When designing a bathhouse on a site next to the house, many owners ask themselves: what building material should they choose? Along with traditional wood, modern gas and foam concrete blocks, brick does not lose popularity as a raw material for the construction of baths.

Advantages and disadvantages of aerated concrete baths

The first bathhouse made of aerated concrete: pros and cons of this material. If we compare aerated concrete with wood, the former has more for a long time operation and low cost. The material contains sand-cement mixture and water.

Cellular concrete blocks have the following advantages:

1. simplicity and speed of installation of blocks;
2. with proper internal waterproofing, they are resistant to high humidity;
3. low level of thermal conductivity;
4. the ability to independently cut blocks;
5. affordable price.

Simple installation of blocks becomes a decisive argument when answering a beginner’s question: what is the best material to build a bathhouse from? Optimal choice – prefabricated buildings made of lightweight aerated concrete.

Review of aerated concrete bath: We converted the sauna into a bathhouse made of aerated concrete, located in the Moscow region. The sauna was 5 years old, the walls were dismantled. The autopsy showed small shoals due to violations of masonry technology. Overall everything is fine. 300mm concrete was used + half-brick cladding. No insulation.

List of strengths and weaknesses of foam blocks as a material for a bath

Despite the recommendations of construction regulations on the strict selection of raw materials for construction bath complexes(in particular, a ban on the use of cellular concrete and hollow brick), many land owners prefer these positions due to their availability and price range.

Analyzing the pros and cons of a bathhouse made of foam blocks, it is necessary to note the hygroscopicity of all concrete-based materials. This parameter is determined by the peculiarity of the internal structure of the raw material - the pores perfectly absorb water and steam molecules. The block is most noticeably destroyed when there is a sharp temperature conflict - hot air indoors and frost outside. Therefore, any building made of foam cellular concrete needs careful waterproofing interior walls sheet foil, and external ones - any facing material. These operations increase the cost of the project, making it unfeasible.

Considering the total costs of constructing a foam concrete building, it is better to build a bathhouse made of bricks.

Advantages and disadvantages of brick baths

A brick bath, the pros and cons of which will be mentioned below, is a good alternative wooden building. Natural clay raw materials are environmentally friendly and can withstand high temperatures. The advantages of such a bath are obvious:

• the period of use of the building exceeds 50 years;
• brick - universal material, the shape of the bath can be any;
• no external finishing required;
• high fire resistance.

Brick buildings are not without their disadvantages:

• high price. Compared to a tree or cellular blocks, brick construction– the most expensive;
• high coefficient of heat capacity of the material, causing significant fuel consumption to heat the microclimate.

The listed options for bathhouse materials can be called less popular than traditional wood. Many owners of country real estate have no doubt that the best sauna there may only be a structure made of wood. And such masters are faced with a completely different question: a bathhouse made of timber or logs?

Review of brick bath: Our bathhouse is made of brick, we wash ourselves all year round. We built it ourselves, the construction was long and tedious. Overall it turned out well, the bathhouse lasted for 2 years with no problems, and it will last for several decades without any problems.

Pros and cons of wooden baths made of logs and timber

In Rus' they have long been building log cabins. Before choosing whether linden or aspen is better suited for a bathhouse, you need to make a choice in favor of timber or logs.

Timber appeared on the market immediately after the discovery of timber processing technology. Building a bathhouse from timber is simple. Profiled raw materials can be square or rectangular section, but any of these types of material has a significant drawback - cracking during operation. Another disadvantage of using timber is the need to wait until the bathhouse shrinks. This takes on average 0.5-1.5 years. This disadvantage also applies to log baths.

A significant advantage of logs is their high aesthetic characteristics. Externally, such a bathhouse looks very colorful, rustic and cozy. In addition to its beauty, a log bathhouse has the following parameters:

• a special indoor microclimate that has a beneficial effect on health;
• the tree “breathes”, allowing steam to escape;
• robust design with correct operation can last for several decades.

Illiterate preparation of logs for construction or use poor quality material leads to rapid wear and tear of the building, requiring its reconstruction or replacement.

Review of wooden bath: A log is more durable than timber, especially if properly prepared at the end of winter.

Which wood to choose?

What kind of wood is best to build a bathhouse from - ordinary people are interested. The best option are hardwood trees, because during use all surfaces will heat up to high temperatures. Deciduous trees, most often used in bathhouse construction– aspen, linden. What material makes the bathhouse stronger?

In Russia, bathhouse buildings are more often built from cordate linden, which can be called a healer because of its positive energy. Light linden wood is perfectly processed and hardly deforms over time. The low density of the material and low weight are additional advantages. Basswood is usually used in conjunction with an oak frame.

Aspen has a soft structure, low susceptibility to rotting and proliferation of microorganisms. Over the years, an aspen bathhouse gains high strength; its walls begin to emit a specific ringing sound when struck. The antimicrobial properties of aspen were used by our ancestors in the construction of wells with spring water. If we talk about the financial side of the issue, an aspen log house will cost the owner of a bathhouse cheaper than its linden counterpart.

To summarize the above, it should be noted that each material has its supporters and the choice of raw materials for the construction of a bathhouse remains with the owner of the site. Below are reviews about each type of building, collected from construction forums.

Review of wood: Aspen has one advantage over linden - price! If the price tag suits you, take the linden. Fragrant tree. Linden is a more resistant tree to moisture and temperature changes.

Profiled timber is made from wood coniferous species. This building material is environmentally friendly. During the production process, the timber is processed on a four-sided jointing and milling machine. As a result, two of its sides receive a tongue-and-groove profile, while the other two sides become smooth. Using this building material allows the construction of a bathhouse from profiled timber chamber drying without the cost of additional wall decoration. Drying the timber in a special chamber reduces its humidity from natural 50-60% to a minimum value of 18-20%.

