The debate about the effectiveness of using foil for finishing a bath began from the first moment the material appeared on sale. On the one hand, aluminum foil acts as an excellent vapor barrier and reflector of infrared radiation. It helps to quickly heat up and retain heat in the steam room. On the other hand, foil is a metal product with thermal conductivity several times higher than the material of bath walls. Consequently, there will be no benefit from foil, because in a bathhouse the main source of heat is the heated walls. On the third hand, the high vapor barrier properties of foil and its usefulness for protecting coatings from dampness are noted. The review offers information about existing materials including foil, a list of manufacturers of this material and the rationality of use for lining baths, saunas, and swimming pools.
Rolled aluminum foil. General characteristics of the material
Rolled foil is produced in accordance with GOST 618-73. Standard dimensions are thickness 0.007 mm - 0.2 mm, width 10 mm - 1500 mm. For the manufacture of the material, the following grades of aluminum are used: AD, AD 1, AD 0, AMTs, A 5, A 6, A 0. The percentage of aluminum content is maintained up to 99.5.
Based on the type of surface, the following types of foil are distinguished:
- Without additional finishing - smooth. It is used as an insulator, in the production of radiators, for the production of rolled household foil and food storage containers.
- Converter foil - for finishing. High-tech foil. For this type, the characteristics and properties of the surface are extremely important: fat-free, wettability, absence of sagging and folds, porosity. Compliance with these characteristics facilitates the subsequent application of covering layers to the foil.
- Finishing. Printing, primer, heat-boiled varnish, paper, polymer film, glue or embossing are applied to the surface of the foil.
Based on the scope of application, foil is divided into the following groups:
- Food fabric. It is used as a packaging protective material in the pharmaceutical, food, cosmetic and tobacco industries.
- Technical fabric. Used for insulating and protecting parts in the electrical, construction, aviation and automotive industries.
- Tape fabric. Used in the construction industry for the production of wall panels.
Based on the condition of the material, foil is divided into two types:
- Solid or unannealed. Foil produced without annealing. Used in pharmaceuticals for the manufacture of blisters.
- Soft or annealed. The material goes through all stages of production, including annealing. Multifunctional material with a wide range of applications.
The foil is marked according to its properties; the annealed soft foil is assigned the letter “M”. Not annealed - assigned the letter “T”. A high-quality fabric has a uniform surface, without stains, folds, tears or other inclusions. When viewed against the light of the thin canvas, there are no small holes or tears. For thick foil, a small number of holes is allowed, regulated by the technical characteristics of the manufacturer. technological equipment. Thin fabric is wound on bushings different diameters, up to 5 breaks per meter are allowed. Thick fabric is produced in sheets, the permissible number of breaks is 3. Easy unwinding of the fabric must be ensured.
Quality control is monitored in each released batch; several rolls are selected and an external visual inspection is carried out on the torn 5 meters of fabric. Chemical and spectral analyzes of the composition of the material are carried out, and the percentage of aluminum is determined. If inconsistencies are detected at each stage of verification, the batch is completely withdrawn.
Aluminum foil for baths. Thermal insulation characteristics
Providing high-quality thermal insulation for the steam room means properly equipping the thermos. Aluminum bath foil is perceived by many as an ordinary shiny non-woven film, thin and unsuitable for work. Users prefer to use polyethylene foam with a Mylar reflector and are not aware that foil can provide an ideal reflective coating.
The nature of heat transfer by a foil surface is radiation. When lit, the stove actively emits infrared rays, which are perceived by the body as heat. IR rays hit the layer of aluminum foil, but are not absorbed, but are reflected back into the steam room. The process is similar to the mirror effect. Conclusion: foil for a bath does not act as insulation; it functions as a heat reflector. The reflectivity of the foil is 97%.
Aluminum foil has high vapor barrier properties. It is considered a good sealant that retains water and steam on the surface, prevents heated steam air from leaking out, and helps retain heat. All these qualities have a positive effect on the rate of heating of the room and ensure long-term preservation of high-temperature air conditions.
It is profitable to buy rolled aluminum foil from domestic manufacturers. The average price for a 25 m roll is $23. Roll 30 m - $27. Imported manufacturers sell these products more expensively: a 25 m roll is $30, a 30 m roll is $42.
How to do a simple sauna lining
To cover bath walls, foil is attached to the surfaces themselves or to a layer of “pie” of insulation.
Simplified process for creating a thermostat from foil:
- Frame made of wooden planks attached to the surface of the walls.
- Insulation is laid between the slats.
- The top of the insulation is covered with foil. The joints are sealed with special tape for tightness.
- Sheathe the foil with clapboard, leaving an air gap of 15-20 mm between the surface of the material and the clapboard. The air gap will reduce the thermal conductivity properties of aluminum; the hot lining will not come into contact with the foil, and direct heat transfer will not occur due to the insulating properties of air. At the same time, all IR rays hitting the surface of the foil will be reflected back into the steam room.
The construction of an insulating “pie” with the presence of foil is similar to the principle of insulation in a thermos, only instead of a vacuum there will be an air gap between the walls. The user will have more time to enjoy the concentrated steam and heat of the air in the steam room, while simultaneously saving the consumption of wood fuel or electrical energy.
Aluminum laminated foil
Laminated foil is made by combining foil, paper and polyethylene. Characterized by high barrier properties
- Has the highest surface impermeability to gases and steam. For example, a film 9 microns thick has a water vapor transmission capacity of 0.1 gm2 day.
- High hygienic indicators. In wet areas the surface does not create a breeding ground for the development of microflora and mitoxins.
- Elasticity. Capable of resisting compressive loads. Maintains shape.
The main types of laminated foil for baths:
- Kraft paper with foil. Three-layer lamination material
- The first layer is kraft paper. It is made from long-fiber cellulose by digestion and the use of chemical salts. Characterized by density, mechanical strength and wear resistance.
- The second layer is thin polyethylene. It has high thermoplastic, water-repellent and vapor barrier properties.
- The third layer is aluminum foil. Thin aluminum material with high heat-reflecting characteristics.
The cost of Chinese-made kraft paper is $26 per sheet. Laminated aluminum foil - prices from European manufacturers from $25 to $45 per sheet. Domestic manufacturers offer kraft paper from $20 per sheet.
The density of kraft paper creates solid foundation for foil. The layered structure is sometimes held together with a reinforcing mesh made of polyethylene thread. Laying a mesh between the polyethylene layer and the foil prevents delamination. Kraft paper with foil has high tensile and tear strength characteristics.
Aluminum laminated foil is used for lining the inside of bathhouses. The material lends itself well to cutting and drilling, allowing you to cut out parts of complex configurations. Temperature applications from - 600 to + 1200. When high temperatures ah, the adhesive softens, so the sheets are attached to the surface with screws and staples to increase strength.
