how to soundproof a hollow door

Do you hear unwanted noise coming through closed doors in your home or apartment? Hollow core interior doors allow sound to travel easily from room to room. But luckily, there are several easy and affordable ways to soundproof doors and block noise pollution.

In this article, we’ll discuss the basics of how to soundproof a hollow door as well as solid core doors.

With simple DIY techniques like adding soundproofing materials to the door, sealing the edges, and installing soundproofing curtains, you can greatly reduce noise transmission.

Soundproofing a door is an effective way to absorb sound, increase privacy, and reduce distractions.

What are the best materials for soundproofing doors? What areas of the door leak the most noise? How difficult is it to install soundproofing blankets or acoustic foam?

We’ll answer all these questions and more. Follow along as we explore different types of doors, where they fail, and how to fix them. With a few inexpensive materials and tools, you can block noise from entering underneath and around the sides of the door.

Ready to create a quieter home? Let’s get started with learning how to soundproof interior doors for better noise control.

How to Soundproof Doors and Block Noise

how to soundproof a hollow door

Is noise from outside or other rooms easily travelling through closed doors in your home? Hollow core interior doors allow sound to pass through quite easily.

But not to worry – there are several straightforward, affordable ways to soundproof doors and significantly reduce noise pollution.

In this comprehensive guide, we’ll discuss how to soundproof a hollow door as well as solid core doors to block disturbances.

With basic DIY techniques like adding soundproofing materials to the door, sealing air leaks, and installing soundproofing curtains, you can greatly reduce noise transmission through the door frame.

Soundproofing a door is one of the most effective ways to absorb sound, increase privacy, and reduce distractions in your home.

Why Soundproof Doors?

Why Soundproof Doors?
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Before we dive into the how-to, let’s review some of the top reasons you may want to soundproof interior doors:

  • Reduce noise disturbances – Limit sound transfer between rooms like loud TVs, music, noisy kids, or barking pets.
  • Increase privacy – Muffle conversations and noise from one room to another.
  • Minimize outside noise – Lessen external sounds like traffic, construction, or noisy neighbors.
  • Improve concentration – Decrease distractions and create quiet spaces to work, read, or relax.
  • Enhance sleep – Block early morning noise so you can sleep better.

Soundproofing doors is an affordable project that can make a big difference in the livability and comfort of your home.

How Do Doors Leak Noise?

To understand how to soundproof a door, it helps to know where doors fail at blocking sound. Noise leaks through doors in a few key areas:

  • The door frame – Sound passes through the gap between the door and the frame quite easily.
  • Under the bottom of the doors – Noise travels right underneath the door through the open space.
  • Through the hollow core – Interior doors have a lightweight hollow middle which allows sound waves to pass through.
  • Around the edges of the door – Gaps around the sides and top of the door let noise leak through.
  • Through the door material itself – Thin wood and hollow cores transfer some sound vibrations.

Now that we know where doors fail, let’s go through some simple DIY fixes.

DIY Soundproofing Tips for Doors

Luckily, doors can be soundproofed fairly easily with minimal tools or construction experience required. Here are some of the most effective DIY techniques:

1. Add Mass to the Door

One of the best ways to block noise is to increase the door’s mass and density which hampers sound vibration transmission. You can add mass a few different ways:

  • Attach sound-deadening fiberboardfiberglass sheets, or mass-loaded vinyl (MLV) to the door with adhesive. This adds dampening limp mass.
  • Use acoustic foam panels – Affix thick foam boards with spray adhesive. The dense foam absorbs sound vibrations.
  • Install a layer of drywall over the existing door with screws and adhesive to add mass. Green glue between layers adds dampening.
  • Adding mass is one of the most effective single upgrades for soundproofing a hollow door. The more dense and limp the material, the better it blocks noise.

2. Seal the cracks in the door frame.

Image of a person using foam spray to fill gaps around a door.
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As we learned earlier, lots of sound leaks through the gap between the door and frame. Here are some great options to seal it up:

Install a door sweep at the bottom which seals the gap when the door is closed.

Fit weather stripping around the entire door jamb to close gaps.

Use acoustic sealant like Green Glue Noiseproofing Sealant to fill cracks and gaps in the frame.

Place draft stoppers or door bottom seals on the sides and top of the door to close gaps when closed.

Sealing the door frame gap helps greatly reduce noise passing through.

3. Install a sound-deadening door sweep.

Image of a person installing a door sweep under the bottom of a door.
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In addition to the door frame, be sure to seal any cracks or openings around the edges of the door itself:

  • Apply acoustic caulk or Green Glue around the edges and hardware cutouts to seal gaps.
  • Use foam tape around the sides and top to close gaps around the door.
  • Install door sweeps on the bottom and sides for a tight seal.

Sealing all the edges, cracks, and openings will prevent noise leaks.

4. Place heavy furniture around the door.

A person is placing rugs against the bottom of a door. The rugs are being used to block out noise from outside the room.
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Adding soft fabrics around a door can also absorb sound and reduce transmission:

  • Hang a soundproofing blanket or quilt over the door to dampen the noise.
  • Use a soundproofing curtain on either side of the door to absorb noise through the frame gap. Heavy blackout curtains work great.
  • Place door rugs inside and outside the door to muffle footsteps and absorb airborne sounds.
  • Add foam tiles to walls adjacent to the door to diffuse vibrations.

