each sample monitored over time. Acoustical restoration coatings typically perform better in these tests than the coatings applied to new tiles or high-quality latex paints, primarily due to its superior composition.

 

Low VOCs
The better acoustical coatings have minimal volatile organic compound (VOC) content and as a result are acceptable by environmentalists. Manufacturers should provide a material safety data sheet (MSDS) report that contains VOC levels.