With most of us spending more time at home these days, we’ve become keenly aware of how much noise there is around our homes. From our living rooms, we can hear trucks rumbling down the street. When the kids are playing video games, we can hear everything in the next room. It can be tempting to go to great lengths to reduce noise transmission in our living spaces, but there’s one element that many of us don’t even think about – a soundproof door.
Here’s an overview of the different types of soundproof doors, and the basics of how sound is conducted throughout our indoor spaces.
Related: Types of Soundproof Portable Rooms | Types of Soundproof Insulation | Types of Soundproof Windows | Types of Soundproof Ceilings | Ways to Soundproof Your Bed | Types of Soundproof Flooring
Types of Soundproof Doors
Sliding Solid Wooden Barn Door
This soundproof door gives your home a rustic look and provides better soundproofing capabilities than a hollow core barn door. Some people don’t like these doors because the sliding makes a noise that can be disruptive to others.
Solid Core Textured Six-Panel Door
These are more effective at soundproofing than their hollow-core counterparts. Their STC ratings are between 27 and 30. This type of door, sometimes also called an accordion soundproof interior door, slides on a track mounted above the door frame. It’s thicker and provides a better sound barrier than doors that are secured within their frames.
Solid Composite Interior Door
A wood composite soundproof door looks a lot like real wood. Made of wood fiber and polyurethane, it makes an excellent sound buffer.
Acoustic Steel Door
An acoustic door is designed to soundproof an in-home music room. This recording studio door provides maximum sound reduction and is relatively easy to install. A metal door like this comes with a few different types of hinges, so make sure you’re choosing the set-up that works best for your home recording studio.
Sliding Glass Door
You can mount soundproof glass doors inside or outside of your existing sliding glass doors. Besides blocking noise, these doors are well-sealed, keeping drafts out in the winter while retaining cool air in the summer to make your home more comfortable and energy-efficient. Most sliding doors come with tempered glass, so they can break easily if an intruder wants to quickly gain access to your home. Sliding doors made with laminated glass provide additional security because they’re a lot harder to break.
Sound Transmission Class Ratings
Sound class transmission ratings (STC) ratings refer to the acoustic performance of doors, walls, and other materials. The higher the rating, the better the material minimizes sound transmission. Here are some common STC ratings and what they mean.
- You can clearly understand normal speech at STC 25.
- At STC 30, you can hear normal speech but not understand it. You can, however, clearly hear loud speech.
- When materials have an STC of 35, loud speech is audible, but you can’t pick out the particulars of what people are saying.
- At STC 41, loud speech is reduced to a murmur.
- When a material rates a 45 on the STC scale, you can barely hear loud speech through it at all.
- At STC 50, even loud musical instruments can hardly be heard.
STC Ratings for Door and Wall Materials
When walls are thin, sound pours through them. Anything that interrupts the wall’s continuity, such as a door, allows even more sound to be transmitted. Most of today’s homes are equipped with hollow core doors, which are the least sound-resistant.
Now that you know a little more about the kind of sound barriers created at various ratings, let’s consider the ratings of common wall and door materials.
- An interior hollow core door has an STC rating of 20 to 25.
- A solid door with particle-board core rates at 30.
- If a standard interior wall has 1/2 inch drywall on both sides and 3.5 inches of airspace, its STC designation is 33.
- When a standard interior wall has 1/2 inch drywall and the 3.5-inch space in the middle is filled with insulation, its rating goes up to 39.
- When you have a double layer of 1/2-inch drywall, which adds up to four layers in total, and 3.5 inches between them are filled with insulation, it has an STC rating of 45.
- A solid core door rates between 55-60.
How Do Doors Block Sound?
Too often, the drywall layers in walls and ceilings are too thin to block sound. Doors play a critical role, too, although they’re a weaker link when it comes to muffling sound. By the way, in case you’re wondering why hollow-core doors are so inadequate at resisting noise transmission, it’s because their cores are made of a cardboard honeycomb material. It’s no wonder that solid wood slab doors are much more up to the task.
