Thermal insulation of a wooden house outside

Wooden houses are one of the most popular types of buildings for construction outside the city. They are environmentally friendly, have excellent characteristics and a spectacular appearance. But in winter, the tree often does not protect against severe frosts. For this reason, the insulation of a wooden house from the outside is a rather popular solution among owners of buildings of this type.. Let’s try to figure out how to properly insulate a house made of wood with our own hands so that it comes out inexpensively and as efficiently as possible.


Wood is an interesting material, the main difference of which is vapor permeability. When exposed to moisture, the tree becomes extremely vulnerable to the growth of fungi and various microorganisms..

It has a porous structure, which will also facilitate the penetration of moisture into it. When choosing insulation for walls made of wood, it is necessary to find a material that will have the same vapor permeability, which will allow moisture to evaporate and breathe wood.

Otherwise, the wood will begin to damp, swell and rot, which will undoubtedly entail a decrease in its characteristics..

When insulating, it is also required to provide for the presence of a gap for ventilation between the outer finishing material and the insulation. This will prevent the thermal insulation material from absorbing a large amount of moisture. To protect against mold and mildew, the wood must be treated with special protective compounds. It is necessary to apply such a composition on the walls and crate several times..

The external type of insulation involves fixing the insulation material to the facade of the building. A windscreen is installed on it, as well as an external finishing material. The most popular will be insulation for siding, block house or professional sheet..

The advantages of outdoor insulation are a number of factors..

  • Installing a ventilated facade will prevent mold and mildew from growing.

  • Dew point will be located on the outside of the building. If the insulation is carried out in compliance with all technologies, then the temperature along the entire thickness of the walls will be positive. From the inside, the walls will not be covered with condensation. This will eliminate dampness in the house, and increase the durability of the building..

  • It will be possible to save the usable area inside the house due to the fact that the insulation and the crate are installed from the outside.

  • From the inside, the house will still be beautiful, because wood allows you to create an amazing interior and provide comfort.


Before insulating a wooden house outside, there is a need to carry out certain preparatory activities. You will need to remove unnecessary items from the outer walls: drainpipes, cables, lighting fixtures, and also install scaffolding. It is necessary to clean the walls from the previously applied coatings, remove dirt in the places of their greatest accumulation. And also it will be necessary to inspect the mezhventsovy heaters. If large longitudinal cracks are found, as well as seams, it is necessary to caulk them with putty, tow or sealant. After that, the surface is leveled. At the end, you will need to treat the cleaned walls with fire retardants and antiseptics..

The above steps must be done exclusively in dry weather.. This moment will be especially important when applying impregnation to the top layer of wood..

If there is moisture on the material at the time of application, then the antiseptic simply cannot be absorbed into the wood structure properly..

How and how to insulate?

It is possible to sheathe a wooden house from the outside with various types of insulation. There are a large number of them on the market.. But the most popular are the following categories:

  • Styrofoam;

  • extruded polystyrene foam;

  • mineral wool.

Consider the properties of each of the above materials, and also try to figure out how to use them correctly to insulate a wooden building.

Mineral wool

This type of insulation is considered one of the most effective, that for an old wooden house, that for a new building. The use of mineral wool makes it possible not only to emphasize the strengths of wood, but also allows you to hide its shortcomings as much as possible. For example, mineral wool insulation prevents wood from igniting when exposed to open fire. This becomes possible due to the fact that most materials of this type are non-combustible..

Using mineral wool as insulation allows the tree to breathe. Moreover, there is no need to create additional ventilation. The only thing that needs to be paid serious attention is to choose the right material for finishing..

Minvata is perfect for wall and roof insulation.

It is resistant to various chemicals, has fairly high sound insulation characteristics.. There are several types of mineral wool.

  • Glass. It is usually supplied in rolls. Differs in low rigidity and certain inconveniences of installation due to its characteristics. When working with this type of cotton, be sure to use protective equipment so that glass fibers do not get on the body and lungs..

  • Stone. It is supplied in slabs and has a high rigidity. Differs in convenience in work due to the fact that it is easily cut into pieces of the required size and is completely safe for humans.

  • Slag. Differs in cheapness and low quality. Made from industrial waste. For this reason, it can be hazardous to health. Therefore, this material is required to be purchased only from trusted manufacturers..

Warming begins with calculating the amount of material that will be needed. First, you need to calculate the height of the walls from the basement to the place where the pediment begins. If the parts of the house differ in number of storeys, then the calculations for them should be made separately..

Then the perimeter of the walls should be determined. This can be done by counting their length. Now we multiply the perimeter of the walls by the value of the height, and subtract the area of ​​the openings. The resulting value will correspond to the approximate surface area that will need to be insulated.

At the next stage, applying formulas to determine the area of ​​a triangle, it is necessary to calculate how many square meters there are on the gables of the house, if they are also insulated. The resulting value must be added to the figure that was obtained earlier.

Now you need to determine which mineral wool of which brand and size it was decided to use. We divide the total area of ​​insulation by the area of ​​a separate slab of material, after which we add 10-15 percent to the result. The resulting value will mean how many slabs of mineral wool will be needed to create one layer of external insulation.

And also you need to decide on the thickness of the insulation material. Usually it all depends on the latitudes in which the house is located. For the southern regions, 5 centimeters will suffice, for the middle lane – 10, and for Siberia and northern latitudes – 15 centimeters.

Consider the most common option for insulating a wooden house from the outside – laying mineral wool on a wooden frame.

At the first stage, you will need to prepare the walls and remove all decorative elements. Treatment with fire retardants and antiseptic should be carried out 2-3 times. Moreover, a new layer should be applied only after the previous one has completely dried. Particular attention should be paid to the processing of corners and end parts of wood, because it is these areas that are most susceptible to the influence of fungus and mold..

