Foil materials for a bath – effective heat retention. Features of insulating a bath with aluminum foil insulation Insulating a steam room in a bath with foil

Internal insulation baths, saunas and hammams have features unique to these objects. In addition to energy saving, “climate” cladding should provide:

• rapid heating of the room;
• thermal inertia (slow cooling after stopping the furnace fire);
• high level of vapor barrier.

Today, foil insulation for a bathhouse is considered necessary, and in some cases, a sufficient element to ensure the above conditions. To understand why this material is a generally accepted standard, it is necessary to consider the physics of heat transfer processes in a steam room.

During operation of the furnace, up to 80% of the heat is transferred by infrared radiation; up to 20% - due to the thermal conductivity of air, surfaces and objects located in the steam room; up to 7% - due to convection (mixing layers of air). That is why the role of the infrared screen is becoming in demand. This is what foil for the bath does, which is produced by industry in the form of a single-layer material, or as part of a two- or three-layer sandwich.

What does heat reflection do?

The use of flexible cladding with a glossy aluminum layer allows you to heat the steam room faster and retain heat longer. Foil for bath insulation acts as a mirror, reflecting the intense infrared radiation of the stove arches back into the room. Skeptics believe that this is only possible in one case: if you do not cover the foil with casing. They are wrong. The sheathing reduces the percentage of reflected heat rays, but when heated with reverse side from foil, the lining becomes a much less thermally conductive material. The design of the thermos thus changes, but the overall energy effect remains the same.

Illustration of the principle of heat reflection from foil material using the example of Alucraft products

What ensures that the cooling of the bath slows down? After all, the foil does not affect the thermal conductivity of walls located outside of it. In this case, other physical laws apply. The heat reflector promotes more uniform heating of air, surfaces and objects in the room. Heat transfer works from more heated bodies to less heated ones. By reducing the temperature difference, we thereby reduce heat transfer.

Why is foil glued to the insulation layer?

If the heat-reflecting material is placed without direct contact with the thermal insulator, then an air layer is formed behind the infrared mirror, heated by heat transfer through the foil. This layer will transfer heat towards the street. Therefore, no matter what kind of bathhouse you are going to equip - chopped, brick or with concrete walls- there is no point in using foil without insulation.

As an analogue, we can consider the operation of a thermos: the inner surface of the glass flask plays the role of a thermal mirror, and the vacuum between its walls is the thermal insulating layer. The difference with the arrangement of baths is that instead of a vacuum, the mirror is in contact with a thermal insulator glued to it.

Insulation of a log bath

Another question is whether an additional layer of insulating material is needed? In log houses, it is enough to use thin bath insulation with aluminum foil. foil sandwich. Log baths do not require any other insulation, except for inter-crown gaskets and caulking of seams. Infrared mirror technology is economically feasible in any steam room, but stone walls require thorough thermal insulation using cotton wool or slab materials, the effect of which cannot be replaced by foil-based coatings.

Additional features of foil-based materials

Foil, being a continuous metal layer, is a guaranteed barrier to steam and air flow. Thus, in addition to the infrared mirror, the materials of this group provide high-quality convection sealing and vapor barrier of the steam room in the bathhouse.

Types of insulators based on aluminum foil

In addition to considerations related to the physics of heat transfer and infrared reflection, the choice of substrate type is related to the ease of installation and mechanical strength of the two-layer material. The foil is easily torn during installation, which requires additional time to seal the gaps with special tape. When paired with a backing, the material becomes much more reliable, which makes it easier to attach it with a stapler to the wooden battens of the sheathing.

Foil insulation for baths

As a strengthening and/or thermal insulation layer, the following is industrially glued onto the foil:

• Mineral wool. The material is produced in rolls with a thickness of 5 - 100 mm. However, not every foiled cotton wool is suitable for arranging baths. In order to increase hydrophobic properties, mineral fibers are impregnated with special compounds that are unsafe for human health when the material is heated. Only insulation without these impregnations should be used with a direct indication of its purpose in the name. For example, "ISOVER Sauna" or "ROCKWOOL Sauna Butts".
• Kraft paper. The main commercial names of the material are “Kraft foil”, “Foil paper”, “Alucraft” and “Isolar”. In Izolar, a third element is added to the aluminum layer and paper - a polyethylene film, which increases strength and serves as a waterproofing layer for the paper layer. The thickness of kraft paper is in the range of 0.3 - 1.0 mm.
• Foamed polyethylene (FPE). The most popular material in the group of foil insulation. Produced under the names "Folgoizol", "Folgoizolon" in rolls with a thickness of 2 - 10 mm and plates (20 - 110 mm). Rolled foil insulation is usually used to equip baths and saunas in log houses without additional thermal insulation. It is produced in large quantities and is distinguished by good installation and performance qualities combined with a reasonable price.
• Fiberglass mesh. As an infrared screen, a three-layer material “Folar” is sometimes used, containing a reinforcing layer of mesh with a cell of 4x4 mm. The original purpose of the folar is vapor barrier.

We insulate the joints with special tape

A separate group of materials includes PIR slabs, which are formed from high-strength polyurethane foam (PPU) and lined on both sides with aluminum foil. This thermal insulator is available in thicknesses from 30 to 250 mm. It makes sense to use PIR slabs with a thickness of 80 - 120 mm for insulating saunas, baths and hammams in buildings with walls made of brick or concrete. In this case, the slabs play the role of both the main insulation and a layer intended for infrared reflection and vapor barrier. Despite the high price, this material justifies itself on objects intended for long-term use.

Features of installation of foil insulation

If work is carried out in a log house, then, as a rule, foil insulation is used. The material can be attached directly to logs (beams) using a stapler with the aluminum side facing the inside of the room. Depending on the thickness of the cladding, butt or overlap joints are used. The joints are taped with metallized tape.

Air gap between foil and lining

To drain condensate, it is planned to release foil material from the ceiling to the wall, and from the wall to the floor. Slats with a thickness of at least 3 cm are attached on top of the foil insulation. They perform two functions: they serve as a lathing for the finishing cladding and form air gap between the foil and the lining. The gap is important in order to exclude direct heat transfer from the lining through the aluminum layer.

The arrangement of baths in rooms with brick or concrete walls has a single, but very significant difference from work in log houses: contact of foil material with the load-bearing wall is strictly unacceptable. First, the main insulation is carried out with heat insulators of sufficient thickness. Then the foil material is installed. The gap between the foil plane and the finishing lining must be observed.

