When you think about soundproofing a room, you may automatically assume that the best place to start is with your walls. After all, that is where you usually hear the noise filter through, right? But, you would be surprised to learn that, in addition to walls, both doors and windows can just as easily allow unwanted noise in!
For that reason, doors and windows are often the weaker links when it comes to soundproofing projects. They actually contribute the most noise entering or exiting the room. (I have mentioned this in a few posts on this site.) But out of the two, soundproofing a door is the more difficult and more expensive task—and I am sure that you have experienced the same.
For example, to soundproof a window, you always have the option to cover it with soundproof curtains, or even drywall (in the worst-case scenario). However, you cannot do the same thing with a door—the door is something you cannot live without! And the worst part is that you cannot simply ignore the door either if you are a home theater enthusiast like me—it has to be soundproof for the best home theater experience.
When I first tried to soundproof my theater room (read how I did it), I did not pay that much attention to the door, mainly because the solutions available on the internet at the time were too confusing and expensive. But, after all that effort I made with treating the walls, ceiling, and floor already, the door was the one part of the room that played spoilsport. I could not just leave it as it was. After all, it is the least soundproof element of a room, to begin with.
I decided that I had to finally do something about it. But, I realized that without any serious research, I would be wasting my money and time.
The expensive door soundproofing options were definitely not an option for me. I wanted to find the best way to soundproof a door that would not break the bank (or leave me incredibly frustrated, trying to figure out how to do it).
Eventually, I found the perfect soundproofing option for me, and I am going to share what I learned with you. Hopefully, you find that these tips are helpful in your next soundproofing project.
How to Soundproof a Door The Right WayThere are three main questions that you should ask yourself before you begin with soundproofing a door:
- What are the problem areas that I should address in order to soundproof the door effectively?
- What are the best soundproofing materials for doors?
- Which type of door assembly is the best for soundproofing?
All of these questions and more will be addressed in the following sections and based on these, we will determine the best ways to soundproof a door.
Problem Areas While Soundproofing a Door
Identifying the problem areas is the first approach that you should take for any soundproofing project. As far as doors are concerned, there are many myths surrounding them that cause people to make the wrong choices in soundproofing. These misconceptions will come up as we discuss the problem areas one by one.
Problem #1 – Hole in the Wall
A thoroughly insulated and sealed room with no doors and windows is fairly soundproof on its own. The moment you install a door, however, you create a break in that seal by creating a hole in the wall. The door itself will allow sound to come through, whether you want it to or not.
Any hole in the wall will completely destroy previous soundproofing efforts. And covering a hole with something other than wall material to provide a similar soundproofing effect is one of the biggest challenges you will face. The materials in which doors are made from are not even half as good as wall material to block sounds out. (This is why soundproofing a door is often the hardest to do in a complete room soundproofing project.)
The problem of soundproofing a door starts here, and although it is obvious, it is important to keep in mind when you move forward with your soundproofing project.
Problem #2 – Door Frames
When assessing the entire door set, you will notice that its frame can be a pretty big weak link. As door frames are shimmed in place, air gaps are created between the frame and the drywall; these gaps can leak a lot of sounds and cause issues when you start trying to soundproof.
Luckily, there are two options to resolve this in order to soundproof the door:
If you are building out an entire room, the door frame can be installed before installing the wall material (usually drywall). After this, you can add a drywall layer over the frame to close the gaps.
This would mean that you will end up with an exposed edge of drywall, but it would be highly effective in sealing the door frame. There are also ways you can try to mask the drywall edges to blend them in with the surrounding wall.
The second option is best for anyone trying to soundproof a room that has already been built out. This method involves cementing the door frame after it has been shimmed in place. This is the easier option of the two and is the one I chose to do when I was soundproofing my home theater.
With either option, you will need to apply acoustic caulk in-between the layers of the door frame and the drywall or cement to completely seal off the gap and prevent any noise from leaking through. You can find inexpensive acoustic caulk at your local hardware store, or online on Amazon. Note that if you have not used caulk before, you will also need to invest in a caulking gun (Amazon) to apply it.
