Is Soundproof Insulation Worth The Cost?
Between kids learning from home and parents working from home, the pandemic has meant some families are together 24/7. All that togetherness could mean a noisy house, but not if you install sound deadening insulation.
That was the experience for Robert Barrington, an electrical engineer from Lowell, Michigan. When his house was being constructed, it was suggested he insulate the interior walls to reduce noise. As a result, his son can host high school string ensemble practices at the house without disrupting the family. “Even when they’re playing, it’s not very loud,” Barrington says.
However, soundproofing with insulation has its limitations and may not be right in every situation. Fortunately, there are other, easy ways to promote peace and quiet in your home.
Basics of Soundproof Insulation
The first thing to know is that there is no such thing as soundproof insulation, according to Kevin Herreman, principal acoustic scientist for Owens Corning, an insulation manufacturer.
While some products are designed with acoustics in mind – such as Owens Corning QuietZone and Rockwool Safe’n’Sound – no insulation can completely eliminate noise. What’s more, even when interior walls are insulated, sound energy may still find a path to travel between rooms.
Consumers should also be aware that there are three categories of sound control, Herreman says.
- Absorption reduces sound inside a space.
- Isolation blocks acoustic energy from transferring through barriers such as walls.
- Diffusion spreads sound evenly across a space.
“Soundproofing is generally tied to isolation,” Herreman explains. And fibrous insulation can be an ideal solution. “The insulation does a great job,” he says. “It soaks up the (sound) energy like a sponge.”
How to Soundproof Your Home With Insulation
Acoustic insulation has a thickness and density that makes it ideal for isolating sound, but homeowners don’t have to buy a specialty product to get noise reduction benefits.
“All insulation will provide a certain level of soundproofing,” says Josh Skolnick, chairman and founding partner of Horsepower Brands, which includes iFoam, a spray foam insulation company. Adding a higher volume of insulation can improve sound absorption; depending on the amount used, that may add anywhere from 30%-45% to an insulation project's total cost, Skolnick estimates.
Barrington used blown-in insulation between his interior walls. His contractor was already using that material elsewhere in the home and the only adjustment needed was adding netting between the main and second floor to hold the material. The insulation added a negligible amount to the overall cost of his home.
Other materials that can be used for sound control include fiberglass and mineral wool. “From a cost performance basis, fiberglass is the best absorber,” Herreman says.
Pitfalls to Avoid When Soundproofing With Insulation
While installing insulation can be a DIY project for some homeowners, Skolnick urges caution. Failing to provide appropriate ventilation could cause problems such as condensation and mold. For that reason, Skolnick encourages people to use a professional, especially if they are retrofitting a home to add insulation.
Also, be careful if buying soundproof insulation foam, Herreman advises. Foam doesn’t inherently absorb sound like fibrous insulation, but it can be useful for noise control. However, that’s only if you purchase open cell foam, which can be pricey. Lower priced foam panels may be closed cell and are the equivalent of packing foam, which has minimal acoustic benefits. “You can’t tell the difference unless you cut it open,” Herreman says.
It can also be expensive and onerous to try to add insulation to existing interior walls. “It has to be done when the house is being built or renovated,” according to Herreman.
Other Strategies to Consider
If you didn’t have the opportunity to add insulation to interior walls when your home was built, there are other ways to quiet a space.
“Hanging curtains off the wall can add quite a bit of absorption,” Herreman says. He also suggests replacing a closet door with a curtain which would allow not only the curtain to absorb sound energy but also all the clothes inside the closet to do the same. Since all fabrics are natural absorbers, items such as comforters and rugs can also reduce sound within a room.
To minimize noise coming in from outside, consider landscaping such as trees or shrubs to screen your property from external sources of sound, Skolnick suggests. “Insulation probably won’t help with noise from the road,” he says.
Still, if someone has the opportunity to add insulation to interior walls, Barrington highly recommends doing so. “I wouldn’t even hesitate,” he says. “I don’t know what the downside would be.”