Another important note for all types of baths and saunas equipped on the principle of a thermos using foil: such rooms must have high-quality ventilation.

Being a 100% vapor barrier, aluminum promotes the formation of condensation. Only intensive air exchange between bathing sessions can promote the natural evaporation of accumulated moisture.

Baths and saunas are premises in which it is necessary to create and maintain a special microclimate. The temperature in the steam room reaches 70-90°C. To reduce heat loss, a thermal insulation system is considered at the construction stage. From a wide range of building materials, experts recommend using foil insulation for a bathhouse. It is resistant to high humidity and effectively reflects infrared radiation.

The need for thermal insulation of the bath

Foil insulation significantly reduces heat loss in the bathhouse

The steam room is good for health, it promotes skin rejuvenation, dilates blood vessels, and speeds up metabolism. When constructing a bathhouse, builders take into account special design requirements. It should warm up quickly and maintain a high temperature for a long time. To meet these requirements, reflective thermal insulation for the bathhouse is installed. Without high-quality insulation, the steam room will not be able to function, or the heating costs will be enormous. Practical bathhouse owners note the advantages of thermal insulation:

• the service life of the bath is extended;
• the amount of time the temperature rises to maximum is reduced;
• the consumption of wood, coal or electricity for heating the sauna is reduced;
• basalt insulation increases the fire safety of the building.

Thermal insulation is installed inside or outside buildings. In the case of steam room insulation, choose the material for interior works. Several layers are installed sequentially, including vapor and waterproofing. The use of insulation for baths and saunas with foil allows you to get by with one material that performs all the listed functions.

Criteria for choosing insulation for a sauna

The insulation must withstand high temperatures and humidity

When choosing optimal insulation For a bath, you should focus on the basic requirements for the material:

• coefficient of thermal conductivity;
• presence of a reflective layer;
• moisture resistance;
• working temperature;
• thickness;
• flammability.

The specificity of a sauna with high humidity and temperature requires paying attention to the quality of the material. Difficult conditions negatively affect the insulation, reducing its service life. Manufacturers take into account the requirements for thermal insulation of baths and create special series with appropriate markings. An important factor is the absence of harmful emissions when heated. When purchasing insulation, you should read the manufacturer's information.

In the baths with wood stoves It is worth considering the flammability of the material. Basalt or mineral wool does not support combustion; polyethylene foam melts.

Characteristics of insulation with foil

Characteristics of insulation

Using bath insulation on the inside walls with foil or metallized coating allows you to create the effect of a thermos. Heat transfer from heating devices occurs due to infrared radiation. To prevent energy from leaving the premises, a metallized screen is installed to reflect it. It is advisable to cover all areas of the structure with thermal insulation: ceiling, walls, floor. A continuous coating will reduce heat and moisture loss.

It is impractical to install foil without a layer of insulation. This is a thin material that is easily damaged during installation. In addition, aluminum has high thermal conductivity, which is unacceptable in baths and saunas. Correct installation and a layer of thermal insulation material eliminate the problem.

Main characteristics of foil insulation:

• High ability to reflect infrared radiation 90-97%.
• Low thermal conductivity due to the cellular or fibrous structure of the material.
• Vapor tightness – the aluminum layer coating does not allow vapor molecules to pass through, no installation of additional protective films is required.
• Waterproofing - the material does not absorb moisture.
• Resistance to high temperatures - insulation materials are designed for operating temperatures over a wide range, the upper limit being 150-300°C.
• Availability of installation - most insulating materials are available in the form of rolls and mats, which allows you to install them yourself.

In addition to thermal insulation properties, sauna insulation with foil has vapor barrier and sound-absorbing properties.

Selection of foil material

Rolled heat insulator

Thermal insulation with foil for a bath differs in technical characteristics and properties. The choice of insulation is influenced by the design features of the room, requirements for fire safety, complexity of installation. Mineral wool is recommended for stone and concrete buildings. This reliable material significant thickness, which will provide an appropriate level of insulation.

A building made of timber or logs does not require much effort to maintain temperature. Wood itself is a good heat insulator. In this case, penofol or kraft foil is sufficient. A review of popular options will help you decide which material is best to use.

Rolled heat insulator

Insulation in the form of a rolled sheet can be from 20 to 150 m long. The thickness of the material ranges from 2 to 40 mm. The basis is foamed polyethylene or propylene. Thanks to the thin coating of aluminum, the material reflects thermal radiation. Penofol is popular in the domestic market. The material is produced with one-sided or double-sided foil coating with a self-adhesive base.

Rolled foil without a base is laid on the surface of the walls after the insulation. Strips 1-1.5 m wide are mounted overlapping. The resulting surface is highly resistant to temperature (up to 650°C), moisture and steam.

Basalt wool with foil layer

Basalt wool with foil

Mineral or basalt wool is a universal fiber insulation. It is resistant to fire and moisture, provides excellent thermal insulation of the room. Foiling the outer layer reduces heat loss and creates a vapor barrier. Among the assortment of leading manufacturers Izover, Parok and Rockwool, you can select special materials with foil for insulating a bath.

• For anti-condensation insulation, ROCKWOOL ALU is recommended. The material is supplied in mats. Its fibers are located perpendicular to the surface. During operation, the strength and elasticity of wool is not lost. The Sauna Butts series is designed for insulation of saunas and baths. Mineral wool slabs with a thickness of 50 and 100 mm serve as heat and vapor insulation. The material is intended for indoor installation.
• Izover Sauna roll insulation is quickly installed on walls and floors and provides reliable insulation. It is safe for health and does not produce harmful emissions when heated or wet. The material allows you to save on the installation of membranes and films.
• The popular insulation of the Paroc brand is offered in the form of lamella and stitched mats. They are easy to use and can be quickly mounted on an insulated surface. The aluminum layer is reflective. Basalt wool does not change its thickness during operation.

The quality of thermal insulation depends on the thickness of the selected mineral wool. The best option 5-10 cm. Basalt wool is fireproof, does not rot from moisture, and has a long service life.

Kraft foil

The use of insulation with a layer of aluminum allows for maximum preservation of infrared radiation inside the steam room. The multilayer construction consists of kraft paper and foil, in some cases polyethylene is added to reinforce the material. Common types:

• foilsolone or foil glassine - an elastic material based on cardboard with a corrugated aluminum coating;
• foil-fabric - fiberglass insulation, backed with foil, reflects up to 97% of radiation, withstands temperatures of about 200°C;
• isolar - bath foil 50 and 100 microns thick with the addition of polyethylene film, resistant to fire, temperatures up to 300°C.

