Soundproofing plaster and myths about it: application technology with and without additional noise insulation

Plaster insulation is frequently promoted as an easy way to lower noise levels in buildings and residences. Many people think that by using this particular plaster on walls, undesirable noises can be considerably reduced, creating quieter, cozier environments. However, what proportion of this is real and what is merely fiction?

Soundproofing plaster is said to be effective in a number of ways, some of which are overstated or misinterpreted. Even though it has some advantages in terms of reducing noise, people looking for total soundproofing may find that using it alone is insufficient. Prior to utilizing this material, it is imperative to comprehend its true potential.

You will learn how to apply soundproofing plaster in this article, both with and without additional noise insulation. By the time it’s all over, you’ll know exactly what this plaster can do, when it’s best to use it, and what additional steps might be required to get the desired level of soundproofing.

What is sound and acoustic insulation of a room

The Greek word for "acoustics" means "hear" or "listening." This is the name of the scientific field that investigates the nature of sound. The definition of "isolation" is dividing something apart and making a barrier in its path. An apartment’s walls can be soundproofed to prevent sound waves from passing through. Sound absorption and reflection are the two strategies for stopping noise from propagating. The enclosing coating’s surface geometry serves as a unique "mirror" that reflects sound waves. Because of the enclosing structure’s multi-layered construction and material structure, the sound pressure level coming from outside can be diminished.

The primary materials with a porous soft structure for sound absorption are:

• polyurethane panels (foam rubber sheets are glued, coating thickness is up to 10 cm);
• foam;
• cork (rolled and sheet, if the diameter of the crumb is 3 mm, and the total thickness of the sheets is 8 – 10 mm, it can be a final sound-absorbing coating);
• fiberglass and mineral wool boards (board thickness >30 mm, require a frame and are covered with plasterboard or gypsum fiber boards);
• liquid soundproofing (a thick layer of the mixture applied to the plaster is covered with plasterboard or faced with decorative panels);
• acoustic plaster compositions.

• gypsum plasterboard or gypsum fiber boards;
• soundproofing decorative panels (cardboard frame with mineral filler backfill, such as quartz sand);
• layered soft fiberboard boards with polystyrene foam spacers (thickness 1 – 10 cm);
• soundproofing sandwich panels (ZIPS);
• wood fiber panels;
• soundproofing mixtures;
• high-density membranes.

Soundproofing under plaster refers to materials that are covered with plaster mortar after installation. Acoustic plasters (AP), also known as sound- or noise-absorbing compositions, are provided by manufacturers of soundproofing plaster compositions as a way to lower the amount of incoming noise.

Features of plaster

These plaster compositions have different sound-absorbing fillers than regular ones.

• monolithic soundproofing coating without joints;
• the structure of the coating must be dense without various delaminations and cracks (even micro), which are sound conductors;
• mandatory removal of metal beacons after plastering (monolized beacons become sound conductors);
• appearance as with conventional plasters;
• the possibility of tinting at will;
• maintainability;
• spraying is environmentally friendly;
• painting, especially with dense enamels, significantly reduces sound-absorbing properties;
• the top layer is not rubbed down (covered with a canvas or panels).

We provide the following technical details of perlite compositions as an example:

Strength of compression (kg/cm2)

Applying the soundproofing plaster composition’s layer over a wood chipboard or pumice concrete base (on a porous base) will increase the soundproofing plaster composition’s effectiveness.

Composition

The following binders are most frequently used as the foundation for soundproofing plaster mortars:

• gypsum;
• portland cement;
• slag portland cement;
• lime;
• caustic magnesite (in powder form – magnesia cement).

The compositions can also make use of their mixtures. To slow down the setting process, 1% by weight of lime-glue retarder is added to gypsum compositions.

The bulk density of sound-absorbing solutions ranges from 600 to 1200 kg/cubic meter because of a light porous filler made of porous granules:

• pumice (or pumice sand);
• perlite;
• expanded clay;
• slag;
• foamed glass.

Grain size: typically one fraction is used in the composition, up to 3–5 mm.

The most well-known remedies consist of soundproofing plaster with the following composition:

• acoustic APC: 1:3-4:1 (cement, pumice sand, water);
• Cement with pumice or vermiculite (granules size up to 3 mm) – 1 hour. cement, 4 h. filler (dry components are mixed and diluted with water, the cement plaster base increases adhesion and noise-absorbing properties, applied in a 25 mm layer without rubbing the surface);
• cement with slag 1:4 (fraction size 3-5 mm; applied to the cement plaster base);
• gypsum with sifted slag up to 2 mm in diameter (slag is mixed with gypsum milk, the solution is applied without rubbing on the primed base, the coating is water-fearing);
• acustolite – magnesite with pumice with a diameter of 1 – 2 mm (caustic magnesite (4.8 l) with particles up to 0.25 mm is mixed with pumice (19.2 l), hydrochloric acid is added to the mixture (strength 12 o, volume 6.4 l), mixed until uniformly moistened, applied even to an untreated base);
• cement with asbestos chips and sand 5 – 10 mm thick (1:2:2 up to 1:6:1, applied mechanically to preparatory cement-sand 1:2 layer 5 – 6 mm).

