1. Before Installation: Essential Preparations Are a Must
Thorough Base Treatment: The installation surfaces (walls, floors, ceilings) must be flat, dry, free of dust and oil. Loose bases need reinforcement (e.g., wall cracks filled with sealant). In humid environments (such as bathrooms, basements), a moisture barrier must be applied first to prevent sound insulation materials from getting damp and moldy, which would affect their performance and service life.
Accurate Measurement + Reserved Allowance: Cut materials according to actual dimensions, with a 5-10mm allowance reserved (to avoid gaps due to undersized materials). The cut surfaces must be flat. Porous materials (such as sound insulation cotton) should be prevented from excessive extrusion and deformation (as this will block pores and reduce sound absorption/insulation capacity).
Materials Adapted to the Environment in Advance: Sound insulation cotton, damping sheets, and other materials need to be transported to the construction environment 24 hours in advance to adapt to the temperature and humidity, preventing gaps caused by thermal expansion and contraction after installation.
2. Installation by Location: Key Details Should Not Be Ignored
(1) Wall Sound Insulation
Avoid "Acoustic Bridge" Transmission: When installing keels, a 5-10mm gap must be maintained from the wall (or rubber pads placed), and direct contact between keels and walls/floors/ceilings is prohibited – otherwise, noise will be directly transmitted through the keels, offsetting the sound insulation effect.
Dense Filling Without Gaps: Sound insulation cotton must be "fully filled" without excessive compaction (especially porous sound-absorbing cotton). Corners, wire pipe perforations should be filled with small pieces of material and sealed with sealant around the edges.
Double-Layer Structure for Higher Efficiency: If conditions permit, adopt a "keel + sound insulation cotton + gypsum board" double-layer structure. The joints of gypsum boards should be staggered (to avoid sound leakage through straight joints), and the joint gaps should be sealed with sealant.
(2) Floor Sound Insulation
Dual Protection of Moisture Resistance + Shock Absorption: First lay a layer of PE moisture-proof membrane on the floor (with an overlap width ≥10cm), then lay sound insulation pads (such as XPE, EVA materials). The sound insulation pads must cover the entire floor, and turn up 5-10cm at the wall corners (to connect with the wall sound insulation layer).
Avoid Material Damage: When laying floors (tiles/wooden floors), sharp tools are prohibited from scratching the sound insulation pads; when installing wooden floors, the gaps between skirting boards and the floor must be filled with sealant to prevent noise transmission through the gaps.
(3) Door, Window, and Gap Sealing
Focus on Blocking "Sound Leakage Channels": The gaps between door/window frames and walls should be double-sealed with foam adhesive + sealant (filled with foam adhesive and sealed with sealant on the surface); install sound insulation sealing strips (silicone or EPDM material, suitable for gap size) between door/window sashes and frames; choose insulating laminated glass for glass (which has better sound insulation effect than ordinary insulating glass).
Hardware Accessories Should Not Be Neglected: Door and window hinges and locks must be installed firmly to avoid increased gaps due to loose doors and windows; sliding doors should be equipped with bottom sealing strips to reduce sound leakage through gaps during sliding.
(4) Pipeline Sound Insulation
Layered Wrapping + Firm Fixing: First wrap a layer of damping sheet around the pipeline surface (wrap tightly with an overlap ≥5cm), then wrap with sound insulation cotton, and finally fix with straps (spacing ≤30cm) to avoid loosening; materials suitable for pipeline bends and interfaces should be cut, and no gaps are allowed. The gaps where pipelines pass through walls/floor slabs must be filled with sealant.
3. After Construction: Acceptance and Protection Must Be In Place
Comprehensive Inspection + Effect Testing: After installation, visually inspect all joints, corners, and perforations to ensure they are completely sealed without looseness or gaps; the effect can be verified through simple self-testing (such as playing noise with doors and windows closed and comparing the decibel difference before and after installation). If there is still obvious noise, focus on checking for unsealed gaps or acoustic bridges.
There are many types of sound insulation materials, and each type has a different sound insulation principle. Different sound insulation materials need to be used according to different sound insulation requirements.
Polyester fiber cotton
Polyester fiber cotton is a safe and environmentally friendly sound insulation cotton. It is made of the same material as the clothes we wear, harmless and skin-friendly, and is often used for home sound insulation. When sound passes through polyester fiber cotton, it continuously reflects and transforms within the micropores, releasing sound energy in the form of heat energy.
Glass wool
Glass wool is a not very safe sound insulation material, often used in commercial places such as shopping malls and KTVs. Broken glass wool is very dangerous; the glass fibers can get stuck in the skin or be inhaled into the lungs. Therefore, protective measures must be taken when installing glass wool.
Rubber and plastic cotton
Rubber and plastic sound insulation cotton is mainly made by mixing rubber and plastic. This material has high flexibility and elasticity, and can effectively absorb and reduce the transmission of sound. It has a high density, good thermal insulation performance and sound insulation effect, so it is widely used in the construction industry.