Among the types of insulation, it is worth noting a new product - PIR slabs from TechnoNIKOL with a foil lining. The line of bath insulation products creates a reliable barrier between the cold from the street and the hot, humid air of the steam room. The plates are lightweight, low water absorption, and resistant to deformation

Installation of insulation with foil

The joints are glued aluminum tape

When installing foil insulation for a sauna, you must follow the following rules:

• The layer with aluminum foil is directed indoors.
• When installing the material on the ceiling, a descent is made to the walls, with vertical surfaces- on the floor. This is necessary for the drainage of condensate.
• Ventilation is required in the steam room.
• A gap of at least 30 mm is left between the foil layer and the finishing of the bath.

Subsequence installation work depends on the type of insulation. The penofol roll is rolled out, cut into sheets of the required length and secured to the walls with a stapler. For basalt wool, it is necessary to make a frame according to the thickness of the material. The mats are laid in the finished sheathing. The joints of the canvases are glued together with metallized tape. 30×50 mm slats are placed on top of the heat-insulating layer. The lathing will provide the necessary ventilation gap between the insulation and the casing of the steam room.

If you are going to build a bathhouse, then first of all you need to think about its insulation. Without high-quality insulation, a bathhouse will not be able to perform even its basic functions. Particular attention should be paid.

However, there are a huge number of materials and technologies that allow insulation to be carried out efficiently and quickly.

One of the best solutions for thermal insulation of a sauna or bathhouse is the use of foil insulation material to protect walls.

1 How does foil work?

Initially, foil was always used as a reflective material. This is important to understand. After all, it is not a complete insulator. Foil simply does not have such qualities. That’s why it’s simply impossible to use foil.

Any rolled basalt insulation, even with the thinnest layer of material, will be much more effective than foil, if we talk directly about thermal conductivity.

The thing is that the foil material itself has fairly high thermal conductivity. If Izover mineral wool or any other insulation has thermal conductivity at the level of 0.03-0.035 W/m, then foil material has thermal conductivity at a much higher level.

That is, they do not directly insulate it. The foil composition is needed for slightly different purposes. Its use involves installing a kind of reflective barrier.

Foil actually transfers heat quite easily. But to do this, the heated object must be leaned against it. If this situation does not happen, then the foil material reflects the waves themselves with high efficiency.

Meanwhile, it is heat waves that account for most of the thermal radiation that falls on the surface of the walls. This is especially true in a sauna or bathhouse, where heat is constantly radiated by a heating element.

The second important point is the vapor permeability of the foil. That is, steam, as well as heat, does not pass through it. As a result, it is also an impenetrable barrier to moist heated air.

It's no wonder that foil insulation has become so popular. After all, it combines many useful functions.

1.1 Application of foil

However, you should not think that simply by covering all the walls with foil, you will suddenly get an increase in sauna performance of at least 50%.

Foil, being a rather specific material, can only really work effectively in combination with insulation. Large manufacturing companies like Isover quickly realized this, so they immediately decided to start production combined insulation materials. Where is the foil? outer part material.

And it is worth noting that the Isover company has made serious progress in this matter. Experts from Izover have learned how to create truly high-quality foil insulation.

How does Isover foil insulation differ from conventional insulation or standard foil? Because it combines both of these materials.

The foil here is a reflective material. The insulation plays the role of the base on which the foil is attached. The only thing to which the presented material is not applicable is.

Thermal insulation from Isover insulation with foil is very useful and effective. This is possible due to the combination of two seemingly incompatible materials. If desired, foil can be combined with.

1.2 The principle of operation of foil insulation

The effect of Isover foil insulation can be explained in just a few sentences. For example, let’s take the setting of a standard bathhouse.

A sauna or bathhouse is characterized by small areas where the maximum amount of steam should be contained. The surface of the walls in them is very heated. Glue only foil insulation to them, and it will quickly gain heat from surrounding objects.

As a result, the surface of the walls will not be insulated as it should be. At the same time, the reflective ability of the foil remains with it. But if you use foil along with the base and secure it correctly, then everything will quickly change.

The foil will reflect the main heat waves that emanate from the center of the bathhouse or sauna to the surface of its walls. It will reflect most of the waves, but some will still pass through the barrier.

This is where the second level of insulation comes into play - its base. It will extinguish all thermal loads due to its extremely low thermal conductivity, and at the same time will not allow the foil itself to heat up. That is, insulation will be as effective and efficient as possible.

Mineral wool or foamed polyethylene are most often used as a base for such materials. For example, the Isover company produces foil-coated advantages on a basalt wool base. Although the guys from Isover produce other similar materials.

As a result, the foil not only works as a reflective element, but also as a vapor barrier film. Protecting the insulation itself, as well as preventing hot steam (which also carries a lot of heat) from escaping from the bathhouse.

Insulation with such materials has become so popular that it has begun to be used almost everywhere. Not only for finishing walls in a bathhouse, but also for mounting on the ceiling and even the roof.

Let us note right away that it makes sense to use such material only from inside the sauna. It is by working from the inside that the foil will be able to reflect heat waves. Outside, it will be of little use.

2 Types of insulation

In fact, there are not many foil insulation materials. And their varieties relate rather to the selection of a specific base. Each company, for example Izover and others, produces its own specific type of insulation, or concentrates on creating an entire line.

For example, the Izover company uses mainly mineral wool as a base for foil. While Izover's competitors prefer foamed polyethylene. There are also foil samples on glass wool or polyurethane foam, but they are poorly represented on the market. This one is not in great demand.

The following bases are selected for foil insulation:

• Foamed polyethylene;
• Mineral wool;

2.1 Installation technology and nuances of operation

It would seem that insulation with ready-made foil-coated thermal insulation material is a piece of cake. Indeed, nothing complicated awaits you in the installation workflows. But still, there are a couple of nuances in the work that you should pay close attention to.

Please note that most branded Izover-type insulation is already equipped with instructions, and therefore you will have a certain understanding of the working concept, but it is far from complete.

Stages of work:

1. We prepare the surface.
2. We lay the waterproofing film.
3. We install the insulation with waterproof glue.
4. We seal all the joints between the rolls using special tape. There should be no gaps or seams left on the surface of the foil. This must be a monolithic plane.
5. We install a supporting sheathing of bars up to 3 cm thick.
6. We stuff clapboard or any other facing material on top of the sheathing that can be used inside a sauna or bathhouse.

One very important point should be noted here. Insulation with foil material from the inside of the bath can only be carried out in compliance with a special air gap.

