How to Soundproof a Hollow Door – Is It Possible?

Author: Brett Clur | Updated: | This post may contain affiliate links.

All buildings have doorways that either have solid or hollow doors. Unfortunately, hollow doors tend to let more sound travel through them than solid ones do. This means that your hollow doors are going to allow your neighbors or people in different rooms in the house to hear all the noise you’re making.

Many people think the solution is to replace hollow doors with solid ones to help with soundproofing. Although that would definitely help, it’s not always a possibility. We’re going to go through some practical and easy solutions for soundproofing a hollow door.

Hollow vs Solid Doors

Many houses are built with hollow doors to save on costs. They’re lighter and a lot more affordable, making them more desirable for builders. Most houses will have hollow doors all over excluding the front and back doors. Doors that need more security tend to be thicker and heavier.

You can tell that a door is hollow if you knock on it and hear an echo. If you’re not quite sure what type of doors you have and you’re having sound leak problems, they’re most probably hollow.

If you have solid doors all through your house, the chances are high that you’ll have a serious amount of soundproofing already. The methods to follow are mainly used for hollow doors. However, they’ll work to further soundproof solid doors as well.

Door Sweep

One of the first things to look out for when thinking of soundproofing is all the big gaps in the area. Any big gap makes it extremely easy for sound waves to pass through. Just think of how the sound coming from a room drops dramatically after closing the door.

One big gap that comes with most doors is the area beneath them. Many doors have enough space beneath them for your fingers to fit through. If this is the case with your hollow door, you need to seal that space up tightly.

The solution to this is to use a door sweep. Door sweeps typically need to be installed by attaching screws and connecting them to the bottom of the doors. Some door sweeps are attached with adhesive material. The door sweep will do a fantastic job in keeping sound from traveling through the bottom of the door.

It will also keep bugs out and regulate the temperature in the room. The gaps under doors are a big reason for air conditioner and heater temperature changing over time.

I’ve found that this Suptikes door sweep works particularly well for soundproofing.

Weatherstrips

Weatherstrips are typically used for sealing windows. They help keep the spaces airtight and prevent any sound from getting out. They unsurprisingly work well for sealing the spaces in doors as well. If you take a weatherstrip and fill the gaps on the side of your door, it will prevent a lot of sound from leaking through.

Weatherstrips use an adhesive material to stick on the wall, meaning you need to clean the surfaces before applying them otherwise they won’t stick on firmly and securely. Once you’ve cleaned the areas, you just need to stick the strip on the inside of the door frame. That’s pretty much all there is to it.

The strip forms an airtight space when the door is closed and that’s what stops the sound from getting through. Another benefit to this is that it stops the door from slamming and making a huge noise. It’s always wonderful to kill two birds with one stone.

The door sweep along with some weatherstrips will dramatically lower the sound that gets through the door. However, there are still a few more things that can be done.

Soundproofing Sealant

Now that you’ve sealed the bottom and sides of the door, you may find that there is still some sound getting through. The reason for this is that there may be some cracks and holes in the door itself. These holes can be covered up with a suitable soundproofing sealant.

It may be quite difficult to find these holes, to begin with. The best thing to do is to turn the light in the room on and then face the door from the next room and distinguish where the lights are shining through. Once you can see that, you’ll know where to apply the sealant.

There are so many high-quality sealants on the market, but the most popular one tends to be the Green Glue Noiseproofing Sealant. It has fantastic consistency and is incredibly easy to work with. Just note that you’ll need a caulking gun to be able to apply the sealant to any door.

Once the sealant is applied, you can paint over it to make sure the door looks neat and presentable again.

Soundproofing Blanket

You may not have expected this one to be on here. Soundproofing blankets are a tried and tested way of eliminating sound from bleeding to other rooms. Place them around the walls and you’re good to go. However, most people would assume that it wouldn’t work when placed on a door. It would also look incredibly unappealing.

Well, there are some ways to get around that. Firstly, finding a blanket that either matches the door or blends in nicely is the first thing you should do, especially if you’re trying to soundproof a door that is going to be seen often.

Some people such as drummers will use a soundproof blanket and not worry about the aesthetic appeal since it’s just for the drum room. Other people will need it to look more presentable.

There are many soundproof blankets out there that can be hung up with velcro. Velcro makes it incredibly easy to keep on the door and it means you don’t need to worry about hanging the blanket from grommets.

Placing a Rug Near the Door

One of the best ways to soundproof any place is to have carpeted floors. The carpets absorb an incredible amount of sound. The insulation makes the acoustics sound better and stops them from bouncing around the room. If the hollow door is not leading to a carpeted floor, a good thing to do is to place a rug near the door.

Having a thick rug will do a similar job to having carpeted floors, especially when placed near the door as the rug will absorb a lot of the sound before it reaches the doorway. You could take this even further and put rugs on both sides of the door.

The thicker the rug is, the more sound it will absorb. This could potentially lead to an expensive purchase, and the rugs won’t be as effective as the door sweep and weatherstrips, but they’ll definitely add to the soundproofing quality of the door.

A benefit of using rugs is that they can add to the visual aesthetic of the space and act as a soundproofing solution at the same time.

Attaching Soundproofing Panels

Soundproofing panels are the cause of the good old egg box story. If anyone ever suggests you use egg boxes to soundproof your room, just know that they don’t work too well. What does work well are dedicated soundproofing panels that have specifically been designed to insulate sound.

Attaching a few of these to the door will undoubtedly help in lowering the amount of sound that travels through. They do the same job that a soundproof curtain does. However, they’re a whole lot cheaper and more accessible. This means that they’re an easier solution to go with.

You could either hang them up with nails or get sticky adhesive hooks. Since soundproof panels are light in weight, you don’t need to worry about drilling in any heavy-duty hooks to keep them secure. They’ll stay in place with stick-on hooks with no problems.

Foam Insulation

I’ve left this solution until the end as it is arguably the most complicated one. Foam insulation is something you can do to soundproof the door without changing any of the outside appearance of it. You basically inject insulating foam into the hollow door to change it into a solid door.

To do this, you need some cans of insulation spray foam. You need to drill a few holes into the door and then spray the foam through those holes. The foam will expand inside the door and then get hard over time.

This is a lot easier said than done as you could run into some trouble if you don’t do it correctly. I’d suggest looking for some guides on the internet before venturing too far with this option.

Conclusion

So, is it possible to soundproof a hollow door? Absolutely. All the methods mentioned above will help reduce the majority of sound getting through the doorway. However, they’ll never completely eliminate it.

This means that you need to take the project on with realistic expectations so that you’re happy with the outcome. Soundproofing a door can either be affordable or very expensive. It’s up to you to decide which method will be best for your environment and budget. Good luck!

About Brett Clur

Brett has been drumming for almost two decades. He also helps his students get better at drumming. He can be found on Instagram (@brettclurdrums), where you can regularly catch glimpses of his drumming.

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