What is stone wool and what is it for?

Stone wool is used to insulate facades and interior walls of premises. It is a durable building material of natural origin. Before use, the volcanic rock is treated appropriately, then the layers are formed from it, which are laid on the surface and fixed. Stone wool has many advantages over other similar materials, while its price is affordable.

The origin of stone wool

Volcanic rock - basalt - is thrown to the surface of the earth in the form of lava, then it solidifies and turns into stone. For some time now it has been used in construction. Due to the fact that basalt is easy to mine and there is a lot of it in nature, the cost of building materials based on it is available to everyone.

There are entire groups of volcanoes that provide the greatest amount of rock suitable for further processing. They are located in Kamchatka and the Kuril Islands. There are more dormant volcanoes on earth, near which basalt layers have already formed - they are the main sources of the rock.

Many islands are of volcanic origin and are entirely formed from basalt rock, such as the Hawaiian ones.

Stone wool insulation goes through the following processing stages:

1. Melting and grinding.
2. Fiber production.
3. Resin bonding.
4. Treatment with water-repellent oils.
5. Formation of layers of the desired shape.

The layers are made of different thicknesses and areas. Sold in rolls with one-sided foil application or in the form of slabs.

Characteristics of stone wool

The material retains heat thanks to the air bubbles stationary inside it. The more there are, the stronger the beneficial properties. The characteristics of the finished insulation are almost the same for all manufacturers, so there is no point in overpaying for the brand. The service life of this material is unlimited compared to other similar building materials.

On sale you can find various modifications of stone wool. A layer of foil can be applied to one side to improve the thermal reflective properties of the material. Such rolls are used to insulate attic or mansard rooms. The foil is laid in the direction of the room, which keeps heat.

Rolled cotton wool without foil is used for laying on floors under laminate, parquet or tiles.

Conventional slabs are used to insulate the facade. A layer of external plaster is applied on top of them. There is also a shaped variety, which is two halves of a circle. They are used to insulate water, gas, sewer pipes in the ground above the freezing level.

Stone wool properties

Natural stone wool has a number of positive qualities, which it is recommended to familiarize yourself with before choosing insulation for your home. First of all, it is fire safety, vapor permeability and durability. The rest of the qualities of the basalt insulation are added during the production process - water resistance, environmental friendliness.

Acidity is an important property of basalt rock. This indicator enhances the strength characteristics. To regulate acidity, carbonate additives are used to achieve the desired quality.

The binder used for bonding basalt fibers can be of synthetic origin, bitumen or bentonite type, as well as combined substances, which include several components. The most popular among manufacturers is phenol-formaldehyde resin. It is sprayed into small particles and forms layers, which then solidify. The amount of resin in the material is not more than 3%.

Fire resistance

The melting point of basalt in nature is about 1000 degrees, so stone wool is not afraid of fire. Any source of fire will not damage the material - when the oxygen burns out, the fire will stop by itself.

When basalt is melted in furnaces, temperatures are developed up to 1500 degrees in order to melt the stone qualitatively.

Also, the material is not afraid of temperature changes. When they decrease in winter, basalt fibers retain their shape well. This is important during construction, as several layers of plaster are applied to the slabs. If the backing material shrinks and expands under the influence of heat and cold, the plaster will crack and collapse.

Thermal insulation

The thermal insulation properties of stone wool are that in winter it does not let the cold through, and in summer the heat. The material allows air to pass through, so condensation and dampness do not form in the room.

Soundproofing

During production, the fibers are arranged and solidified chaotically, in addition, air bubbles are located between them. This provides good sound insulation properties. The thicker the layer, the worse it allows various sounds to pass through. A sound wave, falling on a porous material, is scattered and neutralized.

If you need to completely isolate the room from extraneous sounds, the walls are pasted over on both sides, and sheets of cotton wool are also laid on the door.

Durability

The durability of the material is not due to the stone component, but to the binder - glue. If it is of high quality, the material does not shrink over time and performs its functions well. This is important in the construction of underground water pipes in private houses and sewers. In the ground, in an aggressive environment, poor-quality materials quickly deteriorate, and repairing a water supply system is expensive, given the complexity of the work. Therefore, it is not recommended to save on insulation. Before buying, you need to clarify which substance was used for gluing and how durable it is.

The same applies to the outer facade of a private house, where it is important that the cotton wool keeps its shape and does not decrease in volume.

Moisture resistance and vapor permeability

After the formation of the layers, the cotton wool is treated with oil, which provides water-repellent properties. This prevents water from being absorbed by the material. The porous structure allows steam to escape from the room, therefore, mold does not form on the walls, upholstered with basalt rock slabs. To do this, manufacturers add other substances to the composition that kill the fungus. This property is used to insulate rooms with high humidity - baths, swimming pools.

