How to Soundproof a Room (Almost Completely) in 10 Steps

A soundproof room is one that blocks sound from entering or leaving a room. 100% soundproofing is rarely achievable and would require a substantial investment which very few people can afford.

In this article, you will learn how to soundproof a room almost completely in ways that are most cost-effective but do require some amount of investment.

For inexpensive alternatives, read my article on cheap ways to soundproof a room but keep in mind that the cheaper methods will be substantially less effective.

How to Soundproof a Room – Step by Step

Here are the steps you need to take to properly soundproof a room.

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1. Decouple the Walls

Decoupling is one of the most effective forms of soundproofing. You cannot afford to skip decoupling if you want to achieve a high degree of soundproofing.

Decoupling Walls of a Constructed room

How to Soundproof a Room
Decoupling a Wall with Hat Channel and Clips

If you are soundproofing an existing room, you will need to remove the drywall and apply decoupling to the studs. This can be done with hat channel and sound isolation clips.

  • Install the hat channel horizontally along the wall at a vertical spacing of 24 inches.
  • Install the sound isolation clips as shown in the image with a horizontal spacing of 48 inches.

For a New Construction

If you are building a soundproof room, consider decoupled framing such as a staggered wall or double stud wall.

  • Staggered Stud Wall
  • Double stud Wall
staggered stud wall and double stud wall
Double Stud Wall and Staggered Stud Walls

For a detailed guide, read my article on staggered and double stud walls.

2. Add insulation in the Walls

Insulation is another element of soundproofing that must be looked into. Insulation helps in avoiding resonance in air cavities and hence, helps in soundproofing. Make sure that the insulation is of the low-density type such as Owen Corning R-13 or equivalent. 

Add Insulation
Add insulation

It is important to note that high-density insulation is good for acoustics but not good for soundproofing.

3. Install Double Drywall and Green Glue

Another two important elements of soundproofing are mass and damping. If budget constraints do not allow both, damping can be excluded.

Sound Damping
Apply Green Glue Sound Damping on the Second Drywall Layer
  • Install the first layer of drywall
  • Apply Greenglue on the drywall sheets that will form the second layer and install as shown in the video below.
Applying Green Glue Noiseproofing Compound
Watch this video on YouTube.

4. Decouple the Ceiling

Just like the walls, you will need to decouple the ceiling for soundproofing to be effective.

soundproof the ceiling
  • Remove the existing drywall
  • Add hat channel and sound isolation clips just as you would do for a wall.
  • Add double drywall and Green Glue as per the procedure earlier covered for walls.

5. Insulate the Windows

Double glazing and window plug are the two best options for soundproofing a window.

Double Glazing

double glazed windows
Double Glazed Section of a Window

Double glazing is expensive but is the most effective method to soundproof windows of a room. The air gap between the two layers of glass act as a strong sound insulating layer.

Window Plug

window plug soundproofing
Window Plug

A window plug is a lesser effective but cost-efficient way of blocking noise coming through windows. A window plug is basically thick insulated objects that completely cover the window and help in blocking sound.

The construction of a window plug is explained in this article.

6. Seal the Gaps Around the Windows

Soundproof window with sealant
Seal the gaps with acoustic sealant

If there are gaps or cracks around the windows, sound will leak inside even if you have double glazed windows installed.

So, make sure to seal the gaps and cracks around the windows with acoustic sealant.

7. Install a Solid Core Door

solid-core-door
Solid Core Door is the best for Soundproofing a Doorway

Standard hollow core doors are absolutely ineffective for blocking out sound because of low mass. Unfortunately, cheaper methods such as soundproof curtains do not make much of a difference.

The only way out is to replace the door in the room with a solid core door. Solid core doors are of high density making them effective for blocking noise out.

8. Seal the Gaps Around the Door

seal-door-gaps-with-sealant
Seal Door Gaps with Sealant

Like windows, sealing the gaps and cracks around the door is a step that cannot be missed. The procedure is the same using acoustic sealant.

9. Apply heavy Padding or Carpet on the Floor

The floors should not be ignored especially if you have a concrete floor. Heavy padding or carpets would generally be the preferred choice. However, my favorite is the cork underlay which is an inexpensive yet fairly effective option.

soundproof floor
Cork Underlay is Cost Effective for Soundproofing Floors

Check out my guide on installing cork underlay.

10. Soundproof the Air vents

soundproof air vents

Air vents are a major source of airborne noise leaks. The HVAC system’s air vents should be made soundproof using materials such as duct liners, soffits, and sound baffles.

Check out my detailed guide on soundproofing air vents.

Final Thoughts

Soundproofing a room completely is almost impossible and can be very expensive if it is to be achieved.

while soundproofing a room, there are four elements of soundproofing that need to be applied for the success of the project and they are:-

  • Mass
  • Decoupling
  • Absorption
  • Damping

If you employ all the methods described in this article correctly, you would have applied all the elements of soundproofing and I can assure you that your soundproofing project would be successful.

Check out my recommended products for soundproofing.