Where, When and Why is Sound Insulation Required? Sound insulation products are typically specified for condominiums, hospitals, schools, hotels, and office buildings. IIC and STC sound control standards were developed to regulate the amount of noise allowed to penetrate through common walls and floors within dwellings. Impact Insulation Class (IIC) addresses noise generated by footsteps, dropped objects, etc. The Sound Transmission Class (STC), addresses airborne sound transmissions such a voice, music etc.
How Does Sound Insulation For Floor Coverings Work? Sound control materials used for impact sound insulation are engineered to absorb and attenuate sound generated by footsteps, dropped objects etc. at the floor surface. Our unique Patented Product is engineered to be the best overall product choice for improving IIC - Impact Insulation Class ratings.
Under the IIC/STC rating system, the higher the number the better. In other words; rooms become increasingly quiet as the rating number increases. For example: poorly insulated wood frame constructed sub floors may rate as low as IIC/STC-35 dB (decibels) or less! Larger Condo Associations and Municipalities typically adhere to the International Building Code or Universal Building Code when establishing sound control standards. Many luxury properties and municipalities are now requiring sound control ratings in the high 50's or low 60's range. Impact sound complaints are unfortunately common on floor-ceiling assemblies that meet the bare minimum requirement of 50 decibels IIC.
* The International Code Council (author of the International Building Code) recommends that an “acceptable” level of performance for both STC and IIC is 55 (52 F-IIC).
The “preferred” level of performance for STC and IIC is 60 (57 F-IIC). An IIC and STC rating will generally be 5 points higher than a F-IIC and F-STC rating. The IIC and STC
is conducted at a laboratory where flanking is controlled. The F-IIC and F-STC is conducted in the field where flanking is not as controllable, hence the 5 point difference.
How Do I Determine
The Amount of Soundproofing Required For My Project?
First Step: Determine The Sound Insulation Value of the 'Bare Sub Floor' (without floor coverings attached):
In order to achieve your target (required sound rating of sub floor assembly with floor coverings attached) the formula works like this:
Sub Floor IIC ____ + Soundproofing Δ ____ IIC = Final IIC Rating
Δ IIC = The amount of sound reduction of the soundproofing product by itself. You should be able to add a couple decibels of sound value with wood, resilient flooring or carpet.
If You Have 6" concrete slab:
Assuming a low average value for 6" concrete (IIC 27) - you will need a soundproofing product with a minimum Δ 23 IIC to comply with the minimum building code IIC 50.
6" Concrete IIC 27 + Soundproofing Δ 23 IIC = IIC 50.
You will require: Sound Insulation with a Δ IIC 23 rating when using Tile - other floor finishes may add to the value.
If You Have 8" concrete slab:
An 8" concrete slab with a baseline IIC 32 value will require a soundproofing product with a minimum Δ 18 IIC to comply with the building code IIC 50.
8" Concrete IIC 32 + Soundproofing Δ 18 IIC = IIC 50.
You should specify: Sound Insulation with a Δ IIC 18 rating or better with Tile to comply with minimum code - wood flooring and other floor finishes may add to the value.
Is There a Simple Way To Compare Competing Sound Insulation Products? The ASTM E2179 'Delta' Test was developed for comparing competing Sound Insulation Products.
Why Is Ceramic Tile Used As The Test Floor? Tile does not add IIC value which makes it ideal for isolating the insulation value of sound control underlay products.
Why Does This Particular ASTM Test Specify 6" Thick Concrete As The Sub floor? 6" concrete slabs 'baseline' sound insulation ratings are more consistent for testing purposes which lends itself to reliable laboratory and field test results for the purpose of comparison.
