How to Soundproof Existing Walls

Homeowners might feel that every little sound bounces too much in the room. The chaos created by banging sound waves is more than the actual noise in the room.

Things worsen if you have loud neighbors or excess traffic noise seeping indoors.

Tearing down the entire wall structure and rebuilding it to stop the noise isn’t a convenient option. There are some alternative solutions that you can adopt to make things work without much hassle.

Categories of soundproofing

Before jumping to those strategies, understand the distinct categories of soundproofing solutions:

Direct to wall solutions

These are thin and space-saving structures compared to the soundproofing systems. This feature makes them viable for low-frequency sounds, such as muffled conversations or television noise.

These solutions cannot block vibrations penetrating the walls.

Soundproofing systems

This is a more robust method of soundproofing. It deals with high-frequency sounds, such as loud music and conversations.

Combining the acoustic materials to create a soundproof wall will deal with the high level of airborne noises.

What to know before you get started?

For starters, you should set realistic expectations.

Don’t expect an entirely silent room because soundproofing techniques will reduce the noise transfer, not eliminate it.

Using the methods mentioned below, the homeowners can lower the distracting sounds to a bearable standard.

These techniques are functional for all kinds of rooms, be it a workplace, family room, nursery, or bedroom.

If possible, consider implementing soundproof strategies to the adjacent rooms.

For example, if an attached backyard shares the same wall as the master bedroom, use soundproofing techniques on the walls of both spaces.

How to soundproof existing walls?

How to soundproof an existing room cheaply

After thorough research, our experts have agreed upon the following soundproofing methods. Some of these options are more effective than others.

We strongly recommend evaluating your needs and putting your finger on a workable method.

Install Blown-in Insulation

Removing the wall covering to insulate the wall cavity is cheap and easy.

This type of insulation can seal the small spaces as it sets in. It fills the sneaky spots as the air enters the holes.

Besides creating an insulation blanket, blown-in insulation helps to reduce the transfer of sound between indoors and outdoors. 

The process of implementation is as follows:

  • Use a stud finder to locate a stud and horizontal blocks near the center of wall’s height. Then, mark each stud center and block using masking tape.
  • Use a hole saw and drill to penetrate the top cavity, about 6 inches below the ceiling.
  • Save the disc of wall-covering material that you removed with the saw.
  • If there is a horizontal or diagonal blocking in the wall, make further penetration about an inch beneath the block.
  • Penetrations to install the insulation should be at the same intervals, where they fill one cavity at a time.
  • Remove the old insulation with the vacuum.
  • Blow the new insulation. There are insulation blowers available for rent, but some stores provide the machine at no charge when you buy insulation material from them.
  • The last step involves repairing the holes. You can hire a wallboard contractor to do this job or do it yourself if you are good at handy work.

Once you are aware of the entire process, you should also acknowledge different blown-in insulation types. These include:

Loose-fill Fiberglass

This is manufactured from glass heated into the liquid and spun into thin fibers. The loose fiberglass offers R-2.5 thermal value per inch when blown into walls.


For pro-environmentalists, cellulose is the ultimate choice. It is made from finely shredded recycled newspaper or cardboard.

This is a common type of insulation in the market which can resist mold and fire.

Rock Wool

This type of insulation is made using blast furnace slag. The heated slag is combined with other minerals.

Next, they are spun into an airy product resembling the texture of raw sheep wool.

Hiring professional labor is often a good approach as they know all types and procedures. They will guide you about the category to choose and how you can move ahead with the process.

Seal outlets and cracks

How to soundproof a shared wall

Wall cracks are the culprit that let noises pass through. These cracks vary by the material used to construct the walls.

Almost all kinds of materials eventually start showing cracks at some point. Thus, it would help if you inspected the walls now and then.

Know how to seal these cracks, so they don’t become extensive over time.

Rub the concrete wall surface for inspection. You should clean the dust and check if you missed any cracks.

Once you have spotted the cracks, it is now the time to deal with them.

Sound waves can squeeze through, creating a disturbing room atmosphere if you don’t deal with them efficiently.

Initially, you should consider sealing all corners of your walls.

Make sure that you use an acoustic caulk instead of standard latex caulking available at the hardware stores.

After caulking the wall cracks, you should move to seal the light switches and electric outlets. Using insulation gaskets will bring the best outcomes.

These are the Styrofoam pieces that fit around the electrical points. They keep the sound waves from slipping outside.

The parts are cheaply available and come in ample quantities.

Focus on small areas of the wall

If there are budget constraints, you should focus on the narrow wall areas.

You should figure out the points from which sound escapes a room. Focus on those areas and apply some materials on these spots.

After completing the task, test the efficacy of soundproofing by playing music indoors.

Ask someone to stroll outside the room and examine which areas are causing the sound leakage.

If the point is near the wardrobe or cupboard, fill it with as many clothes as possible. This will help to insulate the sound and prevent it from moving out.

Add another layer of drywall by using Green Glue

Green Glue can be used in building upgrades or new constructions.

