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Exterior and interior wall soundproofing is essential for controlling noise in a home. Sound is a vibration that travels through the air or passes through materials, such as the materials that make up the walls of your home. One strategy for wall soundproofing is to isolate or separate the two sides of a wall so vibrations from the outside are not transferred inside. Separation strategies for timber-framed homes include a stepped stud design, double stud walls, or other stud placement methods that limit sound vibration from getting through the walls. Also, soundproofing inside wood-framed walls absorbs the sound vibrations created by air in the wall cavity, and noise dampening products can be applied between the drywall layers to absorb the irritating vibrations.
Most communities have building codes that require a minimum amount of soundproofing on a home’s exterior walls and ceiling. Wall soundproofing is not common, but offers homeowners some energy-saving and sound-damping benefits. The best time to insulate all walls is during new construction, but it is possible to add soundproofing to existing walls without tearing the drywall.
Considering the need for soundproofing a wall today, it is important to reconsider the original standard of acoustic sound transmission class (STC) wall and start considering increasing the transmission loss by 20 dB ~ 30 dB or more to ensure a high quality living environment. Over the years, many technologies have been used for wall soundproofing or soundproofing existing walls through residential and commercial buildings. Most of the wall soundproofing methods require unusual or difficult construction techniques, and the installer may not be able to follow these techniques correctly. With the development of technology on how to use soundproof walls, more and more new materials, the technology of special-shaped building can be restored to the standard STC level for single wood or steel stud construction.
Mass loaded vinyl (Heavy sound barrier) is a safe, non-toxic acoustic insulation for wall material designed for use as a soft mass suspension in a variety of soundproofing applications. Soundproofing barrier is a low cost alternative to lead cladding noise insulation for walls. Specially designed mass loaded vinyl sound barriers are provided at a density of 4 kg / m².
Wall soundproofing can be defined as an exterior structure designed to protect the inhabitants of sensitive land use areas from noise pollution. Sound barriers are the most effective methods of reducing road, rail and industrial noise sources, other than the cessation of welding activity or the use of source controls.
What is Sound Transmission Class (STC)
It is an industry standard unit of measurement for interior wall insulation materials such as heavy sound barriers for walls, ceilings or flooring components and is known as sound transmission class (STC). Standard tests at certified independent soundproofing laboratories measure transmission losses between the noise source and the target room. The measuring range is from 125 Hz ~ 4000 Hz of six frequency points. The difference between the two chambers is the transmission loss. Quality soundproofing for walls is STC 26, which allows you to get effective soundproofing for your home or office.
Wall soundproofing combines mass, insulation, absorption and damping to achieve optimal application for sound reduction results. Barrier soundproofing for walls increases mass with minimal thickness. The soundproofing barrier is usually embedded behind solid soundproof panels, finished wall, floor or ceiling material.
Modern building applications are faster and more convenient than lathes and plasters of the past, but they are not soundproof. Sound Transmission Class (STC) is a rating system that defines how well different products and building applications work at blocking sound. Values represent ideal laboratory conditions. So real life applications will be lower. Every wall is different, as plumbing and electricity provide noise paths for the sounds in the walls.
STC is still a useful way to compare products and applications. A typical 2 x 4 wood stud wall with 1/2 inch drywall on both sides has an STC rating of 33 or 34. However, it can be different depending on the high, mid and low range sound frequencies. During testing, a noise or frequency is generated on one side of the wall and a sound meter on the other side of the wall records the sound level entering the space adjacent to the wall. The difference is calculated to determine the transmission loss reflected in the STC rating. An STC rating of 40 represents a quiet home. However, the International Building Code recommends a minimum of 50 STC for walls, floors and ceilings. They also increase the minimum recommendation to 52 for bedrooms and 56 degrees for bathrooms, kitchens and living rooms.
Adding sound-rated products to an existing wall or between walls or using improved building practices will increase the STC rating.
Basic Principles of Wall Soundproofing
Identifying the type of noise bothering you is the first step. The next step is to determine how to reduce or prevent that sound or vibration from going in and out of any place.
