Effective Ways to Soundproof Flooring on All Kinds of Floors
Knowing the best ways to soundproof flooring will help you create a more quiet home. This is not just relevant for residential spaces but in all areas where there are multiple levels.
A study from the University of Liverpool tested the impact of floor noise on subjects in that study. They found an increased level of annoyance and irritability when subjected to floor impact noises. This rose as the noise stimuli were increased. Therefore, finding the best ways to soundproof the floor that you have will also make you a calmer person and, almost as important, a better neighbor.
Soundproof Flooring Q & A
Every person’s situation is unique, so certain soundproof flooring options will work better for some than others. Answer these questions to help you understand which options will work best for you.
- Q: Do you have access to the subfloor or will you need a solution that works with an existing floor?
A: If you have access to a subfloor, you can use some type of underlayment strategy. But if you are limited to working with an existing floor, other options like carpet will work best for you.
- Q: What kind of noise are you trying to mitigate?
A: There are certain types of solutions that work best for particular noises. For example, if you generate a significant amount of noise in one area, it is most cost-effective to create a solution for the one room where you generate the most noise like the kitchen or your child’s room.
- Q: Do you own your living space?
A: If you own your home, you will be more willing to invest in solutions that may be more effective, but will also be more expensive.
- Q: Are you planning to live in your space for a significant amount of time?
A: If you are planning to live in your place for a long time, the more willing you will be to invest in a long-term soundproof flooring solution. This is even if you don’t own the place where you are living.
Understanding the Noise Problem
There are two kinds of noise that you need to understand when considering floor noise. These are air-borne sound and structure-borne noise.
- Air Borne Noise – Airborne noise is created through waves that travel through the air. When these waves strike surfaces in the room like floors, they create noise vibrations that transfer through the building. Airborne sound can come from outside as well as inside a building. Common examples of airborne noise are talking, music sounds, or television noise.
- Impact Noise – Impact noise, also called structure-borne noise, is noise generated when there is impact or energy applied to a surface that is transferred to other surfaces through the building.
Measuring Noise
Noise is measured according to two standards: Impact Insulation Class (IIC) and Sound Transmission Class (STC). The International Building Code requires materials to be at least rated 50 before they can be used in multi-family structures.
The ICC rating is a way to compare materials with how well they transfer sound based on impact. Certain floors have a higher impact score meaning that they are better able to absorb sound based on impact.
| Laboratory Sound Rating | Field Sound Rating | |
|---|---|---|
| Code Minimum | 50 STC/IIC | 45 F-STC/F-IIC |
| Acceptable Performance | 55 STC/IIC | 52 F-STC/F-IIC |
| Preferred Performance | 60 STC/IIC | 57 F-STC/F-IIC |
For example, stone and tile have some of the lowest IIC ratings which are both 50. These are compared to dense carpet or cork which have an IIC rating of 65. This rating shows that carpet is better able to absorb sound than stone or tile. Look for IIC ratings when considering floor soundproofing solutions.
| STC | What can be heard at this level |
|---|---|
| 25 | Soft speech can be heard and understood |
| 30 | Normal speech can be heard and understood |
| 35 | Loud speech can be heard and understood |
| 40 | Loud speech can be heard, but not understood |
| 45 | The threshold at which privacy begins |
| 50 | Loud sounds can be heard, but are very faint |
| 60+ | At this level, good soundproofing begins. Neighbors generally are not disturbed by very loud speech from inside. |
The STC measure was designed to measure air borne sound transfer. The higher the STC rating, the more able the material to block or absorb air borne sound. The STC rating depends on the mass of the flooring type, isolation of the material through separation, and the resilience of the floor.
Soundproof Flooring Solutions for Existing Floors
Sometimes you don’t have the budget or the option to change the floor type. Therefore, you must rely on solutions that you can add to an existing floor.
Carpet Rug and Pad
A tile or stone floor does not absorb sound well on its own. By adding a thick carpet rug, you will absorb more sound and create a more comfortable surface. Thick wool or a synthetic carpet with a high pile-like shag carpet will absorb the most sound. Carpet rugs work even better if you use them together with a sound-absorbing rug pad like this one from Mohawk.
Interlocking Vinyl Floor Tiles
An interlocking floor mat created by rubber floor tiles is the perfect solution for creating a quiet gym or exercise floor. These tiles from Xspec are thick to absorb sound and create a comfortable floor that prevents injuries. They come in black but also colorful tiles. These would be a good addition to a child’s room to create a more quiet and injury free zone.
The Best Ways to Create a Soundproof Floor When Installing New Floor
If you have the option of starting with the subfloor and laying a new floor, you have more options available in order to soundproof your floor. By getting to the subfloor and joists, you can better eliminate potential noise problems before they arise.
Solve Noise Issues in the Joists
One of the biggest problems that create noise in the floor is squeaks from the pressure created by walking on the floor above.
