Methods for self-insulation of a wooden house from the outside.

What features of wood should be taken into account when insulating?

Wood is a unique and environmentally friendly material in construction, the properties of which must be taken into account when insulating the facade. After all, over time, cracks form in it, through which cold gets into the room. Subsequently, this leads to the appearance of dampness.

The walls of a wooden house from the outside are constantly exposed to sunlight, precipitation and wind. To protect the facade from negative phenomena, you need to think about its insulation. This approach will help to improve the appearance of the house and you will not have to think about additional heating, because wood has a low thermal conductivity coefficient. In addition, thermal insulation of external coatings will help to avoid attacks by rodents or insects.

Before you start insulating, you need to ensure that the joints between the crowns of a wooden house are tight. The outer walls need to be treated with antiseptics to protect the wood from rot, fungi and pests. In addition, you will have to lay a vapor barrier film so that the product is not damaged by condensation.

Note! The antiseptic can only be applied to dry wooden surfaces, otherwise the pores filled with water will not absorb the required amount of the product and will not receive the required protection.

For this reason, houses made of timber or logs of natural moisture content are insulated and treated with antiseptics only after 2-3 years. During this period, the wood has time to shrink and dry out.

To reduce the risk of fire and improve the fire-resistant properties of wood, the facade of the house should be additionally treated with fire retardants before insulation.

Which insulation is better to choose?

Thermal insulation of a wooden building from the outside has many advantages:

• no need to move furniture;
• the area of the interior remains unchanged;
• there is no dust and debris in the rooms, because all work is carried out outside.

Most often, the following materials are used for insulating facades: mineral wool, penoplex, polystyrene foam, polyurethane foam, and ecowool.

Features of glass wool

This building material is a type of mineral wool. Glass wool is usually obtained from melted broken glass. The material has a number of advantages:

• resistant to chemically aggressive liquids;
• perfectly retains heat in walls;
• does not change physical properties when heated to 450 degrees;
• resistant to temperature changes;
• does not burn;
• good sound insulator;
• absence of toxic components hazardous to humans.

The disadvantages of glass wool for home insulation include brittleness and prickliness of the fibers. Contact of the material with the skin or mucous membranes leads to severe irritation or allergies. It is not difficult to insulate a wooden house with it, but you need to wear gloves, protective clothing, a respirator and glasses when finishing the facade with glass wool.

In addition, this insulation easily absorbs water, so you need to take care of the vapor barrier before work.

Rock wool

This material is made from rocks, usually basalt. It also contains various additives and binders. Basalt wool is produced in the form of tiles or rolls. It can have a coating of fiberglass, foil or kraft paper. The insulation is a non-flammable material, since it can withstand temperatures up to 580 °C. Moreover, stone wool does not change its physical properties when heated. Other advantages of insulation:

• Easy installation. Laying can be done even without lathing, because the material is lightweight and small in size.
• No shrinkage. High-quality basalt wool does not change its shape throughout its entire service life, due to which cold bridges are excluded, while the walls remain breathable.
• Does not absorb moisture. Hydrophobic additives in the composition do not allow water to get inside the material, which has a good effect on thermal insulation characteristics.

Basalt wool has excellent sound-absorbing properties. Mold, fungus and other dangerous microorganisms do not form in it.

The disadvantage of such insulation is fragility. During the cutting process, fine dust is generated that can get into the respiratory tract. It is better to work in a respirator. Another disadvantage is the high price. If the budget is limited, then it is worth giving preference to another insulation.

Using slag wool

This material is made from blast furnace slags, which are drawn into fibers 1-2 cm long during production. This insulation is inexpensive. Slag wool is slightly rigid, and on one side it can have a foil coating. The insulation has good vapor permeability and excellent soundproofing qualities.

The material can withstand heating up to 250-300 °C, but in this property the material is inferior to stone wool. Slag wool can be used to insulate curved surfaces due to its low rigidity. In addition, mice and rats do not gnaw the product.

