The acoustic underlay 12mm cork underlay, alone, achieves 48 dB. Any acoustic floor installed over top (such as 11mm or acoustic underlay 12mm cork flooring) has the potential to achieve 68+ dB. In the acoustic industry, this is a huge advantage.
¼” and 1/8” cork underlayment offers a reduction of 48 dB, 23dB, 13dB, and 10mm and ½” floating cork flooring offer a reduction of 16dB and 19dB.
And if you're looking for the best cork roll thickness or cork sheet thickness for sound dampening, you'll get the most bang for your buck at 1/4 inch (6 mm) thick cork - supplied in roll or sheet form. At this thickness, it has a Sound Transmission Class (STC) score of 50.
Cork underlayment goes under hardwood flooring or carpet and is the perfect option for adding a layer of sound dampening and insulation. Consider using cork if you are re-laying a floor because it will reduce the amount of impact noise transfer drastically to the floor below.
Tests have shown that 4mm cork glue down flooring tiles (can be used on walls, ceilings and floors) will offer 14 dB worth of acoustic insulation. A 6mm cork tile offers (roughly) 18 dB worth of noise control and noise reduction and 8mm cork tiles are said to be 21-22 dB worth of sound control and noise reduction.
It has natural soundproofing qualities as its structure is extremely lightweight and tightly filled with air. Cork has a high Noise Reduction Coefficient (NRC) score of 0.7, which rates how effective an acoustic item is when absorbing sound. This score means 70% is absorbed and 30% is reflected.
Cork's R-value is typically listed at R-3.6 per inch to R-4 per inch.
One of the significant downsides of cork underlayment is its susceptibility to moisture. If you're installing flooring in areas prone to dampness, such as basements or kitchens, cork might not be the best choice.
One of the best products in this range is the Plushwalk 12mm Carpet Underlay. This is a 5* memory foam acoustic underlay, with an impact sound reduction of approximately 49dB and a 3.5 tog rating.
In general, a standard thickness for foam or cork underlayment ranges between 2mm to 6mm. Thicker underlayment can provide enhanced sound reduction and cushioning.
Sound deadening should be at least 40mil (1mm) thick, with most mainstream brands capping out at 80mil (2mm) thick.
While cork is moisture-resistant, it is not moisture-proof. Therefore, a moisture barrier is typically installed with a cork underlayment in damp areas (like basements) or in particularly damp climates.
It is a floor that requires expansion and contraction. It requires expansion gaps be ADHERED TO without fail – or your floor will surely fail! Failure to follow these guidelines will void your warranty.
Impact Insulation Class (IIC) measures a floor/celling assembly's resistance to the transmission of impact sound, such as foot-fall or a chair dragging on the floor. Flooring systems with premium acoustic underlayment usually have an IIC rating above 70.
With an R-value between 3.6 and 4.2 per inch, cork offers one of the best insulation efficiencies available, surpassing many traditional materials. Conclusion: Cork is not just a practical insulation choice; it is a step towards more sustainable living.
If you have a flooding situation (ie: not daily usage), the standing water could possibly re-emulsify the adhesive and thus loosen a few tiles. That's the only foreseeable damage that might be possible by water but this does not typically happen.
However, for the best overall sound deadening performance, rubber underlayment is the top choice. Its exceptional durability and sound insulation properties make it an excellent investment for creating a quieter and more comfortable home or commercial space.
Sound absorption capacity: Rubber is higher density than cork, which enables even a thin layer to dampen impact sound better than the same amount of cork. Moisture resistance: Unlike cork, rubber is waterproof. It can protect your floors from moisture-related issues like mold and mildew growth.
The higher the db number, the better the reduction in sound transference. For carpet underlay the best sound impact reduction is achieved with db ratings of 40 and above, for wood and laminate underlay, 22 db and above are rated as the best. All underlays shown achieve at least those minimum requirements.
The installation of a cork or cork blend underlayment reduces the sound of footstep noise both within the room and in the space below, in the case of 2nd floor and above installations. Cork underlayments can make on grade and below grade floors feel much warmer with their thermal insulating qualities.
If you are floating the top floor, then you float the underlay. If you are planning to glue down a hardwood or tile floor, then you glue down the cork underlayment.
Avoid floors with cork underlayment, as they can promote the growth of mold and mildew. Cork has a natural tendency to expand, contract, and absorb moisture, making it susceptible to mold growth.
3 types of cork insulation
These are created by heating the cork granules using steam, activating suberin – a natural binding agent. They are then pressed into the desired shape, size and thickness, which can range from thick 50mm panels down to thin sheets with less than 10mm depth.
Due to its high heat storage capacity, cork is very effective as an insulation material against the summer heat. It can keep interior walls pleasantly cool in summer, even on hot days. Cork can even be combined with other synthetic materials to make it a viable solution to insulate from the cold in winter.