Problem #3 – Door Jambs
Door jambs are the vertical portion of your door’s frame that holds the door secure. The area between the jamb and the door can create flanking paths for the passage of sound. To soundproof a door jamb, you can use jamb seal kit (Amazon) or weather stripping tape. Both can be found available at your local hardware store or online.
Problem #4 – Gap under the door
There is no such thing as a door without a gap underneath it. It is impossible to design—the gap is required so that the door does not scrape the floor every time you open or close it.
However, for soundproofing purposes, the gap under the door is definitely not something you want to leave alone. After all, that is one more area for sound to come through. In fact, underneath the door is arguably the biggest way sound can get into (and out of) a room. It is why most door soundproofing fixes involve filling this gap.
The best way to soundproof a door bottom this is to buy and install an automatic door bottom (Amazon).
Automatic door bottoms are designed in such a way that when the door is closed, there is a seal that covers the gap. When the door is opened or closed, the seal is automatically lifted through a spring mechanism so that the door can move easily.
Problem #5 – Options for Materials
There are a lot of material choices (RELATED ARTICLE) when it comes to building walls, and inherently, these materials have good soundproofing characteristics. However, we, unfortunately, cannot say the same for doors.
Doors are practically required to be visually appealing to some extent, and cannot achieve that effect if it is made out of drywall. If it was, it would certainly look funny or out of place—especially if the surrounding wall is drywall, too.
So what kind of material can be used for soundproofing doors that simultaneously blocks sound while looking good? What about wood?
The main problem with wood is that the Transmission Loss (defined as a quantification of how much sound is blocked from traveling through soundproof treatments) required for something like a home theater room cannot be achieved even from the heaviest woods. This is why soundproof doors are often very expensive, as they are heavy woods that have been modified for soundproofing purposes.
Suitable Wood For Soundproof Doors
Now that you have identified the problem areas, the next thing to do is look at which types of wood would be best for your door.
Because most soundproof doors are made of heavier wood, one thing that I was sure about during my research was that my new door would have to be really heavy—more mass, the better the soundproofing.
Medium-density fiberboard (MDF) was the first thing that came to mind for a door material because this material is usually used for many soundproofing applications. Oriented strand board (OSB) was another option I considered.
However, the deeper I researched into the subject, the more I found that the material the door is made of is not so much as important as the type of door it is (although the material is still very important to consider).
Types of Doors
You need to know that there are several different types of doors, each having their own level of soundproofing ability. There are mainly three categories of doors to consider.
Hollow Core Doors
Hollow core doors are lighter compared to most soundproof doors. They are built with a honeycomb structure, usually enclosed with fiberboard or a veneer shell.
They can be installed in areas where noise isolation is not so much a priority. Hollow core doors are low-cost, and for that reason are most often found in apartments and homes.
However, as you would guess, the hollow cores in these doors have plenty of air, which makes a strong medium for noise to travel through. This, plus the light quality and build of hollow core doors make them the least optimal choice for building out a soundproof room. Because most apartments and homes have hollow core doors, they are usually the least soundproofed in a room.
Solid Wood Doors
Solid wood doors are made of a combination of natural wood elements that have been put together. These doors are quite heavy and therefore provide decent soundproofing. They also look great in any type of room. However, they are quite expensive.
Solid wood doors may look good and sound good, but they are not necessarily the best option for complete soundproofing, especially for the cost.
Solid Core Doors
Solid core doors are just as the name implies; they are doors that have a solid core made with composite material. Because their cores are denser and heavier than solid wood doors, they make for the best option for soundproofing a room. A flush veneer-covered 1 ¾ inch thick particle core door, in particular, is a great choice for soundproofing.
Solid core doors can be purchased at your local home improvement store; they are also available online on Home Depot’s website.
Best Value Soundproof Doors
We have established that solid core doors are best for soundproofing, but there are many options available among home improvement stores and online, so how do you know which is the very best for your soundproofing project?
Let’s explore what solid core doors provide the most value for your money in the market.
But before we go into that, let’s first talk about the technical terms, Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC). You will need to understand this terminology in order to better search for the right solid core door for your needs.
STC & OITC
STC, or Sound Transmission Class, is a term you will come across often in soundproofing topics. STC is essentially a rating of how well a building element reduces airborne, common sounds (usually with interior and exterior elements, but traditionally only interior). When it comes to researching doors, the STC will tell you how much sound a specific door can stop.