The next step is to create a crate. For it, they usually use the highest quality timber with a cross section of 3 by 3 centimeters. It must not show any signs of damage or damage by rot or fungus. First, the upper and lower bars are installed, which are fixed using galvanized self-tapping screws. Now we install the horizontal parts of the crate, between which the first layer of mineral wool will fit. The distance between the elements should be about 0.5 centimeters less than the height of the insulation plate.

This solution will allow you to better fix the material, and eliminate the possibility of gaps..

Now we install the second layer of insulation, where the elements will be located perpendicularly. That is, in this case, their installation will be carried out vertically. It is necessary to carry out and fix the bars along the perimeter of the openings of windows and doors.

The next stage is the unpacking and preparation of the insulation. If necessary, you can cut pieces from the slabs for installation around openings and in other places where full-size elements cannot be placed. Installation of slabs is carried out between the parts of the lathing of the first layer. They should be fixed in such a way that they hold as tightly as possible. To do this, you can use disc dowels. Now, in a similar way, we lay the plates of the second insulation layer. It will be better if they overlap the horizontal seams between the sheets of mineral wool that were laid as the first layer.

We put a windproof membrane on the insulation and fix it. Some of its elements are joined together with an overlap of about 100 mm. It is best to attach the membrane to the crate with a construction stapler, and the joints must be closed with a special adhesive tape.

Here you need to pay attention to the openings, which must be closed..

On top of the wooden parts of the lathing of the insulation, we attach thicker slats. It is on them that the external decoration of the building will be held. Now we put the external finish on the installed slats. In this case, boards will be used, after which we mount other protruding parts – ebb, slopes, shutters and decorative elements.


The cheapest of the mentioned insulation options will be the use of foam.. This material has good thermal insulation performance, but it also has a number of serious drawbacks:

  • low strength indicators;

  • lack of resistance to fire;

  • instability to mechanical deformations.

But the main disadvantage of such a heater will be that, in general, it does not allow air to pass through.. This means that all the strengths of wood as a building material will be leveled here. But even if you use foam as insulation, it turns out that it will be warm inside the house, but there will be a violation of the temperature and humidity regime due to lack of ventilation. That is, you will need to equip forced ventilation..

In addition, the foam, despite the assurances of the manufacturers, still absorbs water. And with a temperature difference, and its transition from one state to another, it begins to slowly destroy it. As a result, after 1-2 winters, the insulation of a wooden house will have to be done again..

Therefore, it is not recommended to insulate a wooden house from the outside with foam plastic, and its use is most often an exception to the general rule..

Extruded polystyrene foam

Insulation of the walls of a wooden house from the outside can be carried out with penoplex or extruded polystyrene foam. Such material is very similar to polystyrene, but it does not have a number of disadvantages of the latter..

Its advantages include:

  • resistance to moisture;

  • ease of installation;

  • ease of processing;

  • environmental friendliness;

  • safety for humans;

  • high strength;

  • resistance to physical stress.

But external insulation with this material, despite its advantages, requires additional ventilation. After all, it also has poor vapor permeability. Nevertheless, this material is used quite often for outdoor insulation. The preparatory stage with the installation of the lathing here almost completely repeats the preparation of the walls for insulation with mineral wool. The only major difference will be the need to treat the walls with a primer before installing the battens..

After the completion of the preparatory work, the process of applying the glue begins. It can be applied both to walls and to sheets of the material itself. But it would be better to do this on the walls, because they are more rough, and so the expanded polystyrene sheets will be better fixed. When the composition is applied, the heat insulator should be applied and well pressed against the wall..

When everything is glued, you should wait about 72 hours for the adhesive composition to set as much as possible.

Now you need to fix the insulation using special disc dowels. To install such a device, you will need to drill a hole for it with a depth that should be 20 millimeters larger than the dowel head. To calculate the required length, you need to add 5 centimeters to the wall and 1 centimeter to the adhesive layer to the thickness of the thermal insulation material. Usually, 6 dowels are used for 1 sheet of material, but more is possible. When the holes are ready, you need to install dowels in them and carefully drive in so that their cap is flush with the expanded polystyrene.

After all sheets of material are fixed, we check and process the joints. If the gaps at the joints are more than 5 mm in size, then they must be closed by applying construction foam..

If there are gaps larger than 20 mm, then additional pieces of expanded polystyrene must be installed in them..

Then you need to wait until the construction foam is completely dry. This usually happens within 5-6 hours. Unwanted dried pieces of foam can be removed with a knife.

It remains to carry out the application of the finishing coat on the walls. To begin with, we carefully process the walls with a primer, after which we rub it very well with an emery float. The leveling layer should be somewhere around 3 millimeters. After that, the insulation of a wooden house with extruded polystyrene foam from the outside can be considered complete.

Useful Tips

If we talk about useful tips, then a lot will depend on what kind of thermal insulation material was chosen.. For example, if it will be used for external insulation of glass wool, then you can work with it only if you have a protective suit, including glasses and gloves. Otherwise, its particles will get on the human skin and into the respiratory tract, which is fraught with serious inconvenience and problems..

Another tip – it is better not to save money, and opt for mineral wool or foam..

Polyfoam, although sometimes used for external insulation, but its service life will be short-lived, and its use may entail damage to the insulated structure, as well as directly to the house itself.

The third important point is that it is required to strictly observe the technology of using various heaters, as well as safety standards. Very often, full compliance with these standards is the key to high-quality insulation and safe work of this nature..

Watch a video about the mistakes of the insulation of a wooden house.

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