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How to Soundproof a Door
Author: Eric Zuck
Last Updated: February 9, 2024
Read Time: 13 Minutes
How to Soundproof a Door
Author:
Eric Zuck
Last Updated:
February 9, 2024
Read Time:
13 Minutes
Author: Eric Zuck
Updated: Feb. 9, 2024
Read Time: 13 Minutes
Doors are like people; if you want them to open up, you’ve got to be prepared to listen! Doors are designed to be opened (because humans can’t yet walk through walls), which has a little side effect of letting in sound from the other side. That much is obvious. However, it doesn’t stop there; most doors are not fully sealed, especially at the bottom, opening sound flanking paths regardless of whether they’re open or closed. And then finally, some doors simply aren’t dense enough to block sound. This all combines to make doors one of the most important parts of a room to soundproof for home owners and business owners alike.
How great would it be to finally be able to keep things “behind closed doors”? Soundproofing your doors is possible, and it will undoubtedly improve privacy and focus. On top of that, with a properly sealed exterior door, you can reduce thermal transfer and save on energy bills. Doors should be an extension of a good wall, not the undoing.
We’ve developed a full suite of solutions to soundproof ANY door. Keep reading to get an overview of what matters when soundproofing a door as well as solutions you can trust to hit your target level of soundproofing on a full spectrum of budgets. If you have any questions, you can always reach out to a Second Skin soundproofing professional, and we can help you with your next project!
Doors are like people; if you want them to open up, you’ve got to be prepared to listen! Doors are designed to be opened (because humans can’t yet walk through walls), which has a little side effect of letting in sound from the other side. That much is obvious. However, it doesn’t stop there; most doors are not fully sealed, especially at the bottom, opening sound flanking paths regardless of whether they’re open or closed. And then finally, some doors simply aren’t dense enough to block sound. This all combines to make doors one of the most important parts of a room to soundproof for home owners and business owners alike.
How great would it be to finally be able to keep things “behind closed doors”? Soundproofing your doors is possible, and it will undoubtedly improve privacy and focus. On top of that, with a properly sealed exterior door, you can reduce thermal transfer and save on energy bills. Doors should be an extension of a good wall, not the undoing.
We’ve developed a full suite of solutions to soundproof ANY door. Keep reading to get an overview of what matters when soundproofing a door as well as solutions you can trust to hit your target level of soundproofing on a full spectrum of budgets. If you have any questions, you can always reach out to a Second Skin soundproofing professional, and we can help you with your next project!
Overview of Door Soundproofing
Let’s stop for a second and imagine that sound waves are a river, and your door is a dam trying to slow it down. A poorly soundproofed door is like a crack in the dam. It may not be completely broken, but water will continue to rush through until something is done to fix it. In scientific and sound-related terms, this is due to the door’s low STC rating. Here are the basics:
Sound Transmission Class (or STC) is used to measure how much sound a partition (wall, door, window, etc.) is able to stop. It’s not perfect, but it’s a good indicator for how well a material or construction blocks noise. Higher STC rating = more noise blocked.
The STC rating of a structure is heavily impacted by its weakest point, no matter how strong the soundproofing is around it. Think about how much louder it is on the road when you crack your window. A lightweight or inadequately sealed door does the very same thing to walls, even if the rest of the wall is soundproof.
Mass is Key for Soundproof Doors
Blocking sound comes down to mass. The typical wall in your house has an STC rating of about 32. Some types of doors have a much lower STC rating, making it the weakest point in the wall. To give you a quick idea of how bad of a weak point some types of doors can be, check out the table below.
| Type of Door | STC Rating |
| Louvered Door (25% open) | 12 |
| Hollow core door with 1/4" air gap | 19 |
| Solid core door with 1/8" glass vision panel, gaskets, and drop seal | 29 |
| Solid core door with gaskets and drop seal | 34 |
- Louvered Door: Your typical louvered door is about 25% open. You’re done before you even start. Might as well leave the door open… Come on in!
- Door with a Vision Panel: Standard glass is a weak point, reducing the door’s Sound Transmission Class (STC) rating. But you can have glass if you want it! Just make sure to use thicker glass (1/4”+) or double paned glass for the window.
- Hollow Core Door: Commonly used in residential homes, these hollow doors are made of fiberboard or laminated wood and (true to their name) are mostly empty inside. These hollow doors are lightweight, easy to install, and budget friendly. On the downside, hollow core doors are fragile and do little to stop sound from passing through.
- Solid Core Door: These doors are significantly heavier, made up of a combination of solid wood and wood byproducts, and are usually used to partition your home or apartment from the outdoors. They’re more expensive but thanks to their density, wooden core doors are able to do a better job of blocking out noise. For an STC rating of 24, a solid door will be about 1 ¾” thick and 4.5 lb/sq ft.
