Soundproofing in the apartment: walls, partitions, floor, ceiling

In modern construction, there is a clear tendency to reduce the weight of structures. This reduces the cost of the foundation, but negatively affects the sound insulation of the premises. Construction campaigns comply with modern norms, but they do not correspond to a person’s ideas about a comfortable life. After all, not everyone is interested in hearing what the neighbors are doing. Even less like that what you said can be “documented” in the next apartment. So modern norms contribute to the openness of modern society. And this is far from encouraging. That is why soundproofing in an apartment is a concern not only for those who live in old panel and brick houses, but also in new buildings. 

How to soundproof a wall from neighbors

If it is necessary to significantly reduce the level of noise that passes through the wall, a number of measures are necessary. First of all, it is necessary to repair cracks, potholes and cracks on the wall. Sound is transmitted through the smallest cavities, so it is necessary to achieve complete tightness. After that, it is necessary to carefully close up the pipes passing through the walls and other communications, if any. In this case, mounting foam should be used only in extreme cases – it practically does not delay sounds. Better – any plaster composition.

If there are switches or sockets on the wall, it is also better to seal up the cavities behind the sockets, and use a porous blown material for filling – mineral wool of small and medium density. This is only a preparatory stage, but already carrying out all these activities can significantly improve the sound insulation in the apartment.

capital solution

If the noise level is very high, you will have to do additional soundproofing. To do this, at some distance from the main wall (at least 10-15 mm), a partition is placed (from guides and profiles for drywall or wood), sheathed with plasterboard or gypsum-fiber sheets (GKL or GVL). The space between the posts is filled with special sound-absorbing or ordinary mineral wool. Installing such an additional wall can reduce the noise level by 62 times (depending on the selected materials and compliance with the technology). If you want the sound insulation in the apartment to improve significantly, you must adhere to certain rules when arranging it:

• An additional wall should not be connected to the main one. All racks are attached only to the floor and the flow, and special vibration-damping pads are placed under them (SilentLayer tape, SilentJoint pads, Vibrostek-V300 vibration-insulating layer). It is possible to use special guides such as Vibrofix Liner, in which fastening with vibration-acoustic protection is already provided. When attaching to the ceiling, not ordinary suspensions are used, but vibration-damping (anti-vibration) ones. The cost of these materials is high, but without their use you will not achieve good results.
  

• The space between the racks without slots and gaps is filled with special soundproof mats or ordinary mineral wool from a well-known manufacturer with known soundproofing characteristics (should be specified in the technical parameters). The fact is that heat-insulating mineral wool of the same density and thickness, but from different manufacturers, have very different sound absorption characteristics. This is not their main purpose, because few small producers pay attention to it. Only well-known brands test their products also for this parameter. Will there be a difference in sound insulation when using special materials? Of course, but it is not as critical as the difference in price. If the question of price is not worth it, of course, it is better to use special materials.
• GKL or GVL sheathing is standard. It is possible in one, but better – in two layers with a run-up (not a coincidence) of the seams.

You can further improve the soundproofing properties of this wall by laying a layer of GKL and GVL. They have similar characteristics, but there are still differences. So soundproofing in the apartment will be even better.

Yes! Another point: instead of metal profiles, you can use wooden bars of a suitable section (50 mm in one of the sections for laying soundproofing material).

Is it possible to do without drywall

The design described in the previous paragraph is effective, but takes up too much space – about 10 cm. This is far from always acceptable. There are ways to improve soundproofing in an apartment, but require less space. The bad news is that you won’t be able to achieve the same degree of soundproofing. The good thing is that you can significantly increase noise absorption, bringing it to quite comfortable. We will use new materials of small thickness, but with good soundproofing properties.

Not so long ago, heat and sound insulating plates ISOPLAAT (Izoplat) appeared on the market. This is one of the varieties of fiberboard of considerable thickness. There are plates with a thickness of 12 mm and 25 mm (size 2700 * 1200 mm). They are made from wood waste ground into flour, which is pressed under high pressure. The process releases a natural adhesive found in wood fibers. It also serves as a binder. Manufacturers claim that a 12 mm thick slab has a sound insulation coefficient of -23 dB, and 25 mm -25 dB.

Reducing the noise level by 10 dB is perceived by our ear as a decrease in audibility by about 2 times. That is, when using Isoplat with a thickness of 12 mm, it will be possible to reduce the sound load by about 4 times. For most cases this is sufficient.

Mounting method

How to mount ISOPLAAT? On prepared walls (with patched potholes and crevices, relatively flat, etc.) on one of the compositions:

• Adhesive used for fastening thermal insulation, drywall or gypsum-based. It is applied along the perimeter of the sheet with a strip of at least 3 cm thick, then in the central part with dots in increments of 30 cm.
• Mounting polyurethane foam in a cylinder. It is also applied around the perimeter, and in the central part – with a snake.
  