- Expanded polystyrene with foil surface. A combined material consisting of polyethylene foam with a closed porous structure and aluminum foil. It is used for noise protection, as a thermal protective material for external and interior work. The combination of two heat insulators into one building material allows you to efficiently and economically produce high-quality finishing of saunas and baths. Main qualities of the material:
- Does not absorb moisture.
- Has vapor barrier properties.
- Reflects 98% of heat.
- Has shock-absorbing properties.
- Chemically resistant.
- Safe for health.
- Has a long working life.
Industrial sheets have a thickness from 20 mm to 100 mm, length 1200 mm, width 60 mm. The sheets are equipped with stepped locks to eliminate cold bridges. The cost of material per 1 m is from 0.2 $.
- Polyethylene foam with foil. They come in two types: one-sided and two-sided. Available in rolls. Material thickness 20-100 mm, width 1000 mm or 1200 mm. Roll meter is 25 m and 30 m. The cost of material per 1 m is from 0.6 to 32 $.
- Mineral or glass wool with foil. Available in two versions: soft in the form of rolls and hard reinforced in the form of mats. The cost of material per 1 m is from 1 to 34 $.
Carrying out finishing works cotton rolls or mats with foil are more practical and convenient. Regular rolled foil without a base breaks, becomes deformed and is difficult to align. Laminated foil has high strength, but is less resistant to high temperatures than rolled material without a base.
What material is best for insulating a bath?
The constant rise in energy prices forces owners of baths and saunas to take measures to economically operate the steam room. In the case of new construction, the use of materials with heat-saving properties is considered. For wooden baths just pick up natural wood and do not perform finishing. Additional protection against heat loss is performed for baths made of brick, cinder block, foam concrete and other mineral building materials.
Particular attention and a strict selection of finishing materials is made for the steam room equipment. First of all, there are requirements for the environmental friendliness of the material and its heat-reflecting properties. Aluminum foil satisfies all requirements.
Advantages of foil insulation
- Universal insulation, used for walls, ceilings and floors of baths and saunas. Has good reflective characteristics.
- Wide range of products. Thin film foil materials are produced, laminated on different bases, With mirror surface to improve the reflection characteristics of IR rays.
- Used in damp areas without additional treatment with fungicidal substances.
- High hygienic qualities. Unique properties aluminum do not create a breeding ground for the development of fungus and mold.
- Does not deform and does not melt at high temperatures in the steam room.
- Convenient to use. Easily mounted and attached to horizontal, vertical and inclined surfaces.
- For a non-commercial bathhouse, it is enough to finish the walls with 3 mm foil rolls.
- For commercial saunas with a steam condensate temperature of 1200 or more, laminated foil on a basalt mineral base is considered the ideal material.
- To insulate a bathhouse located inside a building, take into account the presence of central heating for additional heating of the air.
Let's start with the fact that many people don’t even know whether foil is needed for a bath. The question is relevant for most owners country houses. If you believe the professionals, then foil must be used when decorating the bathhouse, since a fairly high temperature is required inside, which, in addition, must also last a long time. It is for this reason that the ceiling and walls are covered with insulating material, which prevents thermal energy from escaping outside the room. In almost all cases, the “pie” that is formed on internal surfaces baths for the purpose of insulation, includes aluminum foil. The latter, in turn, is produced in several versions at once.
Be that as it may, we note that foil, recommended by some people for use in a bathhouse, is categorically rejected by others, and the dispute between the parties has not subsided for a long time. That is why we have to figure out whether foil is really so necessary or can it be abandoned? At the same time, we will find out what this material is, what it can be, approximately how much it costs and how to properly install it for maximum efficiency insulating layer.
And now, having familiarized yourself with the features and main varieties of the material described in the article, you can begin to consider some popular brands. For the convenience of visitors, the information below is presented in the form of a small summary table.
Price for foil for bath insulation
Table. Popular foil heat insulators for baths.
| Name, photo | Characteristics, description | Average market value, in rubles |
 1. “Annealed” foil |
Enough soft material, the thickness of which is 100 microns. Sold in rolls of 10 square meters. As for the total length of one roll, it is equal to 10 meters. Complies with GOST. | From 1400 rub. (per roll) |
 2. “Isover Sauna” |
The brand of insulation mentioned above, 5 centimeters thick, is also sold in rolls 12.5 meters long. The total area of one roll is 15 square meters. It is characterized by the fact that it also has soundproofing properties. | From 2200 rub. (per roll) |
 3. “Steam MAT ALUCOAT 35” |
High-quality Finnish heat insulator, still sold in rolls. The thickness of this material is 3 centimeters, and the length of one roll is only 8 meters. In addition, the total area of one roll of insulation is 7.2 square meters. | 1800 rub. (per roll) |
 4. Rockwool Sauna Butts |
And this is foil-coated mineral wool, which is sold in slabs. The thickness of this material is 5 centimeters, and the dimensions of one plate are 60x100 centimeters (WxL). The total area of one slab is 0.6 square meters. | 750 rub. per package (8 slabs) |
 5. URSA GEO M-11F |
High-quality roll insulation - mineral wool with foil coating. What is characteristic is this bath foil covered with kraft paper. The thickness is 5 centimeters, and the length of one roll is 12.5 meters. The optimal operating temperature is +270 degrees. | 2100 rub. (per roll) |
As you can see, the cost of foil varies and depends not only on the variety, but also on the specific manufacturer.
Is the foil layer really necessary in a bathhouse?
As a rule, baths today are insulated with thin foil (thickness varies between 30-300 microns). Typically, the aluminum layer can either be applied directly to a heat insulator or kraft paper, or sold separately for subsequent use in tandem with other insulation materials.
Those who are against the use of foil claim that it is of no use, since its thermal conductivity is quite high, and therefore it is simply unable to retain heat indoors. Opponents of this method believe that buying/laying foil insulation is just a waste of money. Note that this is partly true, because the use of foil can only be effective if it is installed correctly.
That is why a room decorated with sauna foil warms up faster and retains heat longer. Therefore, it is quite logical to conclude that steaming in such a bath will be more comfortable, while heating costs will noticeably decrease.
The main advantages of bath foil
Due to the operational and climatic characteristics of the bath room, a number of requirements can be identified that the aluminum foil used must necessarily meet:
- high moisture and steam resistance;
- appropriate thermal conductivity;
- fire resistance;
- high reflectivity (from 95 to 98 percent), which is obtained thanks to special polishing of the outer layer;
- excellent anti-corrosion properties.
As we have already found out, high vapor barrier characteristics prevent the leakage of heated steam from the room, and it will not accumulate in the coating.
In addition, aluminum foil for a bath has other advantages:
- it does not deform and does not lose its original properties;
- it protects neighboring premises, if any;
- the material is plastic, even if exposed to high temperatures for a long time;
- is characterized by increased resistance to chemicals;
- does not emit harmful gases and compounds;
- hygienic, durable;
- UV resistant;
- extremely easy to install.