A list of some advantages of baths with walls made of chamber-drying timber

Bathhouses made from chamber-drying timber have a number of advantages when compared with buildings made from other materials made from wood:

• the use of environmentally friendly building materials eliminates the possibility of toxins appearing when the temperature rises;
• shrinkage of a log bathhouse made of chamber-drying profiled timber after construction does not exceed, as a rule, 3%, which allows completion interior work within a month or a month and a half after the installation of the log house, significantly reducing the time required to carry out all work;
• a bathhouse made from chamber-drying timber will last for decades, since the timber is not subject to rotting and biodestruction due to the low percentage of humidity;
• the weight of the bathhouse frame is relatively small, which allows it to be installed on the most economical type of foundation - strip;
• bathhouse walls made from chamber-drying timber are waterproof, have a low thermal conductivity, are reliable and durable.

How we build a bathhouse from kiln-dried timber

We divide the entire bathhouse construction process into 4 stages:

1. design;
2. foundation installation;
3. assembly and installation of a log house;
4. insulation of the ceiling and flooring.

To clarify the cost of building a bathhouse from chamber-drying timber, the customer can at any time call the numbers listed on the website, name the estimated dimensions of the bathhouse and find out the estimated cost of construction. In addition, our consultant will also be able to answer other questions regarding pricing and the work process.

Ventilation of the bath is divided into general and preservative. We call preservative ventilation the drying of the bath after water procedures. If in the bathroom and shower the main difficulty is drying towels and floor mats, then in bathhouses it is most difficult to dry wood, especially on floors and in cracks.
Drying of bathhouses, bathtubs and showers is carried out using aerodynamic methods - dry ventilation air enters the zone of moistened materials, evaporating the water. Water vapor enters the air. Through exhaust ventilation Humidified air is removed and fresh air comes in. Thus, technological process drying involves several stages and is far from simple.

Let us immediately make a reservation that if we consider the problem broadly, we should not talk about drying, but about normalizing wood. The fact is that in dry, high-temperature saunas, wood sometimes does not get wet, but, on the contrary, becomes overdried, and after the end of the bath procedure it is moistened again due to equilibrium hygroscopicity. In steam and wet baths, wet wood must also be dried not to an absolutely dry state, but to a certain level of humidity. That is, preservative ventilation is not just drying wood, but drying taking into account the specific bathing process, the characteristics of wood, its possible morbidity and possible consequences overdrying (warping, cracking) and underdrying (rotting).

Moisturize - dry

For all its advantages, wood also has many disadvantages, which makes it a problematic material for baths. Fire hazard, low hygiene and the ability to rot quickly - these are the main features of

natural wood, which at one time put an end to the prospect of using wood in urban public baths for hygienic purposes.

In individual baths, wood continues to be used in a periodic (episodic) mode with mandatory subsequent drying, despite the possible chemical treatment of wood.

Wet wood is susceptible to all three types of biological destruction - due to bacteria, fungi and insects, while dry wood is susceptible only to insects. If wood rot is slimy with unpleasant smell- This is most likely bacterial rot. If plaques, stains (spots of foreign color), or mold with an earthy smell form on the wood, these are probably microscopic fungi (fungi, micromycetes). Bacteria and micromycetes are not so dangerous for country individual baths, which will last for many years even with colors. But for executive and apartment baths, micromycetes are the number one scourge, since they spoil appearance finishing. But the most dangerous for baths are macromycetes - large, real mushrooms with characteristic fruit caps, living directly on the wood (like honey mushrooms, tinder fungi, sponges). Many summer residents, surprised to notice brown fan-shaped mushroom caps sticking out of the floor in their bathhouse, at best will only scrape them off and smear the growing area with vitriol or chromium, not realizing that these caps are only the fruiting bodies of the house wood-destroying fungus. The fungus itself is hidden in the floor, walls, foundation (both in wood and in brick) in the form of a system of branching threads (single GIFs - cords up to 1 cm in diameter), forming a mycelium several meters in size, so the development of the fungus can only be stopped antiseptic treatment large areas. Normal temperature for the development of house mushrooms 8 - 37°C, relative wood humidity 25 - 70%. IN optimal conditions the fungus destroys the bathhouse in one season, forming brown, fissured rot, which breaks up into large prismatic pieces that are easily ground into powder.

It is believed that the development of house fungus stops when the relative humidity of the wood is about 18% or lower. Considering the wood hygroscopicity curves from this point of view, several conclusions can be drawn. Firstly, to maintain wood moisture content of 18% and below at all temperatures for fungal development (5 -40°C), a relative air humidity of no higher than 80% is required. Otherwise, even completely dry (but not treated with water-repellent compounds) wood will become moistened above this level by itself (without contact with room water) due to the absorption of moisture from the air. So in tropical countries there are more problems with wood than in the north. Secondly, considering the hygroscopicity curves of wood in other coordinates (Fig. 1), it can be noted that wood, no matter how strongly moistened at a temperature of 30 ° C and an absolute air humidity above 0.03 kg/m3 (that is, at the calculated relative humidity air 100% and higher relative to the temperature of the wood), dries at a temperature of 40°C to a humidity of 11% (and only up to 11%!), and at a temperature of 80°C to a humidity of 2.5% (and only up to 2.5%! ). All this is extremely unusual: non-porous materials would dry out completely under these conditions. For marble, metal and plastic, only two states are possible: when there is water on them (and no matter how much) and when there is no water on them at all.

