Forna 6mm Cork underlay + Forna Cork floating flooring = Acoustic Insulation Installation – Reduces Annoying Sounds
The numbers, such as Delta IIC, STC or IIC do not give the full image of what cork can do to sound. The numbers achieved in the laboratory are an average. They take all the numbers, put them through a few different equations and are given a single number. These numbers, though handy, don’t get to the heart of the matter.
Where does Forna Cork work best? It works the best against “annoying sound”. Yes, there is a definition for “annoying noise”. The most annoying noises occur at 4,000 hz. Nails on a chalk board = 4,000 hz. The ringing sound of a jackhammer = 4,000 hz. A crying newborn baby. The sound of a phone left off the hook. These are all “annoying” sounds.
Forna cork has an average performance (meets the documented standards) between 100 hz and 350 hz. This is common for most flooring+underlay. Where Forna cork floor+underlay really shines is in the higher frequencies. These higher frequencies are the ones that seem to wake you up at night or feel like “bursts” of noise coming from your neighbors.
Our flooring and underlay have numbers that are off the charts when it comes to medium to high frequency sounds (literally, the documents we received show some frequencies don’t make it to the “receiving room” to be recorded and are thus “off the chart”). Even with higher volume, these sounds are “eaten up” by our cork products.
Acoustical Tests run:
We asked NGC Testing Laboratory in New York to test our 6mm cork underlay together with our cork floating floor. They performed three tests on our 6mm cork underlay + 11mm cork floating floor. We wanted “pure numbers”. We decided against boosting our numbers with “extra” materials manufactured by other companies. We felt no need to spend money testing other materials simply to improve our numbers. Most people do not have these products in their living space, nor do they have the money or the ceiling height to add them in. When we ordered the testing, NGC personnel complimented us on our decision to “keep it simple”. It’s an approach they do not see very often. Most companies want to see “big” (puffed up) numbers that will impress the lay person (the underlayment industry has a long history of using acoustic insulation ceilings to increase the STC and IIC number for their product).
We decided to go against this trend and produce pure, unadulterated test results with the least amount of product required for testing. NGC Testing provided our flooring with a 6 inch cement slab – and nothing else. The numbers produced are attributable to Forna cork flooring and 6mm cork underlay, and nothing else.
The Forna Cork underlay performance was so good, the testing facility had to add “*” to the frequencies above 3000hz. NGC states,
“*Due to high insulating value of specimen, background (noise) levels limit results at these frequencies”.
That means our product dampened the frequency so much, the recording studio could not differentiate between the “silence” of the receiving room and the “silence” our floors produced at those frequencies. Now that is impressive!
12mm Cork Underlay:
Forna has added an impressive cork underlay – 12mm (nominal 1/2″ cork underlay). The 12mm cork underlay has Delta IIC ratings that are beyond impressive. They are astonishing! The 12mm cork underlay was tested underneath 8mm Pergo Presto laminate. The Delta IIC rating for this underlay + floor combination:
12mm Cork Underlay + 8mm Pergo Presto Laminate Delta IIC rating: 22.0 dB
This is an astonishing amount of acoustic insulation. Most laminate floors will have an acoustic insulation rating of “Zero” (0) dB. Which means the 12mm Forna Cork Underlay offers 22.0 dB of insulation all on it’s own. Because of this amazing rating, 12mm Cork Underlay has been accepted in some of the most difficult to please HOA offices in the world: New York City.
If you are having a hard time getting your solid floor covering* approved by your HOA, try adding 12mm cork underlay to the specifications. It will often do the trick where other underlayment options fall down.
*cork underlay is not recommended underneath most vinyl flooring options.