When choosing thermal insulators for finishing external surfaces, it is better to refuse slag wool, since it absorbs water from the air. Due to hygroscopicity, mold can form inside the material. Moreover, when this insulation is near a metal profile, an oxidation process occurs.

Other disadvantages of slag wool are sensitivity to temperature fluctuations, increased fragility of the material. After mechanical impact, the shape of the insulation cannot be restored. The fibers of the material are quite sharp, so work must be carried out in protective clothing. Slag wool is less suitable for finishing the facade, but is often used due to its low cost.

Extruded polystyrene foam

Penoplex is a modern insulation material, in the production of which nano particles of graphite are used. Thanks to them, the product is more durable. Extruded polystyrene foam has good sound insulation, is not susceptible to mold and rodent attacks. The insulation is resistant to chemicals, mechanical damage and loads. It is also not afraid of water. The material can be used for insulation without vapor and waterproofing. Polystyrene foam is perfect for finishing the facade.

A huge disadvantage of penoplex is that it does not allow air to pass through well. When laying it, additional ventilation is required to avoid the greenhouse effect in the house. An equally serious disadvantage of insulating a wooden house from the outside with extruded polystyrene foam is the flammability of the product. The material melts at high temperatures and emits toxic smoke.

Styrofoam panels

This option for insulating external surfaces is the most popular. After all, the porous material is inexpensive, lightweight and small in size. Other advantages of polystyrene foam include:

• easy installation;
• good noise absorption and high wind protection;
• dense surface on which mold does not form;
• service life of more than 50 years;
• resistance to precipitation and temperature fluctuations.

Despite the listed advantages, polystyrene foam is a flammable product that has low strength. The panels are not able to withstand mechanical damage, they have low vapor permeability. A house insulated with polystyrene foam will be warm, but in the absence of sufficient ventilation, the wood will begin to rot due to condensation.

Ecowool insulation

The material contains cellulose fibers with water repellents, antiseptics and fire retardants. Ecowool is sold in bags, its main advantages:

• prevents condensation;
• does not emit toxic substances;
• retains heat perfectly;
• is not of interest to rodents and insects;
• absorbs vibrations and noise.

The disadvantage of using natural insulation is the installation technology. To lay ecowool, a pneumatic installation is required, which is expensive. Only specialists can work with such equipment. Ecowool can be installed manually, but this work will take a lot of time and effort. In addition, uneven distribution of insulation on the wall will lead to shrinkage of the material and the formation of cold bridges.

Sprayed polyurethane foam

The material is applied to the surface using a special gun. Spraying polyurethane foam forms a continuous coating, filling all the cracks of a wooden house from the outside. The seamless surface does not let in the cold. The wall insulation is lightweight, it is resistant to temperature fluctuations, rot and fire, and is not susceptible to rodent attacks.

Polyurethane foam can be applied at any temperature, its service life is about 30 years. The disadvantages of the product are the use of special equipment for installation and the high price.

Suitable insulation methods

Thermal insulation is produced in the form of slabs, rolls and sprayed materials. Each of them has its own installation technology. You can insulate a wooden house with mats and rolls as follows:

• wet method;
• using a curtain wall ventilated facade.

The first option involves creating the tightest possible joint between the cladding and the thermal insulation material. In the process of the “wet” facade technology, a multi-layer cake is created on the outside. To fix the layers, use adhesive solutions, plaster or mastic. This method additionally protects the house from negative atmospheric phenomena, provides good vibration and sound insulation.

The second method of insulation involves installing a frame for the finishing material. To create this structure, you can use a metal profile or wooden blocks. In this case, the thermal insulation is placed between the wall of the house and the interior decoration. In this case, a ventilated gap of about 40-50 mm is left between the cladding and the insulation so that moisture does not linger and quickly evaporates.

On the outside, the slabs are protected with a vapor-permeable film to prevent precipitation. Installation of a ventilated facade allows you to move the dew point outside and provide the external surfaces of the house with additional thermal insulation.