In this regard, let us recall how dry wood is moistened. If you splash water on wooden board, it is gradually absorbed deep into the wood: first into the intercellular spaces (vessels, pores between the fibers), then into the dense (dried) cell cavities, then into the cell walls. All these pores are capillaries with wettable walls. Due to the formation of concave menisci of water surfaces, the saturated vapor pressure above the water inside the wood is less than above the water spilled over the surface. Therefore, not only water, moving along wetted surfaces, but also its vapors rush into capillaries (intercellular and cellular), are moistened (and then dry quickly). The water in them is called free; its content in wood can reach 200%. Small capillaries (in the cell walls) are moistened (and then dry out) slowly, the water in them is called bound (hygroscopic), its content in wood reaches up to 30% (this is what is presented in Fig. 1). Thus, a seemingly “dry” board without drops of water can contain 100% or more moisture, and this moisture, during drying, is extracted from the wood in the form of water vapor and can humidify the air. This effect is used not only when drying a bath, it is also used to create a condensation climate in a Russian steam bath, when, due to the high relative humidity of the air near the ceiling (for example, when water is applied to hot stones), the ceiling (preferably a massive log ceiling) is first moistened. Then, during the periods between applications, high absolute humidity is created near the ceiling - above 0.05 kg/m3. Metal ceiling under these conditions, it would not simply “drip” without retaining moisture, it could only create a very specific relative air humidity at its surface, equal to 100%. A wooden ceiling (like any porous one) can, in principle, create only a very specific relative air humidity at its surface, and at a fixed humidity of the wood (due to the massiveness of the walls, for example), the relative air humidity not only at the ceiling, but also in the room can be maintained also practically constant regardless of how the temperature in the room changes. The effect of stabilizing relative air humidity in wooden residential buildings(in brick and plastered ones too) are associated in everyday life with the property of wood to “breathe”, take moisture from the air and release moisture into the air in the form of water vapor. So a plastic bathhouse and a wooden bathhouse, even with the same steam generator, provide different climatic conditions. Indeed, let’s imagine that the sauna is completely dry at a temperature of 20°C and at normal relative air humidity of 60% (that is, at an absolute air humidity of 0.01 kg/m3). According to Fig. 1 the relative humidity of wood under these conditions is 12%. Now let’s hypothetically warm up this sauna (without ventilation and without humidification) to a temperature of 70°C. The bold dotted horizontal arrow in Fig. 1 shows that the absolute air humidity in the sauna jumps to 0.14 kg/m3, just right to steam with a broom! Where did the water come from! The wood began to dry and humidified the air. By the way, it is the water vapor escaping from the wood that “draws” with it the “smells of wood” that are so valued in apartment saunas. This phenomenon serves as another additional reason for the need to ventilate even dry apartment saunas so that they do not unexpectedly become steamy. And if the sauna is ventilated during warming up fresh air the same absolute humidity of 0.01 kg/m3, then the air in the bathhouse will remain dry, and the moisture content of the wood in the bathhouse will decrease and sooner or later drop to 1% (see the vertical thick dotted arrow in Fig. 1), that is, as they say in everyday life, the boards will “dry out.” And then, after finishing the bath procedure, they will be moisturized again due to the sorption of air moisture to a humidity of 12%. In meteorological parlance, “wood tries to keep the relative humidity of the air constant.” Indeed, in the wooden bathhouse discussed above, the wood “kept” the relative air humidity in the bathhouse at 60%, which can be achieved in conditions of rising temperatures only by humidifying the air with wood. Nothing like this in plastic bath it cannot be: when it is heated, the absolute humidity of the air remains constant, and the relative humidity drops. It is glass sheet metal and plastic are ideal materials for dry physiotherapy and apartment saunas. And if you use wood, then only thin wood, specially treated to prevent hygroscopic absorption of moisture from the air. Decorative craze wood trim baths (not always justified) leads to the fact that even bath hygrometers are sometimes performed in wooden cases(!), “keeping” the relative humidity inside itself constant, regardless of the temperature and true humidity of the air in the bathhouse. By the way, let us remind you that the measuring thread of the hygrometer, located inside the case, stretches when moistened (like an ordinary woolen thread) and thereby shows how much it has been moistened. And it is moistened hygroscopically (due to its porosity) according to the same laws as wood. That is, the thread is moistened and elongated mainly only when the relative humidity of the air changes. This is the principle of operation of hygrometers with natural filament. By the way, wood fibers stretch and contract only when the relative humidity of the air changes. In rural life, the simplest but very accurate “hygrometers” in the form of a thin, sanded and dried bifurcated wooden branch are well known. A thick mustache (the main branch about 1 cm thick) is cut 10 cm above and below the fork and nailed vertically to the wall (baths, houses, cellars). A thin tendril (a shoot about 0.3 cm thick and 0.5 m long) is directed upward parallel to the wall. In dry weather, the long thin tendril of the branch bends, moves away from the thick one (“protrudes” with an increase in the acute angle of the fork), and if it rains, it approaches the thick one. If you have a certified industrial hygrometer, then this homemade hygrometer can be calibrated with marks on the wall opposite the location of the tip of the thin whisker at different relative humidity levels. The principle of operation of such a hygrometer is that when dried, the underlying wood fibers of the main branch are shortened and pull the shoot down (from the trunk of the main branch).

Thus, the processes of moistening and drying wood occur in the bath not only on the floors due to compact water and are associated not only with bath procedures. If wood can be moistened with both compact water and water vapor, then it can be dried only by removing water vapor from it. The drying process occurs in several stages. First, water evaporates on the surface of the wood, then free water in the large capillaries of the intercellular and intracellular spaces, then water in the small capillaries of the cell walls. The latter, as we established above, determines the hygroscopic moisture content of wood, which exists and changes even in a dry, unheated bath. Therefore, the drying of cell walls can actually be controlled in greenhouse conditions dry built-in saunas, although bound water can, in principle, support the processes of wood decay, especially, as we noted, in warm and humid climatic conditions.

The step-by-step drying process is also typical for other porous materials, including brick, plaster and soil (earth). Drying them is also important for the bath, if they are part of it. In this regard, let us recall the fundamental, although only indirectly related to the topic of the article, question of mechanical deformation of porous bodies during the initial removal of bound water from them. It is known that warping and cracking of freshly cut wood occurs during the drying process, mainly in the last The final stage when removing hygroscopic moisture from cell walls. If during initial drying the board is nailed or clamped in a vice, it will retain the shape given to it (for example, arcs), and the better the wood is dried, the better. Under conditions of primary natural atmospheric drying at 20 - 30°C, wood is dried only to a moisture content of 10 -15% (after 2-3 years of drying), and with high-temperature stone drying at 100 - 150°C (including in a bathhouse ) can be dried to a moisture content of 1 - 2 96. With such significant dehydration, especially in conditions high temperatures, irreversible changes occur in the cell walls, and the wood actually ceases to be wood and begins to exhibit the properties of a non-living material. Similarly, clay soaked in water, when dried and heat treated, first loses its plasticity, then cracks, and then becomes a brick, which subsequently does not change its shape and properties when in contact with water, especially good results are achieved by primary drying of wood with superheated water steam, as well as by immersion in a hot anhydrous coolant (paraffin, petroleum products).