The OITC, or Outdoor/Indoor Transmission Class, on the other hand, measures the transmission of street sounds through exterior building elements. OITC factors in low-frequency sounds—such as car horns, sirens, and construction—that STC measurements cannot. If you are trying to soundproof a room that has access outside the home, the OITC of the doors you research should be something you keep in mind.
Both STC and OITC are the most common measurements for sound reduction. They can be used to define how effective a material is for blocking sound; the higher the rating, the more effective a material is at blocking noise.
The main difference between the two measurements is that OITC caters for lower frequencies, while STC does not take into account frequencies below 125 hertz (Hz).
In my own research for finding an economical solid core door for my soundproofing project, I came across Jeld Wen as a good brand to explore. Their website has both STC and OITC data for all of their products.
The acoustical data for interior doors can be found on their website. The data is formatted in a downloadable PDF document that you can save and use to compare different solid core door options.
Once you have downloaded the PDF, take a look at the information provided. As can be seen from the data, the Tria R door series would be best as a soundproofing option. You can purchase them for only a couple hundred dollars. Compared to other doors, this is fairly inexpensive, as most will run several hundred or even thousands of dollars!
However, I will say that for the price, there are some functional issues with these doors that I have found. They may do the soundproofing job fairly well, but there can be problems with improper finishing. With that said, when it comes to these doors, it is best if you purchase them from a physical location rather than online to avoid any hassle.
Of course, there are also plenty of other solid core door options out there that do a good job in blocking sound, while not being very expensive at the same time.
Which Type of Door Assembly is the Best?
So, now that you have a better understanding of STC and OITC let’s talk about the type of ratings you should look for in a solid core door.
According to Wikipedia, with an STC of 35, loud speech would still be audible through a building component such as a door. However, the speech would not exactly be intelligible.
A solid core door may not provide sound isolation as high as an STC rating of 60+. The STC of most doors of this type would be around 35 if anything.
For a home theatre or any application that requires a lot more sound resistance, an STC above 50 is the most desirable. An STC of at least 50 would help drown out loud music to a great extent.
So what does that mean for the kind of door assembly you should choose?
According to Egger Industries, a communicating door is the best assembly option for optimal soundproofing. Communicating door assemblies have an STC of above 50, which is very high in comparison to other door assembly types like Dutch, Transom, and Paired Flush Doors. An STC of above 50 is a fairly good figure to achieve for any type of door.
What is a communicating door assembly?
Technically speaking, a communicating door assembly is a set of two doors that are each installed on the interior side and exterior side of a wall. There is usually a small gap present between the two doors within the wall. (Have you ever stayed in a hotel room that has a set of doors which connect your room to a neighboring room? Those doors are essentially communicating doors.)
Ideally, the gap between the two communicating doors should be 24 inches in length. The gap helps create a strong insulating layer that dramatically increases the STC.
See the video below:
We have seen that communicator door assemblies made of solid core material are best for soundproofing the door area. However, simply replacing a door may not be a practical solution for everybody. The following are a few alternative ways you can soundproof your door while still staying within budget.
Solid Core Door + Green Glue + MDF
Some experts suggest that a medium-density fiberboard (MDF) layer can be added to a solid core door with a noise-proofing, damping layer, like Green Glue (Amazon) compound, in-between. This can help improve the STC by a few numbers.
To install, all you will need to do is get a piece of flat, smooth MDF that is the same size as your existing door. Ideally, it should be a half-inch thick; this will help add some density to your door. Drill a hole to allow room for the door handle to fit through. Apply a layer of Green Glue on the back of the MDF panel or the door, and screw the panel to the door using a set of wood screws.
Watch the Green Glue installation video below.
The benefit of something like Green Glue is that it is quite flexible and does not crack or shrink over time, making it a long-lasting gap-filling solution for stopping sound from filtering through the door’s gaps. It is also quite inexpensive to use.
MDF + Green Glue + MDF
Another option for soundproofing that I have found to be effective is to sandwich two layers of medium-density fiberboard with Green Glue in-between.
