Mineral wool is one of the three main types of thermal insulation materials for external insulation /the other two are polystyrene and fiberboard/.
Mineral wool and its products are very good heat insulators and have a relatively good ratio between thermal insulation qualities and price. The coefficient of thermal conductivity is λ = 0.044–0.052 W/(m K). The material does not rot, is resistant to cold and heat, has low hygroscopicity, does not burn and is not attacked by rodents.
TYPES OF MINERAL WOOL
There are two types of mineral wool: stone and glass, which do not differ much in their thermal and physical parameters. Various insulation products are produced from mineral wool, most often rolls and slabs are used. The bulk density of the rolls varies within the range of 10–150 kg/m³, with lighter ones having better thermal insulation properties.
Stone wool is produced from basalt, limestone, dolomite and bauxite and is an environmentally friendly material. Stone wool slabs have good moisture, water, heat, fire and sound insulation. Solid slabs are used for flat roofs, and other types of slabs for facade and interior insulation. Rolled stone wool is suitable for pitched roofs, interior partition walls and suspended ceilings.
Glass wool is made from sand and recycled glass. It is most often available in the form of rolls.
For wall insulation, stone wool slabs impregnated with water-repellent resins are used. They are divided into groups according to their bulk density and, accordingly, hardness. The higher their bulk density, the stronger they are. Some manufacturers produce slabs with unequal transverse density, and the surface of the slabs is treated with special mineral oils, which make them completely hydrophobic. For external wall insulation, slabs with a thickness of 5–9 cm are used.
The prices of mineral wool vary greatly, mainly depending on the materials and type of products /respectively their applications/ and the manufacturer. It is necessary to know that glass wool products with a bulk density of 10-35 kg/m³ are suitable for ventilated insulation structures, while for insulations on which plaster is directly applied, semi-rigid or hard stone wool slabs with a bulk density of 35-150 kg/m³ are used.
WHY CHOOSE MINERAL WOOL?
Mineral thermal insulations differ from other thermal insulation materials in that they provide very good thermal, sound and fire insulation at the same time. In addition, mineral wools are vapor-permeable and moisture-resistant. Good sound insulation is due to their natural fibrous structure. Their non-flammability and sound insulation properties make them extremely suitable for use inside buildings - for internal non-load-bearing light partition walls, for insulation in suspended ceilings, pitched roofs, etc. A disadvantage of this type of material is that they are more difficult to process and can only be partially recycled.
WHAT MAKES COTTON BETTER THAN STERY?
Mineral wool, whether glass or stone, is extracted as a building insulation material from natural raw materials - stone or glass. Its properties are guaranteed to be durable and do not change over time.
In addition to having a thermal insulation function, stone wool is also soundproof, and unlike polystyrene, it is a non-combustible material, so only facades with stone wool can be treated and classified as non-combustible facade systems.
Another quality of facades with wool is vapor permeability - the ability of walls with wool to "breathe", which is a significant advantage compared to other types of thermal insulation materials. This means that all the vapor that appears inside the room can pass through the walls to the external environment without hindrance (for example, polystyrene foam has 30-40 times greater resistance to the passage of water vapor than rock wool).
HOW IS THERMAL INSULATION MADE WITH MINERAL WOOL?
The plates are attached to the wall simultaneously with glue and dowels. The consumption of glue strongly depends on the roughness of the base and is usually 2–5 kg/sq.m. Mechanical fastening is done by nailing with special dowels, the number of which depends on the height of the building. For buildings up to 6 m high, at least four dowels are used per square meter, and for buildings above this height (up to 20 m) the minimum number of dowels increases to six. The dowels fasten only the plates, without passing through the reinforcing mesh, which is laid on the plastic washers.
A layer of putty (light hydrophobic plaster) is applied to the boards fixed in this way, prescribed by the manufacturer of the system or the insulation boards. While the layer is still fresh, a fiberglass mesh made of alkali glass weighing 145–180 g/m2 is laid on it and stretched. Immediately afterwards, a second layer of putty is applied until the mesh is completely covered. The total thickness of the reinforced putty layer becomes 6–8 mm. The mesh is laid on the wall in parallel strips with an overlap of 10 cm. To achieve greater rigidity and strength around the edges at the ends of the insulation, it is desirable to place the reinforcing mesh in two layers in these places. To shape and reinforce the protruding edges, either universal protective profiles made of aluminum sheet metal or special plastic protective profiles are used, which are characterized by wide strips of fiberglass mesh.
The special metal profiles that close the lower edge of the insulation must have a drip catcher to drain rainwater so that it does not run down the wall under the insulation.
The next operation is the application of a special decorative plaster. The choice of such plasters is quite large – silicate (with potassium water glass), silicone (with a silicone resin binder), polymer (artificial resin binder), etc., which are applied by plastering a thin layer – 2–4 mm. The important thing in this case is not to underestimate and economize on the priming, which creates optimal adhesion between the plaster and the base. The primer depends on the type of plaster and is recommended by its manufacturer.
Good thermal insulation of a building does not end with insulating only the external walls. The same must be done for the roof or at least on the floor of the attic. Mineral wool is most often used to insulate the roof structure and ceilings.
CAN ROCK WOOL BE ADHESIVED ON AN UNEVEN SURFACE?
The plane of the base must be checked before the stone wool slabs are glued. This is done by using a level, which is placed on the wall and the deviations are checked. The requirements vary within approximately ± 1 cm along the length of the level, which is usually 3 m long. Anything outside this tolerance is an unsuitable base for gluing, so it should be leveled with a putty before gluing begins.
If this is not done, an attempt is usually made to level the base with glue, which can be a big problem, since too thick a layer of glue for gluing insulation boards can cause them to separate from the base and jeopardize the functionality of the entire facade. Therefore, first level the surface with putty and only then proceed with gluing the boards.
WHAT DO WE OFFER?
With us you can find mineral wool made of glass fibers, which is available in rolls of different sizes and correspondingly different covering areas. The glass wool is from the brands ISOVER and KNAUF INSULATION.
From our store you can also purchase stone wool from the brands FIBRANgeo and IZOCAM .
The prices of cotton wool here are affordable.