How Does The Delta Test Work? 'Delta Test' test results are stated as follows:
Δ (Delta Symbol) IIC (Impact Insulation Class)dB (Decibel Symbol) and pertain to the insulation value of the floor finish products and or sub floor assembly. This ASTM E2179 Test is conducted with a Tapping Machine (see illustration below right) on Tile installed on a 6" Concrete Slab with no insulated ceiling. The slab is first pre-tested without floor covering attached to establish the 'baseline'
Δ IIC rating. Note: The sound insulation value of 6" concrete slabs can range from
26 to 29 dB depending on the type of aggregate used, atmospheric pressure and moisture content at time of testing etc. After the Test is run with floor covering attached, thebaseline value of the slab is deducted thus isolating the actual sound insulation value of attached floor coverings. Our ASTM E2179 Benchmark Test Results below illustrate how we used the Delta Test to compare SOUND STEP to Acoustic Cork. Note SOUND STEP in thinner applications delivers significantly more sound insulation VS thicker Acoustic Cork when tested on the same sub floor. Regardless of sub floor construction, when comparing sound insulation products, you should always evaluate a product's 'delta' value and be wary of any tests results derived from slabs with baseline values above
Δ IIC27dB as this would be an exceptional rating.
What is SOUND STEP Made From? SOUND STEP is 94% recycled rubber granules from used car tires mixed with multi-colored EDPM rubber 'flecs' recovered from rubber flooring production waste. These two recycled rubber components are cold bonded with a high quality urethane binder and then heat cured into a finished composite. Utilizing car tire rubber for flooring projects is good for two big reasons: (1) It benefits the environment by diverting millions of tons of waste tires from our landfills. (2) Sound tests show that SOUND STEP recycled rubber attenuates more sound than competing products.
What types of flooring can be installed on SOUND STEP? A key advantage to specifying SOUND STEP is the sheer versatility of the product in that most any kind of flooring can be installed directly on top of the product while most sound control underlay products are limited for use beneath specific types of floor coverings such as floating wood floors or carpet. Very few are approved for use beneath Tile. Wood Floors can be floated or glued direct to SOUND STEP and Tile can be bonded directly for use in residential and light commercial areas as tested by the Tile Council of North America. SOUND STEP is also has the advantage of being impervious to the elements so it can be used as underlay or non-slip flooring indoors or out.
What about Sub Floor Moisture Vapor? While SOUND STEP is impervious to the effects of moisture, certain decorative floor coverings like wood and PVC sheet and tile have a specified moisture vapor transmission exposure limits. The upper end limit specified by most resilient and wood flooring manufacturers is 3lbs. per 1,000 square feet per 24 hours (as measured by the Calcium Chloride Test). If moisture vapor transmissions exceed 3lbs., the sub floor must be receive a vapor retarding 'barrier' capable of reducing vapor transmissions to specified levels .
Is SOUND STEP Suitable For Use On Hydronic Or Other In-floor Radiant Heat Floor Systems? Our recycled rubber composite has a nominal BTU rating - less than 1/2 BTU - which means it has very low thermal resistance making it highly efficient for use on heated sub floors. When installing wood or resilient floor coverings on slabs with embedded radiant heating systems, always refer to the flooring manufacturer's installation guidelines and warranty limitations.
What's The Right Thickness For My Floor? If you know the baseline sound insulation value of your sub floor (without floor covering attached), you can refer to the 'Delta' Sound Insulation Value of SOUND STEP products by thickness and add sound insulation value accordingly. Keep in mind, for each 'doubling of thickness of SOUND STEP, you increase the Delta Value by 3-decibels - for example: The 'Delta Value' of 5mm SOUND STEP is 19-dB so if you double the thickness to 10mm, the Delta Value increases to 22-dB. Keep in mind, just 10-dB of sound insulation added to the sub floor assembly decreases sound transmissions by 50% so every decibel of sound insulation you add is extremely important!
SOUND STEP recycled rubber is heavy and adds sound attenuating mass to lightweight (noisier) wood sub floor assemblies. SOUND STEP can be used directly beneath floor coverings (bonded or floating) or used as a de-coupling 'base mat' beneath poured cementitious acoustic materials. Note: When SOUND STEP is used as Base Mat beneath cementitious screeds - the potential exists to increase the sound rating and traffic (Robinson Test Rating) rating to accommodate commercial use.