With this more inexpensive method, you can avoid the costs incurred from buying a solid core door. It can also soundproof a wall pretty decently for a room that is not meant to be a home theater. So, if you just want to block out traffic noise and noisy neighbors, the MDF + Green Glue + MDF method works for such purposes.
Medium-density fiberboard is a common choice for soundproofing projects. But why?
For MDF panels measuring 16 millimeters or more in thickness, the STC is 25. This is fairly high compared to other materials such as plywood, which has an STC figure as low as 15.
However, surprisingly, in the case of any material, the STC does not increase with an increase in thickness. This means that there is no additional benefit of having a thicker layer of MDF beyond 16 millimeters unless you just want a thicker door.
One alternative to making large, physical alterations to your existing door is applying soundproof paint to it. Soundproof paint is different from regular paint in that its main ingredient is latex, which provides a rubbery, more soundproofing effect when dry. It is also denser than regular paint, which can help in subduing noise.
However, soundproof paint is not exactly foolproof when it comes to blocking out noise. In fact, it is highly recommended that you use this method as a supplement to other soundproofing options rather than as a replacement or to use alone. This is because soundproof paint is usually only good for blocking part of medium-pitched noises (such as speech). It is not effective in blocking high-pitch or low-pitch noises.
In addition, there are usually not very many color options for this particular kind of paint, and when applied appears a little chunky in places, so if you are considering it as a way to help absorb sounds, keep in mind that it will most likely not be that pretty to look at.
But even with these disadvantages, it is still an affordable and hassle-free alternative to consider.
Read my article on soundproofing paint where I bring out all the pros and cons of the material.
Foam or Rubber Tiling
Similar to soundproof paint, this method is not as foolproof as other tried and true options but can help get the job done in combination with other soundproofing methods.
A local hardware store or music supply store may have specialized interlocking tiles that you can attach to your door using Green Glue or staples. These acoustic tiles usually have different noise-reduction levels, so make sure you choose the highest level available for the most sound blockage.
Alternatively, rubber flooring tiles could also be attached to the back of your door with Green Glue and staples. They are much easier to find in stores but do not quite offer the same level of noise-reduction as foam interlocking tiles.
Mass-Loaded Vinyl Barriers
Mass-loaded vinyl (MLV) barriers are thick sheets of a vinyl material that can be attached to the back of the door with Green Glue and staples. They are good at reducing noise but are quite expensive compared to other soundproofing methods.
If switching up the door or making physical changes to it is not an option (perhaps you live in a rental home or apartment where you are not able to do so), there is still a way to soundproof a noisy room!
If you really want to make a dent in the sound entering or leaving the room, you will need to invest in industrial-grade soundproof curtains. I know what you are thinking—curtains are for windows, not doors. However, these specific soundproof curtains are designed to keep noise away and are equally effective when used on a door.
All you will need to do to use them on your door is to install a curtain rod above the door frame. From there, you would just hang the soundproof drape on it, just like you would a standard window.
Although I personally do not have experience using these curtains, I know of a few people who have used them and found them quite helpful in blocking out sound. Like the MDF + Green Glue + MDF method, it is a great option for rooms not intended to be a home theater.
This is a solution I feel is worth looking into if you really want to avoid the hassle of replacing the door. It is also much more cost-effective!
To learn more about how soundproof curtains can help block incoming and outgoing sounds from a room, click here to read my article on soundproof curtains.
Another option for temporarily soundproofing a door for those who live on rental properties is using a soundproof blanket (moving blankets work equally well). Simply hang it behind the door using a couple of hooks.
Soundproof or moving blankets are usually made from an absorbing material, such as fiberglass, which is perfect for sound absorption. Heavier soundproof blankets can almost absorb most sounds.
Although a soundproof blanket is not the ideal option, aesthetically speaking, it is a soundproofing option that can easily be added or removed from the door as you see fit.
The best soundproof or moving blanket to use are those with grommets—those tiny rings that are usually found on the edges of sheets; this feature will make it easier to hang behind the door and will make it easier for you to go in and out of the room.
Truths Related to Soundproofing Doors
After going through the many articles and forums it took me to research the best soundproofing options for my door, there are certain truths related to soundproofing doors that I consider worth sharing with you.
