How to Soundproof a Wall From Noisy Neighbors, Fix by Fix

If you’re working out how to soundproof a wall from noisy neighbors, start at the gaps, because a federal noise guide says many party walls can be improved simply by closing their leaks and side paths.

You hear the TV next door at an ordinary volume, the laughing and the bass line, and the foam squares you stuck up last month changed nothing.

Close the leaks first, add a heavier damped layer next, and save the big step, a new layer that never touches the old studs, for noise that still gets through.

This guide ranks each fix from a tube of caulk to a decoupled wall, with the score a lab or maker gave it and whether a renter can do it without asking.

Start with the ladder below, then use the diagnosis to find which rung your wall needs.

How to Soundproof a Wall From Noisy Neighbors, Fix by Fix

That ladder runs from the cheapest, most reversible work to the biggest build, and the table puts a tested number or a maker’s instruction beside each rung. To soundproof a wall from noisy neighbors, find the path the sound takes, seal every opening on your side, move what you can away from the wall, add a damped second layer of drywall, and hang a new layer on isolation clips if voices or bass still come through.

Rungs 1, 3 and 6 are yours to do in a rental, and rung 2 is small enough to be worth asking about. Rungs 4 and 5 change the building, so they’re owner jobs, and they’re where the big numbers come from.

Think of it like a bucket with a hole in it: a thicker bucket doesn’t help until the hole is plugged.

What Are You Hearing Through the Wall?

That table starts with diagnosis because the kind of noise decides how far up the ladder you have to climb. Voices and TV dialogue are the easiest neighbor noise to cut, and bass and thumping are the hardest, because NRC Canada’s acoustician Warnock writes that low frequencies pass through walls much more easily than high ones.

He adds that this is why bass guitar and drums from the next apartment usually stand out. So if you can follow the words of the show next door, a leak or a light wall is the likely culprit, and if you only feel the beat, you’re dealing with the low end that every wall passes most easily.

The old National Bureau of Standards handbook on quieting a home gives a useful scale for speech. Its Table 4-1 rates walls by the privacy they give against intruding speech:

The same handbook says most interior walls in a typical home or apartment rate STC 30 to 35. If your neighbor’s normal conversation comes through as words, your wall is probably performing below that range, and a leak is the first thing to look for.

Thumps are a different animal. NRC Canada’s Building Digest 236 describes impact noise as a solid object striking the structure, like footsteps, which sets the building vibrating and comes out elsewhere as sound.

Here’s a quick test that takes five minutes. When the noise is going, put your ear near the middle of the wall, then at an outlet, the baseboard, the corner and the ceiling line, and note where it’s loudest.

Is the Wall Really the Path, or Is Sound Going Around It?

Those five listening spots matter because the wall you share is often not the only way in. Sound goes around a shared wall through what acousticians call flanking paths, and NRC Canada’s Building Digest 239 (MIT’s copy) says that in a poor design those paths can carry more sound than the wall itself.

The NBS handbook names the usual suspects in party walls: back-to-back electrical outlets, medicine cabinets, master TV outlets, openings around pipes and ducts, and cracks at the ceiling and floor edges left by settlement or poor construction. It calls the chief flanking paths in homes and apartment buildings open ceiling plenums, attic spaces, basements and crawl spaces that run across units.

The floor and the structure can matter as much as the holes. In an NRC study of wood-framed buildings, a double-stud party wall with two layers of 5/8-inch fire-rated drywall on each face scored only apparent FSTC 52 when one continuous subfloor ran under it, and 66 once the subfloor had a gap under the wall.

That’s 14 points lost to one board running under the wall, with nothing wrong with the wall. It’s also why a beautifully built wall can disappoint: the sound simply walks underneath it.

Warnock’s 1990 paper ranks the two kinds of leak. He calls leakage through electrical outlets relatively minor and says leakage around interior partitions can be major, and he adds that such leaks usually let through only high-frequency sound.

So if what you hear is the hiss and clatter of speech and dishes, look for a leak. If the noise seems to come from the ceiling line or the floor rather than the wall’s face, our guides on how to soundproof a ceiling and how to soundproof a floor cover those surfaces.

If what bothers you is really traffic or a barking dog outside, the wall isn’t the problem at all, and how to block outside noise is the better place to start.

What Should a Wall Between Homes Score?