Note! If you handle the foil carefully, even the thinnest sheets will not tear or deform. But in any case, it is necessary to purchase the material with a small margin (at least 5 percent).
The maximum temperature that the foil can withstand can reach 145 degrees. Thanks to the creation of the so-called thermos effect, the heat inside is retained for about 2.5 hours longer. We also note that the material can be used both for walls and for floors and ceilings (that is, it is universal), and does not require any special treatment with fungicides at all.
What to look for when choosing foil for a bath?
If you intend to purchase suitable foil, you must take into account several factors that affect the durability of the material, the ease of installation and future efficiency. Let's consider the main selection criteria in more detail.
Key types of foil thermal insulators for baths
There are many types of foil, as well as combined insulation materials in which it is present, and they all differ not only in cost, but also in different characteristics. Today we will consider only the most common materials.
Option No1. Rolled foil (no base)
This material is quite thin, and its strength can hardly be considered high. The thickness of such insulation can reach 0.2 millimeters, while the width varies between 100-150 centimeters. The material is sold, as one might guess from the name, in rolls 5-20 meters long. Used for installation on walls over an existing base thermal insulator. It must be attached with an overlap, and the joints must be glued with metallized tape to obtain the most airtight reflective coating.
Note! The material can be used at a temperature of no more than +650 degrees, so a steam room trimmed with foil will warm up quickly and retain heat for a long time.
In addition, such foil is resistant to corrosion processes, and when heated it does not emit any toxic substances.
Option No2. Kraft foil
It is made with a paper base or, preferably, in a three-layer design (paper - foil - PE), also known as “Izolan”. The strength is quite high, the material can be laid on top of the timber without the use of additional heat insulation (provided that the walls are well caulked). The material is environmentally friendly, its thickness can reach 1 centimeter. Can be used at temperatures not exceeding +100 degrees. The installation requirements are the same as in the previous case, however, it is more convenient to work with such material, since it is more durable and does not wrinkle so much.
Option No3. Folar
Speech in in this case We are talking about a vapor barrier, which can consist of one or two layers of foil material, as well as a reinforcing fiberglass mesh (the cells of the latter have dimensions of 4x4 millimeters). This kind of reinforcement allows the material to retain all its original characteristics even at temperatures from -60 to +300 degrees! More this material environmentally friendly, able to withstand considerable loads (including mechanical ones). Produced in several varieties. Sold in rolls 100 centimeters wide and 50 meters long.
Option No4. "Folgoizolon"
The next, so to speak, bath foil is foamed PE with a foil coating. Sold in sheets/rolls, may have different thicknesses. A very durable material that can be installed without the use of basic insulation. It can be used not only for log walls (as the main thermal insulator), but also for concrete/brick walls (as an auxiliary one). The maximum permissible operating temperature is about +125 degrees, dimensions (WxLxD) are 60x120x2x11 centimeters. The material is easy to cut, as well as mounted to the sheathing, but it does not deform.
Option No5. Foil mineral wool
The last type of foil that we will look at today. Sold in slabs and rolls, thickness varies between 0.5-10 centimeters. Sizes may vary, and much depends on the specific manufacturer. Excellent reflectivity - up to 97 percent, maximum permissible temperature - +300 degrees.
Note! There are many types of foil mineral wool, but one of the most popular (at least in Russia) is “Isover Sauna”, which has all the properties required by the specifics of a given room.
Video - Rockwool thermal insulators for baths
Key features of insulation: what do you need to know?
Before proceeding directly with insulation, you should learn about the rules for its implementation, as well as what you must pay attention to. So that the foil takes part in maintaining the required indoor microclimate, consider the following important points.
- The room must be equipped good ventilation. Otherwise, all thermal insulation layers will become saturated with moisture and lose their original characteristics. The foil material itself will simply become useless.
- There must be ventilation gaps between the finishing material and the insulating layers.
- Attach all layers correctly, in accordance with the requirements, also do not forget to seal the joints between the sheets.
Remember that if you do not fulfill at least one of the listed requirements, then all your efforts will probably be wasted, and the final thermal and sound insulation properties of the foil will be practically zero.
What should be the thickness of thermal insulation in a bathhouse?
Here, a lot depends on the thickness of the walls, as well as on the material from which they are made. So, for brick/ concrete walls with a thickness of 25 to 35 centimeters, it is necessary to use a heat insulator with a thickness of 10-15 centimeters. For the same walls, but with a thickness of more than 35 centimeters - within 8-10 centimeters. If we are talking about wooden walls with a thickness of 10-15 centimeters, then the thickness of the heat insulator should be approximately 6-8 centimeters, if 15-20 - then approximately 4-6 centimeters, and finally, if over 20 - then about 2-4 centimeters . As you can see, there is nothing complicated here, so let’s move on directly to the installation work.
Step-by-step instructions for insulating a bathhouse
To begin with, we note that if the steam room is small, then foil in rolls or kraft foil, the thickness of which is at least 0.3 centimeters, will be quite sufficient. But if the steam room is quite large, then it is better to give preference to materials based on mineral wool. Also, be sure to think about how the condensate will be drained: if the ceiling is insulated, then the foil from it must be removed to the walls, and if the latter are insulated, then to the floor. The overlap should be approximately 15-20 centimeters, and all joints, we repeat, should be taped with metallized tape.
Note! Also, do not forget about the ventilation gap between the insulating layer and finishing(about 1.3-1.8 centimeters). In this case, you will achieve a healthy indoor microclimate.
The installation process itself is not complicated and consists of several simple steps. Let's look at the features of each of them in more detail.
Step one. To begin, build a sheathing on the walls using a 5x5 centimeter beam. As for the pitch of the sheathing, in this case it depends on the width of the insulation. If it is 60-120 centimeters, then the step, accordingly, should be 60 centimeters; for foil, the width of which is 100-150 centimeters, this is 50. To attach the bars, use self-tapping screws of a suitable length.
Step two. Place insulating material between the sheathing beams. Try to do this in such a way that the heat insulator does not extend beyond the level of the slats.
Step three. When the main insulation is installed, lay a foil covering on top of it, always placing the latter with a reflective layer inside the room. To seal the joints between the sheets, you can use metallized tape, but remember that the glue, being under prolonged exposure to high temperature, softens, which means that the sheets may well separate, which leads to a violation of the tightness of the entire coating.
It is advisable that bath foil fixed with nails or staples - the latter should be nailed directly to the bars. And if the width of the foil is large enough, then it should be fixed both at the edges and in the center.