Sound-absorbing cotton
The sound insulation effect of sound-absorbing cotton is not as good as the above-mentioned sound insulation cottons. Its main function is to reduce sound reverberation, thereby achieving better sound quality. Therefore, it is often used in places with high requirements for sound quality such as live broadcast rooms, studios, and vocal music rooms.
Yes, decorated houses can absolutely undergo sound insulation renovation—no need to tear down existing decor! Non-destructive or minimally invasive solutions target noise without disrupting your space. Here’s a concise guide:
1. Prioritize Sealing Noise Leakage Gaps (Low-Cost & Effective)
Most post-renovation noise comes from unsealed gaps. Install high-quality acoustic seals (silicone/EPDM rubber) around door frames, window sashes, and door bottoms (add a door sweep). Replace single-pane glass with double-glazed/laminated glass (no need to remove the entire frame). Fill gaps around electrical outlets, switch panels, pipes, and baseboards with acoustic foam or sealant—even 1mm gaps reduce insulation efficiency by 30%.
2. Wall Sound Insulation (Non-Destructive)
For neighbor voices/TV noise: Use adhesive-backed soundproof panels (polyester fiber/composite) that mount without drilling—decorative designs match decor. Hanging fabric-wrapped acoustic panels (removable, ideal for renters) reduce echo. For severe noise, professionals can install a "secondary wall" (furring strips + rubber pads + insulation + decorative panels) adding only 5-8cm thickness, no structural damage.
3. Floor Sound Insulation (Impact Noise)
For upstairs footsteps/furniture movement: Add XPE/EVA soundproof underlays when replacing flooring. For existing floors, use self-adhesive pads under furniture legs. Lay thick high-pile carpets/rugs—quick, non-destructive noise absorption.
4. Pipe Noise Reduction (Bathrooms/Kitchens)
Wrap accessible pipes (under sinks, corners) with acoustic damping sheets + sound-insulating cotton, secured with zip ties and sealed with tape—no cabinet/wall removal needed.
5. Ceiling Sound Insulation (Upstairs Noise)
Replace existing ceiling tiles with soundproof ones, or mount lightweight acoustic panels via adhesive/removable brackets. For suspended ceilings, add insulation between the ceiling and upper floor (professionals access via panels).
Noise is generated by vibrations and propagates through solids, liquids, and gases. Therefore, noise control can start with reducing vibrations and blocking propagation.
Sound is produced by vibrations, and the function of a shock absorber is to reduce the vibrations that cause noise, thereby achieving the purpose of reducing noise. Generally speaking, there are two types of shock absorbers: ceiling shock absorbers and wall shock absorbers.
Ceiling shock absorbers
Ceiling shock absorbers are installed inside the ceiling. Noises from upstairs, such as dragging stools, playing basketball, and running, will be absorbed by the shock absorbers, thereby reducing the noise. However, this type of shock absorber is relatively long and requires more floor height. If the floor height of the house is insufficient, installing a ceiling shock absorber will make the room feel relatively short.
Wall shock absorbers
Wall shock absorbers are installed on the wall. If your room is adjacent to someone else's room or an elevator room, it is recommended to install wall shock absorbers. Wall shock absorbers are relatively short; installing keels + shock absorbers + filled soundproof cotton + gypsum boards is approximately 9cm thick, which does not take up much space.
For materials relying on the "mass law" (e.g., mineral wool, glass wool), higher density does enhance blocking of mid-to-high frequency noise (e.g., voices, traffic). However, this effect plateaus: beyond a certain density (around 60-80kg/m³ for most materials), improvements become negligible, but the material grows heavier, harder to install, and more costly.
Material type and structure matter equally. Porous sound-absorbing materials (e.g., polyester fiber cotton) lose effectiveness if too dense—clogged pores can’t trap sound waves. Damping materials (e.g., pipeline damping sheets) rely on viscoelasticity, not just density; a medium-density option with good internal friction often outperforms rigid high-density alternatives. Composite structures (e.g., "sound-insulating cotton + damping layer + air gap") are far more effective than single high-density materials, especially for mixed-frequency noise.
Low-frequency noise (e.g., elevator vibrations, air conditioner hum) can’t be solved by density alone. It travels through structures, requiring damping properties or decoupling designs (e.g., floating floors) rather than just heavy materials. A dense concrete wall may still transmit low-frequency vibrations, while a lighter composite setup blocks them better.
Poor installation also negates high density. Gaps or cracks create "acoustic bridges," letting noise leak through—even the densest material fails if improperly sealed around doors, windows, or pipes. In short, density is a "necessary but not sufficient" condition. Choose medium-to-high density materials for air-borne noise, prioritize damping/composite structures for low-frequency noise, and ensure professional installation with proper sealing. Balance density with material type, application needs, and budget for the best results.
Sound insulation renovation typically reduces noise by 10–30 dB—a range that depends on factors like renovation scope, material quality, noise type, and construction precision. "Complete silence" (0 dB, no sound at all) is not achievable in real-world scenarios, but a "comfortably quiet" environment (35–45 dB, similar to a library or quiet bedroom) is fully attainable.