Joist Gasket Tape
One solution for eliminating squeaky joists is using joist gasket tape. This tape creates a barrier between the joists and the subfloor. It reduces the impact of footfalls from above and ensuing squeaks.
Eliminate Gaps
Squeaks are also created if there are gaps between the subfloor and the joists. Locate the gap and place a shim board in the gap. Use a mallet to tap the shim into place so that it is secure and the squeaking disappears. You can also get rid of gaps between the joists and subfloor by connecting a screw between the two and pulling them together.
Floor Joist Isolators
Manufacturers designed floor joist isolators to fit on floor joists and separate them so that sound does not transfer from one surface to the other.
Acoustic Insulation
Acoustic insulation such as this product from Rockwool, can be applied in between the floor joists or as part of the subfloor. Acoustic insulation as part of a subfloor must be a high-density product. If you choose to apply acoustic insulation between the floor joists, use panels, rolls, or granules of a low to medium density.
Subfloor Solutions
A subfloor is the layer between the joists and the finished floor. Using multiple options can create the best layer for your finished floor.
Underlayments
The type of underlayment you choose depends on the type of finished floor you want.
- Polypropylene Foam Underlayment – This underlayment works for laminate, engineered, and solid hardwood floors. You can use it for floating, nail-down, and glued-down installations. Floor Muffler is this type of underlayment. It is 2 mm thick and has an IIC rating of 74.
- Felt Underlayment – Felt underlayments are not as cost-prohibitive as some of the other underlayment options. You can use this underlayment from Roberts on laminate, hardwood, and bamboo or any floor that doesn’t have to be glued to a subfloor. It will not work for nail-down applications.
- Cork Underlayment – There are both natural and synthetic cork underlayments. Both work well for soundproofing a floor. Natural cork and synthetic cork have good IIC ratings. Natural cork is between 51-61 and synthetic cork from 52-59. Natural and synthetic cork underlayment works with tile, stone, marble, hardwood, and laminate floors.
- Acoustic Underlayment – These are rubber underlayments that fabricators design to resist compression and remain resilient over time. The QuietSound Acoustical Underlayment has an IIC of 50 and above.
Increase Mass
Another great strategy to reduce the sound transfer between floors is to increase mass to absorb the sound. You can do this by doubling up on the subfloor material. Include a noise-proofing compound like Green Glue between the layers in order to get the most benefit from this option.
Cement boards like Durock increase the mass material of the floor. These are effective for blocking noise.
Finished Floor Options
There are five finished floor options that create the quietest floor available. These include carpet, cork, rubber, wood plastic composite, and vinyl.
Carpet
Choosing carpet for your entire floor is one of the best ways to decrease sound transfer as it absorbs sound. It also makes the floor soft so that objects hitting the floor create less impact noise. Choose thick carpet with a high pile and a thick carpet underlayment to create the quietest floor possible.
Cork
Cork is an attractive natural flooring that is sustainable and noise-reducing. Cork does tend to stain over time. Therefore, this is not as popular a solution for a top floor soundproofing material as it is as an underlayment option.
Vinyl
Vinyl tiles are a cost-effective solution for more soundproof floors. They are comfortable underfoot. As luxury vinyl tiles, they take on the look of more expensive material like hardwood. Use an underlayment with vinyl to create an effective soundproof floor.
Wood Plastic Composite (WPC)
Wood plastic composite flooring is a type of vinyl flooring with a rigid core. It contains wood fibers combined with plastic resins to create a product that has the look of wood. This is a durable and soft option for flooring.
Rubber
Rubber flooring is a practical and noise-reducing option. It is ideal for playrooms, gyms, studios, and kitchens. It is mold-resistant and slip-resistant.
Frequently Asked Questions (FAQ)FAQ
What is the most cost-effective way to soundproof an existing floor?
The most cost-effective way to soundproof an existing floor is to identify where you need to soundproof. The smaller the area you need to consider, the less expensive it will be. Next, both interlocking rubber tiles and carpet are good considerations. Before you purchase either, consider how you use the room. Rubber tiles are longer lasting but not as comfortable as carpet. Carpet is more comfortable but more susceptible to staining over time.
What is the best flooring for soundproofing?
The best soundproof flooring is a combination of options including reducing noise in the joists, creating a sound barrier in the subfloor, and using a soft finished floor option.
What is the best soundproof flooring underlay?
To find the best flooring underlay for noise reduction consider the STC and the IIC scores for each brand you are considering. Many of the most popular brands have scores ranging in the 60s which is a good score. Each finished floor type and installation requires different underlayments. It is important to consider this before you choose the best underlayment.
Do soundproof floor tiles work?
Rubber soundproof tiles are a good option for existing floors. They create a quick way to insulate your floors for noise and reduce the impact of items hitting the floor.
Conclusion
Soundproofing flooring can seem like a complicated process. Yet, once you understand the components of a floor, you can better visualize the distinct noise-damping solutions that you can use. The best overall solution is employing multiple options to both absorb air borne sound and soften the impact of objects on the floor.