Check out this video that gives a great demonstration on the density of these different types of doors!
ELIMINATING Air Gaps to Soundproof a Door
Air gaps are the enemy and must be eliminated. Sorry, but I feel the need to say that again. NO AIR GAPS! If you have any gaps, you have what us soundproofing folks call a “sound leak”. A sound leak means that it doesn’t matter how awesome your wall or door construction is. You are capped out at how well you can block sound, because you have an air gap that's still allowing noise right on through.
| Sound Leak (% of Total Surface Area) | Max Transmission Loss by the Barrier |
| 1% sound leak | 20 dB |
| 0.1% sound leak | 30 dB |
| 0.01% sound leak | 40 dB |
Pro Soundproofing Tip
Be sure not to confuse sound absorption with sound blocking. Sound absorption, which acoustic panels are great for, will reduce echoes and reverberations inside a room, but will do nothing to block out noise from outside. Purchasing acoustic panels or sound absorbing foam to soundproof your door is a huge no-no and a giant waste your money.
There’s a quick and easy way to check and see how big your gaps are around the door. Turn off the lights and see where outside light enters. If you see light, you have gaps, and your door could be sealed better. We recommend our Sound Lock™ door seal kit applied to a solid core door, or for a more budget-friendly option, our Sound Lock™ gasket seal kit will ensure everything is airtight.
How to Soundproof a Door
Now that we know the key principles in door soundproofing we can now take them and put them to work. We've made it easy for you with these two simple steps:
STEP ONE: SWITch to a solid core door from a hollow core door
Remember, mass is key to soundproofing, and hollow core doors don’t have much of it, making them poor sound blockers. Replacing a hollow core door with a solid core door can give you as much as 10 STC points, and that may be all that you need.
STEP TWO: SEAL GAPS WITH A SOUND LOCK™ DOOR SEAL KIT
The second key to soundproofing a door is eliminating air gaps. Our Sound Lock™ door seal kit will keep noise out by sealing up those air gaps around the door. You can experience up to 10 additional STC points. Door seal kits are the most budget-friendly way to soundproof a solid core door and are simple to install with just a few tools. Not sure if the installation is in your wheelhouse?
Check out the video below for the how-to:
ALTERNATIVE: REPLACE THE DOOR WITH A SOUND LOCK™ SOUNDPROOF DOOR
This isn’t your typical door. This is the door all other doors aspire to be. Our Sound Lock™ Soundproof Door is an acoustic door specifically designed to have an extremely high STC rating (up to STC 56) and unmatched noise blocking. We recommend these for high performance jobs like government buildings, hotels, and for recording studio doors. You can either install it yourself with the help of a few friends (these babies are heavy!) or hire a contractor and enjoy a cold beer while he or she installs it. You do you.
Check out this video for more on our Sound Lock™ Soundproof Door:
Frequently Asked Questions about Soundproofing a Door
How much do weak points matter in wall construction?
We have a visual for you! The image below shows transmission loss through a weak point in a wall. A solid brick wall is dense and effective at blocking sound. If a noise is 100 dB on one side of the wall, it’ll be 50 dB on the other side. On the other hand, glass is not a good noise barrier. 100 dB on one side of a glass wall will be reduced to 80 dB on the other. Now, let’s turn 1/8 of the brick wall into glass. The result is that 100 dB is only reduced to 71 dB on the other side. The overall effectiveness of the wall is pulled WAY down. So, yes, weak points matter big time!
You can apply this same principle to doors. Even though the door is a small percentage of the wall, it has an outsize impact on the overall soundproofing. A room with a hollow core door is like a high school with no adults — loud and in need of help.
What door is best for soundproofing?
The Sound Lock™ Soundproof Door is the best option for an interior soundproof door. With an attractive, wood finish and an STC rating of up to 56, this beefcake is as soundproof as they come. We combine our proprietary construction and an airtight seal to meet the highest specifications, ranging from recording studios to gun ranges. If you’re looking for “the best”, you’ve found it.
Are heavier doors more soundproof?
As a general rule, heavier, denser doors are better at blocking sound. Hollow core doors are much lighter than solid core doors, therefore less effective at reducing noise transfer. Sound can still flank through openings in or around a heavy door, as total mass is not the only factor that determines how soundproof something is.
Can you soundproof a hollow door?
Sorry, but you can’t soundproof a hollow core door. There are a few methods to slightly improve the soundproofing performance, but the only way to get any noticeable noise reduction is to replace the hollow core door with a solid core door. Hollow core doors simply lack the density needed to effectively block noise.
