We’ve all had those noisy neighbors in our lives: the ones that seem to speak as loud as possible when they’re in their homes. Or the college kid right above you who decides it’s a great idea to throw a party on a school night. Perhaps you’ve figured out that super loud neighbor is you. In either instance, it could be a good idea to soundproof your space or move somewhere that is more soundproof. With all the many materials that can help soundproof a room, a wall and floor that’s already made of cement might look like a good option.
Decoupling, absorption, mass, and damping are essential characteristics for material to effectively soundproof a room. Concrete only has three of these four qualities, making it only suitable for blocking airborne sounds rather than impact sounds.
In the remainder of this article, we’ll discuss the types of sound that concrete can effectively block as well as how you can use the material to soundproof your space.
What Types Of Noise Can Concrete Soundproof Against?
The kind of material you should use to quiet areas of your home is heavily dependent on what type of sound you want to keep out. Sound can be broken up into two categories: impact sound and acoustic sound.
Impact sound can be described as the resulting sound that’s made when one object impacts or interacts with another. This is also considered “structure-borne noise.”
For example, the sound of you walking across a hardwood floor or pushing furniture across the room can be categorized as an impact sound.
To lower the volume of impact sound, it is often recommended to add more material to the most impacted surface. In the above examples, the floor would most benefit from thicker carpeting or some other type of flooring to prevent excess noise.
Concrete isn’t the best material to block out impact sounds. The hardness of the material and how it is spread across the area makes it easy for noises to carry; since concrete is usually found throughout a wall or the ground in a room, a sound made on one side of the concrete can carry over to the other side.
Airborne sound, also known as acoustic sound, is sound that travels through the air and into the ear. Examples of this include singing and talking.
Concrete does an excellent job of blocking out airborne sound. The solidness of the material prevents airwaves from escaping a room and traveling into other areas. However, this is slightly less true for concrete that is very porous and has a lot of air pockets. Concrete mixed and poured with these qualities make it easier for airborne sound to travel through.
Soundproofing A Room With Concrete
To effectively soundproof a room, the materials used must have the following qualities:
- High Mass
(Source: Soundproofing Company)
Cement is known to have some of these qualities—absorption, high mass, and dampening, in particular—making it a suitable option for soundproofing against airborne sounds.[Related Article: 50 Soundproofing Materials and DIY Tips That Fit Any Budget]
Sound travels much easier between two points when there is a solid pathway its vibrations can follow, such as a flat wall. To have a more soundproof room, you will need to break up the wall or add material that works to that same effect. This is referred to as decoupling.
Cement is very solid after it dries; for that reason, it is difficult to break the material up enough to prevent sound from traveling across its surface. This makes cement a poor decoupler, and a good conductor of noise—especially impact noises—regardless of whether it’s in the walls or floors of your home.
Alternatively, for soundproofing, it is usually better to attach something to the wall, leaving some space between the wall’s surface and the object. Examples of things people often use to disrupt sounds from traveling include art pieces, photos, or other décor. For concrete floors, add a few rugs or install carpeting to prevent impact noises from coming through easily.
When the walls or floor of a room is made up of material with a lot of tiny air holes or spaces, it becomes easier for people in the adjacent room to hear you. This is because soundwaves will resonate within the air bubbles.
Materials that are made to be soundproof are likely to be nonporous, or without or with few air pockets and holes; the less holes, the less sound that can escape from the room.
In soundproofing, absorption is a material’s ability to “absorb” sounds. This term is often applied to nonporous material. Concrete, in particular, can have a very high absorption rate, depending on the type of cement you use. As long as it is nonporous cement, however, you can effectively use it as a soundproofing material, at least for airborne noise.
Sound is only able to move through a wall if the wall slightly moves as the sound passes through. To prevent this from happening, you would need to use a material with more mass, such as certain types of concrete; just as there are cement mixes that have more air pockets, some are made up of heavier ingredients.
However, note that using high-mass concrete would only be effective against sounds with high frequencies; lower frequency noises, such as a bass instrument, could still potentially be heard from outside of the room.[Related Article: Soundproofing Walls: 8 Cheap Ways to Make It Happen]
The last quality that can make a material an effective sound blocker is damping. Damping helps reduce the amount of resonance (or vibration) in a room as much as possible. The vibration that is not removed from the air could potentially aid the transfer of noise from inside the space to the outside.
It is worth noting that resonance can be removed via absorption (mentioned previously) or redirection. However, these two functions do not effectively eliminate all the vibration remaining in a room on their own. That’s where damping comes in; it can reduce all the resonance in the room, including those that form impact and acoustic sounds.
How effective material can be used to dampen sounds depends on its other soundproofing qualities. For example, items with high absorption are more likely to be excellent dampeners as well. When it comes to concrete, nonporous cement will guarantee a higher absorption rate and, therefore, better damping.
Soundproofing Alternatives To Concrete
Regardless of whether you already have concrete floors or walls, sometimes that may not be enough to block all the sounds you want. For that reason, there are plenty of additional methods you can use to soundproof a room if the concrete isn’t doing it for you, including:
Ultimately, if you want to block airborne or acoustic sounds, concrete is the material of choice. Its solid, uniform surface prevents sound waves from resonating within it for long by damping it. However, for maximum soundproofing, make sure you opt for nonporous, heavy cement.
On the other hand, if you want to prevent the transfer of loud impact sounds or low-frequency noise, you are better off choosing a different material. Because concrete dries as a flat, solid surface, it is actually more prone to carry noise between rooms. If you happen to have a concrete floor or wall already and are having trouble blocking noise, consider a few DIY soundproofing options, such as soundproofing tiles or adding more décor to disrupt sound waves.