Are All Numbers Equal?

Are All Numbers Equal? Of course not. Some are higher, lower, bigger smaller than others. But that is all. They do not have any meaning unless you references as to what they represent. They are just numbers! In order to give them a relative value and compare them, they need to be given with the same point of reference.

Examples A Canadian asks an American: How fast can you drive on the Interstates? 70 is the reply. A Canadian asks an American: How fast can you drive on the Interstates? 70 is the reply. How fast can you drive on the highways in Canada? 100 says the Canadian. How fast can you drive on the highways in Canada? 100 says the Canadian. The answers are confusing and may be interpreted wrong unless you add 70 m/h & 100 k/h. In fact the American can drive faster!! The answers are confusing and may be interpreted wrong unless you add 70 m/h & 100 k/h. In fact the American can drive faster!! The rest of the answer is in the details The rest of the answer is in the details

Another Example The Texan asks the Canadian from Ontario: What’s the temperature today? 28 is the reply. Hey – you should be here in Dallas, it’s 79. The truth is that it is warmer in Toronto at 28 C than in Dallas at 79 F. Voila! “The rest of the story is in the details”

STC And so it is with STC. And so it is with STC. STC 53, STC 44, STC 50 – “STC anything” is meaningless until you further define what the number represents and when & how it was achieved. STC 53, STC 44, STC 50 – “STC anything” is meaningless until you further define what the number represents and when & how it was achieved. When discussing Moderco STC values you have to explain the number and why it is important for the spec writer to understand the entire STC testing process. When discussing Moderco STC values you have to explain the number and why it is important for the spec writer to understand the entire STC testing process.

Acoustics The acoustic qualities of an operable wall are the most disregarded and casually treated feature at the specifying and purchasing stages of a project but become the biggest concerns if expectations are not realized after installation. The acoustic qualities of an operable wall are the most disregarded and casually treated feature at the specifying and purchasing stages of a project but become the biggest concerns if expectations are not realized after installation. More time & effort is spent on hinges colors & sizes and gauges of frames when writing specifications than proof of acoustic quality. More time & effort is spent on hinges colors & sizes and gauges of frames when writing specifications than proof of acoustic quality.

Typical Acoustic Specification The operable partition shall have been tested in an independent acoustical laboratory in accordance with ASTM E-90 to attain no less than the STC rating specified. The operable partition shall have been tested in an independent acoustical laboratory in accordance with ASTM E-90 to attain no less than the STC rating specified. And someplace else it will say: STC 50 or whatever And someplace else it will say: STC 50 or whatever Few details. Very loose & open. Open to all kind of interpretations. Few details. Very loose & open. Open to all kind of interpretations.

What Should the Specification say? “Independent Acoustical Laboratory”. “Independent Acoustical Laboratory”. This should be clarified as an “NIST/NVLAP accredited, currently operating laboratory, available to verify test results.” NIST: A non regulatory federal agency within the US Department of Commerce. Web site: NIST: A non regulatory federal agency within the US Department of Commerce. Web site: NVLAP: A division within NIST. Stands for National Voluntary Laboratory Accreditation Program. Web site: NVLAP: A division within NIST. Stands for National Voluntary Laboratory Accreditation Program. Web site: An NVLAP laboratory ensures competence, continuity & equality. An NVLAP laboratory ensures competence, continuity & equality.

What about “Independent?” Suppose the laboratory is NIST/NVLAP accredited. What about “independent” from the manufacturer doing the testing? Suppose the laboratory is NIST/NVLAP accredited. What about “independent” from the manufacturer doing the testing? The interpretation of sound test results is an inexact science leaving much to the discretion of the technician. The interpretation of sound test results is an inexact science leaving much to the discretion of the technician. In order to ensure equality & fairness the Laboratory should not be owned by the manufacturer. It should be “independent”. In order to ensure equality & fairness the Laboratory should not be owned by the manufacturer. It should be “independent”.

ASTM International Formerly known as American Society for testing and Materials. Formerly known as American Society for testing and Materials. Develops and encourages standardization for world’s market place. Develops and encourages standardization for world’s market place. World recognition and acceptance. World recognition and acceptance.

