What soundproofing materials are there? Technical characteristics and applications

If there is even an ordinary motorway near your house, you do not need to explain what noise is and how it affects the human nervous system. Even at its best, it will cause constant irritation and increased nervousness in people. It should be remembered that the noise level is measured in decibels (dB). According to the sanitary norms, at night this indicator should not exceed 30 dB, and in the daytime - 40 dB.

Achive this result will help a variety of soundproof materials, which are produced in a variety of modern industries.

A bit about soundproofing

The task of such materials is to protect the room from the penetration of unnecessary noise. Part of the sound is delayed and scattered, and some of it is reflected and leaves back into the external environment. The soundproofing qualities of the building itself are characterized primarily by the thickness of the walls. The thicker they are, the less likely that air vibrations will be able to transmit their energy. The ability to "eliminate noise" is indicated in the form of an index of sound insulation, which in ordinary residential buildings should be between 52 and 60 dB. Good ability has concrete and brick, a normal log and glued beam. Drywall, for example, does not absorb sound well, but has a decent reflective ability. By the way, about her. What soundproof materials are really well able to delay noise, and not just reflect it, creating a resonance already inside the room itself?

Sound absorption

Sound absorption is characterized precisely by the ability to completely neutralize, to extinguish wave vibrations. Compounds that possess such characteristics are granular, fibrous or cellular. As in the previous case, the sound-insulating characteristics of materials are estimated using an index called, as it is easy to guess, the sound absorption coefficient. The spectrum of this quantity is not too wide: from 0 to 1. If the sound is completely reflected, the value of the indicator is "0", if completely absorbed, "1". Quality materials for interior finishing of the house is distinguished by the sound-insulating ability of materials with an index of not less than 0.4.

The simplest sound-absorbing materials

The use of absorbent materials is not necessarily available only to professional builders. So, the simplest fiberglass, which can be purchased in almost any store of construction products, can successfully replace professional analogues. Even by putting a thick carpet on the floor of the room, you can get rid of the annoying echo. Even in cases where these options are not viable, there are ways to significantly "calm down" the environment: furniture with thick upholstery absorbs a lot of noise, as well as heavy curtains, as well as other types of drapery.

Of course, if possible, it is better to provide more effective ways to protect against noise. Acoustic screens with absorbing materials can be bought for use in those rooms where loud noises are in principle not allowed (baby rooms for babies). Most of these screens were designed by designers and engineers in such a way as not to "overlap" the overall style of housing design. In a word, this is an excellent soundproofing material for the walls in the apartment. Unfortunately, it can not be found in every construction supermarket, and the cost is not too humane.

Comfortable noise value. What threatens the increased level of sound?

Scientists have found that the most comfortable average human at 25 dB. If the value is lower, then there is a familiar "ringing" silence that causes a feeling of psychological discomfort. As a rule, in the city people easily tolerate a noise level of 60 dB, but with a permanent residence in the zone with a value of 90 dB, insomnia occurs, which quickly develops into neuroses that can result in serious mental disorders. At 100 dB or higher, there is a threat of complete hearing loss. To protect against such unfortunate consequences, just the same soundproof materials are used. They are soft, semi-rigid and hard.

Characteristics of a solid type

As a rule, they are made on the basis of granulated mineral wool, but there are exceptions. So, there are materials that include natural pumice, "foamed" perlite, vermiculite. Their sound absorption coefficient is 0.5. The mass of such materials should not exceed 300-400 kg / m ³ .

Soft varieties

Again, they are made on the basis of all the same mineral wool, as well as fiberglass. However, technical varieties of ordinary cotton wool are much more often used, felting is also very popular. For these materials, the sound absorption coefficient can range from 0.7 to 0.95. Of course, they are much lighter than the previous species: their mass does not exceed 70 kg / m ³ .

