QuietCORK™ Test Results
QuietCORK™ materials have been tested for their acoustical properties. Certified copies of all testing results may be obtained by request from Jelinek Cork Group.
Interpretation and Cautionary Note: Many published test results, although accurate, may be misinterpreted unless closely analyzed. For this reason QuietCORK™ materials were tested to reflect the ratings as independent of other material influences as possible. For example, test results on underlayment cork materials in conjunction with suspended ceiling systems do not accurately reflect the true acoustical reduction values of impact noise and sound transmission provided by cork. The type of suspended ceiling system used during a testing procedure along with underlayment cork may result in increased IIC and STC ratings by as much as 30 dB. Since there are numerous suspended ceiling systems, it is virtually impossible to provide test results for each and every type of such ceiling system. On average it is estimated that IIC and STC ratings increase by approximately 14 dB when suspended ceilings are used in conjunction with cork underlayments. Where suspended ceilings are included in the ratings shown below, the IIC and STC values are not definitive and are only estimated averages based on information gathered from acoustic consultants and a broad range of industry sources. All other values are certified by the testing laboratories and copies of those detailed test results may be obtained by request from Jelinek Cork Group. Ratings are also further influenced by the type of floor covering placed over cork underlayments but not to the degree of suspended ceilings. Flooring thickness, material type, wood types, installation methods, glues, vapor barriers, and other factors all do influence to various degrees the final IIC and STC ratings. To provide acoustical test results with unknown variables could be misleading unless all the variables are clearly and accurately submitted. As the testing results of QuietCORK™ shown below indicate, the use of QuietCORK™ for acoustical sound control by itself and particularly in conjunction with any suspended ceiling systems and any floor types, clearly meets and surpasses required IIC and STC ratings.
Sound Ratings For QuietCork™ Underlayment
Illustration A: 6mm QuietCORK™ on 6″ concrete slab
Result Analysis: The concrete slab has a fixed rating of 27 dB (IIC). Affixing 6mm of QuietCORK™ to the concrete slab improves the overall IIC rating to 50.
Illustration B: 6mm QuietCORK™ on 6″ concrete slab with suspended ceiling and floor covering of choice.
Result Analysis: The concrete slab has a fixed rating of 27 dB (IIC). Affixing 6mm QuietCORK™ to the concrete slab improves the overall IIC rating to 50 (see illustration A). Adding floor covering may slightly alter the ratings depending on floor type. Adding a suspended ceiling unit will increase the ratings significantly, generally by an average of 14 dB depending on unit type. See the Interpretation and Cautionary Note above.
Table 1:
| Concrete Subfloor | QuietCORK™ | Suspended Ceiling | Sound Ratings IIC | Sound Ratings STC |
| 6" Slab | -- | -- | 27 | -- |
| 6" Slab | 6mm | -- | 50 | 51 |
| 6" Slab | 6mm | yes | 64 | 65 |
Comparative Testing Results of QuietCORK™ To Other Cork Underlayment Manufacturers
Field Impact Isolation Class (FIIC) testing was performed to determine the “rank-ordering” by manufacturer of several different but popular cork
underlayment materials currently being used in the North American market. These relative ratings apply to bare 5/8″ plywood laid over the cork and the cork over the concrete without any binding cement. Such cement may alter the result slightly. Four different specimens of cork from other manufacturers were used, and one test was run without any cork to serve as the control number.
Upper room (shown) separated by 6″ concrete slab from receiving room below. These units were tested to determine QuietCORK™ acoustical values as compared with other cork underlayments being marketed.
Table 2: Expressed on a relative “IIC” scale
| Material | Rating | Ranking |
| Manufacturer 1 – 6mm cork | 54 | |
| QuietCORK™ – 6mm cork | 55 | Best |
| Manufacturer 2 – 6mm cork | 54 | |
| Manufacturer 3 – 6mm cork | 53 | Least |
Result analysis: All (but the no cork) produced acceptable results but QuietCORK™ ranked as the material with best results. This data is not absolutely indicative of the IIC value that may be achieved in the field, but is rather aimed at comparing various materials and “rank-ordering” those materials accurately, the higher number indicating better isolation on a decibel scale.
Illustration C below is the actual data, graphing the impact sound levels of the differing cork underlayments.
Illustration C
Custom Testing Available
Upon request, QuietCORK™ consulting technicians are available to perform laboratory or field testing for companies requiring this service. Accurate IIC and STC ratings for specific full floor and ceiling assemblies can be obtained. For detailed information concerning procedures and costs, contact Jelinek Cork Group.
Testing Organizations &Standards
QuietCORK™ materials have been tested for their acoustical properties. Certified copies of all testing results may be obtained by request from Jelinek Cork Group.
QuietCORK™ by Jelinek Cork Group
Acoustic Solutions For Impact Noise and Sound Transmission
1-800-959-0995
905-827-4666
cork@jelinek.com