It is for its formation that the fifth stage was invented, in which a very thin wooden sheathing is stuffed on top of the foil.

The air gap will create a thermos effect. The warm air in it will not be able to heat up to a very high temperature, and the front wall structures will not be able to transfer their heat to the foil.

In this case, heat waves will calmly pass through the same lining, and then be reflected and turn back. Failure to comply with the rules on air gaps completely eliminates all the benefits of foil.

In this case, she is from a reflective vapor barrier material will turn into a regular roll insulation with properties that correspond to the properties of its base.

2.2 Installation of foil insulation (video)

Foil is produced in both rolls and sheets. Roll material can have a thickness from 0.007 to 0.2 millimeters, a width of 10–1500 millimeters. The percentage of aluminum content in it is up to 99.5%.

Depending on the type of surface, foil is:

• smooth, without additional finishing;
• for finishing;
• finishing

According to the scope of application, the material is divided into canvas:

Depending on the manufacturing method, foil is distinguished:

• soft (annealed), marked “M”;
• solid (unannealed) – it is assigned the letter “T”.

A quality product is a fabric that has no folds, stains, tears or other inclusions on the surface. When viewing a thin fabric against the light, it should have no tears or tiny holes. Thick foil is allowed to have a small number of holes, which is regulated by the technical parameters of the equipment used.

Thin fabric is wound on bushings having different diameters. Thick foil is produced in sheets.

Before starting insulation work, developers are interested in how much foil for a bathhouse costs. Domestic roll products will cost less than imported material. With a roll length of 25-30 meters, the price will be approximately 20-30 dollars.

Aluminium foil

Photo of a roll of foil

It is important to know: aluminum has a high thermal conductivity and high reflectivity. Therefore, heat is retained not by restraining it, as when using other insulation materials, but by reflecting it back into the room

For high-quality thermal insulation of the steam room, the insulation material must have increased water resistance and fire resistance.

Foil for baths and saunas is ideal for these parameters.

Characteristics

• There is no effect of deformation at high temperatures.
• Aluminum does not emit fumes harmful to humans.
• High level of vapor barrier. Thanks to this, hot steam does not escape from the room, but fulfills its purpose.

The steam must remain inside to achieve the correct effect

• No steam accumulation in the material itself. This significantly increases the service life.
• Acceptable price.
• There is no condensation on the walls. This is especially important in the case of wooden walls. Since the presence of condensation can lead to the appearance of mold and rotting processes.
• Isolation of material from harmful effects excessive humidity and other possible effects. This extends the life of the building itself.
• Heat reflection effect. The aluminum surface reflects thermal radiation, which significantly speeds up the heating of the steam room, which allows you to save on heating costs.
• Easy to install. Affordable DIY implementation.
• Durability. Does not rust, does not rot, and is not attacked by pests.

This solid list of advantages generally applies to foil as insulation. But today the manufacturer offers different types, which have some peculiarities.

Kinds

Which foil is best for a bath?

Let's look at its most prominent representatives:

• Folgoizolon for baths is polyethylene coated with aluminum foil. To all of the above qualities, a high level of noise insulation is added and increases strength. And heat conservation is carried out not only due to reflective properties, but also by reducing thermal conductivity.

Folgoizolon sheet

• Paper-based foil for baths significantly increases the strength and reliability of the product and is an environmentally friendly material.

Extra layer of paper for added durability

• Foil insulation for a bathhouse is any classic insulation material, such as isolon or even mineral wool, in which one of the sides is covered with a layer of foil to increase waterproofing, fire safety and protection from the aggressive environment of the steam room. The cost increases accordingly depending on the combined insulation.

Roll of foiled mineral wool

Thus, all varieties simply involve adding an additional layer, which adds some quality, but also increases the cost. In order to save money, regular bath foil is suitable, as it already has a sufficient number of necessary qualities.

Installation

The following instructions will help you install the foil:

• We buy a sufficient amount of foil with a thickness of 100 microns.
• We fix the foil to the boards using a stapler, furniture nails or tacks. At the same time, we make overlaps of several centimeters.
• We fasten the aluminum strips together with mounting tape.

Connect with construction tape

Tip: Aluminum is highly conductive electric current. Therefore, be sure to carefully insulate any wiring in the bathhouse.

• We install a sheathing of wooden planks on top, which will serve both as a reinforcement for the foil layer and as a basis for interior decoration.

The process of strengthening the sheathing strips

• We install the inner finishing layer.

It should be noted that when using an additional insulating layer, it is installed in front of the foil.

For example, if it is mineral wool, then we do the following:

• Nailing wooden blocks with a section of 5 cm by 5 cm for the walls and ceiling of the steam room. In this case, we keep the distance between them equal to the width of the insulation boards.
• We put insulating material between them.
• The above installation steps follow with one clarification: the foil is fixed to the intermediate strips.

Foil over mineral wool

If you use bath insulation with foil, the covering process is even simplified and becomes more cost-effective than purchasing and installing them separately.

Which foil material is better to choose for a bath?

In addition to the usual rolled foil, there are a lot of different foil materials designed for wall insulation. But not all of them are applicable in a bathhouse where the temperature and humidity are high.

Here it is extremely important to choose the right and harmless heat insulator, otherwise visiting the steam room can lead to health problems. An additional layer makes the foil more durable or increases its thermal insulation characteristics

You can insulate a bathhouse:

• kraft foil (paper based);
• foil fabric (on fiberglass);
• folgoizolone (on polyethylene foam).

The first option is a complete analogue of standard aluminum foil, only with a reinforcing layer of paper. The second is the most durable and fire-resistant of all, and the third, thanks to foamed polyethylene, creates an additional layer of classic thermal insulation.

Advice! Experienced craftsmen recommend sheathing the walls and ceiling of the bathhouse near the stove exclusively with fiberglass foil. It is durable, harmless and can withstand temperatures up to several hundred degrees.

The polyethylene backing calmly tolerates the heat of the steam room. But near the firebox, this foil material should not be sewn onto the walls. In the heat of a hot stove, it will inevitably begin to melt.

Foil fabric (folar, foil on fiberglass) is an ideal insulation for a bathhouse

There are also mineral wool-based foil insulation on sale, but it is not recommended to use them in a bathhouse. Some of them contain formaldehydes, which begin to be released when the temperature of the material increases, while others, when wet, lose all of their thermal insulation properties.

