How to Soundproof a Brick Wall
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Soundproofing brick walls can turn a rather uncomfortable dwelling situation into a contented one, where the hustle and bustle of external disturbances will be greatly stifled, and your space will no longer be an echo-chamber for your every word or movement.
So, how exactly could one soundproof a brick wall or room?
Soundproofing a brick wall can be done with Soundproofing Sealant, Mass Loaded Vinyl (MLV), adding Drywall, Insulation, and Decoupling.
Also read: 4 Effective Ways To Soundproof Concrete Walls
There are a few fundamentals when it comes to soundproofing your space. Whether you’re trying to establish a quiet environment in which to focus and work, or simply trying to get some well-deserved privacy from neighbors, we’ve gathered some of the most useful and practical methods to help you attain the tranquil environment of your dreams.
How does soundproofing work?
Sound is produced by various sources and requires continuous mediums in order to travel. The medium could be anything that may act as a conductor for soundwaves, which would be dependent on the individual physical properties of that medium.
Although there are many kinds of mediums that could act as a conductor for sound, air is one of the largest mediums which sound vibrations travel through. Sound will continue traveling by bouncing off molecules and particles that it comes in contact with.
When it comes to soundproofing, the basis of the process is ensuring that soundwaves and relative vibrations are controlled to an extent where the sound is inhibited from external sources, and the movement of soundwaves within the room itself is controlled.
In order for a room to be soundproof, it will require being flexible in the approach considering the density of the structure.
There are 4 main elements of soundproofing that need consideration throughout the process, all of which have a direct relation to the conduction and transmission of sound vibrations.
Decoupling: In short, with decoupling, two layers of drywall are separated from each other. By doing this, a layer of air is created in-between the walls which provides good sound insulation.
Absorption: Insulation material such as fiberglass insulation, cellulose, mineral wool, and recycled cotton is used. These materials are placed into the wall in order to absorb these soundwaves, but the insulation is not compressed.
Mass: The soundwave would need to vibrate the wall itself in order to permeate through it. If the mass of the wall is higher, this movability is less, making it less probable for sound vibrations to travel through.
Damping: There are several products that are used for this, and Green Glue (check my review) is a popular option. Green glue helps in converting some of the sound energy to heat energy.
All elements of soundproofing are major influences for the way in which soundwaves and vibrations behave within the space.
The most efficient results come through the cohesive inclusion of all of these elements in relation to the physical properties of the wall. There may still be ‘flanking’ or soundwaves that leak into the room.
How does a brick wall interact with sound?
Brick walls provide a decent start to creating a soundproof environment. This is due to the fact that brick is naturally thick, is dense in terms of its composition, and its thickness and relative density makes it more challenging for soundwaves to pass through it.
These characteristics will decrease the likelihood of sound passing through from the other side of the brick wall, which is handy for blocking out exterior noises such as traffic, trains, and general sounds from the external environment.
How to Soundproof a Brick Wall
At this point, you’re probably wondering what one could do in order to soundproof a brick wall post-construction. Perhaps, the construction process did not include many of these processes, or these predetermined steps were simply not enough. Rest assured, there are still a few ways in which this can be done.
The density of the wall will be the primary factor that will need consideration when attempting to soundproof it.
It’s important to understand all of the underlying principles of soundproofing in relation to the specifications of the wall or room in question, as one could end up spending a ton on the process only for the soundproofing problem to be persistent.
Contacting a professional for a thorough evaluation of the wall is always advised as opposed to a complete DIY route, as this may at least provide some expert guidance on what would and wouldn’t work according to the specific structure.
Soundproofing a brick wall presents unique challenges due to its physical properties and characteristics, which makes it particularly easier to soundproof.
Caulk or Soundproofing Sealant
If the wall has any cracks or holes that sound waves can leak through, one could seal these before going ahead with more elaborate methods.
Soundproofing sealant (see this one on Amazon) is relatively affordable, can be used in order to seal up any areas that allow for ‘flanking’, and could be a great starting point for further soundproofing methods.