That diagnosis gives you a sense of where your wall stands, and the building code gives you the number it should reach. The 2021 International Building Code, Section 1206, asks walls between dwelling units for STC 50 when lab tested to ASTM E90, or a normalized noise isolation class (NNIC) of 45 when measured in the finished building to ASTM E336.

On the NBS scale above, 50 means shouting barely audible. The same section says penetrations for pipes, electrical devices, recessed cabinets, bathtubs, soffits and ducts must be sealed, lined or insulated to keep that rating, and that entrance doors, though exempt from the number, must fit tightly to the frame and sill.

Notice the gap between 50 in the lab and 45 in the field. The code accepts five points less from a wall measured in place than from one tested in a lab, and GSA’s acoustics guide says it’s not unusual for a measured result to land ten points or more below the lab rating.

Two limits on that rule are worth knowing. According to Burton Acoustix’s look at what building codes and lab tests say a townhouse shared wall should score, townhouses fall under the residential code instead, and it sets the two rules side by side.

It’s also a rule for construction, not a promise about an older building today. Our guide on how to soundproof a joining wall lists the tested scores of common stud, brick and concrete walls, so you can estimate how far below 50 yours might sit.

If the wall is brick or block, how to soundproof a brick wall covers how a lining in front of masonry has to be spaced. NRC Canada warns that even drywall glued straight onto concrete can trap a thin film of air behind it that drags the wall’s rating down.

How Do You Seal Outlets, Baseboards and Cracks on a Shared Wall?

That code line about sealed penetrations is also the cheapest fix you have. Sealing comes first because HUD’s Noise Guidebook says a one-inch square hole, or a crack 1/16 inch wide and 16 inches long, will take an STC 50 wall down to 40.

On the NBS scale, that’s the difference between shouting barely audible and loud speech audible. A gap you could hide behind a baseboard costs twice the five points Table 4-1 credits to doubling the drywall on both faces, from 35 to 40.

Work through the wall in this order:

1. Baseboard and ceiling edges. NBS says settlement cracks at the ceiling edge should be sealed with a resilient caulk, preferably applied under pressure with a caulking gun, and that cracks at the floor edge may mean removing the base boards to do a thorough job.
2. Outlets and switches. National Gypsum’s guidelines say to seal all penetrations with acoustical sealant or putty pads, and to keep penetrations to one per stud cavity.
3. Pipes and ducts. NBS says openings around pipes should be packed with glass fiber and sealed completely with a resilient caulk, and the same treatment goes around ducts, grilles and outlets.
4. Recessed cabinets and niches. The code lists recessed cabinets among the openings to treat, and the NBS drawings advise against cabinets recessed back to back in a party wall.

Turn the circuit off at the breaker before you take an outlet cover off. NBS describes moving an outlet into the next stud space on a wood-stud party wall so the two boxes no longer sit back to back, which is electrician’s work, and Warnock adds that offset boxes work especially well when the wall is filled with sound-absorbing material.

For the baseboard and trim joints, TMS Acoustical Soundproofing Caulk is a sealant sold for exactly these joints. Every product here had at least 4.0 stars and 50 reviews on Amazon and was in stock on 20 October 2026, and prices aren’t shown because they change.

TMS Acoustical Soundproofing Caulk

Type: Acoustical caulk

Package: 1 tube (29 oz)

Use: Baseboards, trim, outlet boxes

✓ Sold to seal sound leaks at perimeters, holes, gaps and spaces, per the listing✓ Paintable once dry, per the listing photos✗ Seals gaps only and adds no mass

See ratings on Amazon

The entry door is the one opening the code exempts from the number, though it still asks for a tight fit. If you can see light under it, how to soundproof a door covers seals and sweeps, and how to soundproof windows does the same for a window beside the shared wall.

Does Furniture Against the Shared Wall Help?

Once the leaks are sealed, the next rung costs nothing but effort. Furniture helps a little, but no lab has rated a bookcase as a wall layer, so treat it as a comfort move rather than soundproofing.

The physics explains the limit. NRC Canada says each doubling of a single wall’s mass per unit area adds only about 6 dB, so a 12 dB gain needs four times the mass, and a bookcase is neither airtight nor fixed to the wall.