Semi-rigid variety

In this case we mean sound-insulating materials for the apartment, made of glass wool or mineral fiber, and also of synthetic materials. For example, in this capacity, polyurethane foam is often used. Semi-rigid varieties also have a sufficiently high coefficient of sound absorption, which can vary from 0.5 to 0.75. The weight can reach 130 kg / m ³ , but more often does not exceed 80 kg / m ³ . Thus, in most cases it is recommended to use soft varieties which, with a minimum mass, have an excellent sound absorption coefficient.

How to choose the right material for living?

However, the choice of the "right" material in many ways also depends on what kind of sounds interfere with being in the room. So, the work of electrical appliances creates so-called air noise (vacuum cleaners, hairdryers, computers). If we are talking about walking, various kinds of construction work and so on, noise of impact type is implied. In our conditions, it is also often the case that a house built without using normal sound-insulating materials and assembled on a rigid frame itself turns into one large source of sound pollution. In this case we are talking about structural noise.

Sound-insulating materials with cellular structure (pumice, expanded polystyrene) perfectly cope with shock loads. Air noise, the most characteristic for most residential premises, is perfectly extinguished with the help of fibrous plates or their analogs. Alas, but with structural disruptions can be fought, only after the analysis of the main structural elements and the use of special pads with good soundproofing qualities.

Eliminate the air noises

It should be noted that the main characteristic for materials that have the ability to absorb airborne noise is the so-called sound absorption index (Rw), which is expressed in decibels. Remember: in order not to hear the speech of the household behind the wall of the room, it is important that the soundproofing properties of the materials (used in the construction of the partition) be equal to a coefficient of at least 50 dB. We have already spoken about the coefficient of sound absorption: the closer it is to unity, the better. For residential rooms, this indicator should be at least 0.5.

The most reliable way to protect against unnecessary noise is to install dense and massive interroom overlapping. In this case, foam concrete blocks and concrete with inclusions of a sufficient volume of expanded clay were the best ones. It is important that the walls were really a monolithic structure. The presence of any slots or holes is not allowed. It should be remembered that different soundproofing materials for walls can be used in one design provided a strong and monolithic connection between them. This is achieved with a quality solution. "Canonical" example - a wall made of foam block, separated by facing brick or artificial and / or natural stone.

It is important, however, to take into account the fact that the erection of such structures in an already occupied building is an extremely difficult and nontrivial task. In addition, if the house itself is built of not very high-quality materials, such a measure will reduce the noise by only 10-15 dB, which is not enough for normal sound insulation.

It is much easier and cheaper to make a partition based on sufficiently strong and rigid structures using different types of soundproofing. If you compare soundproof materials in this case, then you will not see much difference even with cork flooring ...

In this case, a rigid foundation can be not only a brick or foam block, but even a regular drywall on the basis of a wooden beam, for which a dried tree was used to a proper degree. The higher the density, the better the sound-insulating capacity of the material. Of course, the layer of soft materials will play the main role in arresting noise. As we already said, in residential premises it is most expedient to use fibrous varieties, like mineral wool plates or fiberglass: they most effectively absorb air noise.

It should be remembered that in all cases the effective thickness of the partition should not be less than 50 mm. And further. At least 50% of the entire internal volume of the partition must be left on the soundproofing materials for the walls, because otherwise you can not get high efficiency. And now we will discuss specific varieties.

Glass wool

It is made of ordinary fiberglass. Its main characteristic is high strength, as well as elasticity and vibration resistance. Many soundproofing materials for the floor are made on the basis of extruded glass wool. Its characteristics are due to the fact that between the fibers there is a large number of air layers. Glass wool has many positive qualities: it is absolutely resistant to even open flames, has a very low weight, does not absorb moisture with excellent vapor permeability. In addition, cotton wool is chemically passive and does not cause corrosion in the metals with which it contacts. This is very important in this case, as many soundproof materials for walls are made on its basis. When repairing an apartment with it, it is important to remember only that the ingress of the smallest particles of glass wool into the respiratory system is highly undesirable, and therefore a good respirator should be used.

