How to Soundproof an Existing Wall

Table of Contents

What You’ll Learn (and Why It Matters)
Key Tools & Materials You’ll Need
Step-by-Step: How to Soundproof Existing Walls with RSIC-1® Retro (Recommened)
Step-by-Step: How to Soundproof Existing Walls with Green Glue + 5/8" Drywall
Step-by-Step: How to Soundproof Existing Walls with BlocknZorbe™
Step-by-Step: How to Soundproof Existing Walls with Mass Loaded Vinyl + 5/8" Drywall
Step-by-Step: How to Soundproof Existing Walls with Blown-In Insulation
Which Material / Which Approach Is Right For You?
Experience Matters: Why Second Skin?
Need Help or Have Questions?
Helpful Guides You May Want Next

What You'll Learn (and Why It Matters)

Soundproofing an existing wall is challenging because sound has already found its way through every seam, gap, and rigid connection. While there are retrofit solutions, the most effective results come from addressing structural weaknesses first. This guide focuses on realistic methods for improving sound isolation in walls that are already built.

By the End of This Guide, You’ll Be Able To:

Understand why existing walls leak sound and where fixes actually work
Identify which wall soundproofing methods improve STC ratings
Follow step-by-step instructions for proven retrofit solutions
Compare soundproofing options by effectiveness, effort, and use case
Avoid common mistakes like relying on acoustic panels for isolation

Skill

Handyman

Article Read Time

10 minutes

Build Time

1–2 days (solution-dependent)

Key Tools and Materials You'll Need

Key Tools

Drill / screw gun
Stud finder
Utility knife
Caulking gun
Measuring tape

Key Materials

RSIC-1® Retro Resilient Sound Isolation Clips

$7.00

Green Glue™ Damping Compound (Drywall, Subfloor)

$399.99

Choose options

BlocknZorbe™ Multi-Purpose Sound Panels

From $49.99

Shop Wall Soundproofing Material

Before You Start: Choosing the Right Approach

Our standing recommendation is to tear the wall down and start from the studs whenever possible. This allows you to inspect framing, verify insulation, and eliminate structural shortcuts that compromise sound isolation.

If demolition is not an option, the absolute first step is to check for gaps, cracks, and seams around outlets, baseboards, trim, and drywall joints. Sealing these leaks with acoustical sealant is always required before installing any existing-wall soundproofing treatment.

Step-by-Step: How to Soundproof Existing Walls with RSIC-1® Retro

Step 1: Install RSIC-1® Retro Clips

Install your RSIC-1® Retro clips directly over the existing drywall and into the studs. Make sure to take the time to locate studs and map out placement before starting.

Step 2: Snap in Hat Channel

Snap in 25-gauge hemmed edge detail hat channel to the clips.

Step 3: Install Drywall

Screw in a new layer of 5/8" drywall into the hat channel, leaving 1/4" around the perimeter of the walls.

Step 4: Seal the Perimeter

Seal the perimeter and all penetrations with acoustical sealant (again).

Step-by-Step: How to Soundproof Existing Walls with Green Glue + 5/8" Drywall

Alternative Solution: Green Glue + 5/8" Drywall

This approach improves soundproofing by damping vibration between drywall layers. For deeper context, see our article on the ultimate Green Glue alternative.

Expected STC Rating: 49–52

Step 1: Apply Green Glue to the new Drywall

Apply Green Glue to the back of a new 5/8" drywall sheet, leaving about 3" around the edges for handling. Do not allow more than 15 minutes pass after Green Glue is applied to execute step 2.

Step 2: Screw in Drywall

Screw the drywall into the studs, leaving 1/4" around the perimeter of the drywall.

Step 3: Seal the Perimeter

Seal all edges and seams with acoustical sealant.

Step-by-Step: How to Soundproof Existing Walls with BlocknZorbe™

Alternative Solution: BlocknZorbe™ Sound Panels

BlocknZorbe is an exception among panel products because it adds both mass and damping. This is fundamentally different from acoustic panels, which are intended for echo control and do not increase STC.

Expected STC Rating: 40–42

Step 1: Attach Soundproof Panels

Attach BlocknZorbe panels across the entire wall surface using screws or construction adhesive. You must achieve 100% wall coverage for any meaningful sound blocking benefit.

Step 2: Seal the Perimeter

Seal edges and penetrations with acoustical sealant.

Step-by-Step: How to Soundproof Existing Walls with Mass Loaded Vinyl + 5/8" Drywall

Alternative Solution: Mass Loaded Vinyl + 5/8" Drywall

You can install MLV for soundproofing to add mass, but drywall alone cannot support its weight, so the vinyl must be mechanically fastened to studs.

Expected STC Rating: 45–47

Step 1: Map out Stud Locations

Map out stud and header locations using a stud finder.

Step 2: Screw in Mass Loaded Vinyl

Fasten MLV directly to the studs through the existing drywall.

