How To Soundproof A Room With Thin Walls? A Simple Guide

Thin walls are a nightmare, specifically for people living in apartment buildings. You have to deal with traffic and street noise from outside, footfall, noisy neighbors, privacy issues, and much more.

Luckily, you can soundproof a room with thin walls without spending a fortune on it, and achieve the peace and quiet that you deserve. To soundproof the thin walls of a room, you will have to add mass and density to them. This can be done using soundproof blankets or curtains, acoustic panels, soundproof insulation, adding more furniture or wall décor, or layering up with mass-loaded vinyl.

There are numerous options for soundproofing thin walls and all of them revolve around the four principles of soundproofing i.e., Mass, Decoupling, Dampening, and Absorption. The following explanation will tell you what kind of product you must add to the thin walls of your room.

Four Principles Of Soundproofing

The four principles of soundproofing are used in different combinations and intensities to make effective soundproofing products to cater to different soundproofing needs.

Mass

This is a simple one. The greater an object’s mass is, the harder it gets for sound waves to move it or push through it to the other side. And the harder an object makes it for sound to pass, the quieter it will make your room.

Adding mass will make an object heavier and denser. Both the weight and the density act as a strong barrier against the transmission of noise.

Decoupling

Decoupling means separating two sides of a wall mechanically. This is done to eliminate any points of contact that can transfer vibrations from sound waves from one end to the other.

Decoupling is an excellent technique for blocking the transmission of noise, especially impact noise, but it isn’t effective for all frequencies of sound. You must combine this principle with another to create a completely soundproof room.

Absorption

Some materials are naturally more absorptive than others due to their porous composition. This is a key sound isolation characteristic that can reduce and eliminate noise from a room.

The principle of absorption works best for airborne noise and mid to high frequencies of sound. Absorptive surfaces take in sound waves and exhaust the complete momentum of the moving wave. 

Adding an absorptive material to the thin walls of your room will reduce the amount of noise that travels in. Absorptive products are also great for mitigating echoes and reverberations in a room.

Dampening

Dampening helps to reduce vibrations that are produced from the sound source. Sound vibrations travel from one object to another and make their way into your room vibrating through its thin walls.

Sound dampeners eliminate these vibrations and dampen noise. They come in different densities and thicknesses that you can choose from according to your soundproofing needs. The denser a dampener is, the better it is at dampening noise.

How Can You Soundproof A Room With Thin Walls?

Now that you know the fundamentals, you can move on to deciding what’s the best way to soundproof the thin walls of your room.

Soundproof Blankets And Curtains

Editor’s recommendation: the absolute best when it comes to soundproof blankets is the Audimute Sound Absorption Sheet. However, if you’re looking for proper soundproof curtains, then we’d recommend checking out these ones by NICETOWN.

Soundproof blankets have a porous surface to absorb sound before it can enter the room. They are made of polyester, vinyl, velvet, or fiberglass. Soundproof blankets are heavy and thick in their form but very easy to install.

All you need is a hanging rod or rail fixed on the wall. Soundproof blankets and curtains are not only for blocking noise, they are thick enough to block light, and prevent heat and cold from getting in with air.

Keep an eye out for soundproof blankets that come with grommets or eyelets as they will make the installation process a breeze.

Seal All Gaps And Holes

All walls have some gaps, cracks, or holes in them. No matter if it’s the thin walls of your apartment or double-bricked walls of your country house. The small openings can let a lot of noise inside the room and they often go unnoticed.

You need to seal every small gap you can find in the wall. It could be a heating duct, a hole for an electrical outlet, phone jack, or ventilation vents. You can seal these small gaps with a caulking gun to block the free movement of vibrating air (carrying sound waves).

The best material for sealing holes in thin walls is Green Glue. Green Glue is a sound dampening compound that can easily absorb even the tiniest of vibrations from sound waves. It’s one of the best soundproofing products today in the market.

Put Furniture Against The Wall

Achieving a quiet room could be as simple as redecorating the furniture. If you stack the heaviest pieces of furniture in the room against its thin walls, you can block a significant amount of noise coming through them.

You can put wardrobes, bookshelves, and other such heavy furniture items against the wall to add more mass and increase the number of absorptive surfaces sound waves have to encounter. You can also add thick padding, blankets, or soundproof foam between the wall and the furniture piece to increase the absorption further.

Mass-loaded vinyl is another great product when it comes to adding mass without taking much space in your room. MLV mat is a beast at reducing airborne noise. They are thin, sleek, and capable of both sound as well as thermal isolation.

If you can, you must also consider adding more furniture to the room. Fill the room with more fabric-y and heavy items. All you have to make sure is that the furniture item is not touching the wall behind.

The best option is to put a bookcase in front of the thin wall. Not only will it serve as a nice design element in your room, but the pages from books and the shelf itself will also act as an absorber.

Cover Them Up!

There are multiple ways you can cover the walls of your room and make them soundproof. You have to add more mass to a thin wall to make it heavier and denser so it becomes harder for sound waves to penetrate through them.

You can install acoustic foam mats on the wall. They’re cheap and easy to install. The only downside is that they’re not very pleasing to look at. Such foam mats usually have small pyramids or wedges to trap sound waves from different directions. You’ll often see them in music studios as they are great at eliminating echoes and unwanted sound waves.

Just like acoustic foams, acoustic panels work on the same principle of absorption and work to mitigate about 89% of the noise from a room. Acoustic panels have a foamy, absorptive core and a fabric front. The composition and design work best for sound absorption.

You can also hang tapestries, felt, wall hangings made of wood, or soundproof wallpaper on the wall. Soundproof wallpapers are quite similar in properties to mass-loaded vinyl. They add more density to the wall and hinder the transmission of sound through them. If you’re hanging huge wall paintings, you can also add a thin layer of MLV between the frame and the wall.

Layer Up With Drywall

Drywall is composed of viscoelastic, gypsum, or ceramics. All these elements have impressive soundproofing properties. Drywall works best when it’s combined with a sound dampening material.

You can install another layer of drywall onto the thin walls of your room and double their mass. Remember, the thicker the drywall is, the better it will be at soundproofing. Ideally, go for two 5/8” thick drywall sheets that sandwich Green Glue between them.

Green Glue is a noise-proofing compound that acts as an additional layer to block the transmission of noise. Drywall layers will make the walls thicker and up their STC rating.

Soundproof Wall Paint

Soundproof wall paints are formulated with acoustic properties that mainly target mid-frequency sounds. This is one of the cheapest ways of soundproofing a room with thin walls. It’s easy to apply and won’t damage the walls as well.

The ceramic microspheres and sound-absorbing fillers make the paint thicker and denser. The fillers have thermacels that are tiny vacuum sealed cells with soft pigment inside them. The soft pigment acts as a suspension for moving sound waves as they hit the wall.

This is how a sound dampening paint can block about 30% of the sound entering the room through its walls.

Conclusion

Paper-thin walls have a very low STC, around 30 or 33. This means you can clearly hear what TV show the person in the next room is watching, what the couple is fighting about, or what they’re ordering for dinner.

You can soundproof a room with thin walls by using products and elements that employ the four main principles of soundproofing. Mass, Decoupling, Dampening, and Absorption.

You can use acoustic panels, soundproof blankets, drywall, and other rubber-based materials to do so. You have to add mass and density to existing thin walls and make them heavier, denser for better soundproofing.