Soft sound-absorbing materials prevent echoes and reduce noise volume.

5. Increase Door Density

If you want to fully optimize the door’s structure itself, consider these upgrades:

  • Swap the existing hollow door with a thicker solid core door to add mass and density.
  • Replace hollow interior doors with heavy, insulated exterior doors.
  • Add an additional layer of stiff material like thin MDF or plywood to the existing door with adhesive/screws.
  • Inject expanding spray foam or other insulation into the door’s hollow cavity to dampen sound.

A thicker, more dense door itself blocks more noise transmission.

6. Add a Vestibule

For exterior doors, adding a small vestibule room or airlock space allows you to use two separate doors and prevents sound from transmitting outside. The vestibule creates a double-door buffer zone ideal for blocking outside noise.

7. Use soundproofing curtains to dampen noise

Image of a person adding a soundproofing curtain on a door.
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Soundproofing curtains can make a big difference for windows and doors. Look for thick, multilayer curtains made from heavy fabrics like velvet, fleece, or quilted blankets. Sound-dampening blackout curtains absorb noise and add an extra barrier.

Install ceiling-to-floor curtains on both sides of a problematic door. Draw them closed for privacy and noise reduction.

8. Seal Electrical Outlets Nearby

Image of a person sealing the gaps of a door using weatherstripping
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Don’t forget to seal up electrical outlets and fixtures in walls adjacent to the door. Outlets can transmit noise through walls surprisingly easily.

Use acoustic sealant, foam gaskets, or childproof plugs to seal outlets and prevent flanking noise.

Best Materials for Soundproofing Doors

There are a wide variety of materials that can be used to soundproof doors. Here are some of the most common and effective:

  • Mass Loaded Vinyl (MLV) – Dense vinyl sheets that add mass-dampening.
  • Acoustic foam panels – Wedge-shaped foam absorbs sound vibrations.
  • Fiberglass – Insulation batts or rigid sheets add mass and damping.
  • Green Glue – Viscous sealant that blocks sound through cracks.
  • Door sweeps – Vinyl or brush sweeps seal the gap at the bottom of the door.
  • Draft stoppers – Dense foam or fabric-filled tubes block gaps around the edges.
  • Rugs – Dense, padded rugs absorb and block noise.
  • Curtains – Sound-dampening curtains and blankets limit transmission.

When selecting materials, prioritize ones that add mass, absorption, and seal gaps. The denser the better for blocking sound.

Tips for Soundproofing Hollow Core Doors

Hollow core doors are lightweight and allow a lot of sound to pass through. Here are some tips tailored for soundproofing them:

  • Attach acoustic foam boards or mass-loaded vinyl to add damping mass.
  • Inject expanding foam insulation into the hollow cavity through drilled holes.
  • Adhere a layer of drywall over the door with acoustic caulk around the edges.
  • Make sure to seal the door gaps with weather stripping and door sweeps.
  • Consider replacing the whole door with a thicker solid core door for optimal sound blocking.

With some simple modifications, you can upgrade a hollow door to block significantly more noise.

can you fill a hollow core door with foam?

Yes, you can fill a hollow core door with foam to make it more solid and reduce sound transfer. However, it will not make the door soundproof.

To fill a hollow core door with foam, you can drill small holes in the door and spray foam insulation through them. The foam will expand and solidify inside the door. You can also insulate a hollow core door by glueing foam insulation sheets to the outside of the door. This is a cheaper and easier method.

When filling a hollow core door with foam, you can use foam that expands less aggressively to prevent it from damaging the door. You should also keep newspaper or cardboard around the work area to catch any excess foam. Once the foam has dried, you can clean up and remount the door.

Spray foam insulation is good for insulating, but it’s not the best for soundproofing. Open-cell spray foam is better at sound absorption than closed-cell.

Here are some additional tips for filling a hollow core door with foam:

  • Use a high-quality closed-cell foam.
  • Drill the holes in the door evenly spaced.
  • Do not overfill the door with foam.
  • Trim the excess foam with a knife.
  • Let the foam dry completely before reinstalling the door.

FAQs for how to soundproof a hollow door

What is the best material for hollow door filler?

Wood filler is the best option to repair small to medium-sized holes in hollow doors. For small holes, a sharp utility knife is used to cut off any rough edges around the hole.

What is the standard thickness of a hollow metal core door?

The standard thickness of a hollow metal door is 1-3/4 inches. These doors consist of channel-reinforced steel sheets filled with insulation materials like polyurethane, polystyrene, or kraft honeycomb


In wrapping up, remember that soundproofing a hollow door can make a world of difference in your comfort and privacy. You’ve got this! Don’t let noise disrupt your peace any longer. Your home should be your sanctuary, and we believe in your ability to make even better.

So, grab your tools, gather your materials, and let’s make some quiet happen. Take that first step and start your soundproofing journey today. You’ll thank yourself later!

About Mohammad Sameer

My name is Mohammad Sameer, the founder of SoundproofGears. My hypersensitive hearing turned me into a lifelong seeker of silence. After years of research, I've become an expert on soundproofing techniques and materials. In November 2022 I launched this site to share my knowledge and help others find acoustic sanctuary. About More

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