So, replacing a hollow core door is the first step in minimizing sound conduction. Of course, you can also add a layer of drywall to interior walls.
Replacing a door is usually relatively easy. Most come with a standard placement for hinges, so they’re easy to install. Keep in mind though, that a heavy door, such as the wood slab variety, may need longer, sturdier screws to reinforce the hinges.
For ill-fitting doors or odd-sized openings, you may need to make some modifications, such as trimming the door or outfitting the door jamb with the new hinge and strike-plate mortises. And if you’re not up to doing these tasks yourself, this is a good time to call a professional. Another option is to get a prehung door, as these have hinges already in place.
Tips for Soundproofing Doors
If your interior doors aren’t exactly noise-canceling, there are a few steps you can take to make them a bit less sound conductive. Of course, you can always replace an existing door with one made of a tougher material.
Strategic Positioning
In many cases, it may be possible to arrange doors along a hallway so that they swing without transmitting noise to adjoining rooms. Hinged doors will often give you the best results in this area. Bi-fold, pocket and sliding doors make more noise opening and closing and don’t seal as effectively as swinging doors.
Apply Weatherstripping Tape to Knock Out Noise
Gaps between the floor and door and around the door’s edges make the sound more likely to travel through these nooks and crannies. Use weather stripping to soundproof those tiny openings.
Seal It With a Door Sweep
Exterior doors don’t offer a complete seal against noise and weather elements, as they allow a little bit of space under the door for easy opening and closing. However, this opening also gives way to drafts, heat, pests, and outside noise. A door sweep is a narrow barrier consisting of plastic, brush-like bristles, rubber, or other materials, that create a door seal. There are three main types of door sweeps.
- Strip Door Sweep. This is the most effective and easiest to install under door bottoms. That makes replacements painless when they wear out.
- Under-Door Sweep. This type provides the ultimate seal between the floor and the bottom of the door. An under-door sweep consists of two round pieces straddling the door’s base. Some of these come with a hook-and-loop feature that prevents the sweep from sliding.
- Bristle Door Sweep. This is similar to a strip sweep. Instead of a solid barrier under the door, these consist of bristles. That means less friction when opening and closing the door. But since they don’t provide a solid barrier, bristle door sweeps provide less protection against cold air and pests.
Consider Installing Solid Wood Doors
Solid wood doors are extremely dense and come in several styles for just about every home and budget. Because of their thickness, solid wood doors help to mute unwanted sound.
Use Area Rugs, Curtains, and Carpets
Carpets, area rugs, curtains, and drapes go a long way toward muffling ambient noise. If you have an area of your home that seems to be a magnet for sound, try laying down a carpet and adding window treatments (if you don’t have them already). These features can add insulation to your home, too.
Put in Sound Insulation Panels
Since they make such good noise buffers, acoustic panels are an especially helpful addition to loud areas of your home, like a music room or playroom. Noise insulation panels come in several styles, so you can use them to decorate your space to get the look you want.
How to Soundproof a Room
Here are the basics involved in soundproofing a room.
- Figure out what noise you want to control or reduce. Soundproofing is about regulating how much noise gets generated and controlling the quality of sound as much as possible. For instance, you may want to put some limits on your surround sound so it can’t be heard all over the house. But you want to do that without compromising sound quality in the room where everyone watches TV.
- To both control and minimize noise, you’ll want to block and absorb sound. Whenever possible, select soft materials that absorb sound well, such as the already-mentioned carpets and rugs. Upholstered furniture also helps reduce unwanted sound.
- To block noise, you’ll need to keep it from coming through windows, ceilings, and doors. You can accomplish that by installing soundproof doors and utilizing construction techniques, such as installing insulation, to make walls, floors, and ceilings less sound conductive.
General Soundproofing Tips
- You can also use less expensive noise-proofing solutions. Consider what materials other parts of your home are made of and how they can impact sound transmission.
- The type of siding your home has an effect on how much outside noise gets in. Sound passes relatively easily through wood and vinyl. Brick and thick stone create much better sound barriers.