Even thick aluminum foil without a backing can be easily damaged during installation. It should be used in a bath only as a last resort. It is best to choose the fiberglass option, available in three types:

1. “A” with one-sided foil (operating temperature from -40 to +150° C).
2. “B” with foil on both sides (operating temperature from -40 to +300° C).
3. “C” with an adhesive base and one layer of foil (operating temperature from -40 to +80° C).

All listed materials are sold in rolls various sizes and thickness. They fit easily under required sizes. And their fastening in the bathhouse is done with galvanized nails or staplers.

Classification of foil types and properties

To choose the optimal model, you need to decide on functional purpose foil layer. In a steam room, it can serve as a reflection of thermal energy. But for this, the material should not be closed, otherwise the meaning of its use is lost. Also, a layer of foil can be installed in the area of ​​the heater to maximize the concentration of thermal radiation into the room.

When arranging a bathhouse yourself, it is recommended to use aluminum foil with a backing. This will reduce installation time and labor intensity. This approach is due to the relative fragility of foil materials - even a slight excess of mechanical stress can cause the layer to rupture.

Roll without base

The best option for improving the thermal insulation qualities of the steam room. The material is a roll of aluminum foil, up to 250 microns thick. Length varies from 5 to 20 meters, width – up to 1500 mm. The maximum temperature limit for this material is +650°C.

Features of installation and operation:

• rolls are mounted overlapping;
• special foil tape is used for fixation;
• the material must fit tightly to the insulation;
• installing two or more layers does not make sense, since it will not affect the increase in heat-reflecting properties.

The average cost of 1 m² is 48 rubles.

Reinforced foil

It is necessary for arranging walls, ceilings and floors with a complex configuration with many indirect elements and angles. Unlike conventional rolled material, reinforced foil has an additional layer of fiberglass mesh. It increases the mechanical strength of the reflective surface.

Installation specifications:

• some models have an adhesive backing to simplify installation;
• joining several sheets is also done using tape;
• You can purchase rolls with one-sided or double-sided foil coating;
• Roll length up to 50 m, width 100 cm.

Despite all the advantages of the reinforced model, it is rarely used for arranging a bathhouse. This is due to the high cost - from 150 rubles per 1 m².

Kraft foil

For increase mechanical strength and durability, a new type of heat-reflecting material was developed that combines a base of impregnated paper and aluminum foil. In fact, it is an insulation material that combines the properties of cellulose to retain heat and reflect IR radiation.

To increase safety, the paper is impregnated with fire retardants. In addition, the material has the following properties:

• possibility of installation directly on inner part wooden wall;
• the small thickness will not affect the reduction in the useful volume of the steam room;
• increasing tensile strength.

The average cost of kraft foil is 110 rubles per 1 m².

With thermal insulation materials

To fully insulate a bathhouse, it is recommended to use heat insulators, one of the sides of which is foil-coated. The reflective layer is applied to the adhesive base, this increases the strength characteristics of the foil and allows you to create reliable thermal insulation.

The following are used as insulation:

• Basalt (stone) wool. The best option for a bath or sauna. It is heat-resistant, its structure allows moisture to pass through, which is a prerequisite for a steam room.
• Foamed polyethylene. It has increased flexibility and is waterproof.
• Extruded polystyrene foam or polystyrene foam. Budget options for insulating a bath.

The presence of a layer of foil does not greatly affect the cost of these heat insulators.

For a bathhouse, it is better to choose insulation with a foil side. This will reduce labor costs and allow you to maintain the required microclimate characteristics in the room.

The main advantages of the material

The high popularity of foil insulation for baths is due to an impressive list of its advantages:

• The so-called “thermos effect” is created, that is, when heat does not escape from the room at all. This type of insulation is simply ideal for baths and saunas, as it allows you to preserve precious steam as reliably as possible.

Tip: Effective thermal insulation will significantly reduce energy costs. As a result, the bath will warm up much faster.

• This insulation provides excellent protection against moisture and vapors. Therefore, there is no need to create a water-repellent layer. For wooden buildings this is extremely important.
• One of the main features is absolute resistance to temperature changes. They are achieved thanks to the presence of a heat-repellent layer. Simple roll insulation materials will only last a few years when used in such conditions.
• Reducing the thickness of the required insulation layer. This property is achieved through the use of special foil, which increases the efficiency of thermal insulation.
• Increasing the noise insulation properties of the room.
• Absolute environmental cleanliness. High hygiene is important factor for premises of this kind.
• Very a light weight(except for mineral wool). This makes installation and transportation easier. In addition, there is no need to build a frame (in most cases this is the most labor-intensive procedure).

Please note that a similar group of materials is used in many other areas (from apartment buildings to car showrooms). It is perfect for use in conditions of high humidity and sudden temperature fluctuations.

Choice of foil. What to pay attention to

When buying foil for a bath, you should carefully decide on the question: which one is better to choose. The purchase must be made based on the product’s compliance with a number of important criteria, among which are ease of installation and durability in operation.

In this regard, special attention should be paid to the following nuances.

Aluminum sheet, due to its technical features, is a very sensitive raw material to mechanical damage, so you should purchase it on a substrate and, preferably, in a reinforced form. This solution will significantly reduce labor costs during installation due to the absence of wasted time on unnecessary sealing of damaged areas.

Among the most common types of substrates are:

• kraft paper,
• foamed polyethylene,
• mineral wool.

A very important detail that makes foil insulation for a bathhouse an indispensable product is its reflective ability. 95% for this characteristic will be a sufficient value for the product to perform its functions. The higher the reflectivity, the less heat the room will lose.

Thermal insulation must have significant resistance to high temperature and humidity. If we talk about temperature, then the insulation must withstand at least 100 C.

Separately, you should pay attention to the environmental friendliness of thermal insulation. During operation, foil insulating substances will be repeatedly subjected to heat treatments. These processes should not become a catalyst for the release of harmful, toxic substances into the air.

Foil thermal insulation must have certain vapor barrier properties. Thus, vapor permeability during the day should not exceed the level of 0.01 g/m2.

Durability and reliability are also important criteria. Before making a purchase, you should read reviews about thermal insulation products on information sites, and also find out about warranty periods from manufacturers or distributors.

What types of foil exist today?

If we talk about the market for various building materials, then on it you can find several options for foil, with various qualities. To obtain good coverage, when carrying out the so-called installation work, it is necessary to adhere to a certain thickness of the insulation.