Adding Drywall
This method is quite popular and effective and works by adding mass and thickness which will decrease the sound vibrations’ travel. It’s a good long-term solution since it’s relatively simple and the process doesn’t involve taking the original brick wall down.
Increasing the wall’s overall mass will assist in creating an environment that is more difficult for sound vibrations to pass through or bounce around. This will enable only very low frequencies to pass through.
Adding a layer of double drywall which is separate from the brick wall will allow for sound to bounce off the drywall before reaching the brick wall.
Although double layers are most common, one could add as many layers of the drywall as is necessary, and using Green Glue during the process will add an additional barrier.
Using soundproofing compounds such as Green Glue to treat the wall will decrease resonating frequencies. The wall will need to be padded with a layer of drywall, being treated with the soundproofing compound, and a layer of drywall will be fixed after treatment.
Mass Loaded Vinyl (MLV)
Mass loaded vinyl (Amazon) comes in a wide variety of types and price ranges and is an exceptional source of non-resonant mass. It’s made up of vinyl which has high mass and is naturally dense, while still providing a suitable amount of flexibility.
MLV can be applied to isolated walls, floors, and ceilings. Its mass relative properties are what make it effective in reducing sound transmission and coping with excess noise.
It is manufactured in a variety of types, and the most low-cost MLV is created with cheaper materials. Some forms of good quality MLV are extruded and will consist of polymeric plasticizers which provide strength and stability to the MLV.
MLV can be placed over existing walls or surface areas, and is equally effective when positioned loosely or taut against the area being soundproofed, as well as when attached to framings or between layers of drywall.
It can thus be installed in whichever way is most convenient for you and is most suitable for the wall or space in question.
Insulation
Depending on how the wall was constructed, adding some insulation to the interior space of the wall may be a good option. This will need to be done by a professional, but it’s relatively affordable and doesn’t take too much time to complete the process.
Popular insulation includes fiberglass since it dries quickly, and cellulose, since it’s more eco-friendly.
Decoupling
The main idea of decoupling, as described within the primary elements of soundproofing, is to receive soundwaves and break the wavelength in order to stop the traveling of the soundwave and relative vibrations.
Soundwaves are trapped within the air chambers and will be less likely to permeate the other part of the wall.
The method entails the construction of two walls with a relative gap between them. Loosely fitted insulation between studs is generally considered as essential for the effectiveness of decoupling due to the fact that the aim of decoupling will be lost if an air chamber is missing.
There are a few ways in which decoupling can be done.
A room within a room
This is done erecting two walls which are completely detached from each other, and the gap between the surfaces of these walls will essentially act as the air cavity.
While this quite an effective method, it may only be necessary if the entire room needs to be soundproofed, and it’s not entirely practical or cost-effective. There are some other ways to achieve similar effects.
Double stud wall
This is a simpler and cheaper alternative for decoupling and is done by attaching sets of studs to the same base plate, and the drywall is fitted to the outer sides.
The staggered stud wall
This is a more economical and spatial efficient method for decoupling, whereby a 2 x 4 set of studs is arranged on either side of the base plate at around 6 inches wide. This creates a large air cavity which achieves the soundproofing goal of decoupling.
Check out: Staggered Stud Vs Double Wall For Soundproofing
Resilient Channels (read my article on this)
This is a great way to decouple single walls. These are metal channels that are screwed to the studs, and the drywall is installed so that it only connects to the resilient channels without making contact with the studs.
Sound Isolation Clips
This is another good way to decouple single walls, and these can be placed on studs to dampen sound. Hat channels are placed in the sound isolation clips, and the drywall is attached to the channel with screws, avoiding contact with studs.
All decoupling methods are more complex approaches to soundproofing, and some methods are not cheap or simple. It may not be practical to tackle these approaches, and considering some of the simpler methods first is advised. Nevertheless, it’s very effective.
The elements of soundproofing play a key role when considering any of these approaches, and since a combination of these elements creates good soundproofing, a combination of methods may be more effective overall.
There are a variety of ways to soundproof a brick wall, but which methods are best will ultimately come down to the specifications of the room or wall in question, budget, timespan, and how soundproof it needs to be made.
