Insulation of the basement with mineral wool

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Insulation of the basement with mineral wool
Insulation of the basement with mineral wool

Insulation of the basement of the house with mineral wool, features of insulation, its pros and cons, surface preparation and methods of performing work. Insulation of the basement with mineral wool is a set of measures aimed at protecting the foundation from adverse atmospheric influences and increasing the temperature indicators in the premises of the house. This article will tell you about the features and organization of this process.

Features of thermal insulation of the base with mineral wool

The scheme of insulating the basement with mineral wool
The scheme of insulating the basement with mineral wool

The plinth is the upper part of the foundation and is located above the soil surface. It is in contact with the support of the house, walls and floors. Therefore, the reliability and temperature regime of the house largely depends on the correct arrangement of this structural element.

Up to 15-20% of the heat can escape through the walls of the basement, and freezing of the building support threatens with the appearance of dampness, mold and an increase in the cost of heating the premises. To prevent this from happening, thermal insulation of the above-ground zone of the foundation is required.

Warming the basement of the house solves the following tasks:

  • Promotes the improvement of the home microclimate;
  • Protects the base from sedimentary moisture;
  • Eliminates the possibility of condensation on the surface of the base, thereby protecting the construction materials from destruction.

Insulation for the basement must meet the following requirements:

  1. Have low thermal conductivity. The efficiency of keeping heat in the house directly depends on this indicator.
  2. Have minimal hydrophilicity. If the insulation gets wet, its performance will become much worse. Saturation of the insulation with moisture is especially dangerous during frosts - with an increase in volume, water destroys the insulation, which leads to a decrease in its service life and deterioration of its characteristics.

These requirements are met by modern board and sprayed insulating materials. When using mineral wool as a heater, it is necessary to take into account its ability to absorb water. Therefore, such a coating needs waterproofing protection, especially when insulated from the outside.

The technology provides for internal or external insulation of the basement. The system of thermal insulation protection of this element of the house is approximately the same for both external and internal insulation. The difference between them may lie in the design of the thermal insulation and the materials used. It is not necessary to carry out both types of insulation at the same time.

One of the differences is the location of the waterproofing and vapor barrier layers. When insulating from the outside, first a vapor barrier layer is fixed on the basement wall, then a heater, and on top of it - a layer of waterproofing. When insulating from the inside, the wall is first covered with a waterproofing material, then with a heater, and on top with a vapor barrier.

Another difference lies in the materials used to finish the surface of the base / plinth. For example, from the inside you can work with plasterboard sheets, and from the outside - with moisture-resistant tiles or porcelain stoneware.

When insulating a basement with mineral wool, it is important to choose it correctly. For external insulation, the material must have good moisture resistance and a vapor permeability index of at least 0.5 mg / mh Pa.

If the insulating coating will carry any load, for example, a layer of plaster, then it is recommended to choose a mineral wool with a density equal to or more than 150 kg / m3… In this case, the minimum vapor permeability index of the insulation should be 0.35 mg / mh Pa.

The most significant manufacturers of insulation wool on the construction market are URSA, Knauf, Isover and Rockwool. They always provide their products with certificates and hygienic assessments.

Advantages and disadvantages of mineral wool basement insulation

Mineral wool for insulating the basement
Mineral wool for insulating the basement

Thermal insulation of the basement with mineral wool in relation to other types of insulation has certain advantages due to the properties of this material:

  1. It keeps its constant shape regardless of seasonal temperature changes and has an enviable durability when properly installed.
  2. Mineral wool is inert and therefore chemically resistant.
  3. It is easy to handle, it is sawn with a hacksaw and even cut with a knife. Thanks to this, the installation of this insulation is greatly simplified.
  4. Due to the low thermal conductivity, mineral wool insulation is quite effective and therefore helps to reduce the cost of heating the house.
  5. The material is fire safe. This is especially true for internal insulation of the base.

There are much fewer drawbacks to thermal insulation with cotton wool. The main one is the need to use hydro and vapor barrier to protect the insulation from moisture. When wet, its insulating performance decreases markedly.

Another disadvantage is the need for protective equipment when working with this insulation. This is especially true for glass-based mineral wool. Dust and fine fibers of the material can get into the eyes, skin and respiratory tract of the performer during work. Therefore, a respirator, goggles and gloves are essential here. After installation, the coating does not pose a hazard, since it is located under the insulating membrane and outer cladding.

Preparatory work

Cleaning the plinth surface
Cleaning the plinth surface

Before insulating the basement, a number of preparatory procedures must be carried out. First of all, you should clean its surface from dust and other contaminants. To do this, you can use a metal-bristled brush, a spatula and a spray bottle. If, after cleaning, irregularities are found on it, they will need to be eliminated. Any changes in the surface larger than 10 mm can lead to a loose fit of the insulation.

The basement walls can be leveled with gypsum plaster. The curvature of the surface should be determined by the building level. To do this, the tool must be attached to the vertical of the wall, and then measure the difference between the extreme points of its contact. If the required value does not exceed 10 mm, the alignment can be omitted. In case of large deviations, the base will have to be plastered with mortar along the lighthouses.