Experts believe that various coatings and ordinary aluminum foil may not reflect into the room all the heat that has escaped from the house; for this reason, the steam room must be insulated according to the principle called “pie”. Not only glass wool, but also other mineral materials are ideal as an additional material for thermal insulation. This will be especially true not only in saunas, but also in baths, because they are made of concrete or brick. If external walls wooden log house There is sufficient thickness, you can neglect additional thermal insulation.

1. Rolled foil without a base is a fairly thin material, but it is considered not so tensile strength. Foil can be used for installation on all walls of various bath rooms, and on top of various insulation materials installed earlier. This material is fixed mainly with an overlap, and all the joints need only be glued with special tape, which results in a fairly sealed surface with a reflective effect. This material is considered resistant to corrosion and is not at all capable of releasing various harmful substances.
2. Kraft foil is mainly produced on the basis of paper, and in a three-layer version. This foil has the best strength characteristics. You can attach it to well-caulked walls, which consist of timber, without the use of additional insulation. It is an environmentally friendly material that does not emit toxic fumes at all. The operating temperature is usually up to one hundred degrees. If you carry out the installation correctly and glue the joints with special tape, you will have a sealed layer. The material is considered more convenient to install when compared with conventional foil. The fact is that it is considered tear-resistant and wrinkles much less.
3. Folar is a vapor barrier that consists of one or several layers of foil. A fiberglass mesh should be laid between them. Such a material is able to basically retain its excellent qualities in a different temperature range; it can reach three hundred degrees. Folar is also considered one of the most environmentally friendly materials. It contains neither allergens nor carcinogens, and can withstand relatively large loads, especially mechanical ones.
4. "Folgoizolon" is a foamed polyethylene that has a foil coating. It is produced in the form of various rolls or sheets, everything depends solely on its thickness. This insulation is considered quite durable, it has high sound insulation and shock absorption characteristics. Since such fabrics can be quite thick, they can be fixed without the use of additional material for thermal insulation. This material is ideal for insulating log surfaces. It is easy to cut into pieces. Attach it to a special wooden sheathing using a stapler or staples. Double-sided tape is also used.
5. The so-called foiled mineral wool. As a rule, it is made in various slabs or rolls; its thickness should be up to hundreds of millimeters. This material has different widths and lengths. These parameters vary mainly depending on the manufacturer. If we talk about mineral wool, there are quite a lot of them. One of the most popular materials on our market is the so-called basalt heat insulator, which is called “ISOVER Sauna”

Features of bath ventilation

As noted earlier, the arrangement of high-quality ventilation system mandatory for the normal functioning of the insulating 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 is 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 wall opposite the heating device.

As a result, we note that the size of the ventilation holes depends on the specific area of ​​the room. So, for every square meter of the steam room there should be at least 24 square centimeters. That's all, good luck with your 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! Still don't forget about ventilation gap between the insulating layer and the 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, mildew and various kinds microorganisms harmful to health.

Video - How to cover a steam room in a bathhouse with foil

Types of foil

Depending on the type of application and auxiliary components included in the composition, the material is divided into several types:

Plain foil in rolls

The material is represented by a thin aluminum layer with a thickness of up to 300 microns, a roll width of up to 150 cm. It is designed for a wide temperature range, therefore it is used for steam baths and saunas. Considering the high probability of deformations and tears during installation, it is recommended to apply foil to a fire-resistant heat-insulating base with fixation to metal brackets.

Foil backed paper

It is a cellulose base with an aluminum top layer. The paper can withstand high temperatures from 50 to 125 degrees, so it is suitable for auxiliary and technical rooms of baths.

Foil fabric

A material consisting of a fiberglass base and an aluminum layer. It has high sound, heat, steam and moisture insulation characteristics, and is resistant to rotting and mold.

A special type of insulation, the basis of which is foamed polystyrene foam, covered with a thin aluminum layer. It is available in rolls and sheets. The advantages of this material are resistance to high temperatures, excellent fireproof and thermal insulation characteristics and ease of installation.

Foil plates

The material is based on mineral wool coated with a thin layer of aluminum. It has high heat and vapor barrier properties.

The slabs are easily installed on ceiling and wall surfaces, therefore they are intended for use in any bathhouse.

How to choose the best insulation for different applications

The choice of insulation with foil for a bath depends on the material from which the building is constructed and the frequency of its use. In some cases, you can get by with simple aluminum foil, while in others you need cladding using a thermal insulation layer.

Regardless of what type of bath foil you choose, you must proceed from the following considerations:

1. When buying cheap products of unknown origin, there is a risk of purchasing material made from poor quality raw materials. Its performance properties will be at the lowest level.
2. The insulation must be covered with real aluminum foil. Some manufacturers practice spraying, but there is very little benefit from it.
3. The fire threshold is of great importance. Foil in the bath is exposed to high temperatures, so fire safety is the main selection criterion.
4. It is important to choose the right thickness of insulation with foil on the walls for the bathhouse; the effectiveness of the work you do will depend on this.

Bathhouse lining

What foil insulation is needed for a wooden bath

A log bathhouse with well-caulked walls does not require any additional insulation. Wood does not conduct heat well, so it is well retained inside.

In a small building, only the ceiling is sheathed with foil or kraft foil. If the bathhouse is spacious and you need to update the interior, then you can cover its walls and ceiling with simple foil, and then line it with wooden clapboard.

In order to protect the wood from fire, they use wall cladding behind the stove. This measure further increases the temperature in the steam room, as heat is reflected from the foil.

When choosing regular foil for a bath, do not ignore such a parameter as the thickness of the aluminum layer. It ranges from 0.007 to 0.2 mm, and the vapor permeability of the material is directly proportional to this value.

Foil as a vapor barrier

Buildings made from aerated concrete blocks are considered very warm, but a vapor barrier is required here. You can use regular foil for such a bath, but it is better if it is glued to waterproof craft paper. Such insulation will become a reliable barrier to the occurrence of dampness, will retain heat inside, and steam will not harm your health.

Baths with frame and brick walls are subject to mandatory insulation for the reason that they do not retain temperature well. Here you need foil insulation, the basis of which is mineral wool or expanded polystyrene. You can also make a “thermos” from a quencher and aluminum foil.

What is the use of foil in a steam room, scam or undeniable benefit?

Some argue that foil insulation in a bathhouse is of zero use, while others claim that it is an ideal heat insulator. Some craftsmen simply use foil, while others prefer to combine it with heat-insulating material. These discussions are endless, but a choice must be made.

Foil in a bathhouse will only be useful if it is laid according to all the rules

Principle of operation of the material

Heat in the steam room is transferred due to:

• convection;
• thermal conductivity;
• IR radiation.