What furniture can do is put distance and a buffer between you and the noise. HUD’s guidebook suggests designing homes so that “dead” spaces such as closets or corridors act as buffer zones, and you can borrow the idea by putting a full wardrobe or bookcase on the shared wall and moving the bed or desk to the opposite side of the room.

Your own noise counts too. The NBS handbook’s drawings discourage placing TV sets against party walls, so moving your TV and speakers off the shared wall is the courteous half of the same plan.

For a baby’s room on a shared wall, this baby-room checklist adds the anchoring and crib rules that apply there. Tall furniture needs securing to the wall anyway, which is one more reason a renter should check the lease before drilling.

How Much Does a Second, Damped Layer of Drywall Help?

Furniture only rearranges the room, while a second layer changes the wall itself. A damped second layer is the biggest step most owners can take without opening the wall, and National Gypsum’s tests put a 2×4 wall with its damped retrofit board over one face at STC 36 to 45.

National Gypsum’s SoundBook lists a 5/16-inch SoundBreak XP Retrofit board with a viscoelastic polymer on its back for use over existing drywall. It calls the principle constrained layer damping, a soft material sandwiched between two stiffer ones, so that vibration is turned into a negligible amount of heat.

Its four tested retrofit walls show what the cavity and the stud spacing do:

This table doesn’t include the same walls without the damped board, so the gain can’t be read straight off it. Its own new-construction tests give a cleaner comparison: a 2×4 wall with glass fiber and plain 5/8-inch drywall rated STC 36, and 42 with damped board on one side.

That’s six points, roughly the difference between loud speech that’s fairly understandable and loud speech you can hear but can’t follow, on the NBS scale. You can’t know whether your neighbor’s wall is insulated, but these numbers show why the same upgrade can land differently in two apartments.

The other route is a plain second layer of drywall over a damping compound. National Gypsum’s general guidelines for sound-rated walls fit here too: leave a 1/4-inch gap along every edge of the new board, fill it completely with acoustical sealant, and stagger the joints.

For that layer, Green Glue Noiseproofing Compound comes as a case of 12 tubes, and our page on how a Green Glue layer goes on walks through the application. Green Glue’s own site refused Burton’s scripts, so its test reports aren’t cited here, and the tested numbers above are National Gypsum’s.

Green Glue Noiseproofing Compound

Type: Damping compound

Package: 12 tubes

Use: Between drywall layers

✓ Goes between an existing wall and an added layer of material, per the listing✓ Applied with a large caulk gun in a random pattern, per the listing✗ Works only sandwiched between two rigid layers

See ratings on Amazon

A layer of 5/8-inch drywall also adds weight and depth. USG lists its 5/8-inch Firecode X panel at a nominal 2.2 pounds per square foot, and our guides to the best soundproofing material and how to soundproof a wall compare the boards and the retrofit order in more detail.

When Is a Decoupled Layer Worth the Lost Space?

Those damped layers still sit on studs that touch both apartments, and that’s the limit they can’t get past. A decoupled layer is worth it when voices still come through a damped wall or bass is the main problem, because isolation clips took a wood wall to STC 56 in PAC International’s lab tests.

NRC Canada explains why the studs matter. It says the common partition with drywall fixed straight to both sides of wood studs rates about STC 33, that insulation adds only about 3 points there because the sound crosses through the studs, and that rigid connections are the acoustical equivalent of an electrical short circuit.

Clips break that short circuit. A clip with a resilient core screws to the framing, a metal channel snaps into it, and the new drywall hangs on the channel without touching the studs.

The best news for anyone sharing a wall is that this works from one side. PAC’s FAQ says it tested its RSIC-1 clips on a wood-framed wall from the noise source side and from the receiving side, in Riverbank Acoustical Laboratories tests TL01-208 and TL01-209, and got STC 56 both times.

PAC also says clips on both faces scored 2 points lower than clips on one face, so one side is enough. It recommends the noisy side where you have the choice, to keep vibration out of the structure, but your side is the only one you control.

ROCKWOOL’s catalog shows the same pattern with resilient channels: a 2×4 wall with 5/8-inch drywall and 3-inch mineral wool rates STC 38, and 51 with RC Deluxe channels. NRC Canada adds that cavity insulation does far more once the layers are decoupled, and our guide to the best insulation for soundproofing compares the batts.