Step four. Cover the fixed foil with clapboard, not forgetting about the air gap 1.5 centimeters thick. This layer is necessary in order to reduce the thermal conductivity of the foil in order to maximum reflect all the rays that hit the coating back into the room. Obtaining this kind of air “pocket” is possible thanks to the construction of a wooden sheathing under the lining. For this sheathing, try to use bars, the thickness of which is within 1-2 centimeters, and for fixation, use the same self-tapping screws.
Sometimes the sheathing can be built on top of the insulating layer - in this case, the foil will be stuffed immediately over the entire area of the steam room, even onto the beams. If so, then there is no particular need to create air “pockets”, and the lining can be fixed directly to the sheathing. However, practice shows that the use of combined materials, including a foil layer, is preferable not only in economic terms, but also because of the significant simplification of all installation work.
Video - Finishing a steam room in a bathhouse
Thanks to the use of foil when finishing the steam room, you can save from 25 to 30 percent on fuel for the stove, in addition, the service life of the entire structure will significantly increase, since you will prevent the development of mold, fungi and various microorganisms harmful to health .
Video - How to cover a steam room in a bathhouse with foil
Features of bath ventilation
As noted earlier, the installation of a high-quality ventilation system is mandatory for normal functioning thermal insulation cake. This should be taken care of in advance - even before proceeding directly to insulation. There are several layouts of holes for ventilation; let’s take a brief look at each of them.
First
We are talking about the circuit indicated in the illustration above by the letter “a”. This natural ventilation, the supply vent for it is installed at the bottom of the wall next to the heating device, and the exhaust vent is located on top of the opposite wall. The option is simple, but its effectiveness leaves much to be desired. For example, some open doors to enhance such ventilation.
Second
Option “b”, in which both vents are located on the same wall, and the heating device is located on the opposite wall. Suitable for baths with one outer wall. To strengthen the system, a fan is used (in the inlet).
Third
As for option “c”, it must be implemented during the construction of the bathhouse, since in this case the air will move under the finished floor. The location of the ventilation windows is the same as in option No. 1, but the fan should be located in the exhaust hole (the one on top). It's a fairly effective system, it's worth noting.
Fourth
Finally, scheme “d” is effective only when firing a stove. There is only one hole here - the supply hole - and it is located on the opposite side of the heating device wall.
Finally, we note that the dimensions ventilation holes depend on the specific area of the room. Yes, for every square meter The steam room must be at least 24 square centimeters. That's all, good luck with your work!
Among the many types of thermal insulation materials for bathhouses, consumers increasingly prefer aluminum foil. It's simple and available coverage retains heat well inside the building, preventing rapid cooling of the building, thereby reducing energy costs and ensuring a comfortable stay inside the bathhouse.
Taking into account the peculiarities of operation and the microclimate of the bathhouse premises, a number of requirements are imposed on the foil used:
- good moisture, steam and water resistance;
- high fire-resistant qualities;
- good anti-corrosion properties;
- high reflectivity coefficient (within 95-98%), achieved through special polishing of the top layer;
- significant thermal conductivity.
Self-adhesive insulation with foil
Excellent vapor barrier properties help prevent the leakage of hot steam from the room, which will not accumulate in the coating. In addition, aluminum foil has the following advantages:
- complete absence of deformation and loss of original consumer properties;
- high plasticity of the coating under prolonged exposure to high temperatures;
- no emission of substances and fumes harmful to humans;
- UV resistance;
- protection against excessive condensation, mold and pathogenic microorganisms;
- ease of installation;
- durability;
- hygiene;
- resistance to chemical reagents;
- protection of adjacent or adjacent rooms if the bathhouse is located inside the house.
With careful installation, even thin paper-based sheets will not tear or deform. But you should remember that you should buy such material with a small margin of 5-7%.
Aluminum foil can withstand temperatures up to 145 °C, which, combined with high reflectivity, helps retain heat inside the steam room for 2-2.5 hours longer compared to other insulation materials, providing the so-called thermos effect. This is a universal insulation material suitable for walls, floors and ceilings of steam rooms, baths and saunas and does not require special treatment of the premises with fungicidal substances.
Prices for bath foil
bath foil
Types of foil and coating features
The building materials market offers customers several types of foil with different properties and characteristics.
| Coverage type | Advantages | Type of application | Type of application |
|---|---|---|---|
Folgoizolon (foil applied to polyethylene foam in rolls or polystyrene sheets) | High strength, shock-absorbing and sound-proofing properties, the ability to lay the material directly on the surface without additional thermal insulation. | Suitable for log walls, as well as surfaces with slatted lathing or covered with clapboard. | The thickness of the material in sheets is from 20 to 100 mm, the dimensions of the canvas: length - 120 cm, width - 600 mm. Thickness roll material from 20 to 110 mm, standard length 25 or 30 m, roll width 100 or 120 cm. Temperature range from 100 to 125 °C. |
| Ecologically pure material. | Foil material is used on any surface, but in combination with a thermal insulation coating. | The thickness of the sheets ranges from 0.03 to 1 mm, the temperature range is 50-85 ° C. | |
| High degree of vapor and moisture insulation. | Suitable for use on concrete and brick walls ah, as well as all types of wooden surfaces. | Thickness 8-10 mm, maximum temperature withstand: from + 100 to +125 ° C. |
|
| Good insulating properties and ease of installation. | The same as for rolled materials. | Similar to the previous ones. | |
| Low cost, accompanied by tears and deformation of the material during installation. | Only on fire-resistant heat-insulating material with mandatory fastening with metal brackets. | The sheet thickness is 0.01-0.5 mm, the roll width is 1500 mm, the temperature range is from – 50 to +75 ° C. |
For getting high-quality coating When carrying out installation work, it is recommended to strictly adhere to the thickness of the foil insulation.
| Wall material | Steam room wall thickness | Recommended layer of foil insulation |
|---|---|---|
| Brick, concrete | 35-37 cm or more | 8-10 mm |
| Brick, concrete | 25-35 cm | 10-12 mm |
| Wooden log house | 10-15 cm | 6-8 mm |
| Wooden log house | 15-20 cm | 4-6 mm |
| Wooden log house | more than 20 cm | 2-4 mm |
Experts remind that aluminum foil or foil coverings are capable of reflecting not all of the lost heat back inside the premises, so they work best in steam rooms insulated according to the “pie” principle, while basalt or glass wool, as well as similar ones, should be used as an additional heat-insulating material mineral thermal insulators. This is especially true in baths and saunas built of brick or concrete and other frame buildings. If the external walls of wooden log houses are sufficiently thick, additional thermal insulation can be neglected, but thin sheets of kraft foil should not be preferred as a foil material.
Covering installation
To ensure the most effective and high-quality coating and ensure a comfortable stay in the steam room, you should follow a number of tips when laying the material.
- When laying foil materials in steam rooms of non-commercial baths and saunas, it is sufficient to use rolled or kraft foil with a thickness of at least 3 mm.