- Keep in mind that attic and dryer vents, soffits, and chimneys provide the perfect openings to invite noise into your home. Having soundproof windows won’t negate the noise-carrying capabilities of these parts of your home.
- Window frame gaps and window seal leaks conduct noise too. Patch any holes you have around your windows and you may notice a tremendous difference.
- Add insulation to both interior and exterior walls. The more insulation you have, the less sound can get in.
- If outside noise is causing problems in your home, turn on sources of white noise — air conditioners, fans, dehumidifiers. If outside noise makes it hard to sleep, consider investing in a sleep machine that plays soft sounds like birds chirping. You can also find free apps that do this.
- If you notice a lot of sound seeping in through walls, ceilings, and floors, apply some caulk around door casings, light fixtures, switch boxes, and receptacle boxes.
- Place 3/8-inch acoustical caulk beads between two layers of drywall. This cancels vibrations that often echo through walls.
- You can also install mass-loaded vinyl (MLV) between layers of drywall. This flexible material, which comes in 4-foot rolls, can be suspended from walls or placed on floors to help knock out nice. This stuff is a little pricier than caulk, and it’s heavy. So if you order it online, prepare to shell out a sizable amount for shipping.
- If ducts in your home generate more noise than you’d like, place the sound-deadening wrap around them. It serves two purposes, as it adds insulation as well as reducing sound transmission.
Other Soundproof Home Features
Soundproof Window
Soundproof windows can block as much as 95% of incoming noise. They have a much higher STC rating than standard windows. A regular window has an STC rating of 27. If it’s double-paned, that goes up to 28. A soundproof window, on the other hand, has a rating of at least 45; some even score well into the 50s.
Soundproof windows have thicker glass than their non-soundproof counterparts. They also have more space between panes (airspace). They’re constructed with laminated glass, which keeps noise transmission to a minimum.
One potential drawback of soundproof windows is that they are not energy-efficient. Energy-efficient windows are made of thermal panes with low-E coatings designed to reduce heat transmission. You can make a soundproof window more energy-saving by adding a low-E coating. But you can’t make a standard energy-efficient window more soundproof.
Soundproof windows are a big investment, so you want to make sure you really need them before you make a purchase. Sometimes, windows aren’t the biggest noise transmitters. Annoying sounds may be coming from the vents or the attic. Even when they are coming through the glass, there may be a cheaper solution to making them more soundproof. An acoustic consultant can do an assessment of your home to see if soundproof windows are in fact the best choice.
Soundproof Blanket and Soundproof Curtains
It’s common to hear someone say they burrowed under the covers to block out noise that disturbed their sleep. This usually doesn’t help much, unless you have the right type of blanket. Yes…a soundproof blanket or quilt is actually a thing. But it doesn’t go on your bed. You hang it on windows to shield your home from outside sounds. Or, you can hang one over a door to keep noise in the rest of your home from invading a particular room.
Understandably, some people are skeptical about whether soundproofing curtains or blankets really work. When selecting one, it’s important to know what to look for so you can be sure you’re getting the real deal. If a product simply claims to block sound, it probably won’t be very effective. It should have an STC rating, which shows it’s been tested and can live up to its noise-canceling claims. A soundproofing blanket or curtain that really has noise-reduction capabilities will be equipped with sound membranes that reflect incoming sound. These membranes can be field-tested to see just how much sound they block.
Now that you know something about what soundproof blankets are, let’s look at what they are not. Moving blankets are not the same thing as real soundproof blankets. They do have the ability to absorb some sound, but not nearly as much as blankets that have an STC rating. Moving blankets aren’t designed for soundproofing anyway. Quilts and curtains created for this purpose are much heavier than non-soundproofing types. In fact, the blanket’s ability to block sound is directly proportional to how heavy it is. So if a quilt weighs so much that you can barely pick it up, most likely it’ll do a good job preventing outside noise from coming through the window.
There is one instance where it can be somewhat useful to put moving blankets to work as acoustic blankets. If you have a makeshift recording studio in your home or garage, and you want to deck it out with some rudimentary sound-blockers, this is the time for moving blankets (more on that in a later section). Despite their low noise reduction coefficient (RNC), they can make a difference when it comes to keeping sound reverberations to a minimum.