The mechanism of primary drying of freshly cut wood is distinguished by the fact that the walls of its cells have not yet been destroyed, the vapor and water permeability of the membranes is low and the wood dries for a long time, deforming during the destruction of the integrity of the membranes of the cell walls (and they, in fact, are wood - a combination of cellulose, lignin and hemicelluloses). During subsequent drying, the wood dries faster and behaves as if it were “lifeless”, since the cell walls have already been torn. At the same time, dry wood, as a porous material, has specific features that distinguish it from other materials, in particular, anisotropy of properties, secondary warping, etc.

Drying dynamics

Water spilled on the surface of wood evaporates in the same way as water poured into a bathtub or swimming pool. Let us recall that there are two opposite modes of evaporation - kinetic and diffusion. In the kinetic mode, the fastest molecules, overcoming the energy barrier equal to the latent heat of evaporation (condensation) 539 cal/g, fly out from the surface of compact (liquid) water and are irrevocably removed. The kinetic regime is realized during evaporation in a vacuum. In view of high speed the primary act of vaporization (the emission of water molecules from the surface of compact water), which at bath temperatures amounts to thousands of kilograms of water per hour per 1 m2, the water is strongly cooled (since only slow molecules remain in it) until it turns into ice, which is used in freeze drying in industry. In the diffusion mode, the primary act of vaporization remains the same and depends just as strongly on temperature. But the escaping water molecules enter the air (a mixture of nitrogen and oxygen molecules) and, as a result of frequent collisions, only very slowly move away (diffuse) from the surface of the water, experiencing strong resistance from the air environment. As a result, the overwhelming number of emitted molecules “fly” back into the water (condenses). Thus, in the diffusion mode, tons of water turn into steam and immediately condense (which is not felt by us at all), and only very a small amount of water (kilograms) completely evaporates. It is this diffusion mode of evaporation that takes place in the bathhouse: both during the evaporation of sweat from the human body, and during the evaporation of water from the shelf. It becomes clear that if the concentration of water vapor molecules is equal everywhere in the bath (including at the surface of the human body), then no evaporation processes are possible (homothermal mode). But at the same time, it becomes clear that if tons of water per hour simultaneously evaporate and condense in a bathhouse, then we can assume that this should manifest itself at some point. Indeed, if the air in the bathhouse is dried, the rate of water evaporation will increase. If the surface of the water is blown with dried air, the evaporation rate will increase even more, since the air flow removes those water vapor molecules that previously condensed. For orientation, we point out that at a relative air humidity of 5096, the rate of water evaporation at a temperature of 30°C is approximately 0.1 kg/m2/hour. When air moves at a speed of 1 m/s, the evaporation rate approximately doubles, however, it should be noted that the air speed in the room is always much greater than directly above the surface of the water, and any quantitative indicators are extremely approximate. For assessments, you can use experimental formulas for swimming pools. In any case, the characteristic drying rate of floors in bathhouses is 0.1-1 mm/hour (0.1-1 kg/m2/hour) and increases with increasing floor temperature and with decreasing air temperature (that is, with decreasing absolute air humidity). So, for example, in open pools at a constant water temperature, evaporation is maximum not during the day, but at night in cold air, as well as in winter. During the day, in hot weather, evaporation may stop, and condensation of water vapor from the air on the surface of the pool may even be observed, just as water condenses on human skin in a condensation-type steam bath in a mode higher than homeothermal. For any pool with a certain water temperature, any floor, wall and ceiling, each bathhouse has its own “homo-thermal” curve, separating the modes of water evaporation and condensation of water vapor, summing up the above-mentioned processes of evaporation and condensation on the surface of the water. Let's call it conditionally condensation. In terms of condensation curves, drying looks like this. In Fig. Figure 2 shows condensation curves for the floor with a temperature of 20°C (curve 1) and for the ceiling of a steam bath with a temperature of 40°C (curve 2). Modes below the curve correspond to the evaporation of water, regimes above the curve correspond to the condensation of water vapor on the surface of a given temperature. Thus, if the air in the bathhouse has a temperature of 40°C and a relative humidity of 6096 (and it does not matter whether the air in the bathhouse is stationary, circulates or comes from outside in the form of ventilation), then in this mode (point 3) the ceiling is dried and the floor is moistened . In other words, air with such parameters transfers water from the ceiling to the floor, but even if the ceiling were dry, the floor would still take moisture from the air, that is, dry it out (in in this case up to a relative humidity of 40%). The floor can be dried only if you reduce either the air temperature or its relative humidity, or better yet both, so that the air characteristics are located below curve 1, for example, if the mode corresponding to point 4 is implemented. The fact of possible air movement (blowing the floor) does not change the qualitative picture, but only affects the rate of evaporation or condensation. By the way, it is precisely this mechanism that works in case of catastrophic moisture in the underground of a residential building, to which a bathhouse with leaking floors is attached. Warm wet air from being poured onto the ground hot water spreads over long distances and releases condensation on cold subfloors and the foundation of the entire residential building.

The main conclusion is that preservative ventilation is not just changing the air in a damp bathhouse. It is necessary to supply air with as low a temperature and relative humidity as possible, or rather with as little absolute humidity as possible. In addition, it is necessary to keep the surfaces to be dried as warm as possible, and the higher the absolute humidity, the high temperature must have a dryable surface. This means that it is necessary to heat not the air, but the floor of the bathhouse, for example, with infrared radiation. And if you still manage to warm up only the air, then it must be dried, as is done in washing and washing machines. dishwashers. Note that the sometimes recommended methods of drying a bathhouse with the release of hot moist air through the floor into the underground only lead to additional moistening of the cold (and therefore the most problematic) elements of the bathhouse. It is better to release hot, humid air through overhead vents where condensation is impossible. In fact, almost all baths use general ventilation for conservative interior drying.