- For large steam rooms, foil on a mineral or basalt base is suitable.
- When the bathhouse is located inside the house or in basement important to take into account central heating and the location of its sources, if possible using it for additional heating of the steam room air.
- Before starting work, it is necessary to provide for the removal of condensate by making a small withdrawal of the canvas from the ceiling to the walls, as well as from the walls to the floor. To do this, the foil material is laid with an overlap of 15-20 cm and taped with foil tape.
Important! To create a “thermos” effect, a gap of 13-18 mm must be left between the layer of foil coating and the finishing to ensure ventilation and maintain a healthy microclimate.
Foil installation process occurs in several stages, the most convenient to use are rolls or sheets 60 cm or 1.2 m wide.
- The walls of the steam room need to be lathed with beams with a cross-section of 5x5 cm. The distance between adjacent planks depends on the width of the material. For rolls of 600 and 1200 mm it is 60 cm, for foil materials with a width of 1000 mm and 1500 mm - 50 cm. The bars are fastened with self-tapping screws of a suitable length.
- A layer of mineral insulation is laid between the slats so that it does not protrude beyond the level of the beams.
Fastening insulation boards to the ceiling. In the photo - the use of foil insulation 
- A foil material is fixed on top of the insulation layer with the obligatory placement of a reflective layer inside the steam room. The joints of adjacent canvases or sheets can be glued with metal tape, but it should be remembered that under the influence of high temperatures the glue can soften and the panels will separate, breaking the tightness.
It is best to fix the foil with staples or nails, nailing them directly onto the beams. If the width is large, the foil material is fixed not only at the edges, but also in the middle.
- The laid foil is sewn up with clapboard, leaving a one and a half centimeter air pocket, the main function of which is to reduce the thermal conductivity properties of the foil layer and to maximize the reflection of all the rays that hit the foil back into the steam room. An air pocket will allow you to create a sheathing for the lining. Choose planks 10-20 mm thick and fix them with self-tapping screws.
Sometimes the order of arrangement of materials can be changed - a layer of foil is stuffed onto the insulation layer placed between the sheathing bars, staples or nails, which is fixed on top with thin slats placed strictly on top of the sheathing with self-tapping screws of sufficient length.
In some cases, wooden sheathing can be placed on top of the insulation layer, laying foil over the entire area of the walls, including. and on the uneven bars. Then it is impractical to leave air pockets, and the lining is fixed directly on the sheathing. But, as practice shows, the acquisition of combined heat-insulating materials with a layer of foil is not only more economically profitable, but also significantly simplifies the entire installation process.
Foil for a bath, which one is better to choose, and is it needed at all? This question arises for all owners of suburban areas who have decided to acquire their own steam room. Experts consider foil one of the most important materials for finishing bath rooms, since they must quickly reach the required temperature and remain warm for a long time.
For this purpose, insulation is installed on the surface of the walls and ceiling, which will block the exit routes for the generated heat outside the bathhouse. Almost always, the traditional insulating “pie” created on the internal surfaces of this structure includes aluminum foil, produced in different versions.
However, we have to admit that this material, which is welcomed by some users, is completely rejected by others, and there is an irreconcilable dispute between these “camps.” Therefore, it is worth understanding how necessary this thermal insulation material, or you can do without it. At the same time, let's see how the installation should be done so that the created insulation layer works properly.
Do you need a foil layer?
For commonly used thin layer aluminum foil, the thickness of which averages from 30 to 300 microns. It can be applied to kraft paper, directly to insulating material, or it can be used separately from them and used in combination with other heat insulators.
Opponents of the use of foil argue that it is of no use, since aluminum has high thermal conductivity and therefore is not able to retain heat in the room - it will freely escape outside. In their opinion, it turns out that purchasing and installing foil material is a waste of money and effort. It should be noted that to some extent this is completely fair, since the foil will “work” only if its installation is carried out according to all the rules.
- The high thermal conductivity of aluminum foil will manifest itself negatively if it is attached directly to cold wall, built from materials such as brick, concrete or foam concrete, without an additional insulating layer between them.
- Secondly, in addition to the high thermal conductivity of the material due to its structure, which is unable to retain heated air inside the bathhouse, there are other methods of heat transfer - these are convention and infrared radiation. Thus, a hot stove releases the generated heat into rooms mainly in the form of infrared rays, which heat surfaces when absorbed.
When heat rays hit a layer of aluminum foil, they are not absorbed by it, but are reflected from it back into the room. Thus, thermal energy is not wasted on heating the walls, but is usefully used inside. Therefore, it follows that the foil retains heat not due to its thickness or the structure of the material, but due to the creation of a reflective surface. Moreover, it should be noted that it is capable of reflecting up to 97% of the heat generated by the stove.
- Thirdly, foil is an excellent vapor barrier for insulation laid on the surface of the walls. It creates a sealed, moisture-proof coating, therefore preventing heated steam from escaping through the walls and ceiling. This not only helps to retain heat in the room - the vapor barrier prevents the insulation from becoming saturated with moisture and thereby losing its thermal insulation qualities
Therefore, sheathed with insulating material and supplemented with a foil layer, it heats up quickly and retains heat longer. The logical conclusion is that in such a room it will be more comfortable to take bath procedures, despite the fact that the cost of fuel or energy will be much lower.
Criteria for choosing foil for a bath
To make a choice, first of all, it is necessary to take into account some factors that influence the effectiveness of the material, the ease of installation of the panels and the longevity of operation. Such criteria include the following:
- Foil that has a backing is much easier to attach to the sheathing, since the likelihood of damage to it becomes much lower. Therefore, purchasing such material is much more practical.
Materials such as mineral wool, foamed polyethylene or kraft paper can be used as a substrate for this heat insulator. In addition, foil reinforced with fiberglass mesh is available for sale, which has a thickness slightly greater than that of the material without a base.
Bath foil
- For bath conditions, it is very important that the wall decoration is resistant to elevated temperatures. This indicator should not be lower than + 100 degrees. The material for the bath must be resistant to sudden temperature changes, and rolled foil, even without a base, or having one, fully meets this criterion.
- High-quality foil material must have a high reflectivity of at least 95÷97%, since heat retention in the bathhouse will directly depend on this parameter.
- If , then high thermal resistance values should also be assessed.
- The vapor permeability of the foil layer should not exceed 0.01 g/m² in 24 hours.
- The strength properties of the material are important from the point of view of ease of installation.
- Very important criterion is the environmental friendliness of the foil material. When heated to high temperatures, it should not release toxic substances.
- Of course, you should evaluate the durability of the foil material - what guarantees the manufacturer gives for it, and how consumers respond to it.