Mineral wool

Perhaps, it is known to every builder. It can be made from melts (silicate) rocks, as well as from slag, which is a waste of metallurgical industries. As in the previous case, the material does not respond to open flames, nor does it cause corrosion of the metal structures with which it contacts. Excellent ability to sound absorption due to the presence in its composition of a huge number of fibers, located in a completely chaotic, intertwined form.

Important note

Do not confuse mineral wool and fiberglass, as the characteristics of their fibers are different. At glass wool its length is not less than 5 cm, while in mineral fiber this figure does not exceed 1.5 cm. In addition, the first material (mineral wool) is much lighter, and its cost is somewhat lower. In particularly noisy rooms, it is often necessary to arrange a so-called acoustic ceiling: the reflecting elements will reflect excess sound, while soft materials absorb it effectively. The latter are placed in the space between the "native" ceiling and the outer layer of the acoustic coating.

Production of a multilayer panel

To simplify the work, take the finished elements of the system ZIPS. They can be used as an effective sound insulation of single-layer walls made of hard materials (brick or concrete). Structurally, such panels are very simple, since they consist of sandwich panels and covering material in the form of plasterboard. The "sandwich" itself consists of all the same drywall, which is interleaved with layers of mineral wool or fiberglass. It is important that special models with different thicknesses of "active material" can be selected for different rooms. In particular, for this type of make some soundproof materials for doors.

The advantage of such panels is that they, without a metal frame, have extremely low weight and can be fastened to the wall with conventional screws of suitable length. Note that between the load-bearing wall or even a partition it is advisable to place a special pad for soundproofing. Unlike previous materials, ZIPS is classified as poorly combustible, which limits the use of panels in baths and other rooms where there is a possibility of contact with an open flame.

Depending on the model, the thickness of such material can reach 13 centimeters. With this index, the soundproofing index is 18 dB. Thus, when the ZIPS is hung on such a thickness on the wall of a typical living room, the degree of soundproofing can reach 63-65 dB. Take into account: the use of such soundproof materials for walls during the repair of an apartment is possible only in the case of sufficient strength of load-bearing structures, since the mass of a square meter of ZIPS can reach 21 kg, or even higher.

How to protect yourself from shock noise?

In this case it is necessary to use designs that could repel and scatter sound waves, rather than absorb them. For this purpose, porous, resilient materials are suitable. Most often used option with special pads, which are laid during the installation of the finishing floor.

Cork lining

A unique natural material that is not affected by mold, fire, fungi and rodents. It is very inert in chemical terms, completely safe for any type of metal structures. The service life may exceed 40 years. The most qualitative varieties can reduce the level of impact noise by just 12 dB. Alas, but the cost at times crosses out all the merits of the material, since for a square meter ask for five or six dollars. With the current course, this is a bit expensive ... If not for this circumstance, the cork floors could be described as "the best soundproof materials".

Polyethylene foam

More "budget" version of protection against impact noise. Foamed polyethylene has a density of 20 to 80 kg / m ³ , which makes it possible to use it in almost all types of living quarters. It has several varieties:

• Uncoated. Molecules of the substance are not connected with each other by chemical bonds. The cheapest version, allows you to reduce noise levels by three to four decibels.
• Physically sewn. Some of the molecules form a fairly dense structure. Due to this, the soundproofing properties of this variety are replaced above (allows to reduce noise by five to six decibels). Based on this type, some soundproofing materials for the ceiling are made.
• Chemically crosslinked. Molecules have a strong chemical bond with each other. Due to this, the material has indicators that are only slightly inferior to those for the cork lining.

Regardless of the type of polyethylene is well used in the installation of concrete screed, it is placed under the parquet board and laminate. In some cases, it can be used to strengthen joints. Physically strong, resistant to the action of many chemicals. Flammable, and therefore should not be used in those rooms where there is an open fire. Under the action of ultraviolet radiation rapidly loses its protective properties. It is undesirable to cover such a substrate in the presence of the premises, since under strong mechanical loads it wears out quickly. Do not let the moisture, which in some cases creates the prerequisites for the development of mold. Despite this, many sound-proof materials for the floor (lining) are made on its basis, since the cost of polyethylene is very low.