Commercially available ready-made soundproofing compounds contain extra ingredients. Occasionally, manufacturers will add aluminum powder, which increases the sound-absorbing properties by causing pores to form when the solution dries from the escaping gas.

Pros and cons

The following are the benefits of sound-absorbing plaster over other acoustic materials:

• ease and speed of application;
• seamlessness;
• undemanding to the evenness of the base;
• versatility (any, even complex shapes can be created);
• environmental friendliness.

It has benefits as a coating.

• vapor permeability, allowing the walls to breathe;
• low dead weight (does not place a heavy burden on foundations);
• repairability;
• additionally has insulating properties;
• fire resistance;

• is not a finishing coating;
• high cost (compared to conventional mineral compositions, but significantly lower than other soundproofing materials);
• the coating is not elastic and (like mineral) is afraid of vibrations.

Application area

For rooms that need to absorb a lot of sound, soundproof plaster is used.

Where are they most in demand?

• museums;
• theaters;
• cinemas, exhibition spaces;
• libraries;
• galleries;
• educational institutions;
• arts and leisure centers;
• sports facilities;
• conference halls;
• airports, train station buildings;
• in some types of production;
• office premises;
• medical institutions;
• psychological relief rooms;
• elite housing.

Plaster insulation is frequently promoted as an easy way to cut down on noise, but there are a lot of misconceptions about how effective it is. It’s not a miracle cure, though; how well it works mostly depends on how it’s applied and whether or not other soundproofing techniques, like insulation, are employed. This post will clarify common misconceptions about soundproofing plaster, examine the facts about it, and walk you through the proper application methods both with and without additional noise insulation.

How to apply

In terms of application methods, soundproofing solutions do not differ from other types. There is a difference only in the case of applying sound insulation to walls under plaster. In this case, the surface of the building structures is prepared specifically for it. Additional measures are also used to improve the performance of the acoustic coating. For example, a 10 mm cement primer from a 1:3 solution is pre-applied under soundproofing plaster.5 or 1:4 with the addition of lime dough up to 10%. Apply the mixture to the damp soil. The final layer of the solution is leveled with a float, but not rubbed. After drying, tighten with a cloth or grid.

Three layers of soundproof plaster are applied:

• preparation of walls;
• application of primer;
• installation of leveling beacons;
• a layer of splashing of a sour cream consistency (for a wooden base, its thickness is ~9 mm, for concrete and brick surfaces – 5 mm);
• leveling layer;
• fixing layer.

Preparation of the base

Strictly speaking, special base leveling is not necessary for the majority of soundproof plasters. Certain materials, like Akustat and Acoutex, need a flat base when applied thinly. In this instance, the wall is leveled prior to the application of plaster or gypsum plasterboard (gypsum plasterboard).

The surface is always cleared of any outdated, peeling wallpaper. Metal parts can be cleaned or coated with anti-corrosion agents. neutralizes biological damage foci, such as efflorescence. Get rid of oil stains. Brick walls have deeper masonry joints. Dust is removed from the base. If needed, apply two layers of primer.

Two techniques to increase sound absorption are the installation of a metal mesh (10 mm cells) and the application of 10 mm cement mortar mixed with sand.

Beacons are mounted on the base of curved walls and in situations where a thick coating is being applied. The foundation has dried thoroughly. adjacent surfaces, such as window sills and door frames. d.) taped shut using masking tape.

Tools

• grater;
• narrow spatula;
• rule;
• trowel/trowel;
• rule;
• maklovitsa;
• mixer;
• mixing container,
• stepladder or scaffolding;
• rags.

Preparation of the solution

The solution must be diluted and soundproofing plaster applied in an environment with a minimum temperature of +10 °C, a maximum temperature of +30 °C, and a maximum humidity of 60%. The actual cooking is done in phases:

1. A dry mixture is poured into a capacity of 30 – 40 l (be sure to use the entire volume from the package for kneading).
2. Pour the water of cool temperature in the volume indicated on the packaging.
3. Mix ~ 10 min.
4. Give the solution to "brew" for 5 – 8 minutes, and then mix.

Mixtures based on cement can last up to four hours.

Because they are suitable for shorter periods of time, gypsum compositions are prepared slightly differently.