They can be made from wooden battens and installed on the walls of the base / plinth after the appropriate markings have been applied. First, the vertical position of the extreme slats must be fixed with alabaster. Then, pulling a cord between them, intermediate beacons should be installed. The step between them should correspond to the length of the rule, which will need to level the layer of applied plaster.

The working mixture must be laid from bottom to top between the slats, using a spatula for this. After aligning it with the lighthouses, the plaster must be given time to dry.

In order for the insulation not to get wet and mold and dampness do not appear in the house as a result, two layers of coating waterproofing should be applied to the walls of the basement on a dry surface. As a material for it, you can choose bituminous mastic or a more modern dry insulating mixture. Both of these options involve applying the composition to the base with a paint roller or brush.

To achieve the maximum result, work on the thermal insulation of the basement should be carried out at a plus temperature of more than 5 ° C. For outdoor insulation, this is possible from spring until autumn frosts.

Mineral wool basement insulation technology

Before installing the heat-protective coating of the base, it is necessary to prepare the following materials and tools: a perforator, dowels and a screwdriver, a tape measure, a plumb line and a building level, a hammer, insulation plates, glue or galvanized profiles, a set of spatulas. Work can be done dry or wet. Let's consider each of them separately.

Wet insulation method

Installation of mineral wool
Installation of mineral wool

In this case, the insulation is glued to the vertical surface of the base without using a frame system. The adhesive mixture can be purchased at your local hardware store. For its preparation, it is convenient to use an electric drill with a special mixer attachment. Unlike hand kneading, using this tool will speed up the process and help smooth the mixture. The composition should be prepared according to the instructions located on the packaging of the material.

For installation of mineral wool slabs, glue should be applied to the insulation and the insulated surface. A conventional spatula is used to apply the composition, and a notched spatula is used to evenly distribute it over surfaces. Insulation sheets must first be cut, taking into account the size of the base.

For the sticker, each element of the insulating coating must be attached to the wall and gently tap it in order to get a snug fit. This can be done with a small block, using it as an impact cushioning pad.

Installation of insulation plates must be started from the bottom of any corner of the basement, forming the bottom row. Subsequent upper rows should be staggered with a shift of 1/2 of the slab. In this case, the joints of the slabs should be T-shaped. The lower row of insulation must have a support, which can be crushed stone bedding, the base of the foundation or a galvanized profile previously nailed to the wall. If not secured, the bottom row of boards can slide down before the glue sets.

After 1-2 days, it is necessary to perform additional fastening of the thermal insulation with umbrella dowels. Holes for them are drilled with a perforator. One sheet of mineral wool should have five dowels: four of them for the corners, and the fifth in the center. After installing the "umbrellas" of the dowels, they need to be sunk into the material by 2-3 mm.

The next stage of work is the reinforcement of the insulating layer. Before that, glue the recesses formed as a result of the installation of umbrella dowels and the gaps between the insulation plates with glue. To eliminate cracks, you can use polyurethane foam.

Reinforcement of the fixed coating must be performed using fiberglass mesh. First, it is necessary to evenly apply a two-millimeter layer of special putty on it, then apply a mesh to the surface and press it tightly with a spatula to the insulation. On top of the mesh, you need to apply another layer of the reinforcing mixture. Thanks to this reinforcement, a flat and monolithic insulating surface is obtained. This eliminates any risk of cracks and other defects in the base.

For the finishing of such a coating, brick, stone or decorative plaster are most often used. Facing with a stone or brick gives not only resistance to the insulation in relation to external factors, but also increases the insulating parameters of the system. In addition, such a base will look pretty solid. As for decorative plaster, after applying it, the textured surface of the base can be given any color with the help of moisture-resistant paints or leave everything in its natural form.

Dry method of insulation

Dry method of insulating the basement with mineral wool
Dry method of insulating the basement with mineral wool

This method involves laying the insulation in the cells of the prepared frame. Before insulating the basement with mineral wool, it is necessary to perform a vapor barrier and assemble a crate of metal profiles or wooden bars on its wall.

The frame made of profiles should be mounted at a distance of 5-10 cm from the wall surface. The profiles must be fastened vertically with a step corresponding to the dimensions of the insulation plates - 60-100 cm.

A foil film can serve as a vapor barrier. With internal insulation, it should face the shiny side inside the room. The film canvases should be overlapped, gluing the joints of the panels with tape.

After the installation of the vapor barrier layer and the assembly of the frame, you can lay the insulation, placing it between the profiles. If, during the installation of mineral wool slabs, gaps are formed between them, you can remove them using polyurethane foam.

After that, the frame can be sheathed with a suitable finishing material. With external insulation, these can be siding panels that will reliably close the insulation from moisture. For internal insulation - plasterboard sheets.

How to insulate the base with mineral wool - look at the video:

Regardless of the method of basement insulation, with a competent approach to business and adherence to technology, basement insulation will protect your house from the loss of precious heat for a long time.