When water has completely evaporated from the surface of non-porous materials, drying can be considered complete. But when we are dealing with wood, it is also necessary to remove internal water. If wood is treated with water-repellent compounds, then the pore walls are not wetted by water, which means that the water vapor pressure in the pores is greater than on the surface of the wood. This leads to the “evaporation” of water from the pores onto the surface of the wood in the form of droplets, which then evaporate a second time as described above.

Water filling pores with wetted walls, including unimpregnated wood, evaporates in a diffusion mode, and steam removal is extremely difficult. Although wood contains 50 - 90% voids, the tortuosity of the pores means that the actual path of removal of water molecules can be several times greater than the characteristic dimensions (thickness) of the wood product. In this case, possible air flows, even very small ones, can greatly influence the drying speed. The “blowability” of materials is characterized by a parameter called vapor permeability, equal, for example, to mineral wool 8 - 17, for pine along the grain - 10, pine across the grain - 2, brick - 2, concrete - 1 in units of 10"6 kg/m/sec/atm. So, with characteristic differences static pressure due to wind 104 atm. actual drying rates for porous materials 10 cm thick at 20°C are less than 1 g/m2/day for vapor-insulating materials (hydraulic concrete, asbestos cement, extruded polystyrene foam), 1-20 g/m2/day for vapor-permeable materials (wood , brick, plaster), more than 20 g/m2/day for vapor-permeable materials (mineral wool), more than 1000 g/m2 per day for superdiffusive materials (perforated membranes). The drying rate increases with increasing wood temperature and with decreasing temperature and humidity of the blown air, just as in the case of water evaporation from the surface. The required ventilation air flow rate is selected experimentally depending on the degree of humidification and time of year, but temperature has a much greater influence internal elements baths It would be possible to continue analyzing the issues of drying wood and consider the most reasonable solutions for preservative ventilation. But there is no point in deceiving: centuries-old operating experience wooden baths shows that no matter how dry wooden floors are, there are still no guarantees of drying quality, they still rot. Indeed, if 1 m2 of wooden floor absorbs approximately 1 kg of water, then drying it at a rate of 20 g/m2 will last 50 days. Therefore, wood is covered with roofs and canopies wherever possible (and not only in bathhouses), but even in this case it is capable of moisturizing. condensate from the air (for example, under iron roofs) and rot (turn brown, darken, crumble), especially in poorly ventilated places. The presence of vents, that is, holes and cracks larger than 3-5 mm in size, is an indispensable condition for the safety of unheated areas wooden structures. Vents less than 1-3 mm in size, on the contrary, are stagnant, poorly ventilated areas; moisture from them evaporates slowly, which creates conditions for rapid rotting, especially when in contact with vapor-proof materials, and even more so with constantly moistened ones. The question is not about how to properly dry the wood, but about how to eliminate it from the bathhouse altogether or reduce its wetting and reduce the rate of decay. This is typical not only for wood, but also for all porous mineral materials(brick, foam concrete, gypsum) and rusting steel. After all, no one makes floors from foam concrete and then makes incredible efforts to dry it. This is how they paint rusting steel, and don’t try to quickly dry it after every rain. IN modern baths all wood that may come into contact with water must be impregnated with water-repellent compounds (preferably under pressure, as is done in the case of railway sleepers and ship masts), and protected from above with waterproof paint and varnish coatings, as well as shelters, not to mention antiseptic and fire-fighting treatment. Wood in a bathhouse is a problematic material, and the prevailing opinion that the only good thing about a bathhouse is that it is wooden and there should be no “chemistry” in it is absolutely groundless. Of course, in the conditions of a built-in fun sauna, operated in the greenhouse environment of an apartment corridor, unimpregnated wood is permissible even on the floors, but even there only in the form of a removable dryable grate.

CEILING VAPOR PROOF

Methodologically more complex is the issue of ventilation of the wood of the upper parts of the walls and ceiling. The task of preservative ventilation here is to supply dry air to humidified areas to dry them. Therefore, in each specific case, it is necessary to clarify what and how can be humidified, and only then decide where and how to supply ventilation air.

The ceiling (or rather ceiling) can be moistened by precipitation during emergency roof leaks and steam condensation. Previously, humidification due to trivial leaks was predominant, since until the 19th century in cities and until the 20th century in villages there were no bathhouse roofs except wooden ones (board, shingles), thatch and reed roofs. If the roof was faulty, log walls and ceilings could absorb hundreds of liters of water in the rain. Therefore, there was no need to talk about any possibility of periodically drying them after constant leaks, although wooden roof it worked precisely in this mode of constant moistening and drying (as a result of which the wooden roof was made thinner so that it would get wet less). The task was simple: to prevent leaks, but if they happened accidentally, then the walls and ceiling had to be dried sooner or later. This was achieved by constant ventilation attic space, by organizing where possible air vents, gaps and cracks in log and plank structures, that is, the same techniques were used as in the natural drying of firewood in woodpiles, but, of course, preserving the heat-insulating ability of the walls and ceiling.

Currently, individual developers do not take leaks seriously, relying on the reliability of steel and slate roofs, although the issue remains serious, and the consequences are the most dangerous. So what happened, as a result of which everyone around began to talk about the indispensable need for vapor barrier of the walls and ceilings of the bathhouse as the most important thing? After all, previously, for centuries, in log black and then in white steam baths, no vapor barrier was known, and steam humidification is so insignificant compared to leaks that they cannot create a dangerous level of wood moisture content above 18 percent for a long time (especially in dry built-in saunas ).