Types of foil materials for thermal insulation of baths
So, there are many types of foil and foil-coated materials that differ in their properties. The table below shows the most popular of them:
| Illustration | Name and main characteristics of the material |
|---|---|
 | Rolled foil without a base is a thin material that is not particularly tensile. It is produced in thicknesses from 0.007 to 0.2 mm, in rolls of 5, 10 or 20 meters, with a width of 1000 to 1500 mm. Baseless foil is used for installation on the walls of bath rooms, on top of previously laid insulation. The material sheets are secured with an overlap, and their joints are necessarily glued with metallized tape, forming a sealed reflective surface. The operating temperature limit for foil reaches +650 °C. Ability to reflect thermal radiation is up to 97%, so foil can provide quick heating of the steam room and keep it in it for a long time comfortable temperature. The material is resistant to corrosion and does not emit toxic substances when heated. |
 | Kraft foil is produced on a paper basis, as well as in a three-layer version consisting of foil, kraft paper and polyethylene - this material is called “Izolar”. Kraft foil has good strength characteristics and can be used for fastening to well-caulked timber walls without the additional use of insulation. Kraft foil is an environmentally friendly material, as it does not emit toxic fumes when heated. The thickness of this insulator varies from 0.03 to 1.0 mm. Operating temperature – up to 100 degrees. At correct installation and gluing the joints with metallized tape, the material creates a sealed, heat-reflecting layer - the reflectivity reaches 95%. The material is more convenient to install compared to baseless foil, as it wrinkles less and is tear-resistant. |
 | Folar is a vapor barrier consisting of one or two layers of aluminum foil, between which is laid fiberglass mesh with cells 4×4 mm, which is a fabric reinforcing element. Thanks to this strengthening, the foil insulator retains its qualities even in the temperature range from -60 to 300 degrees. Folar is an environmentally friendly material that does not contain carcinogens and allergens and can withstand high loads, including mechanical ones. This material is produced in three types: - “A” - sheets with one-sided foil and operating temperature from -40 to +150 degrees; - “B” - sheets with double-sided foil and operating temperature from -40 to +300 degrees; - “C” - sheets that have a one-sided foil coating and an adhesive base for fastening to flat surfaces of walls, ceilings and floors. Operating temperature from -40 to +80 degrees. Standard roll parameters are length 50 m, width 1000 mm. |
 | “Folgoizolon” is foamed polyethylene with a foil coating. It is produced and sold in the form of rolls or sheets, depending on its thickness. This insulation has high strength, shock absorption and sound insulation characteristics. Since such canvases (sheets) can be quite thick, they are often fixed to the surface without additional thermal insulation materials, provided that certain conditions are met during the arrangement of the room. "Folgoizolon" is used for insulating log surfaces, as the main heat insulator, or concrete and brick walls, as an additional layer to the main insulation, installed between the sheathing bars under the clapboard cladding. Material sheets have the following parameters: - thickness - 20÷110 mm; - length 1200 mm, - width - 600 mm. Rolls: - thickness - 2÷10 mm; - length - 25÷30 m, - width - 1000 ÷1200 mm. Operating temperature range – up to + 100÷125 degrees. The material does not deform, is easy to cut and attach to wooden sheathing using staples and a stapler, and on metal profile– using double-sided tape. |
 | Foil-coated mineral wool is produced in rolls and slabs with a thickness of 5 to 100 mm. The material can have different lengths and widths - these parameters may vary among different manufacturers. The reflectivity of the material reaches 97%, the operating temperature is from -60 to 300 degrees. There are many varieties of foil-coated mineral wool, and one of the most popular of this line of materials on the Russian market is the basalt heat insulator for baths “ISOVER Sauna”, which has all the qualities necessary for such specific operating conditions. |
Video: foil mineral wool slabs “ROCKWOOL Sauna Butts”
How to carry out insulation correctly?
Before moving on to insulation measures, you need to find out how to carry them out correctly, and what must be provided for.
In order for the aluminum layer to participate in maintaining the required microclimate properly, as intended by the manufacturer, the following points must be taken into account:
- Ventilation of the bathhouse is mandatory. Otherwise, all the insulating layers will be saturated with moisture and lose their thermal insulation qualities, and the foil will simply become useless.
- Compliance with the parameters of the thickness of the insulation in relation to the thickness and material from which the walls are made.
- Proper fastening of layers of insulation and foil material and sealing of joints between sheets.
- Formation of ventilation gaps between layers of insulation and finishing.
We must not forget that failure to fulfill even one of the listed conditions is fraught with the fact that all the efforts made during the installation of materials will be wasted, and the vapor barrier and heat-reflecting qualities of foil insulation will be reduced to zero.
Ventilation of bath rooms
A properly organized steam room ventilation system is one of the main conditions that are necessary for the proper functioning of thermal insulation. Ventilation is planned in advance, before insulation operations begin. There are four main layouts for ventilation openings in rooms with high humidity and, accordingly, the distribution of air flows with the obligatory condition of maintaining the optimal temperature regime.
- The first option, presented in the diagram under the letter “a”, is a natural ventilation system. For it, holes are made on opposite walls of the room:
- an inlet hole is made in the lower part of the wall, next to the heater stove;
- on the opposite wall, in its upper part, there is an exhaust window. It is advisable to place the exhaust window behind the partition so that a direct draft is not created in the steam room.
Both windows must have doors that regulate the inflow and outflow of air.
This option can be called the simplest to set up, but not effective enough. The air flow entering the supply opening heats up immediately as it passes by the stove, and then it immediately rises to the ceiling and goes into the hood. As a result, proper ventilation of the room does not occur, since air masses move along one trajectory, without covering the far corners of the steam room. That is why it is better to place the exhaust window behind the partition.
Such ventilation will have to be strengthened after the procedures are taken by opening the door.
- The second diagram (b) represents a ventilation system in which both openings - inlet and exhaust - are located on one wall, and the stove is installed near the opposite one. Such ventilation is usually arranged if the bathhouse has one external wall, in which it is mounted ventilation windows. In this option, the ventilation system is reinforced by a fan, which is installed in the lower inlet, and is therefore called forced. The fan makes the flow of air into the room more intense, so its flows are separated and cover a larger part of the steam room.
More effective method ventilation of the steam room: the supply opening is located below the stove, the exhaust opening is on the wall opposite, but not at the top, but at the bottom. In this case, the exhaust vent must be equipped with a fan. With this arrangement of vents in the steam room, the cold air is heated from the stove, rises, cools there and falls down.
- The third option (c) is implemented during the construction of the bathhouse, since it involves the passage of air under the “clean” floor. In this case, the ventilation windows are located in the same way as in the first option, that is, on opposite walls, but the fan is installed in the upper exhaust ventilation window. In addition, air flows are separated due to holes in the floor and the gap between the opposite wall and the “clean” floor surface, since this design creates additional draft. Such a system can be called effective, since the evaporation does not have time to large quantities settle on the walls and ceiling.
