Currently, developers in the construction of new buildings pay special attention to the thermal protection of external walls. This is required not only by building codes, but also by the desire to increase their competitiveness. However, the situation with the walls in old houses is somewhat different. Owners of private houses have to conduct insulation of the premises with their own hands in order to keep the heat inside, and leave the cold outside.
There can be several reasons for lowering the temperature inside the house: poor heating system, the presence of gaps, drafts. However, the most common reason is poor thermal insulation of the walls. Walls occupy the largest area in the room and are the main source of heat loss. There are several ways to insulate the walls in a private house outside.
Why insulation should be done outside
Experts recommend insulating walls from the outside, and resorting to thermal insulation from the inside only in extreme cases. This is due to some features:
- When warming a house from the outside, the material protects the walls not only from heat loss, but also from the negative effects of moisture. Home heat warms up the wall and in the event of moisture and condensation, it contributes to its drying out as soon as possible.
- The dew point shifts closer to the outer edge of the wall. This prevents condensation.
- Warming the house outside with your own hands not only protects the room from the cold, but also preserves the useful area of the rooms.
Wall insulation options outside
There are several options for how to better insulate a private house outside:
- Installation of heat-insulating material on the wall using adhesive solution and further coating with plaster.
- The formation of a three-layer unventilated wall. The insulation is fixed with a solution. Next, the external wall is laid in one layer of brick, taking into account the air space.
- Installation of a ventilated facade. A heater is mounted on top of the waterproofing, on which wind protection is installed. The final stage is lining with decorative lining or other siding.
Each method has its own nuances in execution. There are combined materials, as well as modern modified ones, the installation of which should adhere to special technology.
Installation of a ventilated facade can be carried out even in the cold season, since its technology does not provide for the use of adhesive.
The better to insulate the house outside
There are several types of insulation material. Each of them has its own characteristics and price range. The following heaters are considered the most popular:
- polystyrene (expanded polystyrene, extruded polystyrene foam);
- mineral wool;
- polyurethane foam;
- basalt slabs;
- cellulose based heaters.
Proper insulation of the walls of the house outside with your own hands depends on the choice of the best option for wall insulation. The main differences of the above materials are vapor permeability, moisture resistance and thermal conductivity. The first two parameters are selected based on the climatic conditions, as well as the method of attachment to ensure maximum protection of the room from moisture. Thermal conductivity is taken into account when calculating the required thickness to achieve the optimal effect.
Calculation of insulation thickness
To begin work on wall insulation from the outside, it is necessary to calculate the thickness of the heat insulator. Calculations are based on SNiP, GOST and SP data. If you can’t do the calculations yourself, it’s better to use the services of private design organizations. The thickness of the insulation depends on the heat loss of the house through the external walls, window frames, foundation, ceiling and roof. Given the data obtained, as well as taking into account the power of the heating system, calculate the thickness of the insulating layer.
Then they are determined with the choice of material and they perform insulation of the house outside with their own hands. It is important to consider not only the type and size of the insulator, but also the number of layers required. For example, it is better to refuse polystyrene foam if laying in several layers is required. Mineral wool or polyurethane foam, the thickness of which is much smaller, is suitable for this.
Preparing walls for insulation
After choosing what it is better to insulate the house from the outside, proceed to the main work. The main goal is to prepare the walls for further installation of the material. To achieve a perfectly smooth brick, wood or concrete surface, the old layer of plaster or other insulator is completely removed.
Particular attention should be paid to the primer of the walls. If there are differences in the levels on the wall (protrusions and indentations over 2 cm), it is better to patch them with a special solution or comb them to the desired level. Use a deep penetration primer. Before applying the primer, the wall is cleaned of dust and dirt.
In order to insulate the walls from the outside with a even layer and not interfere with the erection of the external wall from decorative bricks or plastering, you should think about a system of plumb and lighthouses in advance. They are used to determine the plane of the outer edge of the insulation, which facilitates its installation.
Anchors or screws are installed to the upper edge of the wall. A strong thread is tied to them and lowered with plumb lines to the very bottom. Between them horizontal threads are attached, which form a control grid. It serves as a guideline when installing the frame or installing insulation.
Installation of foam and extruded polystyrene foam (EPS)
Polyfoam is attached to the wall with a special adhesive for polystyrene foam boards. Sometimes they use building "fungi" for these purposes.
When insulating EPS walls, the surface on which the adhesive solution will be applied is made rough. This contributes to a more reliable bonding. There are no such problems with polystyrene, since the glue fixes it without additional processing.
Often, glue and “fungi” are simultaneously used to strengthen the fastening. This is a more correct solution, which extends the life of the insulation.
The final stage of wall insulation from the outside is plastering or lining with decorative materials.
How to insulate walls in a private house from the outside with polystyrene foam using wooden battens
In practice, another method of attaching foam sheets is used - by forming a frame of wooden battens.
For the construction of the frame, rails are used, the thickness of which is not less than the thickness of the insulation. If the thickness is a little more, this will create a ventilated space between the insulation and the facing material. The distance between the slats is calculated so that the plates fit tightly into the niches and do not fall out.
This type of installation is acceptable if a siding or lining will be used for the finishing of the walls. Reiki will serve as the basis for fixing the cladding material.
Mineral wool: features of fastening
Using mineral wool, you can also insulate a private house outside. Materials and advice on the implementation of work are similar to the instructions for fixing basalt slabs and cellulose-based heaters.
For more reliable installation of mineral wool sheets, a frame system of wooden battens is formed. The width of the crate should be less than the width of the insulating material by 2-3 cm. This ensures a tight entry of mineral wool between the boards and the absence of gaps. Additionally, anchors are installed, on which sheets of insulation are later put on. If the wall surface is uneven, a two-layer mineral wool is used, the layers of which have different densities. The soft layer provides reliable adhesion to the wall.
In terms of the external finish, mineral wool is more versatile, unlike other types of heat insulators. On top of the insulation, you can install an external horizontal cladding, under which a windproof layer is attached in the form of a dense plastic film. For wall cladding, decorative brick, lining or other siding is used. This technology allows you to create a three-layer ventilated insulation, which is suitable for most climatic zones.
How to insulate the walls in a private house outside with polyurethane foam
The installation principle of polyurethane foam is similar to the technology of attaching mineral wool. However, it is almost impossible to independently carry out wall insulation using this material. The method involves the use of special expensive equipment that distributes the liquid mixture on the treated surface. In addition, without the availability of professional skills, working with the installation causes many difficulties.
The main feature of this method of insulation is the very fast execution of work. Using the above installation, polyurethane foam is sprayed on the surface. As a result of the chemical reaction, the liquid substance transforms into a solid state and foams. The insulation does not form an air space between the wall and the heat insulator, which provides a more durable and durable coating.
Features of polyurethane foam
Polyurethane foam has many advantages, among which:
- after hardening fills all cracks and troughs;
- vapor permeability is much lower than that of other materials;
- quickly and reliably fixed to the wall;
- excellent mechanical strength;
- good heat and sound insulation.
However, the cost of the material and its installation are quite expensive. Durability and high quality indicators justify the high cost of installing it.
If sooner or later the question arises of how to insulate the house with your own hands outside, the instructions for using polyurethane foam will help solve the problem of heat loss and maintain a comfortable temperature in the room.
Despite what material is used as a heat insulator, any of the above options copes with its main task - insulation of the room. In addition, the external insulation allows you to save heat and protect the surface from moisture. Step-by-step instructions and practical recommendations of specialists will tell you how to insulate walls in a private house outside.