FAQ for Acoustic Foam

General Questions

Can the foam be cut down to the size that I need?

Yes. If the standard sizes we carry do not meet your requirements, we can cut the foam down to the size you need. You can also cut the foam yourself if you wish, using a sharp carving knife or electric knife.

How do I apply the acoustic foam to the mounting surface?

We suggest using our spray adhesive, which can be found in the Accessories section of our website.

Temporary Hold*: For temporary use, lightly mist the foam with adhesive and apply it to the mounting surface.
Permanent Hold: For maximum hold, spray a generous coating of adhesive without saturating the foam. Apply adhesive to the mounting surface as well. Wait for the adhesive to become tacky before applying the foam to the mounting surface and hold in place for a minute or two.

For concrete surfaces, brush off loose particles before installation.

*NOTE: For temporary applications, using less adhesive will not form as strong of a bond with the mounting surface, but be aware that based on the type of mounting surface, removal of the acoustical foam may still leave residue or remove paint from the wall. The longer the foam is mounted to the surface, the greater the chance of this occurring. We are not responsible for any damage caused by the personal application of this product, within or outside of its recommended use.

Can I mount the foam without using adhesive?

The acoustic foam can be mounted directly to the wall using T-pins, or by applying the acoustic foam to a board and resting or hanging the board on the wall.

Ordering Questions

Can I have different colors in the same package?

No. While a package can be in a color of your choosing, each package can only have one color. However, when you order more than one pack, each pack can have its own color.

Acoustic Foam Questions

What do I need to stop sound from traveling through a wall?

While acoustic foam can be used to stop sound from traveling through a wall to a certain degree, its primary purpose is for improving the clarity of sound in a room. If you were to exclusively use foam and completely cover the walls in a room with our 4 inch wedge foam, you would only block about 20 to 30 percent of the sound traveling through the wall. If you need to block more sound, you will need to build a "room inside of a room" with airspace and multiple physical barriers to achieve more than 30 percent deadening. Our Polyethylene Roll and Neoprene foams can be used in this construction.

How much acoustic foam do I need?

Typical applications call for 25 to 75 percent coverage, with the average being 50 percent. We suggest 50 to 75 percent for rock, pop, techno and other musical styles with varying styles of sound waves. For jazz, classical and other similar styles, 25 to 50 percent coverage is suggested.

Where should I place my wedge and pyramid foam or bass absorbers?

For corner bass absorbers:
We suggest placing two in each corner, starting from the ceiling and going down. If you decide to go with four bass absorbers in each corner but the ceiling is higher than eight feet, space the bass absorbers out evenly, having the top bass absorber touch the ceiling and the bottom bass absorber touch the floor. When it is not possible to put the bass absorbers in the corner, you can either put them in the ceiling juncture (which is preferable) or floor juncture. For corners that are not 90 degrees, you may want to consider our male/female broadband absorbers. Suggested placement of broadband absorbers is the same as the placement of corner bass absorbers.

For wedge and pyramid foam:
We suggest starting from the ceiling, and working your way down. For most applications, foam panels do not need to be lower than two to three feet from the floor. Placement should be concentrated around where the sound originates. Wedge foam will perform in similar fashion whether they are horizontal, vertical, or at a 45 degree angle. If absolute deadness is not required, we suggest mounting the foam in a checkerboard style, alternating pattern direction, for aesthetic purposes.

What does NRC mean?

NRC stands for Noise Reduction Coefficient. The NRC of a material can be found by using either the Reverberation Room Method (ASTM C423) or the Impedance Tube Method (ASTM C384). We use the Reverberation Room Method.

  1. Approximately 72 square feet of material is rested on the floor of a reverberation chamber. This chamber usually has all hard concrete surfaces.
  2. The change in absorption from the empty room to the room with the material is measured.
  3. The changes in sound are measured for octave bands ranging from 125Hz to 4000Hz, recording the differences in Sabin absorption coefficients. The overall NRC rating is the calculated average of frequencies 250Hz, 500Hz, 1000Hz and 2000Hz.