Let us immediately note that the question of vapor protection of wood and insulation first arose in bathhouses in connection with the appearance of soft waterproofing materials in everyday life. roofing materials(which are also often used inappropriately) direct purpose), and dangerous levels of wood moisture acquired an exclusively local, long-lasting character. However, before moving on to this issue, let's consider general features moisturizing wood with condensing steam.

Usually in the literature the humidification process is described briefly and simply: moist air is filtered through porous wood from the inside out, and where the temperature of the wood drops to the level of the dew point of moist bath air of 40 ° C, local steam condensation occurs and the wood is humidified only at this point. In fact, the process is more complex. Firstly, wood is a wettable porous material, so the released condensate is absorbed by the wood and distributed along the wettable pore walls throughout a large volume of wood (blotter effect). By the way, then l<е самое происходит и в других смачивающихся пористых материалах: кирпичных, гипсовых, пенобетонных. Во-вторых, древесина является непросто смачивающимся пористым материалом, она имеет и мелкопористую составляющую, обуславливающую гигроскопичность материала (способность впитывать пары воды из воздуха). Для таких материалов характерно отсутствие четкой точки конденсации. На рисунке 3 изображена еще раз перестроенная в иных координатах кривая равновесной гигроскопичности древесины в зависимости от температуры. Это фактически график влажности древесины по срезу стены бани, имеющей температуру внутренней поверхности стены - 100°С (справа) и температуру наружной поверхности стены - 0°С (слева), при условии движения влажного воздуха изнутри наружу (справа налево). Мы видим, что при влажности воздуха, например, 0,05 кг/м3 (точка росы 40°С) равновесная влажность древесины на внутренней стороне стены равна 2 процента, затем по мере углубления в стену влажность древесины плавно, но быстро повышается и по мере приближения к точке росы 40°С резко возрастает до бесконечности. Это означает начало конденсации в крупных порах, но вся вода из воздуха в этой точке росы отнюдь не выделяется. Несколько осушившись, воздух продолжает перемещаться влево, непрерывно и постепенно отдавая воду уже при новых пониженных точках росы (например при влажности 0,017 кг/м3. Таким образом, увлажняется довольно протяженная зона, причем находящаяся у внешней стороны стены, которая впоследствии высыхает с выделением водяных паров наружу, но которая отнюдь не прогревается горячим воздухом при сушке интерьера бани. Так что очень большое значение имеет не столько температура воздуха в бане при ее сушке, сколько сухость этого воздуха, а также направление движения воздуха, фильтрующегося через стенку.

If the wall material is not finely porous (for example, like mineral wool, which has practically no capillaries) or if the material is treated inside with a water-repellent preparation and is not wetted, then the wood moisture curve will transform into a vertical dotted line at a dew point of 40 ° C, that is, at temperatures above dew point, such a non-hygroscopic material does not absorb moisture from the air at all, and at temperatures equal to the dew point and below, constant condensation of moisture from the air occurs in the same way as described above. However, in the case of non-wetting of the internal surfaces of the porous material, the released condensate cannot be distributed over large volumes of walls (that is, it cannot be absorbed) and inevitably accumulates in certain zones, also forming drops. When using mineral wool, drops of condensation flow in streams onto the lower elements of building structures, for example, onto wooden beams, joists, crowns, greatly moistening them. In any case, in vapor-permeable (air-permeable) walls it is advisable to make ventilation ducts (vents) in areas near the dew point, as well as near load-bearing wooden elements. In particular, a good solution is to upholster the log house of a bathhouse with planks (boards, clapboard, siding) inside and outside so that the gap between the boards and logs plays the role of steam ducts (ventilating facade).

Needless to say, there was always a desire to keep water out of the walls altogether.

Thus, in particular, in stone (brick) city baths the walls remained moist for years, despite ventilation. Therefore, the internal surfaces of the walls, where possible, were protected with ceramic tiles, paint and varnish coatings, and natural stone. Of great importance was the introduction into everyday life of cheap soft roll waterproofing vapor-proof materials, including roofing (first - roofing felt based on wood or coal tar, then - roofing felt and glassine based on bitumen-rubber mastics, synthetic polymer films and metal sheet foil). They began to be widely used in individual rural bathhouses, first for their intended purpose - as roof coverings, and then to protect the outer sides of ceilings and walls from rain and wind, especially frame ones insulated with non-waterproof materials (moss, paper, shavings, wood fiber boards, wood concrete, sectioned wood). straw wetted with glass wool). It is quite natural to want to cover, for example, a layer of shavings lying on top of the ceiling with something non-leakable, or to cover the wooden walls of a bathhouse outside with roofing felt to protect from wind and rain. As a result of this, the shavings, which previously were moistened only during rare leaks, and when moistened under the influence of steam penetrating from the bath, immediately dried out, under a layer of roofing material lost the ability to dry out after any moistening. More precisely, the shavings under the roofing felt can dry only when the moisture is removed back into the bath, which is very difficult. Therefore, it is necessary to make a ventilated gap (vent) between the chips and the roofing felt or make punctures in the roofing felt for ventilation. Instead of roofing felt, special roll materials called windproof materials were developed for these purposes. They do not allow compact water (raindrops) to pass through due to non-wetting, and at the same time they slightly allow air and water vapor to pass through due to porosity or perforation, but protect from gusts of wind. It should be noted that gusts of wind create pressure drops of up to 10 "atm., exceeding pressure drops due to heating the air in the bathhouse of 10 5 atm., so wind pressure certainly plays a major role in drying the walls. It is these pressures that are saved by windproof materials, although the air is passed in a very limited amount. The fact is that the gas-dynamic resistance of the windproof material is much less than the gas-dynamic resistance of the protected wall made of logs. Therefore, the logs practically do not “feel” the windproof material. At the same time, if the wall is not made of logs, but of easily blown insulation , then wind protection plays a decisive role, limiting the speed of air flow through the wall. The simplest windproof option is traditional wall upholstery with clapboards (boards), so upholstery can play not only a purely decorative and hygienic role.