- The fourth system (d) will only work while the furnace is firing. When arranging it, they make only one supply hole, which is located on the wall opposite the stove. In this option, the hot air from the furnace rises, then, when cooled, it falls down, mixes with the incoming cold air, and is discharged through the blower door.
There is another system in which exhaust air is discharged through a blower. It is placed in such a way that the blower hole is below the level of the “clean” floor, and in the upper part of the foundation an inlet opening is arranged, which will be located in the space between the “subfloor” and the “clean” floor. Thus, the air entering through the hole in the foundation will provide ventilation not only for the underground space, but also for the gaps between the foil and facing material bathhouse premises.
Ventilation windows should have a size that is proportional to the area of the steam room. So, per 1 m² of ventilated area, the window must have at least 24 cm².
Foil insulation
Proper ventilation of the bathhouse is the key to its long-term operation!
More detailed information You can learn about all the nuances of the arrangement from a special publication on our portal.
Thickness of walls and insulation used
The effect of the foil material will depend on how correctly the thickness of the insulation for the walls of the bathhouse is chosen. In order to determine this parameter, you can use this table:
| Wall material | Steam room wall thickness, mm | Insulation thickness (recommended), mm |
|---|---|---|
| Concrete, brick | 350÷370 and more | 80÷100 |
| Concrete, brick | 250÷350 | 100÷150 |
| Wooden log house | 100÷150 | 60÷80 |
| Wooden log house | 150÷200 | 40÷60 |
| Wooden log house | More than 200 | 20÷40 |
It should be understood that the indicated thickness of insulation is specifically for a bath, that is, for short-term bath procedures, and with the obligatory use of a foil reflective layer directed indoors. For indoors permanent residence people, the criteria for choosing the thickness of insulation will be different. And there is no way to do without calculations.
How to determine the thickness of insulation for the external walls of a residential building?
There is a very accessible and convenient algorithm for calculating the thermal characteristics of a wall. It is presented with all the details in the article on our portal dedicated to. There is also a convenient calculator for independent calculations.
Insulation of bath walls using foil materials
Properly installed “insulation pies” on the walls and ceiling of a bathhouse directly affect how comfortable the atmosphere in the premises will be. In addition, violation of thermal insulation technology can render not only the insulation itself unusable, but also the walls of the building.
The installation procedure for the insulation system may vary slightly, depending on the material from which the walls of the bathhouse are built.
Insulation of a bathhouse - a wooden frame
Wood has low thermal conductivity and a high ability to retain heat inside a log house, subject to high-quality caulking of the joints of logs or beams. Therefore, there is a special technology for insulating a bathhouse made of this material.
1 - Log wall.
2 - Foil polyethylene.
3 - Lathing made of timber.
4 — — wooden lining or tongue and groove board.
Work on securing materials is carried out in the following order:
| Illustration | |
|---|---|
 | Foamed foil polyethylene or even baseless foil is stretched and secured onto the walls insulated with caulking logs using a stapler and staples. The material sheets are attached with a reflective coating inside the room with an overlap of 150÷200 mm. If you choose insulation that has a sufficiently large thickness - 10 ÷ 15 mm, then in this case, the sheets are fixed end-to-end, without gaps. |
 | When securing the foil material, it is necessary to constantly monitor its integrity, since even minor damage can disrupt the intended effect of insulation and vapor barrier. If the material is accidentally damaged, it must be immediately sealed with special foil tape. The next step is to glue all the canvases along the lines of overlaps or joints with the same tape, so as to create an airtight coating over the entire area of the wall. |
 | On top, on the foil insulation, slats with a cross section of 30x50 mm are fixed. They can be installed vertically or horizontally, depending on how you plan to install the lining boards: in any case, perpendicular to the inner lining. |
 | The trim is attached to the installed sheathing. There must be a gap between it and the foil surface. ventilation gap, which, in fact, is what the sheathing slats set - 30 mm. |
All operations on internal insulation bath rooms are made only after shrinkage and secondary caulking, otherwise deformation of the finish and rupture of the insulation may occur.
Video: using foil to insulate a wooden bath
Insulation of brick or concrete bath walls
Insulation of cold walls made of brick, concrete, as well as foam concrete blocks is somewhat different from similar operations with wooden structures, and is carried out as follows:
| Illustration | Brief description of the operation performed |
|---|---|
 | The first step is to mark the walls, and fix the sheathing bars on them, with a cross-sectional thickness equal to the thickness of the insulation, since it must fit flush between the beams. Moreover, if you plan to install the paneling vertically, then the beam is also attached vertically, since to secure the sheathing after fixing the foil, another row of counter-lattice bars will be installed, perpendicular to those already installed. The frame guide bars are attached at a distance from each other, which will equally allow the slabs of insulating material to be laid between them as tightly as possible. |
 | If ventilation windows or openings are installed on the walls, it is necessary to secure around them bars of the same cross-sectional size as the rest of the sheathing elements, since foil will also need to be secured around them. |
 | Next, insulating material is installed between the beams. For bathhouses, modified hydrophobic basalt wool is most often used, for example, vapor-permeable and waterproof insulation “Rockwool”. |
 | The next step is to cover the insulation with one of the types of foil material - it can be regular foil without a backing or foamed foil polyethylene. Attaching the foil to the sheathing bars is done using staples and a stapler. If the foil sheets are fixed horizontally, then its installation begins from the floor. If the foil is small in thickness, then its second strip is overlapped with the bottom strip by 150÷200 mm. When the thickness of the foil material is 10–15 mm, the panels are mounted end-to-end, as when mounting on a wooden wall. |
 | Around ventilation holes and windows, the foil also needs to be well secured, nailed to pre-installed bars. If possible, it is advisable to seal the edge of the foil around the holes or windows with tape. |
 | The foil sheets are fastened together at the joints with metallized tape. If the surfaces of the walls and ceiling are insulated, then it is recommended to lower a part of the sheet, approximately 200÷300 mm, mounted on the ceiling, onto the wall so that the joint between the two planes is hermetically sealed. |
 | On top of the foil, slats 20÷25 mm thick and 40÷50 mm wide are fixed, which will fix the foil and insulation, create a gap between the foil and the sheathing, and also serve as a lathing for further installation of the lining. |
 | The next step is to cover the sheathing with clapboard, but you need to make sure that a distance of at least 20÷25 mm is maintained between the clapboard and the foil. This space is necessary to ensure effective ventilation and evaporation of condensation formed after each bath procedure. |
In conclusion, I would like to note again that foil will be an excellent barrier against moisture penetration into wall structures and ceilings, and will help maintain a comfortable temperature in the steam room, but, of course, subject to all technological rules its use when insulating the walls and ceiling of a bathhouse. Therefore, there is absolutely no need to doubt its necessity.
Foil in the bath. Myths and legends!