The board is smooth on one side and rough on the other. The adhesive is applied to the rough side. Having installed and pressed the sheet to the wall, it is additionally fixed with self-tapping screws (with flat caps). The holes remaining after the hole are covered with putty.

Preparation for finishing

The surface of soundproofing boards can be puttied. In order to apply a minimum layer of putty, it is advisable to chamfer about 3 mm at the edges of the plates, putty the joints after installation, glue them with a mesh or special tape. After the putty has dried, you can mount the finish.

Under the wallpaper, you can only seal the seams, without puttying the entire surface. But in this case, there will be a large consumption of wallpaper glue, since this material absorbs water well. But at the same time, it does not warp, does not change its structure when wet and dry. Also, this material is breathable. That is, it also serves as a regulator of the microclimate in the room. And this is in addition to insulation and soundproofing. It turns out that soundproofing in an apartment with the help of ISOPLAAT heat and sound insulating boards is a good choice.

What else to pay attention to

As mentioned above, sound passes through the smallest cracks. Therefore, when installing profiles or wooden bars, when filling a soundproof partition with sound-absorbing material, everything must be laid very tightly so that there are not even minimal gaps. It is necessary to achieve tightness. It is easier to do this using acoustic sealant. They coat all joints, which significantly improves performance.

Another important point: to improve soundproofing characteristics

Frameless soundproofing with ZIPS boards

When using special panels, soundproofing in an apartment can also be done without erecting a frame. These panels consist of GVL (gypsum fiber sheets) to which a layer of sound-absorbing material (basalt or glass wool with certain characteristics) is attached. The plates are connected to each other according to the tongue-and-groove principle, so the installation is simple. Vibration isolation nodes are built into each panel, through which they are attached to the base wall. This method of attachment allows you to achieve good results: a certain level of “damping” of vibration is built in. At the moment, panels with a thickness of 40 mm to 120 mm are on sale.

When mounted on a wall, ZIPS do not have a rigid connection with the floor, ceiling and adjoining walls. A vibration-insulating pad (of the Vibrostek-M type) is placed under the plates in two layers. All joints are coated with a non-hardening sealant (soundproof silicone).

Sound insulation of walls with vibroacoustic plates involves subsequent plasterboard cladding. It is also better to seal its joints with a special sealant, and putty on top, then glue the finish.

How not to soundproof walls

Often you can find recommendations to use foam plastic or polyurethane foam as soundproofing boards. This is not worth doing. It has good thermal insulation properties, but it works very poorly as sound insulation. After you stick it on the walls, it may turn out that the situation has become worse – you now hear speech behind the wall more clearly. This is all due to the soundproofing characteristics of the foam plastic – under certain conditions (no one has yet been able to formulate exactly) there is a significant dip in the characteristics at frequencies characteristic of speech. In this case, the sound insulation in the apartment will only worsen. You will have to remove everything and start over.

The graph shows two curves. Dotted line – soundproofing characteristics of the plastered wall, black line – if foam is laid under the plaster. It saves well from very low (less than 100 Hz) and very high (more than 2000 Hz) frequencies, but the entire conversational spectrum is “failed”.

The only place where polystyrene foam can be used as sound insulation is in a floating floor screed. In this case, it suppresses impact noise well.

Important! The above is true if the foam is glued from the inside. Its use outside as a heat-insulating material usually has a positive effect on the sound insulation of rooms. That is, foam can be used to reduce the level of noise coming from the street.

Sound insulation of the ceiling

In addition to the noises that come through the walls, neighbors from above often disturb – steps, creaking floorboards, etc. interfere with sleep. The way out in this case is to make a suspended plasterboard ceiling, but not simple, but on special vibration-damping suspensions. Why? Because sounds are transmitted through vibrations, and stomp – especially. If you use the usual rigid mount for plasterboard to the ceiling, there will be no effect, the sound insulation of the ceiling will not improve, even if the space between the main and suspended ceilings is filled with sound-absorbing material. Vibrations will be transmitted through suspensions and spread by drywall. Therefore, it is necessary to use special suspensions with a vibration damping gasket. For example, Vibrofix SP and Vibrofix P.

The use of these hangers reduces the level of noise penetrating through the ceiling by 18 dB with Vibrofix P and 25 dB with Vibrofix SP. The soundproofing of the ceiling made with their use will cut off not only shock noises, but also airborne ones – speech, etc. (if you fill the space with a layer of mineral wool).

To save money, you can use conventional suspensions, but fix them to the ceiling through foamed thin soundproof materials (Knauf Dichtunsband), but better – staple fiberglass (Vibrostek, folding it in two layers). The fact is that foamed materials are crushed, lose their properties, and fiberglass stably keeps its characteristics. If you are afraid of fiberglass dust flying in the air, do not. The design must be airtight in order for it to be effective.

