Sound Proof Insulation

We expect our home to be a haven where we can rest and relax after a hard day. However, our home can also be a center of activity where all kinds of noises mix to form a cacophony of sound that can disturb even the soundest of sleepers. Some people don’t really think they need sound proof insulation for their homes until they start being bothered by all the noise coming in. You’d be surprised how many people don’t really consider their homes as a noisy place.

Think about it. Preparing food in the kitchen, people eating in the dining room, people watching TV or listening to the stereo in the living room, and all the other appliances in your home like the dishwasher, washing machine, vacuum cleaner, etc. – all of these create sound and noise that can be an annoying distraction. What’s more, sounds from the outside like cars passing by on the street, pedestrians on the sidewalk, a construction crew working at the next block, and other daily occurrences can all add to the bothersome distraction.

You don’t have to put up with all the noise, however. You can have sound proof insulation installed in your home to combat all those sounds, or if you have the skills and tools, you can also do it yourself. There are several different ways to insulate your home against sound, but they all have some pros and cons to them.

For example, the common materials that people use to insulate their homes against heat or cold, like glasswool (also called fiberglass), can work very well when used as sound proof insulation. They just need to be installed meticulously to perform to their fullest capabilities. Glasswool insulation can help reduce noise that’s coming through the walls, but the material will need to be painstakingly cut and fitted around the pipes, wiring, and other elements inside and in between the walls. Furthermore, all holes and cracks in the walls will need to be sealed to help reduce noise as well.

Generally, fiberglass insulation is not really recognized as an excellent sound insulator, although they do make great insulating material for heat or cold. However, modern technology has allowed manufacturers to create high density glasswool insulation that can offer extraordinary performance for both acoustic and energy purposes. There are glasswool products nowadays that are rated up to R-2.7 for wall installations and up to R-6.0 for ceiling installations.

Installing glasswool or fiberglass insulation alone will not provide high level soundproofing, of course. You will also need to take additional steps such as using solid core wooden doors, tightening up the spaces between the wall and the windows, installing high quality storm windows, and even installing thick carpets. If you install storm windows, take note that the wider the space between the storm window and the primary window, the better it blocks sound from coming in. Also, if you have a wall that faces a busy street, adding another layer or two of drywall to that wall will significantly improve noise reduction.

Noise proof Insulation

Noise is simply unwanted sound. In the home, most people consider noise to be just about any sound other than the sound made by what they’re doing. Limiting the transmission of sound from one area to another requires a material that encloses the source of the noise and forms a barrier that absorbs vibrations between the source and the adjacent areas. This is exactly how soundproof insulation works.

Installing soundproof insulation for walls, floors, and ceilings:

• Drywall, (also called wallboard, plasterboard, or gypsum board), such as Sheetrock. An excellent and inexpensive source of mass, which is a key element in soundproofing. Drywall is a great cheap soundproofing material.
• Damped drywall. Drywall which incorporates a sound damping layer. You can also get the same results more cheaply by creating your own damped drywall, by applying damping compound between two sheets of regular drywall.
• Sound-deadening fiberboard. Because of their low mass, these are not the best choice for soundproofing walls, but are sometimes useful in floors as a spacing layer if additional mass is not needed. They don't provide damping, decoupling, or absorption.

Moreover, not every type of insulation reduces noise. Reflective insulation such as radiant barrier works by reflecting radiant heat from the sun. It is installed in the attic, right under the roof and reflects energy from the sun, which keeps your home a lot more comfortable but doesn’t act as a sound barrier at all. If you want a sound proof insulation, cellulose, fiberglass and foam insulation are great choices. These types of insulation reduce outside noises and noises from room to room and between different levels of your home or building. Fiberglass and cellulose can be installed in walls, floors and ceilings. There are two different types of sound: airborne and impact. Airborne noises come from outside and also include noises from the TV, music and other things inside the house. Impact noise includes footsteps and vibrations from large appliances such as your washer and dryer. Insulation reduces both airborne and impact noises. If your walls are properly insulated, you’d probably be surprised at how much quieter noises from the outside seems.

Fortunately, there are a number of soundproof insulation or noise-reducing initiatives you can take to alleviate the problem. The most effective of these are best done during a building or remodeling project because they involve the way walls or other structural elements are built. Many housing experts believe that using permanent, soundproof insulation solutions isn't necessary. This is mainly because the performance of a soundproofing installation may not be up to the expected levels. Then you have to tear down the existing soundproofing additions, a situation which results in unwanted expense. Furthermore, such permanent solutions pose a problem if the house has to be redecorated. Homeowners should use soundproofing solutions that are affordable, effective and flexible. Unlike professional solutions that might create the need to seek legal permissions, easy soundproofing methods pose no such issues. You should understand that at the core of every soundproof insulation technique lies a simple concept which sound waves create reverberations and echoes that you need to limit.

Sound Proof Insulation - Experimental Samples

There are now several ways to soundproof a wall and insulate it. Improvements in the soundproofing industry have resulted in products that are now more effective and cost less than the old traditional ways in soundproofing methods. Soundproof insulation had come a long way.

Some principles

However, one must understand some of the main principles of sound movements and how to minimize or totally eliminate it. Some of these include getting the information that the effect of insulation is minimal in both low and high frequencies.

In a conventional wall, the effects of insulation are very similar to having insulation. The largest gains are just above the primary low-frequency resonance, low frequency gains are non-existent and high frequency gains are very minimal.

More experiments

The effects of adding layers to a normal single wood stud wall results in having the gains in the midrange higher at middle and high frequencies. Low frequencies, however, the performance is not as good as with the lighter installation.

Here the STC rises by a mere 2 points (from 32 to 34). Insulation has much more value in decoupled walls.

In walls having mechanical connections between the two sides, the insulation has proven the benefits of insulation at middle and high frequencies. In low frequencies, however, the capacity of the insulating materials to absorb sound falls dramatically. The benefit of insulation at low frequencies is to lower resonance points.

Still, lowering the resonance is valuable and in walls with damping or decoupling, the insulation has considerable value at middle and high frequencies which should be considered mandatory for any sound isolation application.

As a sample on how insulation becomes less effective as frequency falls, place a fiberglass in front of the mid and high frequency speakers in your room and listen to what happens. The sound would probably be muffled and muted.

Now put the same fiberglass in front of the subwoofer cones. Nothing happens. This is the same with the walls.

STC

Dealing with sound, one needs to be familiar about STC ratings, or the sound transmission class ratings. STC ratings measure how much a particular sound proofing construction material reduces sound.  (R-values in thermal insulation are the values of retained heat in the materials used.)

Higher STC rating indicates that the materials used are better at noise reduction. A wall with an STC rating of 30 will allow most sentences to be heard clearly in a conversation. A wall having an STC rating of 50 will block most of the loud speech and only transfer faint sounds of loud musical instruments. 

Tips

Most often, people thought using denser insulation materials cures every sound problem. Generally, it is preferable to use standard building type insulations (like fiberglass).

It is not desirable to use expensive and very dense insulations. In addition to the expense, they also tend to make low frequency performance worse by raising the resonance frequencies.

Some notes

The use of sound proof insulation is critical and valuable, but insulation alone doesn’t win, especially in conventional walls where direct structural connections exist between the sides.