Someone very smart once said that to preserve heat in a steam room, you need to insulate it with a thin layer of foil, the purpose of which is to reflect heat! Thus, it is possible to reduce energy losses, saving considerable resources and time for heating and maintaining heat in a steam room. And the whole country began en masse to cover their bathhouses with foil, telling people left and right how right and cool it was!
But it’s only the bath house builders who are so smart. Everyone else who builds houses, dachas, mansions and villas, as well as high-rise buildings and skyscrapers, stadiums and trading houses are idiots! Well, it’s realistic if every house, apartment, room was covered with foil - how much heat the country would save! And why spend so much money on developing environmentally friendly insulation and insulation materials if the issue is solved so simply?
And here solar panels By the way, they are made of aluminum! Do you know why? Aluminum is one of the best materials in nature by thermal conductivity! Collect efficiently solar energy and transfer it for processing into electricity - this is a task that aluminum plates can handle in no time!So, let’s understand the essence and purpose of foil in a steamy room!
The first postulate is that foil reflects heat - and this is true, for example, the visible spectrum of infrared radiation is reflected from aluminum by almost 100%! And if you covered the stove in your steam room with foil, you could see this with your own eyes, but the problem is that the foil is not near the stove and, moreover, is hidden behind the lining! Tried to sunbathe under the sun wooden canopy? And How? No way! Because all these waves are dampened by the wood on the way to the foil! And what about the foil? Only the radiation from the wood that covers your steam room reaches the foil! Bears the brunt of electromagnetic waves wood upholstery, converting the energy of waves into heat - therefore it is hot, and itself becomes a radiator of heat into the steam room. The thermal conductivity of this material is not high - from 0.09 to 0.18 W/mS. Well, nevertheless, it heats up not only from the outside, but also from the inside - the back side, with everything, as you understand, the back side of the lining will have a temperature much lower than the outside. If you heated wood (not air, but wood) on the surface to 90 C, then the back side will have a temperature of about 60 C - part of this energy in the form of waves will follow to the foil, part of it will be reflected back to the lining! Is everything like this? Yes, yes, if you don’t take into account the thermal conductivity of aluminum, which is almost 2000 times higher than that of wood! So, just in case, I’ll say what thermal conductivity is for the smartest ones - it’s a process that arises as a result of the thermal movement of particles during their mutual action on each other, in which energy is transferred from more heated parts of the body to less heated ones. That is, not in the steam room, but behind the steam room! You wanted to keep the heat in the steam room - alas - you did everything to effectively use up the heat from the room to uselessly heat up the insulation hidden behind the foil!
Summary: Losses from thermal conductivity of foil are SIGNIFICANTLY higher than the reflectivity of aluminum!Myth number two – aluminum foil is an excellent vapor barrier! Yes it is! Steam molecules are not able to penetrate a thin layer of aluminum, but they happily condense on it! This is probably great too, since specialists in the construction of bathhouses unanimously assure this! You can easily replace the concept of “damp, wet” with the concept of “Russian bath”, where the humidity should reach 90%! If water does not drip from the ceiling, then this is a good result, but you still will not leave the feeling of dampness, since the bathhouse must breathe! What does your bathhouse breathe? By the way, air molecules do not pass through the foil either! With the same success, you can take bath procedures in tin can- but for some reason no one agrees to this, but in vain, because creating a humidity of 90% in such a structure is very simple - why not a Russian bathhouse?
In addition, high humidity between the foil and the wood inevitably leads to the process of rotting and mold on the part of the latter. Builders solve this problem by creating gaps between the foil and the lining - like so that it can be “ventilated”! In fact, not for this purpose, but so that they (the builders) are not forced to remodel the facility in a year or two, when the wood becomes unusable. In this context, I will return to the first question: high humidity is formed in the gaps between the foil and the lining - small and large drops of water and steam - and so, infrared radiation does not pass through this mixture but is extinguished, thereby further reducing the effect of reflection of the foil!
Since everything described above for the bathhouse market is apparently fiction (since there will definitely be those who will foam at the mouth to prove the miraculous properties of bathhouse foil), I’ll add a few more fabulous judgments about the truth of its purpose! The thing is that heat loss in the steam room due to high temperatures is impressive, especially in the upper perimeter of the steam room. Therefore, insulating a bathhouse is an important and valuable point in construction. Basically, steam rooms are insulated using soft insulation based on glass wool or basalt wool and slabs! By their properties, they really are an excellent barrier that prevents heat from escaping from the steam room. But they also have significant drawbacks; I would even say that they are fraught with great danger! The fact is that all these materials are formed using phenol-formaldehyde resins, which are used as a binder in the production of one or another type of mineral wool. What it is? CH2=O - very toxic, has extremely Negative influence on the genetics of living organisms, on the respiratory organs, vision and the entire skin. Formaldehyde has a strong effect on nervous system person. Formaldehyde is rightfully included in the list of highly carcinogenic substances. The concentration of formaldehyde in a room depends on the air temperature, and it is maximum under warm and humid conditions, especially in closed (enclosed), unventilated rooms. Anyone who has such material as insulation for baths will probably understand me very well now. And those who don’t understand what we’re talking about we're talking about, will continue to insulate their baths with various imported and Russian wool. But I am not a psychiatrist and I will not be able to cure such complex deviations in those who come to the bathhouse for a healing effect! This also applies to the group of insulation materials based on polystyrene foam and polyurethane foam, no matter what the manufacturers of these materials say. All of them contain extremely dangerous groups of carcinogens in their composition, which begin to be released much earlier than the stated operating temperatures. So, in order to reduce the emissions of hazardous substances into your steam room, you need to insulate it and not only isolate it well from air, but also from humidity. The fact is that when wet, cotton wool sharply loses its properties of low thermal conductivity, since heat is no longer transferred through the fibers, but through water. For comparison, the thermal conductivity of dry wool averages 0.040 W/mS, compared to water
0.56 W/mS, i.e. 14 times higher. In this context, foil immediately solves both problems: it reduces the emissions of carcinogens into the steam room and insulates the cotton wool from moisture to reduce heat loss.
The last question remains - will it be possible to completely seal it with foil? The task is very difficult, since the material breaks easily, given the hundreds of nails that make holes in it as the lining is stuffed, and one can only hope that these holes will not be so significant and will not harm your health!In conclusion, it will be of interest to readers to look at hygienic certificates for insulation materials containing certain substances in their composition. These include formaldehyde, ammonia, benzene, phenol, toluene, xylene, styrene, ethylbenzene, methyl alcohol, butyl alcohol, fiberglass dust and mineral wool, as well as (!) potassium, rhodium, thorium, etc. And it’s hard to believe the thesis about compliance with the maximum permissible concentrations of substances released into the air, and moderate irritating effects on skin, mucous membranes of the eyes and upper respiratory tract.