On the one hand, aluminum foil has high thermal conductivity, but on the other hand, it reflects almost all infrared radiation that hits it.

The first point is often mentioned by opponents of this material. But they forget to say that the foil can only heat up from the lining or walls of the bathhouse. First, the lining must heat up, and only then will it transfer some of the heat to the aluminum. To the walls thermal energy The foil surface itself will give away.

Important! The high thermal conductivity of the foil will play a negative role only if the area of ​​its contact with the casing is large. Lathing for lining is not capable of releasing a significant amount of heat due to minimal contact between these two building materials

With infrared radiation it’s quite the opposite, and this is where the fun begins. This is what the hot stones and stove emit in the bathhouse. However, due to its properties, IR rays are almost completely reflected back into the room by foil. Therefore, it is more correct to call it a heat reflector rather than insulation.

More than half of the heat in the sauna is transmitted through infrared radiation, which aluminum reflects 95–97% back into the steam room

There is one more nuance - a hermetically sealed layer of foil is an excellent vapor barrier. As a result, the heated steam remains inside the room, increasing the temperature of the bath air. The bathhouse heats up faster, and after the wood burns out, it cools down more slowly.

Benefits of use

Among the advantages of using foil in baths it is worth mentioning:

1. No harmful emissions and hygienic.
2. Preservation of the coating during prolonged exposure to excess moisture and high temperatures.
3. Easy installation.
4. Impervious to rotting.
5. Increased sound insulation.
6. Fire resistance and heat reflection of the material.

However, if the foil layer has holes, then its usefulness will sharply decline. It's all about condensation. It will fall out not on the outside of the foil inside the bath, but on the inside, facing the wall. The accumulation of moisture will certainly lead to mold and wood rotting.

The nuances of installing foil and foil insulation in a sauna

The choice of foil heat insulator depends on the material from which the bathhouse is built. In some cases, just aluminum foil is sufficient, while in others it is recommended to use only insulation for sheathing.

Option #1: Insulating the log house

If the walls of the bathhouse are made of thick logs, then covering them with foil is a waste of money. Here quality is more important caulking, and additional insulation of the log house is simply pointless. In this case, the thermal insulation layer will have little positive effect.

In a log sauna, foil insulation should only be used when covering the ceiling. Upstairs it will be of at least some use, especially if the ceiling is made thin and without an insulating layer on top.

You can also cover the walls around the stove with aluminum foil without a backing. Such a screen will reflect heat in the form of infrared radiation into the steam room, instead of wasting it on useless heating of the wall behind the heater.

Thick foil makes an excellent screen for a sauna stove

When covering the ceiling, foil insulation is laid with a reflective layer down, overlapping and with a slight overlap of 5–10 cm on the walls. The joints must be taped with special aluminum tape.

It is very important to create a sealed layer without the slightest loopholes for steam.

After installation, the foil can be left as is. This way condensation will definitely not accumulate on it. But from an aesthetic point of view, it is better to cover it with clapboard. To do this, you will need to fill a sheathing of 40x40 mm bars, to which the wooden planks will be nailed.

Option #2: Cladding a brick or frame structure

If the walls of the sauna are made of brick or frame technology is used, then they will have to be insulated with foil heat-insulating material. Otherwise, the heat in such a bath will not last long.

Installation diagram of foil insulation on walls and ceiling in a bathhouse

The sequence of work in this case is absolutely identical to the technology used in a log house. Only covering with foil is done in a circular manner over the entire area of ​​the walls and ceiling to create a thermos. You need everything possible ways block heat output as much as possible.

Advice! When thermally insulating a bath using aluminum foil, special attention must be paid to windows and doors. The material to be laid should be securely nailed to the jambs and sealed with tape.

Ideally, the sheathing for the lining should be made independent, with a gap between the frame and the foil. The larger the space, the better ventilation and less condensation. And this is the most important point in insulating a steam room.

Types of insulation with foil for baths

During operation, a thin, soft foil sheet is easily wrinkled and torn, which is why new technologies for its use have emerged.

Currently on sale:

Foil paper

Its other name is laminated foil on a paper base for a bath. It is an elastic and dense material and has excellent vapor barrier characteristics. It is produced in two types: foil plus kraft paper and foil plus paper plus polyethylene.

Foil paper can withstand 130-degree heat. Resists compressive loads. It holds its shape and is easy to cut. The standard strip width is 120 centimeters. Self-tapping screws, construction staples and nails are used to secure it. The material is used for lining the inside of baths. It is not recommended to use laminated foil on the surface of walls adjacent to the stove.

Foil fabric (foil fabric)

This soft two-layer material is made from fiberglass and foil. The thickness of the foil fabric is in the range of 0.12–3 millimeters. The panels need to be fastened end-to-end. Foil fabric is used to insulate bathhouses; it can be used to sheathe walls near the heating unit.

Its main characteristics:

• ability to withstand temperature regime up to 500 degrees;
• resistance to mold and other harmful microorganisms;
• good moisture resistance.

Foiled polystyrene foam

The insulation is made from expanded polystyrene and covered with a thin layer of aluminum foil. The material is produced in sheets measuring 1.2 x 0.6 meters with a thickness of 2-10 centimeters. They are used to insulate the premises of a bathhouse building from the inside. The sheets are equipped with stepped locks that prevent the formation of cold bridges.

Foiled polystyrene foam has the following qualities:

• does not absorb moisture;
• reflects about 98% of thermal energy;
• differs in vapor barrier properties;
• resistant to chemical influences;
• safe for health;
• has a long service life.

Foil polyethylene foam

This roll insulation with a thickness of 2 to 10 centimeters has a one-sided or double-sided foil coating. It is used when arranging thermal insulation for the interior of baths.

This material can withstand temperatures of no more than 100 degrees. It is not used for covering surfaces near the stove.

Foil mineral wool

It is produced in rolls or in the form of mats different thicknesses. Has excellent thermal insulation properties. Ideal for insulating frame bath buildings. Using rolls or mats with foil makes holding finishing works lighter and more convenient.

Steam room cladding

Foil for steam rooms is usually purchased on kraft paper or polyethylene. It is not recommended to use foil mats with mineral wool due to their low moisture resistance.

The ideal option is safe and environmentally friendly kraft paper. The steam room differs from other rooms in the bath due to its increased temperature and humidity. This imposes corresponding requirements on all finishing materials.

Important! Pay attention to each area. Carefully seal the joints of the rolls and the joints near the ventilation window, grilles and doors

You should not save foil tape.

