How much does soundproofing cost?

It depends on the method and the area. Budget approach (add a second layer of drywall with Green Glue to existing walls): $2-$5/sq ft (materials + labor). This is the best value — it adds significant soundproofing without major construction. Mid-range (insulation + resilient channel + double drywall with Green Glue): $4-$8/sq ft. Premium (isolation clips + hat channel + insulation + double drywall + Green Glue + sealed gaps): $6-$12/sq ft. Typical bedroom (all four walls + ceiling, ~400 sq ft of surface): DIY: $800-$2,000. Professional: $2,000-$5,000. Home theater or music room: $3,000-$15,000+ (requires the highest level of soundproofing, often including a room-within-a-room design). The most cost-effective single upgrade: replacing hollow-core doors with solid-core doors ($100-$300 each) + adding door sweeps and weatherstripping ($30-$80). This blocks the most sound for the least money.

What is the best soundproofing material?

There is no single best material. Effective soundproofing uses a combination of techniques. The most effective combination: insulation in the wall cavity (mineral wool/Rockwool is slightly better than fiberglass for sound), decoupling (isolation clips with hat channel, or resilient channel), mass (double layer of 5/8-inch drywall), damping (Green Glue between the drywall layers), and sealing (acoustical caulk on all edges, outlets, and penetrations). If you can only do ONE thing: add a second layer of 5/8-inch drywall with Green Glue to the existing wall. This adds both mass and damping, and it is the easiest to install (no need to remove existing drywall). Expected improvement: 5-10 STC points (noticeable reduction in speech and TV sound through the wall).

Does soundproofing actually work?

Yes, when done correctly. A standard interior wall (single drywall, no insulation) has an STC of 33-35. At STC 33: normal speech is easily heard through the wall. At STC 40: loud speech is audible but not intelligible. At STC 45: loud speech is faintly audible. At STC 50: loud speech cannot be heard. At STC 55+: most sounds are completely blocked. A well-executed soundproofing upgrade (insulation + decoupling + double drywall with Green Glue + sealed gaps) achieves STC 55-65. The most common reason soundproofing fails: gaps. Sound travels through the smallest openings. Unsealed electrical outlets, gaps around the door, HVAC ducts, and cracks in the wall allow sound to bypass even the best wall assembly. Sealing gaps is free-to-cheap and absolutely critical.

Can I soundproof an existing room without removing walls?

Yes, several methods work without removing existing drywall. Add a second layer of drywall with Green Glue: screw new 5/8-inch drywall over the existing wall with Green Glue sandwiched between. This adds mass and damping without tearing anything out. Cost: $2-$5/sq ft. Add mass-loaded vinyl (MLV) under the new drywall for even more mass. Replace hollow-core doors with solid-core doors and add door seals. Seal all gaps with acoustical caulk (around the perimeter of the wall, around electrical outlets, around baseboards). Add heavy curtains or acoustic panels (these help with echo and room acoustics but do NOT significantly reduce sound transmission through walls). For ceilings: add a second layer of drywall with resilient channel or isolation clips (does not require removing the existing ceiling drywall — the new layer attaches to the clips). These methods provide significant improvement (5-15 STC points) without the mess and cost of a full tear-out.

Article

Flooring

Soundproofing Guide: Materials, Methods & Cost

Lumberama Editorial Team, Soundproofing & Acoustic Treatment Specialists Aug 14, 2026 13 min read

How Sound Travels

Sound travels through your home in two ways.

Airborne sound: Voices, music, TV, and other sounds that travel through the air. These sounds pass through gaps, thin walls, and lightweight building materials.

Structure-borne (impact) sound: Footsteps, dropping objects, slamming doors, and vibrations from appliances. These sounds travel through the building structure itself (floors, walls, joists, studs). Effective soundproofing addresses both types. Sound is measured in STC (Sound Transmission Class) for airborne sound and IIC (Impact Insulation Class) for impact sound. Higher numbers mean better soundproofing. A standard interior wall (single layer of drywall on each side, no insulation) has an STC of 33-35. A wall with STC 50+ effectively blocks normal speech (you cannot hear a conversation through the wall).

Key Principles

Mass: Heavier materials block more sound. Adding more drywall (double-layer, or using 5/8-inch instead of 1/2-inch) increases mass and reduces sound transmission.

Decoupling: Breaking the physical connection between surfaces so vibrations cannot travel through. Examples: resilient channel (metal strips that attach drywall to studs with a gap), staggered stud walls (alternating studs so each side of drywall attaches to different studs), and isolation clips with hat channel. Decoupling is the most effective single technique for reducing structure-borne sound.

Absorption: Filling cavities with insulation absorbs sound energy and prevents resonance. Fiberglass or mineral wool (Rockwool) insulation in the wall cavity adds 5-8 STC points.

Damping: Converting sound energy into heat using viscoelastic compounds. Green Glue is the most common damping compound — applied between two layers of drywall, it reduces sound transmission by 5-9 STC points.

Sealing gaps: Sound travels through the smallest gaps (like water through a leak). Sealing electrical outlets, gaps around doors, cracks in walls, and HVAC penetrations is essential. A wall with a 1% gap in surface area loses 50% of its soundproofing value.

Methods by Location

Walls: Basic: add a second layer of 5/8-inch drywall with Green Glue between layers (STC improvement: 5-10 points, cost: $2-$4/sq ft). Good: add insulation in the cavity + double drywall with Green Glue (STC 45-50). Best: resilient channel or isolation clips + insulation + double drywall with Green Glue (STC 55-65). Seal all gaps with acoustical caulk.

Ceilings (floor/ceiling assembly): Basic: add insulation above (blow-in fiberglass or mineral wool batts). Good: resilient channel + second layer of drywall with Green Glue. Best: isolation clips (like Whisper Clips) + hat channel + double drywall with Green Glue + insulation in the joist cavity. For impact noise from above: add carpet or thick underlayment on the floor above (addresses footstep noise at the source).

Floors: Add carpet with thick pad (the easiest and most effective method for impact noise). For hard flooring: use an acoustic underlayment (mass-loaded vinyl or specialized foam) under the flooring material. For basement ceilings: insulate the joist cavity and add a decoupled drywall ceiling below.

Doors: Standard hollow-core interior doors have an STC of 15-20 (basically no soundproofing). Upgrade to solid-core doors (STC 30-35, cost: $100-$300 per door). Add door sweeps and weatherstripping to seal gaps around the perimeter. For maximum soundproofing: acoustic-rated doors (STC 45-55, cost: $500-$2,000+).

Windows: Add storm windows or secondary glazing panels (the air gap between the two panes significantly reduces sound). Upgrade to double-pane or triple-pane windows with laminated glass. Use heavy curtains or acoustic curtains as a supplemental measure.