Soundproofing existing walls methods will highly depend on whether you live in a rental home or a house you own.
If you live in an apartment where the landlord doesn’t allow minor and major structural changes, your options may be limited.
On the other hand, if you have control over any structural modification over your home, then you have all the options available at your disposal.
In this guide, we shall be looking at some of the most recommended methods on soundproofing existing walls.
A-List of Methods on Soundproofing Existing Walls
First, before you start soundproofing, it’s important to get to know the type of sound you’re dealing with.
We have structure-borne noise/ impact sound and airborne sound.
Each of these is transmitted differently.
For instance, airborne noise is transmitted through the air, while impact noise is transferred via structures through vibrations.
Luckily, I will be explaining the type of sound each method deals with and the effectiveness.
Soundproofing Existing Interior Walls
Interior walls are prone to both impact and airborne noise.
If you share a common wall with your neighbor who regularly plays bass noise- then you’re dealing with impact sound.
You don’t want to fill your entire room with soundproofing materials.
Not only will this cost you an arm and a leg in the long run, but it also interferes with the aesthetics of your home.
1. Use Acoustic Sealant
The first and the most step would be to identify the tiny gaps and cracks on the existing walls and seal them for good.
This will help prevent airborne noise from transferring from one room to the next.
A perfect example and one of my most recommended materials for this purpose is Green Glue Acoustic Sealant.
Use this product to seal all the cracks and holes in the walls, the spaces around electrical outlets, and the gaps around the door and window frames.
By entirely sealing these leak ways, you’re able to significantly deal with airborne noise from leaking out or inside the room.
It is best if you use green glue on all edges where the walls meet the floor and the ceiling.
Don’t just buy any regular caulk, but if you can’t find green glue, then I would recommend these amazing green glue alternatives.
Green glue is perfect for dealing with impact noise- it converts sound vibrations to small amounts of heat energy.
It doesn’t harden and stays viscoelastic hence retaining its acoustic abilities.
2. Hang Mass Loaded Vinyl
Mass-loaded vinyl is a perfect product for soundproofing walls, ceilings, pipes, and ducts.
You can read an article here on soundproofing ceiling using mass-loaded vinyl and other sound dampening materials.
It’s an effective material that effectively blocks impact sound waves, including blocking footfall noise from loud stomping upstairs neighbors.
You can simply pin MLV on existing drywall or simply glue it to a plastered wall.
Additionally, if you’re doing extensive soundproofing work that involves adding layers of drywall (check out this detailed comparison: Quietrock sheets vs. Regular Drywall), you can sandwich MLV between the sheets.
Sandwiching it leaves you with aesthetic options since the grey, shiny mass-loaded vinyl appearance isn’t the most appealing surface.
However, if you decide to just hang it on the hang, the good news is that you can simply paint it with your desired color.
In this case, I would recommend soundproofing paint as it will also help improve the acoustic quality of your room.
If you can’t get hands-on MLV, then why not check out these effective mass-loaded vinyl alternatives.
3. Soundproofing Curtains and Blankets
Soundproofing curtains will not only add aesthetic value to your home but also help block out unwanted noise and ultraviolet sun rays.
On the other hand, acoustic blankets can be hanged from the door to help block out airborne noise from transferring through the door.
Both acoustic blankets and sound dampening curtains are made of dense, thick, and heavy materials that contribute to their noise reduction properties.
One of my recommended soundproofing curtains is the NiceTown Soundproof Thermal Insulated Curtains.
The good news is that the curtains are available in a variety of colors, sizes, and patterns, allowing you to pick one that matches the aesthetics of your home.
4. Soundproofing the Doors
Doors form a part of the existing walls.
It’s unfortunate that most modern doors are made hollow, making them highly prone to leaking noise.
There are 2 ways you can deal with this problem.
Changing the door and replacing it with a solid core door that’s dense has more mass and is capable of blocking sound waves.
However, you should note that solid core doors are quite expensive and require professionals to get them fixed.
On the other hand, you can soundproof the hollow door using readily available materials.
5. Soundproofing Spray Foam for Existing Walls
Spray foam insulation can only be used for plaster walls and not on existing drywall insulation.
In the case there’s drywall insulation, you’ll need to contact a professional for proper installation.
In most cases, the drywall needs to be removed before you can install the spray foam.
This is because spray foam expands rapidly, and if you apply without removing the drywall, it could overfill and exert pressure against the plasterboard, which can break or crack the drywall.
Cheap Ways to Soundproofing Existing Walls
Cheap doesn’t mean ineffective or most effective.
If you employ these cheap methods, you’re most likely going to get a better noise reduction, but you shouldn’t expect total silence.
Below are the methods you can apply to reduce noise coming through walls.
6. Household Items
Did you know that you can use household items to soundproof your room?
The first step would be to identify the source of the noise problem.
Then, move heavy furniture such as portable closets or bookshelves to the adjacent position to the wall.
You should also stack the closet with clothes or the bookshelves with books to add more mass which is responsible for dampening vibrations from being transferred to the room.
You can apply the same method when it comes to soundproofing doors.
Check out my previous article on soundproofing a doorway using household items.
7. Acoustical Wallpaper
Soundproofing Wallpaper is only effective against airborne noise, echoes, and reverberations.
It doesn’t soundproof against impact sound, so if you’re dealing with bass noise or low-frequency sounds, this isn’t the option for you.
While it doesn’t soundproof against noise, this product is highly effective in high-frequency sound-absorbing.
It will only absorb sound and prevent sound waves from escaping a room. However, acoustical wallpaper won’t block noise from leaking inside the room.
It can’t to block noise like drywall or mass-loaded vinyl.
Another product that works similarly to acoustical wallpaper is acoustic foam panels.
They are highly effective in sound-absorbing but don’t block out noise.
Therefore, if you’re looking to improve the acoustic quality of your room- for example, home theater acoustic treatment, then I would highly recommend acoustic foam.
Check my comprehensive guide on how to hang acoustic foam panels without causing damages to the existing walls.
Soundproofing Existing Office Walls
Soundproofing existing office walls involves the same concept as soundproofing regular walls.
You will need to employ the methods highlighted above for proper office soundproofing.
On Soundproofing Existing Walls
Soundproofing existing walls can be a cheap or expensive venture depending on the levels of sound deadening you need achieved.
For ultimate wall sound dampening, I would highly recommend adding a layer of drywall materials and sandwiching soundproofing materials between them.
This is quite effective but also very expensive and time-consuming but quite recommended if you’re dealing with impact noise.
However, if you’re dealing with airborne noise, then other simple DIY soundproofing methods highlighted above could easily work for you.