The second method of insulating a wooden house from the outside is the most suitable option.

There is another method of insulating the walls of a wooden house. Today, liquid thermal insulation is often used for these purposes. Spraying is performed on dry and clean boards with a special high-pressure apparatus. Before insulating a wooden house, a frame is created, then a windproof membrane is fixed to it. Holes are made in the film through which the insulation is blown. The material is introduced until it fills the entire surface. The holes are sealed and they move on to the external cladding.

How to calculate the correct thickness?

Before insulating the external walls of a wooden house, it is necessary not only to select thermal insulation, but also to correctly calculate its thickness. In this case, it is necessary to take into account climatic conditions and the thickness of the walls. If the insulation layer is too thin, it can lead to freezing of surfaces, dampness, rot and mold.

Quite often in the southern regions, insulation about 50 mm thick is used. When the house is in a moderate climate, a product thickness of 100-150 mm is sufficient. In regions with severe winters, it is better to use insulation of at least 150-200 mm.

Preparatory work

Before you start insulating the walls of a wooden house, you must first prepare the base. First of all, the surface is thoroughly cleaned of dirt, dust and mold. If there are voids in the crowns, they must be sealed with a sealant, and the seams must be sealed with a sealant. The cracks in the walls must also be sealed. There should be no nails or screws left on the surface. Only dry walls can be insulated, so it is advisable to carry out the work in the summer.

After the preparatory work, priming is carried out. The mixture is applied to the walls with a brush, covering up irregularities, depressions and ends of logs.

Please note! If the wood instantly absorbs the primer, it is advisable to apply the product in several layers. Then you need to wait until the surface is completely dry.

On the prepared facade of the house, install a waterproofing film with vapor-permeable properties using a stapler. Such a membrane has a porous surface on one side and a glossy surface on the other. The first must be fixed to the wall surface, and the second to the thermal insulation. To fasten the joints of the film, use tape.

Step-by-step installation instructions

Thermal insulation of the facade with lathing

The next step will be assembling the lathing for effective insulation of the facade. It is created from wooden bars with a thickness equal to the thickness of the thermal insulation. The distance between the vertical frame guides should be 15 mm less than the width of the insulation. After all, tightly laying the slabs between the posts will help to avoid cracks and cold bridges.

To make the lathing even, you need to set the horizontal and vertical guides strictly according to the level. To attach the bars to the wall, use galvanized screws or nails.

Then the insulation boards are prepared. The insulation elements that do not fit into the frame openings are cut into pieces. The installation sequence is as follows:

• the boards are inserted between the battens;
• the products are pressed to the surface, avoiding the appearance of cracks;
• the insulation is secured with dowels with a wide head.

In regions with a cold climate, multi-layer insulation with mineral wool is used. In other words, the insulation is installed in several layers. The second layer of insulation is laid according to the same principle as the first. They should overlap the horizontal seams between the boards of the previous row.

A windproof film is installed over the fixed thermal insulation. Individual sections of the membrane should be joined with an overlap of approximately 10 cm. There is special marking on the material for this purpose. The film is fixed to the frame using a construction stapler, and the joints are sealed with tape.

In order for air to circulate freely between the finishing and the windproof membrane, a gap of about 4-6 cm must be left. To do this, slats 4 cm thick and 5 cm wide are mounted on the frame planks. The cladding will subsequently be attached to them.

Block house or vinyl siding can be used as external finishing. Manufacturers usually indicate on the packaging how to properly attach them. External cladding of the walls of a wooden house provides additional thermal insulation, perfectly absorbs external noise, and protects load-bearing surfaces from early destruction. Decorative cladding, in addition to insulation, will help improve the appearance of the facade.

Insulation without lathing

If it is not possible to create a frame, then brackets can be used to fix the thermal insulation. They help reduce the load on the walls and foundation of the house.

First, prepare the surface, as in the previous case. Then fix the metal fastening elements to the wall using long self-tapping screws with press washers.

Advice! To achieve better heat and sound insulation, it is worth placing sealing paronite under the brackets.