Step 3: Install Drywall

Attach your new layer of 5/8" drywall to the MLV and studs, leaving 1/4" around the perimeter of the walls.

Step 4: Seal the Perimeter

Seal the perimeter with acoustical sealant.

Step-by-Step: How to Soundproof Existing Walls with Blown-In Insulation

Alternative Solution: Blown-In Insulation to Wall Cavity

Many people ask if soundproof insulation works when added to existing walls. Blown-in insulation can slightly reduce airborne noise, but it should be consider supplementary to other methods. You will make a small access hole and blow in the insulation when there is none.

Expected STC Rating: 31–33

Which Material / Which Approach Is Right For You?

Feature	RSIC-1 Retro	Green Glue + Drywall	BlocknZorbe™ Panels	MLV + Drywall	Blown-In Insulation
Noise Reduction	Very High	High	Moderate	High	Low
Ease of Install	Moderate	Moderate	Easier	Moderate	Easy
Best For	Maximum isolation	Adding damping	Retrofit without drywall	Mass-driven blocking	Supplemental improvement
Cost	Higher	Mid	Mid	Mid-High	Lower
	Shop RSIC-1® Retro	Shop Green Glue	Shop BlocknZorbe	Shop Luxury Liner MLV

Experience Matters: Why Second Skin?

25+ Years
in business

3,500+
5-star reviews

Used By
Professional installers and DIY enthusiasts

Made in the USA
Headquarters in Charlotte, NC

Featured In
Redfin, Garage Gym Reviews, Family Handyman, Breaking Muscle

Quality Guarantee
Expert help with premium products

Need Help or Have Questions?

FAQ

How is soundproofing a room different from soundproofing just one wall?

Sound will always find the weakest path, so treating a single wall helps but may not fully isolate the space. See our guide on soundproofing a room for a complete approach.

Do acoustic panels help block sound between rooms?

No. If your office needs an acoustic treatment, panels control echo inside the room but do not stop sound from leaving it.

Is Green Glue enough on its own?

Green Glue works best at mid to high frequencies. For the most meaningful results, decoupling is necessary.

What about doors and flanking paths?

Walls are only one part of the system. You may also need to install a door seal kit to prevent sound leakage.

Are condos or townhouses different?

Yes. Structural limits and shared assemblies make soundproofing in a condo more restrictive and require careful method selection.

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How to Soundproof an Existing Wall

What You'll Learn (and Why It Matters)

By the End of This Guide, You’ll Be Able To:

Skill

Article Read Time

Build Time

Key Tools and Materials You'll Need

Key Tools

Key Materials

Before You Start: Choosing the Right Approach

Step-by-Step: How to Soundproof Existing Walls with RSIC-1® Retro

Recommended Solution: RSIC-1® Retro (Highest Performance Retrofit)

Step 1: Install RSIC-1® Retro Clips

Step 2: Snap in Hat Channel

Step 3: Install Drywall

Step 4: Seal the Perimeter

Step-by-Step: How to Soundproof Existing Walls with Green Glue + 5/8" Drywall

Alternative Solution: Green Glue + 5/8" Drywall

Step 1: Apply Green Glue to the new Drywall

Step 2: Screw in Drywall

Step 3: Seal the Perimeter

Step-by-Step: How to Soundproof Existing Walls with BlocknZorbe™

Alternative Solution: BlocknZorbe™ Sound Panels

Step 1: Attach Soundproof Panels

Step 2: Seal the Perimeter

Step-by-Step: How to Soundproof Existing Walls with Mass Loaded Vinyl + 5/8" Drywall

Alternative Solution: Mass Loaded Vinyl + 5/8" Drywall

Step 1: Map out Stud Locations

Step 2: Screw in Mass Loaded Vinyl

Step 3: Install Drywall

Step 4: Seal the Perimeter

Step-by-Step: How to Soundproof Existing Walls with Blown-In Insulation

Alternative Solution: Blown-In Insulation to Wall Cavity

Which Material / Which Approach Is Right For You?

Experience Matters: Why Second Skin?

25+ Years in business

3,500+ 5-star reviews

Used By Professional installers and DIY enthusiasts

Made in the USA Headquarters in Charlotte, NC

Featured In Redfin, Garage Gym Reviews, Family Handyman, Breaking Muscle

Quality Guarantee Expert help with premium products

Need Help or Have Questions?

FAQ

How is soundproofing a room different from soundproofing just one wall?

Do acoustic panels help block sound between rooms?

Is Green Glue enough on its own?

What about doors and flanking paths?

Are condos or townhouses different?

Have Questions?

Call

Fill Out

Helpful Guides You May Want Next

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25+ Years
in business

3,500+
5-star reviews

Used By
Professional installers and DIY enthusiasts

Made in the USA
Headquarters in Charlotte, NC

Featured In
Redfin, Garage Gym Reviews, Family Handyman, Breaking Muscle

Quality Guarantee
Expert help with premium products

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