This Glue is intended to be sandwiched between two sheets of building materials, like drywall. It eliminates the need to remove existing wall structures.

Using Green Glue is a hassle-free process that goes as follows:

  • Use a standard quart-sized gun
  • Its thin consistency allows dispensing Green Glue within seconds
  • It doesn’t flow off the board during application
  • There is no specific coverage pattern to follow when using the Green Glue
  • A larger tip opening will help to apply instantly without being concerned about its performance

Green Glue has proven itself an incredibly effective way to soundproof the walls.

It works for different frequency sounds, making it the easiest option to soundproof the existing walls.

Hang noise-reducing curtains

How to stop hearing neighbors through walls

Soundproof curtains are available in various colors, patterns, and sizes. These curtains aren’t only for windows; you can use them on walls too.

You must have noticed how cinemas and theaters use huge curtains on their walls.

Besides uplifting the aesthetics of a room, the curtains help to contain sounds.

When choosing soundproof curtains, the rule of thumb is to get them more expansive than your walls. Many manufacturers will customize these curtains according to your space requirements.

Some tips to follow when installing soundproof curtains are:

  • Instead of using wall brackets, opt for ceiling brackets
  • Get a soundproof curtain wider than your wall size
  • Go for drape-designed soundproof curtains
  • Attach blankets to your walls

Sometimes the voices coming from outside make it tough to live peacefully.

Meanwhile, in some cases, the space residents want to block the sounds from passing through the walls.

Soundproof blankets are the answer to all such woes. They absorb sound vibrations and prevent them from entering a room.

The blankets can also dampen sound within the room.

Attaching blankets on the wall is similar to putting up a poster. Here are the steps to follow:

  • Nail blanket against the wall.
  • Use tape or glue to stick it on the wall. Make sure that you deploy industrial adhesive to carry the weight of your blanket.
  • Use the mounting putty to tack the blanket against the wall.
  • Suspend the blanket with curtain rods or curtain tracks.
  • From all the above techniques, the first one brings the best outcomes. You have to leave the nails exposed when pinning the blanket. It is also easy to take off the blankets if you want to send them to the laundry.

A soundproofing project on an existing wall is tricky.

If you live in a rented space or a hostel, you don’t have the luxury of pulling off the entire structure and rebuilding it. Blankets are a viable option in these scenarios.

Some perks of using the soundproof blanket are:

  • It is easy to install
  • You can easily buy it on a budget
  • You can use it anywhere due to its flexibility
  • It works as interior décor, so that’s a win-win

Use acoustic foam

Acoustic foams are panels with pointed and tiny wedges on the surface. They are made out of polyester or polyethylene foam.

It is widely used in soundproof theaters, churches, and studios. However, using it to cover residential places is a relatively new practice.

The acoustic foam works as a sound absorber.

The foam absorbs all kinds of sounds that strike upon it. Simultaneously, it can also accentuate the sound in a room.

It also eliminates any impact and vibration noises entering a room.

The foam mat functions as an insulator. It contains rubber foam and is resistant to water, petrol, and oil.

Here are some steps to follow when trying to determine how you will put acoustic foam on your wall:

Determine the type of sounds you want to block

If you deal with low to mid-frequency sounds, there is no need to install thick acoustic foam.

Take measurements

It is best to know the size of your room before you go shopping.

This makes it easy to see the number and size of acoustic foam you will be buying.

Tailor fit on the walls

It is essential to get the foam cut according to your space.

Get a double-sided tape and put it up on the wall. It lets you test how the wall will look so you can finalize if you want to go with it.


Avoid using regular glue when sticking acoustic foam. It contains acidic compounds that could melt the foam.

Instead, use the foam tacks to install the panels. It doesn’t damage the foam and keeps them stuck for a long time.

Change the doors

How to soundproof walls between two rooms

Most doors nowadays are hollow within.

They have two panels of thin wood kept apart by a layer of thick timber. This means that most hollow doors will bang like a drum.

Apart from this, some houses also have solid doors.

You can get these doors on the wall to enhance its density. In fact, some soundproof doors also have insulation inside.


How can I cheaply soundproof a wall?

If you don’t want to invest heavily in soundproofing operations, we suggest that you play around with your furniture.

Another way could be placing a thick carpet or area rug within the room to create more sound-absorbent surfaces.

Adding bookshelves and hanging thick drapes are also cheap ways to contain noises inside the room.

Can you soundproof the thin walls?

Soundproofing thin walls don’t ask for a major construction project. You can enhance the soundproofing qualities of all wall types by using many techniques together.

How can I soundproof the existing walls without damaging them?

Combining mass and damping is an effective way to soundproof a room without creating a ruckus.

This involves adding extra layers of drywall and spraying Green Glue before you place it on the existing wall structure.

Final Thoughts

It is essential to acknowledge that sound waves have more chances to spread if the room is vast and spacious.

Knowing all the features of your room will allow you to make an informed decision.

All the steps listed above will help you soundproof your existing walls without burning a hole in your pocket.

Pick a strategy after doing background research into methods and whether they are functional for your space.