Mineral wool slabs are laid horizontally. They need to be fixed along the entire facade from the bottom up, layer by layer. Work should start from the bottom of the wall at a height of 80-100 cm from the ground. Holes are cut in the thermal insulation with a knife. Then mineral wool for insulation is placed on brackets. They are fastened diagonally using self-tapping screws with a washer.

You can create a tighter fit of the thermal insulation to the wall using plate dowels. They are fixed in the center of the insulation and in each corner. The entire facade of the house, as well as the gables, is covered with mineral wool. A windproof membrane is mounted on top of the thermal insulation. It is fixed using plate dowels with an overlap. In places where the brackets are located, cuts are made in the film with a knife. The fasteners should protrude above the windproof membrane.

For insulation, all that remains is to fix the horizontal and vertical strips made of beams or metal profiles. It is important to make the lathing even. For this, use a building level and a plumb line. External cladding, for example, siding, is mounted on the assembled frame.

Popular Mistakes

Sometimes after self-insulation of external walls, the problems do not go away. Cold air also penetrates the house, the wood deteriorates, and dampness appears. This situation usually occurs due to errors during thermal insulation of the facade.

Mistake No. 1 – insulation without preparing the walls

Over the years, wooden surfaces are inevitably affected by mold, fungi and bark beetles. Therefore, the walls must be thoroughly inspected before insulation, especially the lower crowns. If the defects are not eliminated, high humidity will remain under the layer of thermal insulation. As a result, such an environment becomes an excellent place for further reproduction of mold and fungi. This leads to rapid destruction of the insulation.

Before thermal insulation, the facade must be carefully examined, the surface must be cleaned, and rotten logs must be replaced. The walls must be treated with antiseptic agents to prevent the development of pests and pathogenic microorganisms. To protect against fire, fire retardants are applied to the wood. Treatment with these substances is carried out in 2-3 layers, waiting for the previous one to dry completely.

Error No. 2 – improper transportation and storage of thermal insulation

It is important to check the packaging with the insulation for leaks before delivery. There should be no damage. If the product gets wet during transportation, its thermal insulation properties will deteriorate. There are several tips for using insulation:

• The product must be unpacked under a canopy on the site a day before use. It is advisable to do this in the house.
• After installing the thermal insulation, you must immediately begin finishing. You cannot leave the insulation open for a long time, precipitation will quickly spoil it.

Error No. 3 – problems with caulking

To prevent heat leakage, the seams of the log house are sealed with fibrous material. When insulating the facade, be sure to check the condition of the joints between the logs. Loose or incorrect laying of caulking leads to the fact that birds drag away the fibrous material and cold bridges appear. Before insulating the house, you need to take care of sealing the gaps between the logs.

Mistake #4 — finishing the interior walls

Log houses can only be insulated from the outside. You shouldn’t break this rule. Only thermal insulation of the facade will allow you to create a comfortable temperature in the house. Insulation from the inside threatens the appearance of condensation and wetting of the wood. As a result, the outer walls will freeze, and the air humidity in the rooms will increase. This will lead to a violation of the microclimate in the house.

Insulating the facade of a wooden house, on the contrary, has its advantages:

• the walls are additionally protected from the effects of precipitation;
• the interior space does not decrease;
• there is no need to move furniture;
• simple installation scheme;
• improved sound insulation.

Mistake No. 5 – using soft material

The facade should not be insulated with products in the form of soft slabs or rolls. On a vertical surface, such thermal insulation will sag and slide down after a while. Gaps will appear between the cladding and the insulation. It is advisable to use rigid slabs that will not change their shape for many years.

Flexible mats are more suitable for insulating floors or interfloor ceilings. Soft slabs on a horizontal surface will not sag.

It is easy to insulate the external walls of a wooden house yourself. The main thing is to adhere to the installation technology, avoid mistakes and decide on the material for thermal insulation. Then you will be able not only to keep the house warm, but also to decorate the appearance of the wooden building.