The higher the NRC rating, the more sound the material can absorb.

What does STC mean?

STC stands for Sound Transmission Class. This rating is used to compare the acoustic isolation of different materials. The method used to calculate the STC rating is ASTM E413.

  1. There are two rooms, a "source" room which contains a speaker and a "receiver" room which contains a microphone. Between the two rooms is an opening typically sized 8 by 9 feet.
  2. In decibels, the sound is recorded in 1/3-octave bands from 125Hz to 4000Hz.
  3. The next step is to record the sound again in decibels with the material(s) completely covering and sealing the opening.
  4. Then, the difference between the before and after test is measured and recorded. These measurements are the transmission loss or "TL" of the sound.
  5. Lastly, the transmission data is drawn across an axis of frequency in Hz and transmission loss in dB. This transmission data curve is referenced to standardized STC curves. The standardized curve that most closely matches the transmission data curve gives the transmission data curve its STC rating. The requirements used to match the curves are that the reference curve shall not exceed the measured transmission loss by more than 8 decibels in any 1/3 octave band and that the sum of all "negative discrepancies" shall not exceed 32. Once these requirements are met, the value of the closest-matching reference curve at 500Hz is read as the STC of the material.

NOTE: Lab and field measurements may vary 1 to 5 STC depending on application. This should be taken into consideration when choosing materials for acoustic isolation projects.

DISCLAIMER: Any product suggestion made by Foam Factory and its employees should be taken as just that - a suggestion. Foam Factory and its employees will attempt to make every effort to suggest the best product(s) for an application as described, but these suggestions should not be substituted for the advice of sound professionals or the customer's own judgment. Additionally, any suggestions must be taken into consideration while understanding there are variables unique to every space and situation that may affect results.

Questions about Fire Retardant Foam

Is your acoustical foam fire retardant?

Yes, all of our acoustic foam is fire retardant. The fire rating can usually be found under the Details tab for a particular product or on the acoustical foam Data Sheet. All of our acoustic foam has fire retardants added to the foam's formula, not just sprayed on the surface.

Why go with acoustic foam instead of regular "bedding" or "packaging" foam?

Our acoustic foam is suggested for sound treatment applications because it is specially engineered to perform sonically, and has also been treated to be fire retardant for safety.

What would happen if fire were exposed to your acoustic foam?

Our acoustic foam will smolder and smoke, but it will not burst into flames. After the source of fire is removed, the foam will burn slowly with a high probability of self-extinguishing.

Note: Foam Factory does not encourage exposing our products to extreme heat, fire, or performing any home testing. Foam Factory will not be held liable for any injury or loss sustained from the use or misuse of our products.

What information is needed to pass my building codes?

Our acoustic foams have been tested in accordance with ASTM E84 and NFPA 255 for surface burning and meet a "Class A" or "Class 1" standard. This is accepted by most building codes, but be sure to check requirements in your area before installation.

What does the "Class" refer to when talking about fire retardant specifications?

In regards to the surface burning standard ASTM E84, this test calculates two numbers. One is the Flame Spread Index and the other is the Smoke Developed Index. These numbers determine whether the material is Class A, Class B, or Class C (or Class 1, Class 2 or Class 3, respectively). Class A represents that the material will not burn or smoke much, and Class C represents that the material will burn heavily and produce more smoke. Class B will burn a little more than Class A, and also produce slightly more smoke than Class A, but not ignite or smolder to the extent of Class C.

What does MVSS-302 mean?

The MVSS-302 standard means that after brief exposure to flame, the foam will burn and smoke at a slow rate, with a possibility of self-extinguishing.

What do UL 94 HBF and UL 94 HFI mean?

The UL 94 HBF and UL 94 HFI standards mean if you were to briefly expose the foam to flame, it will self-extinguish.