Wood is the best heat insulator and does not require additional insulation. But some owners understand that wood does not last forever and needs protection, so the question immediately arises of how to properly insulate a wooden house from the outside under siding.
In a wooden house it is easier to prevent the formation of dampness than to deal with it. The appearance of fungus and mold can be seen visually, like stains on wood, or you can smell their specific smell. These signs indicate that the house is in urgent need of “treatment.”
Increased wood moisture – consequences
Dampness is the most common and most harmful damage factor for wood. Such material requires a minimum level of humidity both in the solid wood itself and indoors. If in one of these cases the indicator is allowed to increase, then problems with dampness begin in the wooden house. Usually craftsmen, even at the construction stage, warn the log house against the encroachment of moisture. The first step is to check the moisture level of building materials: boards, timber and logs. In wooden products, a humidity level of 15 and a maximum of 20% is allowed.
What happens to the log at elevated humidity levels? At first everything will be fine, but as your house begins to settle, a displacement will form that will be much larger than it should be. As a result, you will get large gaps and crooked seams between the crowns. And that's not all, the problem of blue staining will appear. It is formed when wood with excess moisture is exposed to cold. Simply put, the tree begins to freeze. Further changes in climatic conditions do not save the situation; the wood turns blue, turns black and becomes unusable.
Thermal calculation of the walls of a timber house
Looking ahead, let's say that ZlojGenij considered it sufficient to increase the heat transfer resistance coefficient of walls to a value of 3.4 (m²*°C)/W (for Perm, according to the new SNiP, the required heat transfer resistance of enclosing structures should be 3.64 (m²*°C)/W ). To do this, the user decided to insulate the 15 cm thick beam with 10 cm thick stone wool.
For clarity, we will make a simplified thermal calculation and find out what thickness of thermal insulation is required for a wooden house built from timber sawn from pine or spruce for the Moscow region.
So, let's set the initial values:
- The thickness of the timber walls is 150 mm.
- The thermal conductivity coefficient of pine or spruce across the fibers is 0.14 W/(m °C) (operating conditions A - “normal”).
- The required heat transfer resistance for the Moscow region is 3.28 (m²*°C)/W.
Important nuances: in the tables, the thermal conductivity coefficient for wood is indicated in two directions - along the fibers (along the length of the timber) and across the fibers. The thermal conductivity coefficient of pine/spruce along the fibers is almost 2 times higher than across them (0.29 W/(m °C), versus 0.14 W/(m °C)). This must be taken into account when calculating, because the lower the thermal conductivity coefficient of the material, the warmer the walls .
In addition, the thermal conductivity coefficient of a wooden wall is affected by the amount of moisture contained in the material. Wood has a natural moisture content due to its structure. Freshly sawn wood has a higher percentage of moisture than dried wood. Let us also remember that during the operation of a wooden house, the walls are constantly exposed to the negative effects of negative weather conditions - snow and rain. This means the thermal resistance of the walls decreases.
Moreover, fluctuations in the thermal conductivity coefficient of wood occur seasonally. For example, prolonged autumn rains will lead to additional moisture saturation of the unprotected walls of a timber house, which directly affects the thermal insulation properties of the enclosing structure.
Conclusion : additional insulation and protection of wooden walls from atmospheric factors is required. For comparison, we present the thermal conductivity coefficients of pine/spruce across the fibers for three states: (1) in dry, (2) normal operating conditions (we use them for calculations), (3) in a moisture-saturated state:
- 0.09 W/(m °C).
- 0.14 W/(m °C).
- 0.18 W/(m °C).
We perform thermal engineering calculations using the formula:
R= d/λ, where:
- d—material thickness;
- λ is the thermal conductivity coefficient of the material.
We find:
Rph = 0.15/0.14 = 1.071 (m²*°C)/W
Let us recall that the required heat transfer resistance for the Moscow region is 3.28 (m²*°C)/W.
Now we find the difference between the actual (Rph) and normalized (Rн) values of the thermal resistance of a timber house.
Rt = 3.28 - 1.071 = 2.209 (m²*°C)/W
Those. timber “cold” walls do not reach the norm by the value found above. There are two options for getting out of this situation: do nothing and simply pay more for heating, essentially throwing money out into the street, especially in the absence of mains gas. The second is to insulate the walls and install a hinged ventilated façade.
Thermal insulation materials
Insulating a wooden house from the outside under siding will be ineffective if the thermal insulation is not performed correctly. The range of building materials offered by the market in this area is very large. Among the most common thermal insulation solutions for a wooden house are the following:
- stone wool;
- slag;
- glass wool;
- expanded polystyrene;
- Styrofoam.
We would not recommend the last two insulation materials for insulating a wooden house, but they still provide insulation.
How to install siding with insulation - step-by-step diagram
Step 1: Preparing the work surface
If this is an already built house, then you need to remove the drainage systems, platbands, decorative elements and everything that can fit into the finishing work. The surface of the walls must be thoroughly cleaned of dirt, and all cracks and crevices must be sealed using tow or silicone sealants.