The cost is depth and care. PAC says the clip and channel create a 1-5/8-inch cavity between the framing and the back of the drywall, and its installation guide asks for a 1/4-inch gap caulked around the whole perimeter and a special backer for cabinets, headboards and TVs.

PAC says the clip fastens directly to the framing or structure, so on a finished wall that usually means opening your side to the studs, and the outlets have to come forward to the new face. PAC’s product page says the clip works on wood, steel, block or concrete walls, so the same idea covers a masonry party wall.

The clips themselves are sold in small packs. RSIC-1 resilient sound clips come 10 to a pack with mounting screws, and the furring channel and drywall are bought separately.

RSIC-1 resilient sound clips

Pack: 10 clips with screws

Layout: 24 x 48 in.

Use: Walls and ceilings

✓ Isolation clips with mounting screws, 10 per pack✓ Laid out 24 by 48 inches, per the listing✗ A part for a rebuild, not a stand-alone fix

See ratings on Amazon

What Can a Renter Do Without the Landlord?

Clips and new drywall are owner work, which leaves most renters on the first and third rungs plus one tool that doesn’t touch the wall at all. A renter can rearrange the room, cover the remaining noise with steady sound and ask the landlord for the rest, because anything that changes the wall belongs to the owner.

Here’s what usually needs no permission:

• Rearrange. Put the bed, desk or couch on a wall you don’t share, and a loaded wardrobe or bookcase against the one you do.
• Mask. GSA’s guide to office acoustics treats absorbing, blocking and covering as three separate tools, and calls a sound masking system the way to get low, steady background sound, from a tabletop fountain to an electronic system.
• Stop adding to it. Move your own TV and speakers off the shared wall, as the NBS drawings advise, which makes the request you’re about to make easier to hear.
• Talk. A short, friendly note about the times the noise is worst can solve what no material can, and it costs nothing.

Masking doesn’t stop a single decibel getting through the wall. It works the way a running fan hides a dripping tap, making the gaps between your neighbor’s sounds less noticeable.

For that, the Yogasleep Dohm Classic is a white noise machine whose sound comes from a real fan, per its listing. Set it between you and the shared wall, at the lowest level that covers the noise.

the Yogasleep Dohm Classic

Type: White noise machine

Sound: Real fan

Use: Bedroom or office

✓ Makes its sound with a real fan, per the listing title✓ White noise with no recording to loop✗ Covers noise and blocks none of it

See ratings on Amazon

Renters who want more of these options will find them in our guides on how to soundproof an apartment, how to soundproof a room cheaply and Burton Acoustix’s guide to a rented room.

Which Jobs Need the Landlord’s or the Board’s Permission?

Everything past rearranging and masking touches the building, and that’s where the owner’s say starts. Caulking the trim, opening outlets, adding drywall and hanging clips all change the wall, so a renter should check the lease and get the landlord’s permission in writing, and a condo owner should check the association’s rules before starting.

The reasons aren’t only legal. Moving an outlet is electrical work, and many of the tested walls in National Gypsum’s book carry a UL fire-resistance design number, so a wall between units may be part of the building’s fire separation as well as its sound separation.

There’s also a strong case for asking the owner to do the work. The code wants the openings in a wall between units sealed to keep its rating, and the owner can reach both sides of a party wall, the ceiling space above it and the floor junction below, which no single tenant can.

When you ask, be specific. Name the loudest spot from your listening test, ask whether the outlets on the wall sit back to back, and ask for the gaps at the baseboard and ceiling line to be sealed with acoustical sealant, which is National Gypsum’s own instruction for wall edges.

Why Don’t Foam Panels and Blankets Stop a Neighbor’s Noise?

Sealing, mass and isolation all block sound, and that’s exactly what soft products don’t do. Foam panels and blankets absorb echo inside your room but barely slow sound passing through a wall, and the NBS handbook warns that the porosity of sound-absorbing materials actually makes it easier for sound to pass.

It calls soft absorbers such as acoustical tile, carpet and drapery relatively poor sound insulators and compares them with a blotter: very good at soaking up liquid, but nobody would build a swimming pool out of one. The handbook says using sound-absorbing treatment to cut noise between adjoining spaces has often been an expensive and annoying error.

That doesn’t make panels useless. They make your own room less echoey, which is a separate job, and our page on whether acoustic panels can cut a neighbor’s noise explains where they fit.

