How to Soundproof a Hollow Door: 8 Easy Steps to Make it Happen

A majority of the modern houses come with hollow doors for their interiors.

Understandably, hollow doors are inexpensive than the solid doors and their lightness makes them easier to install. Furthermore, they’re less susceptible to expansion or contraction.

Unfortunately, they’ve their share of cons; besides getting damaged easily, they provide little in the way of insulation or noise reduction.

Now, if you’re concerned about noise penetrating through your hollow doors, no need to go through the expensive door replacements.

Instead, we shall share with you some simple, yet effective ways to soundproof your hollow door. Whether you need to keep the sound of noisy roommates out, or to keep bedroom sounds from leaving the bedroom, it’s possible to soundproof a hollow door.

While at it, note that you may not completely soundproof the door, because of the door’s nature. If you need a completely soundproof door, you might have to replace the hollow core door with a solid door. If that is not an option, try out some of these methods to keep the noises in or out.

1)  Adding Door Mass

Other than blocking the door, the easiest way to soundproof your hollow core door is to add mass. The only limitation here is that the door cannot be so thick as this will make it hard to close or open.

To this end, you need a mass with a low thickness to noise canceling ratio to cancel noise without adding unnecessary thickness. Deadening foam, same as what is used in car’s interiors, is a great option here. The right foam should be less than an inch thick to ensure the door still opens with ease.

Foams come with an adhesive that is easy to stick to your door. However, it is not easy to peel off the foam. You might want to stick the foam to a sheet of wood and then screw the sheet to the door. This way, if you ever need to remove the foam, you will only unscrew the sheet of wood.

Besides deadening foam, you can use a sound deadening fiberboard. The board is, however, a more expensive option. You can use sound-deadening mats as used in vehicles. These mats fit on a piece of wood and add thin mass on the door. They are pretty effective at absorbing sound.

Lastly, you can also use mass loaded vinyl, also known as limp mass. This method works by dissipating sound waves against the door surface. It is a cost-effective method and doesn’t add so much thickness on the door. The only downside is that it adds weight on the door and the hinges need to be strong to handle it.

Even with the best mass-adding method, you will still not completely soundproof your door as there are gaps around the door and the frame.

2)  Adding Mass on the Frame

The frame of the door provides an easy way for sound to enter your room, so you can start by adding more mass to the frame.

If the frame has gaps or cracks, you can seal them using acoustic chalk. Unlike other sealants, acoustic chalk is strong enough to hold its position without cracking even if the house moves.

Don’t forget the other side of the door. To keep sound off, you need to soundproof both sides of the door by adding mass.

Soundproofing material on the outer side of your door might not look so impressive, but you can always disguise it. Outside your door, you can use acoustic foam. This is not so effective at blocking noise, but it creates a textured and open-celled surface on which sound waves cannot bounce off. In this case, it is challenging for sound waves to get to the door.

3)  Seal the Gaps

All doors have a gap around them. The gap is bigger on some doors and smaller on others. The gap can let in noise and sealing it keeps noise out.

You can seal the gap by use of a soundproof door strip, for instance, a fire safety gasket. Most products used to insulate the door and those that protect against fire work well to keep sound off, seeing that they share the principles as soundproofing foams and other devices. Using the strip creates a seal around the door that keeps noise out.

You can also choose weatherstripping to soundproof a door. Weather stripping goes around the edge of the door to reduce the gap and keep noise out. This option is less invasive compared to a door gasket. If you live in apartments, weather stripping is a better choice as it doesn’t leave any trace.

4)  Using Soundproof Curtains

Curtains can also block sound. All you need is a curtain rail above the door and a soundproofing curtain. When you pull the curtain after closing the door, it reduces that noise that comes through.

If you do not have a special soundproofing curtain, you can use heavy drapes. The heavy material of the curtains dampens the sound waves. However, the curtains will also lock the heat in which can be a disadvantage during summer.

5)  Use a Soundproof Blanket

Using an indoor insulation blanket is an easy way to dampen sound waves, but it is not the most effective solution. To do this, you only need hooks on the door and a soundproof blanket.

If you choose to go this route, hang the blanket on both sides to make it more effective. Normal blankets are not as effective as soundproof insulation blankets even if you choose the heavier ones.

6)  Dampen Sound Before they Reach the Door

Instead of making the door soundproof, you can dampen the sounds from their sources. This will reduce the noise that comes in through the door. However, this method only works best if you combine it with other soundproofing methods.

There are many ways to dampen sound at the source. For hallways, you can lay rugs on the floor to keep vibrations and echo to a minimum. Wall paintings and frames can also reduce the echo and the vibrations to keep the sound out or in.

Other ways to do that is to use bookcases and heavy furniture close to the door. This will not soundproof the door, but will reduce the echo and vibrations from the room. If you use bookcases, the books absorb the sound waves such that not much reaches the door.

7)  Use of Soundproofing Fiberglass Panels

These panels are the same as blankets, acoustic foams, and curtains. The panels come with grommets so that you can hang them on the door like a curtain or blanket. However, you can also glue or pin them on the surface of the door.

These panels reduce noise pollution by absorbing the noise that hits the door and reducing echoes.

8)  Using a Door Sweep

Most doors, even the solid ones, leave a gap at the bottom. This gap allows a lot of noise in and may not seal even with weatherstripping. You can use a door sweep to seal the bottom gap and keep the noises off.

The door sweep is also advantageous in keeping bugs and dust from entering into the room. This door sweep will also help you keep the temperatures in the room constant when you turn on air conditioning. Most door sweeps feature a rubber material that ensures hot air doesn’t leave the room.

Unlike weather stripping, a door sweep is not as easy to install, but you can find some that easily attach to the door.

Solve the Sound Problem Completely

The only way to completely handle the noise problem is to replace the hollow core door with a solid core door. This is an expensive route, but it is the only way to ensure that the sound doesn’t leave one room into the next.

You can tell the doors in your home are hollow if you knock on them and hear an echo. Even though this is an expensive method, it ensures that all noise stays out. After installation, you might need to install a door sweep at the bottom to seal the gap at the bottom for complete sound proofing.

If replacing your door is not an option, start by adding mass to the door and see how it goes. Instead of just one method, try a few soundproofing methods and see how it works. For instance, try using rags and wall hanging and a soundproof foam.



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