These truths will provide some clear insight for anyone intending to start soundproofing a room; the truths are meant to help quell any myths you might have heard regarding soundproofing doors specifically.
- As mentioned before, doors—in most cases—are the weakest link in a soundproof room. They are more likely to allow sound through due to the number of problems they present, such as door frame gaps and gaps under the door, jambs, and unsuitable soundproofing material. Long-story-short, they provide numerous challenges to soundproofing on their own.
- Most door seals are designed for weather-stripping, but they perform more or less the same when you use them for sealing any gaps in doors. The quality of the seal you use does not have much of an impact on how effectively they can block sound.
- Door jambs can create a flanking path, and within the door structure itself, they are certainly the weakest links. Even if you install a custom or Do-it-Yourself (DIY) door that is dense and good for soundproofing, door jambs are a challenge you will have to deal with separately for the door to be completely soundproof. Ready-made soundproof doors have the jambs problem sorted out in advanced, but like most already-build soundproof doors are very expensive.
- To achieve a high transmission loss for both low- and high-frequency sounds, a large airspace such as that found in a communicating door assembly is required. A single, standard door, no matter how dense or heavy it is, cannot attain this quality.
- Solid wood doors provide many benefits for soundproofing but are not nearly as good as solid core doors. Solid core doors are denser and heavier, which makes them a great option for blocking the most amount of sound.
Below are a few tips for summarizing what we have covered here:
- Assess your soundproofing needs first. Are you soundproofing a home theater, or do you just want to avoid hearing your neighbor’s dog bark at night? The level of soundproofing you need will determine which soundproofing method is best for you and a quieter home.
- Come up with a plan based on your soundproofing needs. Will you be able (and are you willing) to change your door out for one that blocks more sound, like a communicating door assembly, or will you need to use alternative methods for soundproofing? Do you need to save up for a ready-made soundproofed door or buy soundproof curtains?
- Address the gaps in the door frames and seal them as described earlier. Sometimes, all you need is Green Glue or another form of acoustic caulk to do the job; apply the caulk where the frame meets the drywall or cement.
- If you are still hearing a lot of sounds come through your door even after filling the gaps, there may be some hidden gaps or cracks not easily visible or big enough to notice. To find these elusive gaps, turn the lights off in the room and have someone else hold a flashlight from the other side of the closed door. Where you see the light shine through is where a gap remains.
- After you install the door, use a sealing kit for the door jambs and sides. Ensure that there are no gaps remaining and that the door shuts snugly into the frame.
- Door gaskets are another option to consider for filling in gaps and door jambs. They work similarly to weather stripping tape, with the main difference being that it is made up of a pair or set of magnetic gaskets that are meant to be attached to the door jamb. The only drawback to using door gaskets, however, is that they are typically more expensive to use.
- Install an automatic door bottom to close the gap underneath the door.
- Alternatively, you can also use weather stripping tape; believe it or not, although the material is intended to keep away dust and dirt, it actually works quite well as a sound absorber! There are different types of weather stripping material you can use, but rubber weather stripping tape has shown to be more durable and effective compared to foam or vinyl.
Outside of these tips, there are other alternative ways you can soundproof your door, from applying a layer of soundproof paint to hanging up a moving blanket or soundproof curtains. You could also try laying down rugs or moving large furniture (such as bookshelves or a decorative chair) next to or nearby the door to help absorb local sounds and prevent all of the noise from getting through.
Of course, to achieve complete noise blockage—and a quieter space overall—you may want to use a combination of the above-mentioned methods.
Soundproofing a door is no easy task; it often requires quite a lot of work, simply because ready-made soundproof doors that you could otherwise swap out are very expensive. However, soundproofing a door to a soundproof room is an unavoidable necessity and cannot be done away with. For serious noise isolation, a cheaper solution is unlikely.
So, pay special attention to the tips I have provided; do not take the issue lightly. Making the right decisions for your soundproofing needs will help you avoid wasteful expenditure. Even enlisting in the help of a professional is not a bad idea even if it will cost a little bit more—at least the job will get done, and it will get done well!
Thanks for reading! Before you go, take a minute out and check out my top recommendations for soundproofing products.