Environmental friendliness

The question of the environmental friendliness of stone wool remains open. If it contains toxic substances that are used to connect fibers, when heated, the material will release toxins in small quantities. Basalt itself is absolutely not harmful, as it is a natural stone.

It is not recommended to install stone insulation without a protective mask. During the installation process, dust containing harmful substances is generated. Formaldehyde and phenol are dangerous toxic carcinogens that can cause allergic reactions on the skin and pulmonary edema when inhaled.In solid form, the resin is less dangerous, the migration of poisons is limited to the minimum allowed by sanitary and epidemiological control.

Application area

Stone mineral wool has been used for a long time - since the middle of the 20th century, therefore it has established itself as a reliable building material. It is used by:

• For insulation of external walls. This allows you to build buildings with less consumption of building materials. A 10 cm layer of cotton wool replaces 2 meters of brickwork, which allows you to significantly save on building houses.
• For strapping pipes made of various materials. The metal does not corrode in contact with chemically neutral wool, therefore it lasts longer.
• For insulating the interior walls of the house, as well as increasing the sound insulation properties. With single-layer brickwork, you can also increase the interior space by covering the walls with a thin mineral wool slab.
• The material is placed under a concrete screed in the floor. This reduces sounds and also controls heat consumption.
• Roof insulation to exclude heat loss in the winter season, as well as additional cooling of the room.
• In the attic, wooden parts are upholstered with mineral wool to protect them from accidental fire.
• The pipes in the apartment can be insulated with rolled cotton wool to avoid the formation of condensation due to the flow of cold water.

Rock wool is believed to deter mice and other rodents. According to recent reports, this is not the case. Animals do well in natural material and do inside the nest, so it is recommended to use additional anti-rodent products.

Options for wall insulation outside

For the facade, large-area slabs are used, at least 100 mm thick. Suitable roll, not covered with foil. Fastened with dowels or special glue for mineral boards. Better to use both options at the same time. An important indicator for the facade is the density of the mineral wool. It should be at least 45 kg / cubic meter. Cotton wool with a density of more than 100 kg / cubic meter is used for decorative plaster.

From the inside, the walls are insulated with mineral wool with a density of less than 45 kg / cubic meter.

Insulation of floors

For floor insulation, slabs with a density of 30 to 45 kg / m are used. They put it in cells of wooden blocks before pouring concrete. A film is placed under the wool layer for additional protection against moisture.

Pros and cons

There are few disadvantages of basalt mineral wool:

• Depending on the fiber splicing resin used, the material may not be very safe. For use in childcare facilities, hospitals, additional tests and quality certificates are required.
• Doesn't scare off mice and rats.
• Additional safety measures are required when working with mineral wool.

There are many more advantages:

• Low material cost.
• Versatility - can be used in any premises for external and internal work, as well as underground utilities.
• Non-flammability. Cotton wool is used to cover rooms where there is a risk of fire or where flammable substances are stored.
• Hydrophobic - does not absorb moisture and does not deform under its influence, although it allows steam to pass through well.
• It can stay in aggressive environmental conditions for a long time, without changing its shape and without crumbling into small parts.
• Installation can be carried out by a person who has no experience in construction work.

There are requirements for the transportation of rolls and plates: during transportation there should be no pressure on the boxes in which the material is located, therefore they are transported in an upright position.

Which wool is better - mineral or stone wool

If we compare the varieties of mineral wool - glass wool or slag wool with basalt insulation, we can conclude by the following parameters:

• Basalt wool retains heat better.
• Glass wool is much more environmentally friendly, because it contains no carcinogenic substances that are used to combine basalt fibers. Glass wool contains glass and quartz.
• Slag wool is not used as insulation for residential premises. For this, glass wool and basalt insulation are more suitable.
• The density of basalt wool is higher, does not get wet, does not change shape. Glass wool is softer, but it is susceptible to moisture and shrinks. It is better to use glass wool in dry rooms or to insulate ground communications with it.
• Basalt does not require additional materials. For glass wool, a film is needed to cover it on top and protect it from moisture.
• During the operation of basalt wool, harmful dust is formed, since the fibers tend to break. Glass wool does not generate dust, as its fibers are long and soft.

If you carry out internal work, it is preferable to use glass wool - it does not emit harmful substances into the space, since the binder is acrylic resin - it is absolutely safe for health. For external work, basalt insulation is more suitable, since its moisture-repellent properties are much higher and the material does not react to temperature changes, continuing to perform its functions.