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Spray foam insulation, also called polyurethane foam, is an expanding foam that can be sprayed onto roof tiles, metal walls, and wall cavities. It usually comes in two types: open-cell and closed-cell spray foams, both of which have varying properties. But do they reduce noise?
Spray foam insulation is not a good choice for noise reduction, as open and closed-cell spray foam is more suitable for thermal insulation, not sound insulation. This is because they are not good at blocking sound waves, but are good thermal insulators as they reduce air infiltration.
In this article, we will look at why open and closed-cell spray foams are not the best choice for noise reduction. We will also discuss the various materials you can use instead of spray foam, which will insulate your room from noise pollution effectively. Let’s dive in!
Is Open-Cell Foam Good for Soundproofing?
In an open-cell spray foam, the ‘cells’ are left open, making the material softer and more flexible. They are also less dense than closed-cell foams. Additionally, the R-value (which is its resistance to heat) is lower than closed-cell foam, making it a comparatively average thermal insulator.
While open-cell foam is definitely better than closed-cell foam when it comes to sound reduction or insulation, it is not your best and most efficient option. This is because spray foam lacks sufficient mass to absorb soundwaves.
So even though open-cell spray foam is not as bad as closed-cell foam when it comes to soundproofing, it underperforms when compared to other soundproofing materials.
Is Closed-Cell Foam Good for Soundproofing?
Closed-cell foams are made up of completely closed cells, thereby preventing air and moisture from penetrating the building through the foam. It is also denser than open-cell foams. Additionally, they are excellent thermal insulators and are used extensively in that field.
When comparing the noise-reducing properties of all the materials typically employed for sound insulation, closed-cell foam insulation has comparatively low noise deadening ratings. Though they are more rigid than open-cell foams, they are not resistant to sound transmissions and are not efficient when it comes to the sound insulation of rooms or buildings.
What Are the Best Alternatives for Soundproofing?
Apart from using open or closed-cell spray foams (which are efficient only in thermal insulation), you may consider using a few other materials like fiberglass, rockwool, and acoustic foam. Let’s have a look at the effectiveness of these types of insulation below.
When it comes to sound insulation, fiberglass is one of the most commonly used materials due to their highly efficient insulating properties. Insulating a building with fiberglass is a great option as it not only prevents soundwaves from penetrating the building from the outside but also blocks waves that may exit the building from the inside. In addition to this, it also improves the room’s temperature.
Another benefit of using fiberglass is that it can be used in different formats to insulate your walls, ceiling, and floors as well. Before we move on, here is a little information on what fiberglass exactly is.
Fiberglass is an insulation material that is made up of very small glass particles. While some manufacturers use recycled glass, others heat sand and spin it to form the glass. Usually, people who insulate their walls use rigid panels made out of fiberglass. These rigid panels are usually a combination of foam plastics and fiberglass and provide thermal and acoustic insulation.
Fiberglass insulation works by trapping the heat and soundwaves inside a room. When choosing a sound insulation product, always check the NRC (Noise Reduction Coefficient) rating of the product. Materials with an NRC rating of 0.75 and higher and usually considered highly absorbent, and fiberglass has an NRC rating between 0.9 and 0.95.
However, do remember that though fiberglass is a good sound absorber and barrier, it does not provide a completely soundproof room.
If you would like to see what fiberglass insulation typically looks like, I suggest you give the videos below a watch:
Rockwool insulation, also known as stone wool or mineral wool, is a rock-based mineral fiber insulation. They are usually made out of basalt rock and recycled slag. These minerals are first melted and then spun into fibers.
Rockwool is usually used to provide structural insulation, thermal insulation, and soundproofing. They are usually compressed into rolls or sheets, and their ability to permeate soundwaves makes them excellent sound insulators. In addition to this, they also show some resistance to fire (though they are not completely fireproof) and are thus used extensively in buildings.
Some manufacturers provide rockwool insulation with an NRC rating that goes up to 1.1, which is a little higher than fiberglass as well. In addition to this, rockwool has a slightly higher density than fiberglass, which makes it slightly better at soundproofing a room.
Another reason people sometimes prefer rockwool is because of its durability. Rockwool insulation is known for its long life and does not get worn out or damaged easily, making it highly efficient from an economic point of view as well. It is also made of a breathable material, reducing the risk of mold or bacterial formation inside the building.
If you are curious to know what rockwool looks like and how it is supposed to be installed, give these videos below a watch as they provide a step-by-step explanation of the process:
Acoustic Foam Insulation
Acoustic foam is made from polyurethane foam and is usually lightweight and easy to install. One additional benefit is that they not only absorb sounds but also enhance the quality of sound in a room.
They are mostly used to reduce noise pollution while also preventing echoes and background noises. Unlike fiberglass and rockwool, they do not provide the added benefit of thermal insulation.
A few of the key factors that affect the performance and effect of acoustic foams are the thickness of the tiles and the surface patterns on the tiles. Be sure to choose the thickness based on the thickness of the wall you plan on insulating.
Additionally, if you simply want to soundproof a room, then you need not worry about the 3D patterns present on the tile as those are only applicable for acoustic performances.
In addition to this, there are also acoustic foams that are fire retardant and some which are not, so be sure to buy non-combustible panels if you plan on insulating a building with it.
Here is a video that provides information on acoustic panels and how they must be installed:
To answer your question once again, spray foam insulation is not the best type of insulation if you want to soundproof a room or building. They are more apt for thermal insulation. However, there are other types of insulators which are great in reducing and preventing soundwaves from traveling through the walls. Here is a short list below:
- Fiberglass: It provides thermal and sound insulation. It is easy to install and acts as a good sound absorber and barrier.
- Rockwool: This material also provides thermal and sound insulation. It is slightly more efficient than fiberglass and is more fire retardant as well.
- Acoustic foam: This is used mainly for acoustic purposes and can block soundwaves to a certain extent.