Step 2: Vapor barrier
The vapor barrier film is attached with the rough side to the beam using a stapler. The joints can be taped with construction tape to ensure complete insulation.
Step 3: Preparing the frame for insulation
At this stage it is necessary to arrange a vertical sheathing. For lathing, you can use bars with a section of 50x50 and 40x50 mm. It is better to treat these bars with a special compound that prevents the wood from rotting. The slats can be fastened with dowel nails, at a distance of 2 cm less than the width of the insulation boards.
Step 4: Installation of insulation
The installation of mineral wool slabs must be carried out very tightly without gaps. Thanks to its structure, the material can be held without the help of fasteners. If the house is located in a region with a harsh climate, then the insulation can be laid in two layers, in which case it will be necessary to fill a higher frame.
Stone wool
Basalt wool is a material that, in all its properties and characteristics, is the best for external insulation of facades. The only significant drawback of the material is its high price. This kind of house insulation under siding will cost you a pretty penny, but the unique distinctive properties of stone wool will cover this disadvantage.
This insulation for siding for a wooden house has the following properties:
- thermal insulation;
- fire resistance;
- durability;
- soundproofing;
- vapor permeability;
- moisture resistance;
- environmental friendliness.
Differences between old and new technologies
Wooden construction in Rus' is a centuries-old tradition. For centuries, houses were built exclusively from log houses, from massive round and semicircular logs, the thickness of which was sufficient for good thermal insulation. Just like today, the tree dried out over time, and cracks appeared between the logs. But earlier there were other ideas about the beauty of the facade, so ordinary wood moss was used to caulk cracks. It landed in the cracks between the logs and over time reliably filled the entire space between them.
In modern construction, issues of economy come to the fore and force the use of timber, the thickness of which does not always meet the requirements of the developed standards. If the cross-section is insufficient, complete freezing occurs in winter, which means that the walls of the house are not able to retain heat. In addition, over time, the wood begins to dry out, causing heat loss to increase even more.
This is what a timber wall looks like after the wood has dried Source bredmozga.ru
Slag
This is an inexpensive and accessible type of mineral wool. It is made from glassy or rocky mass, which is waste from metallurgical enterprises. Temporary structures or non-residential premises are usually insulated with slag.
Advantages:
- the possibility of insulating curved surfaces;
- excellent sound insulation performance;
- durability;
- low cost;
- ease of installation.
Flaws:
- does not tolerate temperature changes well;
- has high acidity levels;
- It is recommended to work with the material in overalls, since during its installation, fiber particles peel off.
Builders who use this external insulation consider slag wool to be an inexpensive and durable material with a long service life.
Windproof membrane
When the main work of laying the mats is completed, they should be sheathed with a membrane, the sheets of which are glued together using specialized tape. Regardless of the point at which you connect them, the canvases must be laid with an overlap, the width of which should be at least 10 cm.
Additionally, the heat-insulating structure is stitched with “fungi” - these are special fasteners made of plastic and having a wide cap.
To install them, you will need to drill holes through all layers of insulation and into the wall. Next, the “fungus” is installed in the hole and driven in like dowels, opening up inside the wall. “Fungi” promote better adhesion of mineral wool to the wall surface and hold it. When the work is completed, your home should look like a quilted mattress.
Before you begin cladding the facade, you should install a counter batten on the frame, with the help of which a ventilation gap will be formed; it is on these beams that the façade trim, in our case, will be attached - this will be siding.
Glass wool
The latest technologies are used in the production of glass wool, so it is completely safe. Glass wool is a universal insulation for a wooden house under siding, since it can be used at any temperature.
Such insulation of a wooden house from the outside with mineral wool under siding has many advantages:
- frost resistance;
- fire resistance;
- glass wool is convenient to use in hard-to-reach places;
- the material does not absorb moisture at all and at the same time allows steam to pass through;
- has water-repellent properties;
- low cost;
- easy to install;
- environmentally friendly;
- resistance to temperature changes.
Flaws:
- undergoes shrinkage;
- has low density;
- thermal insulation properties are slightly worse than those of mineral wool;
- increased fragility of fibers.
Preparation for installation
If you are installing siding in temperatures below 10 degrees, remember that vinyl panels may crack.
Installation of almost any type of siding does not depend on the time of year, the only exception being vinyl panels, which in frost below 10 degrees become highly brittle and can simply crack. Otherwise, there are no restrictions in terms of climate.
There are no special restrictions or requirements regarding the surface of wooden walls. It doesn’t matter what condition they are in, whether they are logs or beams, the insulation will still be laid between the bars of the sheathing frame, which will hide any flaws and defects.
The only thing that needs to be done first is to dismantle all elements that will interfere with the work: window shutters, decorative elements on the walls, drainpipes, plants located on the walls or touching them with branches, etc.