It’s more difficult to reduce low-frequency sounds, such as the noise of a diesel engine, air conditioning unit, or other equipment that has a motorized hum. If you’re trying to keep these types of noises out of your space, you’ll need to use a double layer of moving blankets on the walls. These provide a cost-effective solution to heavy soundproof products.
To get the most out of your soundproofing material, you will need to seal it around the door or window. Otherwise, sound leaks are likely. To secure the blanket in place, use glue, magnetic strips, Velcro strips, or nails.
Acoustic Tiles and Acoustic Foam
Lightweight and porous, acoustic foam or tiles can transform sound quality in a room. The foam is used in an acoustic panel to absorb noise and echoes, so they don’t bounce all over the room. Foam reduces distortion quite a bit from the reflected sound. That’s why you’ll often see foam in recording studios and music rooms. This is especially helpful when your child is practicing a musical instrument that they’re just learning to play, and the whole family doesn’t want to listen in.
Many people can attest to how successful foam is in reducing in-home noise, but what about canceling the clamor of neighbors or kids playing in the backyard? If you live in a townhouse, your neighbors are literally on the other side of the wall. Unfortunately, foam isn’t the best at muffling outside noise.
How to Make Your Own Acoustic Panels
If you’re all about some DIY soundproofing, you may want to try your hand at making your own acoustic tiles. They’re relatively inexpensive to build. Panels in this guide will be 24″ wide by 48″ long.
- Tools You Will Need:
- Power drill
- Circular saw
- Screwdriver
- 8″ x 1-1/4″ wood screws
- Wood glue
- Tape measure
- Pencil
You can try making two panels simultaneously so there is virtually no waste. For each pair of panels, you will need four 1x 4 x 8 wood pieces. Cut them into 4 46.5″ pieces. (These are for the sides of the frames). You’ll end up with 2 pieces for each 8-foot length. For the top and bottom, you’ll have 4 24-inch pieces. You’ll need to also put in inner support rails for each panel. The support rail measures 22-3/4. You will need four rails (2 per panel).
You will also need 24-inch sections of insulation material for the panels. You may want to do some research ahead of time to ensure the insulation material fits the frames. Otherwise, you may have to tweak the frame dimensions to accommodate the size of the insulation blocks.
When putting the frames together, make sure the top and bottom pieces sit on the ends of the side pieces, not on the insides between each side piece. You may want to drill pilot holes first before securing the wood screws into the corners. Put some wood glue between the two wood pieces to make sure they’re bonded together as well as possible.
Repeat those steps for remaining corners until you have built rectangular frames.
For the inner support, you may want to measure it first to make sure it will fit snugly into the frame. It should be between 22-1/2 and 22-3/4″. Drill pilot holes before adding screws. Draw a thin line of glue along the support rail to bond it to the frame. (Support rails are secured on the inside widths of the frames as reinforcements. They also cradle the insulation pads).
Lay the frames on the floor. The insulation should fall into place, so you don’t have to cut it, which eliminates the possibility of a mess.
To make your panels more aesthetically pleasing, the next step is to wrap them in fabric. Rigid fabrics are easier to work with and less likely to form unsightly creases. For this part of the project, you will need:
- Roll of your favorite fabric (a 58″ roll is an especially good fit for wrapping the panels).
- Staple gun
- Good, sharp pair of scissors
- Hammer
Roll the fabric out facedown. (The outside part of the fabric should be touching the floor). You may want to roll the fabric out on the carpet if possible because the carpet provides some resistance, which makes it easier to wrap the panels tightly.
Place the frame and insulation facedown on the inside of the fabric. The back support pieces should face upward. Make sure the panel is laying straight on the fabric. You will need at least 6″ on either side of the frames. If you’re not sure whether the panel is lying straight, take measurements around the fabric. These measurements should be equal all the way around.
