How to Sound Proof a Wall Already Built – 11 Ultimate Tips

The traffic, the neighbors, the bars on the street ... The noise at home is unbearable! Many of us experience the same. A recent study by the National Institute of Statistics (INE) reveals, one in three homes suffers excessive noise levels. Although the  World Health Organization (WHO) advises not to exceed the 65-decibel noise limit during the day and 55 decibels during the night, still we face the problem on a regular basis. 

To soundproof a house you can fill the bookshelves. There is also the option of placing carpets and paintings or using insulating paint to muffle the most annoying noises in the home. More effective, although a little less economical, is to build a false ceiling, put a wall or shelf of plasterboard or isolate the wall with fiber wool, wood or cork.  In this article, we will help you to figure out how to soundproof a wall already built.
How to soundproof a wall already built

The Magical Tips to Make Your Walls Soundproof

Let’s check out some effective tips on how to soundproof a wall already built. 

1. Use insulating paint to Mitigate Residential Noise

Like many other advantages that we use daily such as disposable diapers, the ear thermometer and more,  the paint to isolate the noise was created from technologies of NASA (National Aeronautics and Space Administration of EE .UU.). Based on latex and water, this paint contains microspheres, resin, and filters that create a membrane capable of absorbing sound and reducing it by 30%.

All you need to do is to roll and paint it on the walls (it is effective even on existing paint). In addition, it does not have a bad smell, dries quickly and cleans easily. This anti-noise paint is marketed by various brands. This is quite helpful and you don’t have to keep on searching for “How to soundproof a wall already built” if you apply this unique technique.

2. Soundproofing with curtains and carpets 

One of the easiest ways to isolate the house from noise is to place a carpet on another thick carpet. This serves as an obstacle to prevent the sound from penetrating and bouncing on the floors.  Also, the curtains and the tapestries of consistent fabrics such as velvet, very thick linen, corduroy help to absorb the sound waves.

3. Cover Your Walls with Insulating Materials 

How to soundproof a wall already built

If you are looking for more effective to know How to soundproof a wall that is already built, you need to be a  little more elaborate and laborious. This is quite an effective trick.  You can cover the wall with an insulating material like cork or wool fiber. Once done, you can hide them with drywall. Solid wood or chipboard panels can also be useful insulators. The only downside of this measure is that it does lose a bit of space (10/20 centimeters).

4. Take the Advantage of Weight For Preventing Noise

The answer to the question, "How to soundproof a wall already built, has numerous easy answers. One of the most effective of them is using the mass. The weight works best to prevent noise from passing from one place to another. For this reason, it insulates more a wall of 15 centimeters thick than a partition of 5cm: the material is the same, but one wall will weigh more than the other just because of its thickness.

A one-centimeter thick steel plate, for example, is a solution that you can easily apply if you don’t want to lose centimeters in a room.

5. Take Help of the Advantage Materials

For example, rock wool, a material composed of volcanic rock fibers. Since it is a very light material, so you might wonder how it would work. Actually, it’s very simple. It simply works as a spring. By slowing down the movement of air it dissipates the propagation of sound. It is excellent for absorbing the echo in an empty space, but to isolate from the noise of another room it is only working as a complement to other elements like the mass.

6. Install bookshelves

How to soundproof a wall already built

 If the noises of the neighbor are unbearable, there is no cheaper way to mitigate the noise than attaching shelves (better with background) to the walls. The more books they have, the more the sound will be muted. It is also very useful to place cabinets or furniture from wall to wall or fill them with mirrors or paintings that act as a barrier.

7. Double glazing to avoid outside noise

To insulate the house from outside noise you can put double glazing. There is a wide variety, with different levels of insulation.

Famous architect Carlos Sánchez says, "blind boxes are a great acoustic bridge: they allow a lot of noise to pass from outside to the house". To reduce it, a good solution would be to place sheets of sound absorbing the material on the lid and, if possible, on the inside faces of the blind draw.

8. Try DIY 

You can also use DIY methods to soundproof the wall with some homemade solution. When it comes to “How to soundproof a wall already built”, there are two types of materials, sound blockers, and sound absorbers. 

To prevent the noise , you can easily opt out the sound blockers. You can fix this product on doors, windows, and walls or between cracks.

9. Know the Source of Noise 

How to soundproof a wall already built

In order to reduce noise, first, you need to determine the source of the noise.  Is it the noisy neighbors, the construction site across the street, colleagues talking loudly or anything else? This will help you point out the areas that are in an urge for implementation of soundproof methods

10. Soundproof the Windows

If you want to know more aboutHow to soundproof a wall already built,  here’s is another magic trick that will help in every way to reduce noise.


Remember, glass is a fantastic conductor of light, heat, and noise. And this is not always an advantage. Like cold air, noise can easily enter when there is a single layer of glass and amplify the noise itself.


 installing double-glazed windows is an effective measure to eliminate the noise that filters through them while thermally insulating the house. At night, when the noise is more annoying, you can hang the heaviest or thickest curtains you can and consider using several layers of fabric.


11. Soundproof the Walls  

If the walls are thin and you’re able to listen to neighbors' TV through the walls, you can apply this final trick. Try adding shelving and other thick pieces or furniture. You can also prevent noise by adding a thick layer of foam between the wall and the furniture. If you have a decent relationship with your neighbors, you can also have a conversation with them about adding more acoustic absorbent or insulating material to their part of the home. That will ensure less noise interference through the walls.

Hope this post helps. Now you know how to soundproof the walls already built. Try these amazing techniques and give your ears a peaceful home environment.

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