Extruded polystyrene foam
The material is a plate made of foamed polystyrene. It is characterized by high strength, low moisture absorption and excellent heat saving properties.
Advantages:
- ease;
- cheapness;
- durability;
- possibility of internal and external insulation;
- corrosion resistance;
- low water absorption coefficient;
- simple insulation of the walls of a wooden house with your own hands.
Flaws:
- flammability;
- non-vapor permeable.
Styrofoam
It is a white cellular material consisting of 98% air. The material has excellent thermal insulation properties due to the insulation of the cells. Insulating a house under the siding from the outside with polystyrene foam is a way to protect the wood from the adverse effects of the environment and save interior space.
Advantages:
- has excellent thermal insulation properties;
- the material does not absorb moisture;
- mold and fungus do not form on its surface;
- easy to cut;
- easy to install;
- has an affordable price;
- ease;
- When installing foam plastic, no additional waterproofing is required.
Flaws:
- destroyed upon contact with nitro paints;
- does not allow air to pass through;
- needs additional protection from mechanical damage.
The advantages of this type of siding
Brick siding with insulation The facade of a house can be insulated in different ways, but the simplest and most cost-effective is siding. The owner can be sure that using such cladding will not only ensure heat preservation, but will also give the house a beautiful appearance.
So:
- It turns out that with the help of thermal siding, a living space is not only effectively insulated, but also decorated.
- If you take panels that look like brick, then, from a distance, you won’t even be able to tell that it’s not brickwork.
- Now the price - this cladding option will cost several times less! It is for these very reasons, which are the advantages of thermal siding, that it is so popular and in high demand.
Siding with insulation Here are just a few features of thermal siding that make it clear how good this material is:
- It is distinguished by enviable strength;
- It stands the test of time excellently;
- It always maintains an affordable price;
- You can choose from a huge range of colors and textures. On our resource you can learn more about the combination of siding colors.
Insulated siding In addition:
- Can be installed in any weather, no matter what time of year it is outside. Thermal siding panels are made from polyurethane foam, and the latter is not afraid of temperature changes;
- It is also good that thermal siding has low thermal conductivity. In other words, by retaining heat in the room, such panels contribute to significant savings in money that the owner would spend on heating;
- Thermal siding protects the facade of the house from the effects of various climatic factors;
- In addition to thermal insulation, the panels perfectly soundproof the house and effectively protect residents from external noise;
- Panels and other components of any type of siding are easy and simple to install. Despite the fact that the panels are strong and reliable, they are very light, and this significantly reduces the complexity of installation;
- There is no need to strengthen the foundation when facing with thermal siding panels, which is also very good.
Insulation for siding All these advantages cannot but make this material very popular among builders and owners of residential premises.
In fact, insulating the facades of houses using the described materials reduces heating costs by 50 percent, which, you see, is very profitable. In addition, the walls of the houses are protected from excess moisture; mold and mildew do not appear on them.
Warm siding
Technology of insulating a wooden house from the outside with mineral wool
Properly performed insulation will extend the life of the log house, improve the microclimate in the house and save on heating.
Preparatory work
The reliability and service life of the insulation will depend on the quality of this activity. You need to check the walls for any gaps or cracks. They are cleaned of dirt and dust and blown with antiseptic agents. You can use felt, moss or tow to seal cracks.
Frame structure
The frame is made of boards with a width of 100 mm and a thickness of 40 mm. They are packed vertically so that the distance between 2 adjacent boards is slightly less than the width of the seal. The sheathing is secured with nails or self-tapping screws. The timber must be treated with antiseptic solutions.
Laying insulation
Mineral wool slabs must be inserted between the frame boards so that there are no gaps between them. It is recommended to lay mineral wool in 2 layers so that the middle of the second layer of slabs is aligned with the joint of the first. Since mineral wool slabs are elastic and rigid, they do not require additional fastening.
Vapor barrier
This is a very important stage in insulating a wooden house under siding. Can be used:
- roofing felt;
- special vapor barrier film;
- plastic film;
- foil (aluminum).
You need to ensure ventilation of the facade of the house under the film. This only applies to houses with smooth wooden surfaces.
Price for façade insulation work under siding
Any of the chosen methods is easy to do with your own hands, but if circumstances do not allow, you can order work from professionals. Similar work is carried out in any construction company that has finishing specialists. The price depends on the scope of work:
| the type of materials | Material price, rub./m2 | Price of work without material, rub./m2 |
| Membrane waterproofing | From 55 | From 100 |
| Bituminous mastic for wall treatment | From 15 | From 55 |
| Mineral wool (glass/min.) | From 100/250 | From 250/200 |
| Styrofoam | From 70 | From 120 |
| Vapor barrier | From 25 | From 50 |
| Vinyl siding | From 100 | From 450 |
You can save money by doing the insulation yourself and inviting specialists to install the siding. In any case, the work must be done with high quality; this determines whether frequent façade repairs will have to be made, and how warm it will be in the house.