Once your panel is lined up on the material, use a straight edge to cut the fabric. Then, it’s time to start wrapping. Want to know how to make perfect corners? Make a cut that is parallel to the top and ends right at the edge of the side. You’ll want a 1/2-3/4″ overhang on the top rail, which allows you to wrap the fabric neatly around the edges of the corner of the panel. Cut slowly — it doesn’t have to be perfect, but you’ll want to make it as precise as you can.
Next, it’s time to staple the rest of the fabric to the panel. Start on the long side of each panel. Pull the fabric tightly around the edge and make sure it doesn’t move during wrapping. When you’ve folded it over, put a staple in the middle. Keep stapling down the length of the panel. Staples should be no wider than an inch apart.
Then, move to the opposite long side. Pull the fabric tightly and take care not to rip it. You want there to be plenty of tension to ensure the material lays neatly on the panel. Pull tightly each time before you staple to make sure there are no creases. When covering the corners of the panels, you may have a little excess fabric, which you can trim if it’s getting in your way. Fold the corners similar to the way you fold wrapping paper around the corners of a box. Make sure there’s plenty of tension so the fabric doesn’t crease. Staple all the folds securely, smoothing the fabric each time you staple.
As you continue folding, make sure the fabric lines up perfectly with the frame. Use a hammer to secure any staples that didn’t go completely through the material.
The last step is to cover the backside of the panel. This is the part that goes against the wall. It’s not visible to others, but covering it gives it a finished look. You can use any kind of fabric you want since no one will see it. A good material to use is underlining fabric, the kind you often find on the undersides of couches and chairs.
You don’t have to strive for perfection when covering this part of the panel. The goal is to attach the backside fabric so that none of it is visible from the front. Also, you want to avoid stapling the backing into the staples you used for the fabric that covers the front and sides of the panel. For best results, it’s easier not to measure and cut the fabric first, because it’s harder to have tension on it when you are stapling it. Instead, have overlapping fabric on two sides so that you can pull on the other two sides to create the tension that keeps the material from puckering. Then you only have the line the fabric up on two sides and make two cuts instead of four. As you’re cutting the backing fabric, be careful not to cut the material you used for the front of the panel. If you think this might happen, lay the panel front side up on a hard surface with the backing under the panel, and use the edge of the panel as a cutting guide.
You can watch this video for more details on the panel-making process.
Door Sweeps 101: Tips for Installation and Maintenance
- Always install door sweeps on the outside of exterior doors. That’s where they can provide the most protection against the elements and outside noise.
- Strip sweeps come with adhesive backing, making them simple to install, provided everything’s lined up correctly. You may want to have someone else on hand to help you apply this type of sweep to make sure it goes on straight. It should be placed on as tightly as possible too. Drawing a straight pencil line on the door as a guide can help you place the strip on so it’s level.
- If you have a rubber, plastic, or bristle sweep that has a guide, you’ll need to nail some screws into the door to secure the material.
- A quick caveat about under-door sweeps. Most of the time, they slide right on. Occasionally, though, they require you to take the door off its hinges to put the sweep on properly, especially if it comes with a hook-and-loop reinforcement.
- Door sweeps don’t last forever. When your plastic or rubber seal becomes bent or damaged, it’s time for a new one.
Ideas for Soundproofing Ceilings and Floors
- Contrary to popular belief, fiberglass insulation for ceilings isn’t the best sound-killing solution. Medium density, fiberboard, heavy vinyl sheeting, or drywall are much more up to the task.
- Installing the equivalent of a second floor or ceiling stops noise transmission, as it interrupts vibrations through the joists.
- For floors, use MDF plywood to absorb sound. Use sound-damping plywood to interrupt noise. It has an elastic layer for this purpose. It attaches with adhesive rather than screws.
- To soundproof under a laminate, wood, or ceramic tile floor, apply 4×8-foot rolls of self-sticking 1/2-inch recycled rubber sheeting underneath.
- You can even make carpeting more soundproof with underlayment made to reduce airborne noise.
- You can add mass-loaded vinyl to floors, too. It can block up to 90% of airborne noise.
