Where, When and Why is Sound Insulation Required? Acoustic sound insulation is 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 physical objects impacting a floor surface such as footsteps, dropped objects, etc. The Sound Transmission Class (STC), specifically addresses airborne noise transmissions such a voice, music etc. Today Condo Associations and Municipalities are subject to Building Codes that address sound transmission limits.
How Does Sound Insulation For Floor Coverings Work? Sound control underlay materials are used to attenuate or 'deaden' floor impacts by insulating the sub floor assembly from footsteps, dropped objects etc. at the floor surface. Our unique Patented Product is engineered to be the best product choice available for improving IIC - Impact Insulation Class ratings.
Under the IIC/STC rating system, the higher the rating 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 minimum rating of IIC-STC-50. Some luxury properties and municipalities have higher requirements.
* 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
Calculate The Soundproofing Requirement For IIC 50 Needed to comply with the International Building Codes?
In order to achieve a minimum rating of 50 IIC, assuming Tile as the floor finish - the formula works like this:
Slab of concrete IIC ____ + Soundproofing Δ ____ IIC = 50 IIC
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 building code IIC 50.
6" Concrete IIC 27 + Soundproofing Δ 23 IIC = IIC 50.
You need to specify: 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 need to specify: Sound Insulation with a Δ IIC 18 rating or better with Tile - other floor finishes may add to the value.
How Can I Tell Which Sound Insulation Product Is The Best Choice For My Project? The ASTM E2179 'Delta' Test simplifies comparing competing Sound Insulation Products.
Why Test With Ceramic Tile? Tile is at best a 'neutral' sound insulator which makes it an ideal test floor for comparison testing.
Why Test On A 6" Concrete Sub floor? The point of the Delta Test is to zero out the 'baseline' insulation value of the sub floor. 6" concrete sub floor ratings don't vary significantly from slab to slab which is a crucial aspect of running comparison tests.
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 on Tile installed on a bare 6" Concrete Slab. The slab is pre-tested 'bare' (without floor covering or sound insulation) to establish the 'baseline'
Δ IIC rating. Note: 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 competing products. Note SOUND STEP in thinner applications delivers significantly more sound insulation VS thicker Acoustic Cork when tested on the same sub floor. Be wary of Delta Tests results obtained from slabs with baseline values above
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. Most sound control underlay products can only be used beneath specific types of floor coverings such as floating wood floors and not Tile. Wood Floors can be floated or bonded directly 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 impervious to the elements so it can be used as underlay or non-slip flooring for applications such as activity floors (surface and or substrate), deck-patio covering, marine decks etc.
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? There are no limitations other that those imposed by manufacturers of wood or resilient floor coverings. Our recycled rubber composite has a nominal BTU rating - less than 1/2 BTU which means it has very low thermal resistance. 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 Thickness Do I Need? That depends on the sound rating you need to achieve on your planned or current sub floor assembly. For example, wood frame sub floor assemblies are noisier than concrete slabs due to a lack of comparative mass. In addition to adding sound insulation, SOUND STEP recycled rubber adds sound attenuating mass and can be applied directly beneath floor coverings 'and or' used as a de-coupling 'base mat' beneath self-leveling acoustic materials such as gypsum-concrete. Note: When SOUND STEP is used for Base Mat beneath cementitious concrete screeds - the potential exists to increase the Robinson Rating to a commercial traffic rating.