At the same time, windproof materials cannot completely solve the problem of moisture. Indeed, by covering the chips on the ceiling with windproof material, we can only be sure that an accidental leak in the roof will not wet the chips, and if they do get wet (in any way), they will dry out sooner or later. But if the temperature of the windproof layer is below the dew point, then moisture will condense on this layer, which in a liquid state cannot pass through the windbreak. Since moisture enters the windproof material in the form of steam in the air flow from the inside to the outside, it is advisable to protect the ceiling from the inside with a vapor-insulating layer (air-tight film). This sandwich-type structure with three layers (wind protection - insulation - vapor barrier) is the basis of modern enclosing structures. A common technical requirement is to install a vapor barrier in areas with temperatures above the dew point. If the vapor barrier is carried out in the form of wall cladding (plastic, steel, ceramic), then questions about its installation usually do not arise. But what if the vapor-proof film is placed inside the walls? For example, is it necessary to create a gap between the aluminum foil and the decorative paneling? The answer is simple: if there may be compact water there, then a ventilated gap is necessary. For example, it is very difficult to create a gap on the ceiling. And if you open the ceiling of a steam bath after several years of operation, you will see that where there was no water (in the center of the ceiling), the reverse (upper) side of the lining is absolutely fresh. And closer to the walls, where there could be water, there are dark spots of damaged wood.

Vapor barrier prevents steam from penetrating into the wall, but at the same time stops the through blowing of the walls and, thereby, makes it difficult to dry them if the roof leaks. Therefore, having prevented the penetration of steam, it is still desirable to restore the possibility of blowing through the wall by organizing vents along the outside, and better yet, along the inside of the vapor barrier, although the role of preservative ventilation on the inside can be taken on by the general ventilation of the room. In this case, the supply and exhaust openings of the vents should go out onto the street or into the rooms adjacent to the bathhouse (dressing room, vestibule). To estimate the required dimensions of the vents, consider a log bathhouse with a volume of 10 m3 and an area of ​​enclosing structures of 25 m2. Let us take the degree of emergency moisture equal to 20 kg of water. Based on the characteristic vapor permeability of log walls at the level of 20 g/m2 day, the duration of natural drying in diffusion mode at wall temperatures of 10 - 20 ° C will not exceed 40 days (the value is quite large). If there is a vapor barrier on the logs, this duration of wall drying can be achieved at a wall ventilation rate of 1 m3/hour, which is significantly lower than the ventilation rate of the bathhouse premises - 10 m3/hour or more. This speed can be ensured by the supply and exhaust openings of the vents between the logs and the vapor barrier, with a total cross-sectional area of ​​10-50 cm2, that is, in fact, cracks (along the entire perimeter of the bathhouse), less than 1 mm wide, which is ensured by inaccuracies in the mechanical processing of wood and the assembly of structures .

In log walls, wood plays the role of windproof, heat-insulating, and load-bearing material. Modern construction design, including multi-storey buildings, involves the development of insulating materials with highly specialized functions and only sometimes combined functions. So, for example, waterproofing, windproofing, vapor barrier, heat insulating materials are, as a rule, completely different materials. At the same time, specialized film (roll) and tubular (cord) moisture-removing materials that can be placed inside walls and which, playing the role of vents, could remove moisture from hard-to-reach, most critical places in any form (in the form of compact water or in the form of steam). It is these drainage materials that will apparently become the basis for progressive solutions for preservative wall ventilation in the future. Indeed, how to dry (or keep dry) massive brick walls that have been in a damp state for years, the walls of city public baths, laundries, and swimming pools? Neither elevated bath temperatures nor maintaining relative air humidity at 40 to 60 percent in laundries and swimming pools can completely ensure dry walls, even those protected by ceramic tiles. Recently, hollow building materials have become widely used (slit bricks and concrete blocks with cavities, foam materials), but these voids in the walls must somehow be connected to each other and connected to centralized supply and exhaust devices that regulate the speed of preservative ventilation within the required limits. This role will be taken on by new ventilating materials, primarily in ventilated facades and roofs.

One way or another, using ultra-modern or traditional materials and structures, it is necessary to provide vents (ventilation ducts) in all places on the walls and ceilings where compact water may appear. The transverse size of the vents (slots - 1 mm or holes with a diameter of 3 - 10 mm) is not so important, the main thing is that the vents cover all problematic parts of the walls (especially load-bearing structures) and are ventilated exclusively with external air under the influence of wind pressure. If the vents are large, it is advisable to close the ventilation ducts to local supply and exhaust openings, the flow sections of which can be adjusted if necessary. It is not advisable to combine the supply and exhaust ventilation of a bathhouse with a wall ventilation system due to the possible increased humidification of the walls with moist bath air.

The relevance of a healthy lifestyle in the modern world increases every year, and against this background, many city dwellers strive to leave polluted cities and settle closer to nature. Low-rise construction is increasing the volume of houses being built and the quality of structures. When building a fairly comfortable country house while preserving all the benefits of civilization, in particular utilities.

Commitment to tradition

For a Russian person, the construction of a bathhouse on the site is a mandatory condition. Of course, it’s convenient to wash in the shower or in the bathtub, but nothing can compare with a bathhouse: the resinous smell of wood, the fragrant infusion of a steamed birch or oak broom in the steam room, hot and gentle steam, and then an ice-cold shower and strong herbal tea... This is what it looks like the dream of a bathhouse for most of its lovers and connoisseurs. In order for the bathhouse to bring only positive emotions, it is necessary to build it correctly and use it correctly. The easiest way is to order the construction of a bathhouse from professionals who will take into account all the requirements and wishes of the customer. What size to choose for each of the functional rooms, what is best to build a bathhouse from, how to determine its location and even the depth of the foundation. Most owners of a plot of land outside the city prefer to build a bathhouse themselves, which is much more economical from a financial point of view and much more pleasant for self-esteem. In the future, you can brag about the result and share your experience with the air of an expert on the subject.