Since one of the requirements of a good soundproofing structure is the presence of a massive outer layer, it is advisable to hem with two layers of gypsum plasterboard with a seam spacing and sealing the seams with sealant on each of them. But again, the combination is better – GVL + GKL. If the sounds are very loud, a soundproof membrane can be placed between them.

For soundproofing the ceiling in the apartment, you can use basalt or fiberglass mats. If possible – special soundproof ones; if not, choose one of the normal brands (more on this below).

There is one more point: it is necessary to seal the joints not with putty, but with soundproof acoustic sealant. It does not harden and does not transmit vibrations. If you make a false ceiling according to these rules, the sound insulation in the apartment will improve significantly.

What to do if you want to make a stretch ceiling? The same, but without finishing. If there are noises from above, but not very strong, you can try to get by with Isoplat, but again: the noise reduction will not be so significant.

Floor Soundproofing

In order for the soundproofing in the apartment to be complete, more measures are taken to soundproof the floor. Two goals are pursued here: as little as possible to interfere with neighbors from below and reduce or remove the reflective effect of hard flooring (laminate, parquet).

If during the repair process the floor is leveled with a screed, then a layer of expanded polystyrene can be laid in its thickness. In addition to thermal insulation (important when installing a warm floor), it will also protect against impact noise. If you do not need thermal insulation, it is better to use thin foam materials. By soundproofing the floor, they will give the same effect as 5 cm foam.

In any case, when installing a floating screed, care must be taken to isolate the slab from the walls so that vibrations are not transmitted. To do this, a special vibration damping tape is rolled around the perimeter, but you can cut the same material that you put into the screed into strips 10-15 cm wide and roll it along the walls. After the screed has gained at least half the strength, the excess tape can be cut off.

If the floor is relatively flat, it is leveled by laying plywood (in two layers, seams in a run, seams, and on top there is a substrate under the laminate and the coating itself. With this method of laying, the floor turns out to be quite “boomy” and your movements are clearly audible to the neighbors from below. To reduce effect, it is recommended to use a special soundproofing substrate (for example, ACUFLEX) or cork.Just also note that these materials will remove impact noise and make it not so “boomy.” You will not achieve complete soundproofing of the floor with this.

To get the best effect, all the same soundproofing boards are laid under the plywood – the Rockwool or Max Forte Shumoizol brands are suitable (smaller thickness with better performance). Top – two layers of plywood or GVL + plywood. The sheets are stacked in a run-up, fastened with self-tapping screws. Along the perimeter, do not forget to lay an edge tape (sound-vibration-damping) or cut material with similar characteristics. In this case, the soundproofing of the floor will cut off not only impact noise, but also conversations, and you will not hear the neighbors from below, nor they you.

Soundproofing in an apartment: how to choose materials

There are two types of materials that reduce the level of noise in the apartment: for sound insulation and sound absorption. Materials for sound insulation reduce the level of noise when passing through them, for sound absorption – reduce the level of the reflected signal. In order for the room not to be “boomy”, sound absorption is required, in order not to hear the neighbors – sound insulation, but the best results are achieved using both types of materials.

When soundproofing according to traditional schemes, sound-absorbing materials are usually mineral wool – basalt or fiberglass with a density of 35-40 kg / m3. It is they who have optimal characteristics – they scatter sound waves characteristic of speech in their thickness. Rigid enclosing materials are used as sound absorption – GVL, GKL, plywood, OSB. They can all be used, as they have approximately the same sound reflection characteristics, but two layers of different materials work better – the sound is more attenuated when passing through layers of different densities.

A little about whether it is worth using soundproof mineral wool. When using it, the sound insulation characteristics increase by 2-5 dB. In some cases this is important, in others it can be neglected. Especially if you look at the price: it is 2-3 times higher than that of ordinary mineral wool of this density. So if there is a need to save money, you can choose from normal brands of ordinary basalt or mineral wool. The characteristics of some of them are shown in the table above, and some common grades of specialty materials are shown in another table – below.

As you can see, it is quite possible to pick up basalt wool, which is close in characteristics to specialized ones.

A few words about the use of various thin materials – films, foamed, metallized and others. They cannot be used as protection against airborne noise (speech that we hear through fences). They almost never work. They can reduce impact noise a bit, but you’ll still hear your neighbors talking just as clearly (if you’re lucky, it’s a tad quieter).

If you want the sound insulation in the apartment to be good, you definitely should not save on vibration decoupling from the walls and ceiling (when organizing frame sound insulation). The fact that it is worth laying soundproof gaskets under the profiles has already been said, as well as the use of vibration damping suspensions. But it is also very desirable to mount the racks also not rigidly, but using SilentJoint – a vibration-decoupling mount, which gives an additional improvement in performance. These are gaskets made of special material Sylomer. By the way, it can be used as linings for vibro-sound decoupling instead of these mounts, but it is unlikely to be cheaper. Another question is if you do not find such mounts. Then “Silomer” is the best way out.