The same goes for thin “soundproof” wallpaper or paint. If a product weighs almost nothing and doesn’t seal a gap, it can’t do the job of a layer of drywall.

What If the Noise Comes From Above or Below?

The ceiling and floor came up in the listening test, and the same code section covers them too. If footsteps or thuds are the problem, the fix is in the floor or ceiling, not the wall, and the code asks floor-ceilings between units for an impact insulation class (IIC) of 50 in the lab or a normalized impact sound rating (NISR) of 45 in the field.

NRC Canada’s Building Digest 239 notes that floors are particularly prone to extra impact sound through the supporting structure. The subfloor result above points the same way: one continuous board under the wall cost 14 points.

Our guide to footsteps from the apartment above covers what a tenant below can do, and how to soundproof a room puts walls, floors, ceilings and doors in one plan when the noise comes from more than one direction.

When Is It Worth Measuring the Wall or Calling a Professional?

That whole-room view is also where a professional earns their fee. Bring in an acoustical consultant when you’re about to lose several inches of room to a decoupled wall, or when sealing and a damped layer haven’t fixed the problem, because a test in the finished building measures what the wall actually does.

The code’s field rating, NNIC, comes from a test in the finished building to ASTM E336. It measures the whole room-to-room result, flanking included, and GSA notes that improper installation and poor detailing can open a big gap between lab and real performance.

Before you spend on a rebuild, put the costs side by side. Our guide to how much it costs to soundproof a room puts numbers on the work, and the soundproofing hub links every surface guide on the site.

The Bottom Line

Those tests and costs come back to the ladder you started with. Seal first, because one small hole can cost a wall 10 points, and rearrange the room, because it’s free.

Then add mass with damping, and if the noise is still there, decouple your side on clips, which PAC measured at STC 56 from the receiving side as well as the noisy one.

Renters have the first rungs and masking, and the owner holds the keys to the rest. Owners who climb the whole ladder are building toward the code’s STC 50, which ROCKWOOL’s channel wall and PAC’s clip wall pass in the lab, as long as the floor, ceiling and outlets don’t let the sound walk around it.

Frequently Asked Questions

How can I stop hearing my neighbor through the walls?

Find where the noise is loudest first, by listening at the middle of the wall, the outlets, the baseboard and the ceiling line while the noise is going. If it’s loudest at a gap or an outlet, sealing it is the cheapest fix, since HUD says a one-inch square hole can drop an STC 50 wall to 40. If the wall face itself is loud, add a damped layer of drywall or, for bass and stubborn voices, a new layer on isolation clips. In a rental, move your bed away from the shared wall, put a loaded bookcase or wardrobe against it and run a fan or white noise machine, and ask the landlord to seal the gaps.

What can I put on my walls so I don’t hear my neighbors?

Nothing soft and light will block the noise. The NBS quieting handbook calls soft absorbers such as acoustical tile, carpet and drapery relatively poor sound insulators and warns against using sound-absorbing materials to stop sound passing to the next room. What works on a wall is weight and isolation: a second layer of 5/8-inch drywall with a damping compound, damped retrofit board, or a new layer hung on isolation clips. A full bookcase or wardrobe against the wall helps a little by adding distance, and a white noise machine covers what remains.

Can soundproofing a wall stop bass from next door?

Partly, but bass is the hardest noise to stop. NRC Canada’s Warnock notes that low frequencies pass through walls much more easily than high ones, which is why bass and drums from a neighboring apartment stand out. Leaks mostly let high-frequency sound through, so sealing helps speech more than bass. For bass, you need mass and decoupling together: a damped second layer at minimum, and ideally a new face on isolation clips, which kept a wood wall at STC 56 in PAC’s tests. The floor and ceiling matter too, because bass and thumps travel through the structure.

How do I block my neighbor’s banging through a shared wall?

Banging, like a door slamming or a cabinet closing on the shared wall, starts as an impact on the structure. NRC Canada describes impact noise as vibration set off directly in the building that comes out as sound somewhere else, so it can reach you through the floor and framing as well as the wall. A decoupled layer on isolation clips does the most for vibration in the wall itself, because it stops the studs from carrying it to your drywall. If the thuds come from overhead, the fix belongs in the floor above. Ask the neighbor or landlord about soft-close hardware or bumpers on the source, since a softer impact puts less vibration into the structure in the first place.