Finishing work

Sealing and removing lighthouses

They begin with noise insulation if it is installed beneath the plastering coating:

1. Sound -insulating panels are glued on the wall or attached.
2. After which the joints are sealed and a sand-cement leveling layer is applied, the thickness of which depends on the curvature of the walls (optimally 10 – 12 mm).
3. Soundproofing plaster is applied to it in layers of ~ 15 mm. Each layer is leveled with a float. Layers are applied when the previous one dries. Manufacturers do not recommend making layers thicker, as this increases the potential for cracking. Total layer thickness ~ 40 mm. If you need to take a break from plastering, and the wall is not completely plastered, then a step 30 mm wide is made at the edge of the laid layer. After resuming work, they step on this step, applying fresh mortar. This avoids the appearance of a seam and the transmission of sound along it.
4. When the last layer of plaster has set, remove the beacons, and cover the grooves with acoustic mortar.
5. A layer of putty or decorative plaster can be applied over the acoustic coating. Textured plaster, which can be painted with water-based paints, is well suited.

When plasterboard sheets are used for wall soundproofing, gypsum solutions perform better as soundproofing plaster. Beacons vanish.

Myths, misconceptions and rules of use

Wall soundproof plaster is marketed as the solution to all noise problems. This is a marketing ploy. In fact, if everything is done properly, using ASH can help you reduce incoming noise levels by 8 dB, which is comparable to the effect of building a thick brick wall. Simultaneously, the room’s sound comfort improves by a third to a quarter. Installing acoustic structures is a must if you want to attain better outcomes. It is possible to add an external soundproof layer to a building in addition to its interior.

The second myth concerns flooring made of cork. It works best as impact noise insulation under parquet flooring or beneath a neighbor’s feet who lives above you in an apartment. Footsteps are muffled, but TV voices and sounds are not. That is to say, the cork coating’s only function in all other situations is heat insulation.

Only by thickening the sound-absorbing coating will the sound-absorbing effect be amplified. Consequently, it is optimal to use AS in conjunction with other techniques (soundproofing and sound-absorbing). The thickness of the structure should be at least 40–50 mm.

Popular manufacturers

Plasters that are soundproof are not a modern invention. After nearly a century of development, many businesses currently manufacture goods based on gypsum and cement binders.

Pl Group

The Moscow-based "PL Group" is the owner of the Paladium brand, which is used to manufacture dry building mixes. mixture for soundproofing Glass filler with foam is used to create palladium. It is adaptable and appropriate for both indoor and outdoor use. This mixture yields coatings that are durable for over a decade. Fire-resistant insulating material that is biodeterioration-resistant and simple to apply.

Ivsil

The company manufactures IVSIL TERMOSIL, a special (unmatched) mixture that insulates against heat and sound. Both mechanically and manually, a cement and foam glass mixture is applied. It has a long-lasting coating. In a single pass, a layer as thick as 30 mm is applied. Average amount of dry mixture used per square meter = 3–4 kg.

Favorit

Brand De Luxe is owned by "Favorit," a Russian company. Teplolux is a heat and sound insulation mixture that is inexpensive without sacrificing quality. It can be used in bathrooms and other damp areas because it is moisture-resistant. All-encompassing. can provide long-term protection for rooms and facades. withstands changes in temperature between -50 and +50 °C.

Knauf

The renowned German business Knauf is well-known for producing goods of the highest caliber. Mineral components are mixed into a gypsum base for Knauf AkustikPutz. universal in nature of work. Simple to lay and dependable for a long time. However, it is nearly impossible to locate this kind of plaster in a store!

Myth	Reality
Soundproofing plaster alone can block all noise	Soundproofing plaster reduces noise but cannot block all sound without additional insulation.
Thicker plaster equals better soundproofing	While thickness helps, the material composition and application method are more crucial for effective soundproofing.
Plaster can replace other soundproofing materials	Plaster works best in combination with other soundproofing materials, not as a standalone solution.
Soundproofing plaster is difficult to apply	Applying soundproofing plaster is similar to regular plastering but requires attention to detail for maximum effectiveness.
Additional insulation isn"t needed with soundproofing plaster	For optimal soundproofing, combining plaster with additional insulation is often necessary.

Plaster insulation can be a useful way to reduce noise in a variety of spaces, but it’s important to know its limitations as well as its possibilities. It is not a miracle cure that gets rid of all noise, even though it can successfully muffle some noises. The way soundproofing plaster is applied and the walls’ overall structure both affect how well it works.

It might be essential to combine soundproofing plaster with other noise-isolating materials for best results. This method improves the effectiveness of soundproofing, particularly in areas where silence is crucial or where noise levels are high. The right application method is also essential; improper application can cause even the best materials to perform below par.

In the end, soundproofing plaster is a useful instrument for reducing noise, but it should be utilized in conjunction with other tactics. It will assist you in creating a more comfortable and quiet living or working environment if you comprehend its function and combine it with other soundproofing techniques.

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