Material selection

At the initial stage, every owner of a future bathhouse has a lot of questions: what to build a bathhouse from, what is the best foundation to make, what roofing materials to use, what materials for a bathhouse can be used as interior decoration? The owner of the future bathhouse must answer each of these questions independently, depending on preferences and financial capabilities. Modern technologies provide a wide choice of building materials and construction methods. The following types of materials can be used as a basis:

Each option is pre-calculated to determine the amount of material used and, accordingly, its cost. It is possible to use a combination of materials both for the construction of the main structure and for its finishing.

Preparatory calculations, design

Having decided what is best to build a bathhouse from, we proceed to designing it and planning it on site. At this stage, it is necessary to pay special attention to safe operation measures. The bathhouse should be located at a distance of 5-7.5 m from other buildings. If there is a natural source of water supply (well), the distance of the structure from it should be at least 15-18 meters - this will prevent wastewater from getting into the water; the maximum distance from a river or lake is 3-5 meters. must take into account the dimensions and materials for the construction of the bathhouse. The areas of the steam room, dressing room and washing section of the bath are determined depending on the properties of the material used and the number of people who can be in it at the same time. Depending on what materials are used for the bathhouse, the load on the foundation is calculated. Particular attention is paid to drainage and ventilation, which are planned depending on the operating mode and construction materials. The issue of insulating the walls and roof of the bathhouse is carefully considered - the quality of steam, duration and efficiency of use depend on this.

Construction stages

The site for the construction of the structure has been chosen, we begin construction. Before we clear and level the area chosen as the location of the bathhouse.

Foundation - the basis of the structure

We choose the type of foundation - it depends on the weight of the structure and the type of soil. The optimal solution would be to deepen it to the extent of freezing. The least expensive method is to first replace part of the soil (a bed of crushed stone of various fractions and sand). The pillars are located under the load-bearing walls and in the corners of the bathhouse. This way you can install this type of foundation around the entire perimeter.

For areas with nearby groundwater, the pile option is used. A prerequisite is the presence of a platform for the stove, which has a large mass (especially modifications with a water tank), and, accordingly, needs solid support, and a separate foundation will ensure fire safety.

The foundation must stand for some time and gain strength. It must be treated with special means to protect it from external influences. During the foundation construction phase, a drainage system and ventilation vents are installed.

Walls

The construction of walls is carried out in parallel with the process of their insulation. The owner, who has decided on the question of what is best to build a bathhouse from, must take into account the need, quality and quantity of the insulating layer used at the design stage. The final stage of wall construction is the construction of internal partitions and division of the bathhouse space into separate functional rooms. Partitions can be made from a basic building material or (as is most common) made from wood planks of varying widths. The final stage before finishing is thorough waterproofing of the walls and ceiling of the bathhouse.

Roofing and finishing

The construction of the roof will be the final stage of the construction of the bathhouse. The design of the roof depends on climatic conditions: the simplest and most cost-effective option is a gable roof. The attic will perform the function of retaining heat if it is built correctly, i.e., provides good waterproofing. The choice of material for covering the roof depends on the capabilities of the owner, and the structure of the sheathing also depends on this. The roof is sheathed on the inside with waterproofing material and additionally insulated. You can begin interior finishing work, which will again return the owner to the question of what is best to build a bathhouse from. The cladding of the walls inside each sector of the bathhouse has several functions: protection from moisture, aesthetics of the room and functionality. It is important to remember about such a concept as “bath spirit” or steam; it directly depends on the material of the interior decoration.

We build bathhouses from timber

For many bathhouse lovers, the question “What to build a bathhouse from?” absolutely not relevant - only wood, there can be no other opinion. This material has been used for many centuries: it is used for the construction of Russian baths everywhere. Bathhouses made of timber of any size are found on every second suburban area. Much has been said about the positive characteristics of wood used as a building material, but the conclusion is clear - this is the best option for a bathhouse. The only negative point is the short duration of operation, but at the current level of development of the chemical industry, processing wood from external influences increases the life and quality of service of any structure. The timber must be well dried and processed - only in this case the owner receives not only a magnificent appearance and pleasure from use, but also a great charge of vigor and health. For interior decoration, you can use different types of wood, it all depends on the preferences and capabilities of the owner.

Use of frame technologies

When building a bathhouse, the most budget-friendly option is to use frame technology. It is being developed in the vast expanses of our country very quickly, and one of the advantages, in addition to the low cost, is the speed of construction of the bathhouse.

The design is lightweight, does not require a powerful foundation, and the finishing possibilities both inside and outside are unlimited. After the main frame is erected, the walls are lined with insulation and hermetically sealed. The internal microclimate can be created by covering the walls with clapboard of any type of wood. Exterior finishing with siding, wood and tiles will give an aesthetic appearance to a structure such as a frame bathhouse (the photo will demonstrate this more clearly). One of the disadvantages of its operation is the increased level of humidity, but with proper use of the ventilation system and good sealed lining, this disadvantage can be eliminated.

Construction of a bathhouse from blocks

Many owners of country real estate, due to limited financial resources, have to save on building a bathhouse, but with the modern development of the construction market, the issue can be solved simply - we build a bathhouse from blocks. This material has a relatively low cost, is practical, lightweight, has an additional heat-saving function due to its cavities, does not shrink, and construction time is significantly lower than when using other materials.

At the same time, there is a choice of blocks; they are made of sand, cement, clay. There are several made from expanded clay, cinder blocks, foam blocks, and aerated concrete blocks. It is necessary to settle on one of the options, for example, we build bathhouses from foam blocks. Due to the qualities of this material, cost savings begin at the foundation laying phase, and the lightness of the material reduces the percentage of load on the foundation. Foam blocks are easy to process, which makes it possible to use any finishing materials. The negative aspects of using it in construction include the costs of additional thermal insulation; mortar is used when fastening the blocks; the masonry must be even. The principle of building a bathhouse is the same as when using bricks, but the weight of the structure is much lower and the number of rows of masonry is less. For the steam room, the walls are finished with wood after laying the sealant. Humidity is the main enemy of foam blocks, because due to the porous structure, the block quickly gains moisture, so special attention should be paid to the quality of the foam block and the sealing of the bathhouse.