For next steps and more information on how to soundproof a hollow door, read our article on the topic.
How do you make a solid core door soundproof?
The best way to soundproof a solid core door is to seal the perimeter of the door using our Sound Lock™ Door Seal Kit. Simply measure your door to make sure the kit will fit for an airtight seal and install using our door seal kit install guide. The door seal kit improves the STC rating by 10+ points.
If you budget or if you don’t have the space for the adjustable jamb seals, we have our Sound Lock™ gasket seal kit, which includes the bottom seal and our gasket tape that you’ll use to seal the perimeter of the door.
For more on this, read our guide on soundproofing a solid core door!
How do you get a soundproof exterior door?
The number one thing you can do to soundproof an exterior door is ensure that it’s completely sealed. Most exterior doors have a rubber gasketing and a threshold to keep them sealed, mostly for thermal reasons. If the door has gaps, our Sound Lock™ Gasket Tape can be used.
If you are curious about how to soundproof a front door or back door, you can read our guide on the subject for a deeper dive.
Can you soundproof French doors or double doors?
You can soundproof double doors by sealing it with our Sound Lock™ Door Seal Kit with the astragal seal add-on. You’ll need to give us a call or email us to request a quote. As for French doors, the window panes are a major weak point. We would recommend replacing French doors with solid core double doors. If you really want to keep the natural light look you get, give us a call to discuss how you might use a Fantastic Frames™ window insert to soundproof the windows in some French door designs.
For more on how to soundproof French doors, swing on over to our article to get more details.
Is there a DIY soundproof door solution?
If you’ve plugged the air gaps and are closed shut to the idea of a doorway overhaul (IT’S A DOOR JOKE!), you can use mass loaded vinyl to increase the mass of a hollow, lightweight door by adding metal framing around the door and using industrial strength magnets to completely seal an entryway. This is an effective strategy but should only be used on a door you plan to use infrequently.
In the video below, we use MLV to create some privacy in an attached Airbnb rental. An absorptive material (like CelluZorbe™ or EcoVerb™) is installed between the MLV and the door to increase the barrier's overall effectiveness. Again... it's a bit unconventional, but it’s a budget friendly way to block noise!
Can you use soundproof blankets for doors?
Yes, but soundproof blankets are another niche fix. For starters, you can’t walk through the door with a blanket hanging there. The other problem is that the types of blankets people want to hang are not dense enough to block sound. We recommend upgrading to a solid core door.
If you’re willing to move a blanket each time, heavy curtains or a moving blanket will generally block ~3 decibels (20% reduction). If you want a more effective soundproof blanket, the Quiet Quilt™ Acoustic Blanket will reduce sound through a hollow core door by ~7 decibels (35% reduction). We don’t recommend our heavier blankets for doors because they’re too heavy to easily hang and remove. Just remember that any blanket will be ineffective if you have air gaps around the blanket.
For more on this, check out our guide on soundproof blankets for doors.
Does weatherstripping work for door soundproofing?
Weatherstripping can be part of an effective door soundproofing strategy. Consider our Sound Lock™ gasket tape for a more effective alternative to standard weatherstripping to both seal and insulate your door. Where weatherstripping comes up short, though, is sealing the gap below the door. It should be combined with a Sound Lock™ Bottom Seal to create positive pressure on the floor below the door. Our Sound Lock™ gasket seal kit has both!
Are door sweeps soundproof?
No, a door sweep is only meant to help seal the door from weather and thermal transfer. When it comes to sound, even the slightest of air gaps can compromise your soundproofing efforts, and typical fabric door sweeps won’t cut it. For a soundproof door sweep, we recommend our Sound Lock™ Bottom Seal!
Can you use a door bottom seal on carpet?
No, our Sound Lock™ door bottom seal is not compatible with carpet. If you have carpet, you’d need to add a hard transition beneath the door so the bottom seal can drop and create an airtight seal.
Sound Lock Door Seal Kits: Cost-Effective Door Soundproofing that WORKS
The typical door can have up to 1 square foot of airspace around it. The Sound Lock™ Door Seal Kit is fully adjustable to seal off those air gaps below your door and around the entire perimeter. By adjusting the neoprene seal to the contours of your door, you can soundproof it without breaking the bank.
- Used to soundproof any solid-core door
- Durable, adjustable, and customizable lengths
- Neoprene rubber seals in anodized aluminum casing
- Free shipping and made in the USA
Control Your Doors to Stop Unwanted Sound
You can make a huge difference in your home or office by filling air gaps and taking steps to soundproof entryways. Whether the noise you want to get rid of comes from inside or outside the house (or your garage door), soundproofing the right door(s) will help. When you're ready to close the door on noise, give us a call. We're here to help.