Adding Mass; increasing the mass reduces the amount of sound that can penetrate a wall or obstacle. Adding a 5/8 inch layer of gypsum to an existing 1/2 inch drywall wall will only increase the transmission loss by approximately 3 dB.
Absorbation; The denser the material, the better it absorbs sound. MDF (medium density fibreboard), Mass Loaded Vinyl (MLV, Heavy Sound Barrier) and drywall have better STC ratings than regular insulation and are denser. Installing fiberglass or mineral wool in wall cavities will increase their degree of absorption.
Transmission; Conduction is the passing of sound through wall and floor materials. Drywall nailed or screwed to wooden 2 x 4 studs will be made to the adjacent space or room through attached structures. Decomposition, increased mass or absorption will reduce transmission.
Mechanical Separation (Decoupling); Separation is currently the best building practice for preventing or reducing sound transmission through walls, ceilings and floors. Use of; Double wall construction of soundproofing clips and ducts are two effective ways to stop the movement of flanking and impact noise.
Resonance; Noise or pulse frequencies (usually low frequencies) that vibrate a wall will resonate even through an insulated decoupled wall. The use of sound absorbing products will help reduce vibration resonance with barriers.
Note: Wall soundproofing is a multi-step process. The more sound paths are blocked or reduced, the better the soundproofing effect is achieved.
Separation Description
During your research on wall soundproofing, you have definitely come across the term decoupling (separation). Decoupling means mechanically separating the two sides of the wall to make it harder for sound to pass through the wall. A simple example of separating two sheets of drywall.
Here we present a simple outline showing how wood nails join the traditional wall and how products such as flexible duct or flexible sound clips can separate it and increase performance.
The rigidity of wood studs connects the two sides of a traditional wall. As a result, sound can easily pass from one side to the studs to the other. Sound can pass through such walls without going through air and insulation, so insulation has only a limited effect on a single wood stud wall.
By including a flexible separation assembly, sound trying to get through the structure to the other side is prevented and performance can be improved. Since sound cannot easily pass through the structure, it must pass through the air gap and the wall soundproofing is much more effective.
Internal Wall Soundproofing
Soundproofing can be done without spoiling the general appearance of your room. Wall soundproofing often comes into play when you want to protect a bedroom from outside noise. Another example is in a theater room where you might want to keep the noise inside. If you don’t want the room to look like a recording studio, the same basic procedure is used in all cases. The contractor can complete this project if he or she has a basic working knowledge of drywall and electrical. There are many methods of soundproofing an existing wall, but it depends on the room’s use.
To choose the right soundproofing material, you need to consider whether you want to block or absorb sound. Some of these materials help prevent sound from passing through walls, ceilings or floors, while other materials help absorb sound as it hits these surfaces. When sound is blocked, it is prevented from entering or escaping the room. When sound is absorbed, it often becomes muffled, limiting sound penetration. A dense material is often needed to block out sounds.
External Wall Soundproofing
Exterior noise control products are important in construction areas, airports, highways, industrial areas, or in applications where a noisy environment will cause noise pollution. A range of exterior wall soundproofing products are available to suit all outdoor applications.
To meet noise reduction requirements, flexible barriers and absorbers come from many types of materials such as porous expanded polypropylene, polyethylene, fiberglass or metal, making it possible to create a cost-effective and easy-to-install system. If a home requires permanent noise control solutions, installing a reusable sound barrier/absorber for fencing improves conditions for residents and surrounding areas. Products such as exterior acoustic wall panels are resistant to harsh environmental conditions and mold.
For those of us who don’t have cavity walls to fill, a mineral wool exterior wall insulation system has tremendous acoustic benefits. The open pore structure of stone wool allows sound waves to pass through the fibers within the material as vibrations in trapped air molecules and eventually disperse as heat energy. Ideal for reducing external noise. Meanwhile, EPS external isolation systems are more suitable for blocking higher frequency sounds such as noisy neighbors.
