Does Insulation Reduce Noise?
Insulation is used to keep consistent temperatures inside of a home, which is particularly useful this time of year here in Washington State. However, insulation has multiple properties that make it useful for soundproofing. For homeowners with properties near busy roads or train tracks, insulation can make a huge difference and reduce the amount of street noise they can hear inside of their homes.
Too Much Noise Is Unhealthy
According to Mathias Basner, a professor at the Perelman School of Medicine at the University of Pennsylvania, the term “noise” can be used to describe “unwanted sounds.” Humans never stop hearing, even when they’re asleep. Noise influences both auditory and non-auditory health. Unwanted sound and other noises can trigger panic responses. Loud noise can damage hearing. But that’s not all. According to research published by Basner and his team in The Lancet, noise is associated with sleep disturbance, hypertension, cardiovascular disease, and cognitive impairment in children. Essentially, noise acts as “an unspecific stressor on the body. Prolonged periods of unwanted noise can cause the body to release stress hormones like adrenaline, and can negatively affect blood hormones like cholesterol.”
How Does Insulation Reduce Noise?
The insulation forms a barrier between a source of noise and adjacent areas (such as the walls of a house), and it absorbs vibrations to reduce the amount of noise in the home. Not all types of insulation are suitable for this purpose, however. Consider reflective insulation, which is meant to reflect heat from the sun and doesn’t act as a sound absorber or barrier.
The Difference Between Airborne Noises and Impact Noises
Airborne noises come from outside of the home, such as sounds from traffic, voices, trains, and airplanes. Airborne noises also include sounds from televisions, speakers, and other sources inside the house. Impact noises, however, include sounds from footsteps and vibrations. Insulation helps reduce both types of noises.
Types of Insulation
There are multiple different types of insulation, including:
- Foam spray insulation. Foam spray insulation is liquid polyurethane that contractors spray into a cavity through a small hole. The foam then expands to fill the space.
- Blown insulation. Most often found in attics, blown insulation typically consists of fiberglass and cellulose. Contractors blow the insulation in chunks into the cavity.
- Batt insulation. Most often found within walls, batt insulation comes in rolls or panels and typically consists of cotton, fiberglass, or rock wool.
Batt insulation is by far the most popular type of insulation to use for soundproofing due to its density and thickness.
Types of Batt Insulation
Batt insulation works to block sound by absorbing air (and, therefore, the sound waves traveling within it).
Fiberglass Insulation
Fiberglass insulation is the most common form of insulation found in American homes. The benefits of fiberglass insulation include:
- Easy to install: Fiberglass batt insulation is easy to install since manufacturers make the rolls to comply with the standard joist width that most builders use for walls and floors.
- Fire-resistant: Fiberglass batt insulation is noncombustible, which improves safety within the home.
- Renewable: Nearly half of fiberglass insulation is recycled, and the rest is made from sand, which is a renewable resource.
- Moisture-resistant: Fiberglass batt insulation is resistant to moisture, which makes it less prone to mold growth and suitable for high-humidity climates.
However, fiberglass insulation also comes with a few disadvantages, such as:
- Lower efficiency than other materials: When compared to different types of batt insulation, fiberglass insulation tends to have a lower efficiency rating, especially at low temperatures.
- Energy use during manufacturing: During the production process, fiberglass insulation manufacturers use more energy than other materials, and the process releases more air pollution than different types of insulation.
Mineral Wool Insulation
Mineral wool insulation, also known as rock wool insulation, is another common insulation material in the United States. Some of its advantages include:
- Moisture-resistant: Mineral wool insulation retains its insulating qualities even when it’s wet, and it is naturally moisture-resistant.
- Effective soundproofing: Mineral wool is an excellent material to use for soundproofing as it is denser than other materials.
- Fire barrier: Mineral wool doesn’t burn unless temperatures reach higher than 1800 degrees Fahrenheit.
However, mineral wool insulation also has a significant disadvantage: it’s incredibly harmful if inhaled. The small slivers of mineral wool can lodge into the skin. It’s possible that mineral wool inhalation can lead to cancer due to its ability to slice DNA and cause cell mutation within the lungs.
Cellulose Insulation
Cellulose insulation consists of recycled paper, including newspaper and cardboard. There are multiple benefits to cellulose insulation, including:
- Eco-friendly: Cellulose insulation reduces the amount of discarded paper in landfills.
- Fire- and mold-resistant: Manufacturers treat cellulose insulation with boric acid, which increases its fire resistance and mold resistance.
- Cheaper than other materials: Cellulose insulation is up to 25% less expensive than fiberglass insulation.
- Health: Cellulose insulation doesn’t carry as many health risks as mineral wool and fiberglass.
Some of the disadvantages of cellulose insulation include:
- Installation Costs: Cellulose insulation is more expensive to install than fiberglass insulation.
- Vapor barrier required: Whether homeowners choose dry or wet cellulose insulation, both forms require a vapor barrier.
- Absorbs moisture: Unfortunately, cellulose insulation absorbs moisture quickly, making it unsuitable for humid climates.
Best Type of Insulation for Soundproofing
Most insulation types will help reduce noise within the home. However, high-performance mineral wool and fiberglass tend to be the best choices for soundproofing.
How Can Northwest Weatherization Help?
With a decade of experience in the Pacific Northwest, including Lakeview, WA, Northwest Weatherization is dedicated to conserving and sustaining energy through weatherizing homes in the area. The talented staff cares about their customers, and every effort is made to provide an affordable service. Call today for a free estimate!