ASTM E-90 ASTM E-90: Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements. ASTM E-90: Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements. Original ASTM E-90 test standards was issued in Original ASTM E-90 test standards was issued in Since then there have been many revisions (maximum 5 years span) indicated by a suffix of the year: E Since then there have been many revisions (maximum 5 years span) indicated by a suffix of the year: E E (2009) is the most recent revised E-90 procedure. E (2009) is the most recent revised E-90 procedure.

Equality of ASTM E-90 Tests Unofficially, ASTM has concluded that E-90 tests are considered equal based on an upward progression of a maximum of 4 tests. Unofficially, ASTM has concluded that E-90 tests are considered equal based on an upward progression of a maximum of 4 tests. According to this fact, the only E-90 tests that should be considered as valid today are E-90-99, 02, 04 & 09. According to this fact, the only E-90 tests that should be considered as valid today are E-90-99, 02, 04 & 09. Tests conducted prior to E should be viewed as suspect. Tests conducted prior to E should be viewed as suspect. We have seen tests identified as E being submitted as proof. We have seen tests identified as E being submitted as proof. One manufacturer regularly submits E One manufacturer regularly submits E The same manufacturer has not completed any STC testing since The same manufacturer has not completed any STC testing since 1990.

Conclusion &What to do? Talk to your spec writers about more than an STC number. Just considering the number as proof of acoustic validity is misleading. Talk to your spec writers about more than an STC number. Just considering the number as proof of acoustic validity is misleading. Get them to include an oldest acccepted version of E-90 in their specification. Get them to include an oldest acccepted version of E-90 in their specification. Not all numbers are equal. Not all numbers are equal. Talk about NVLAP accredited “Independent” laboratories. Talk about NVLAP accredited “Independent” laboratories.

This is the Specification The partitions shall have been tested in a NIST/NVLAP independent (not owned or operated by the manufacturer) accredited, currently operating laboratory, available to verify test results, in accordance with ASTM E-90 sound test procedure. Sound tests conducted prior to 1999 (E-90-99) will not be considered as proof. Products tested prior to 1999 are not acceptable. The partitions shall have been tested in a NIST/NVLAP independent (not owned or operated by the manufacturer) accredited, currently operating laboratory, available to verify test results, in accordance with ASTM E-90 sound test procedure. Sound tests conducted prior to 1999 (E-90-99) will not be considered as proof. Products tested prior to 1999 are not acceptable.

How do we Sell 54 & 55? #1 – Educate your designers in that there is more to STC than simply a number. Tell them the rest of the story. The submission of a “number” is not a proof. #1 – Educate your designers in that there is more to STC than simply a number. Tell them the rest of the story. The submission of a “number” is not a proof. #2 – Custom write a specification including the paragraph that details acoustic STC standard. #2 – Custom write a specification including the paragraph that details acoustic STC standard. #3 – Moderco will guarantee a NIC 42 on both the STC 54 & 55. You must discuss with us prior to bidding. We recommend that all projects requiring a NIC 42 be priced by Moderco. #3 – Moderco will guarantee a NIC 42 on both the STC 54 & 55. You must discuss with us prior to bidding. We recommend that all projects requiring a NIC 42 be priced by Moderco.

How do we Sell 54 & 55. #4 – Bid Smart. If a STC 53 is specified – bid a STC Series. We should be very competitive. Do not bid a STC 53 Signature. #4 – Bid Smart. If a STC 53 is specified – bid a STC Series. We should be very competitive. Do not bid a STC 53 Signature. #5 – Bid Smart. If a STC 55 is specified, bid a Signature STC 55 with an alternate for an STC Series. #5 – Bid Smart. If a STC 55 is specified, bid a Signature STC 55 with an alternate for an STC Series. #6 – When you can, always bid an alternate for a STC Series. We will be very competitive. #6 – When you can, always bid an alternate for a STC Series. We will be very competitive. #7 – Read Sales-Bulletin #10-01 and the ±1 factor. #7 – Read Sales-Bulletin #10-01 and the ±1 factor. #8 – Custom write a specification saying “STC less than 54 is not acceptable.” #8 – Custom write a specification saying “STC less than 54 is not acceptable.”

Any Questions? Keep in mind, we have a huge edge over our competitors when it relates to sound tests, let’s use it to our benefit.