Foil is always used in conjunction with other insulation materials and... The moisture resistance of all materials is the main condition that must be taken into account before choosing foil for the steam room.

Kraft paper has good moisture resistance, although it is an organic compound. The same applies to polyethylene. An exception should be made only for mineral wool and basalt.

Apply insulation for the steam room with foil with an overlap.

Thin sheets are joined with tape overlapping, thick sheets - end-to-end.

The ideal option for joints, especially for thick materials, is to seal the entire seam with foil tape on both sides.

If this is not possible, then glue the joints on one side.

In the steam room of the bath Special attention You need to pay attention to the fit of the foil insulation to the frame of the ventilation window, to the valve and door.

These are weak points where steam rushes and condensation forms. Thin foil in these places can be applied in several layers.

Benefits of use

Aluminum foil, GOST 618-73, a rather fragile material that is necessary to create an insulating layer for baths and saunas, is used either in the form of a regular aluminum film or in combination with a substrate.

Rolled foil

A heat insulator is necessary to increase the efficiency of the bath. The benefits of its use are as follows:

• promotes rapid heating of the room;
• retains heat, preventing it from escaping;
• protects walls and a layer of insulation from the destructive effects of moisture and steam;
• protects against the formation of mold and mildew;
• withstands high temperatures and temperature changes;
• extends the life of the building as a whole.

Environmentally friendly foil is non-corrosive, non-toxic, environmentally friendly, and meets all sanitary and hygienic requirements.

On a note! The use of foil is useful; energy consumption (electricity, firewood) is reduced by at least a third! The service life of the bath is doubled! The material is inexpensive and easy to install.

The benefits of use are obvious; it is only important to choose the right material for the steam room and other rooms of the bathhouse and sauna. .

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.

• The foil will negatively manifest its increased thermal conductivity if it is fixed directly to a cold wall constructed of foam concrete/concrete/brick in the absence of an additional thermal insulation layer between them.

So, the structure of the material is such that it has high thermal conductivity. But, in addition to this, do not forget about other methods of heat transfer - IR radiation and convection. The heating device gives off heat inside mainly in the form of infrared rays, heating all surfaces. But if these rays hit an aluminum surface, they will not be absorbed by it, but will be reflected back. Simply put, heat will not be wasted to warm up the walls, which means that the foil retains thermal energy not because of its special texture or thickness, but due to the creation of a reflective coating. And, remarkably, up to 97 percent of all heat generated by the heating device is reflected.
Finally, the foil effectively protects the insulation underneath from steam. A fairly tight coating is created that prevents the penetration of hot steam. Thanks to this, not only is heat retained in the bathhouse, but the heat insulator is also protected from moisture, and therefore does not lose its original properties.

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.

Advantages of the material

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.

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.

Smooth foil 150 microns

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.

Reinforced foil with sticky layer

Overview of foil thermal insulation

From the information above, it became clear that aluminum foil is used both with and without insulation. In the first case, the foil is applied to the insulation, and in the second - to a beam or log.

On sale you can find:

1. Polished aluminum foil according to GOST 618-73 in rolls or sheets
2. Foil Kraft Paper
3. Insulation with foil layer

Let's look at all the varieties separately, in more detail. The picture shows foil in rolls.

1. Depending on the thickness, foil is sold in sheets or rolls. Annealed (soft) foil is marked in the form of the letter M, and non-annealed foil is marked with the letter T. The thickness of the foil is from 0.007 to 0.2 mm or more, the width is usually 1 - 1.5 m.

Rolls of thin foil most often consist of five pieces of fabric, and thicker ones - of three.

In stores it has a specific purpose - for baths and saunas.

2. Foil paper is a high-strength paper with added cellulose and a thin coating of aluminum. The product is attached to the walls using nails, screws or construction brackets.

It is ideal for insulation building structures in hard-to-reach places.

A roll 1 m wide consists of 30 m of fabric. Price 1 m2 = 420 rub.

This type of coating can withstand temperatures from - 50 to + 120 degrees. WITH

3. This foil insulation is designed specifically for finishing rooms with high humidity.

Penotherm NPP LF is a thermal insulation material made of foamed polypropylene with aluminum foil. It is reflective insulation because it uses polished aluminum foil. It is mainly used for thermal insulation of walls and ceilings in baths and saunas.

Penotherm NPP LF is easy to cut with a utility knife, can be mounted using a furniture stapler, and glued with tape.

Main characteristics: application temperature from - 50 to + 150 degrees. C, good thermal insulation, good vapor barrier, good sound insulation, does not rot or corrode, environmentally friendly material.

Penotherm NPP LF is produced in different thicknesses and therefore prices will also be different:

• thickness = 2 mm costs 134 rub/m2
• thickness = 3 mm costs 145 rub/m2
• thickness = 4 mm costs 154 rub/m2
• thickness = 8 mm costs 244 rub/m2
• thickness = 10 mm costs 278 rub/m2 (prices are for Perm)

Once again let’s return to point 1 - to aluminum foil in rolls to get acquainted with the prices:

• thickness = 0.04 mm costs 570 RUR/roll
• thickness = 0.08 mm costs 950 rub/roll
• thickness = 0.1 mm costs 200 rub/m2
• thickness = 0.2 mm costs 300 rub/m2
• thickness = 0.8 mm costs 450 rub/m2

Knowing the prices of foil thermal insulation and the material of the walls of your bathhouse, you can compare them with yours in cash and it’s better to choose it and buy it.

And when the material is purchased and delivered, you will be able to edit it the way the author of this video did

Thanks to the foil insulation, bathing procedures will be a joy and pleasure. Good luck!

Features and feasibility assessment

Reflectivity is the main property that makes aluminum foil suitable insulation for a bathhouse - a room that needs to be heated quickly and strongly. The second argument in favor of choice is resistance to humidity and high temperatures. Not every material can withstand the hot conditions of a steam room.

How to use foil to its fullest potential

In a bathhouse, foil can be used as an independent reflective heat insulator or as one of the layers in a “pie” with other materials. If you place foil between the thermal insulation layer and the lining, you get the effect of a thermos. This thermal insulation option is ideal for baths made of brick, concrete blocks and those built using frame technology.

Aluminum foil without insulation will act solely as a reflector or vapor barrier, protecting vulnerable materials from moisture. This option is often chosen to increase the air temperature in small steam rooms, as well as to protect wall materials and for fire safety purposes near the stoves.

Insulation of walls under cladding

Benefits and good reasons to choose

Significant advantages of foil for bath insulation compared to other options arise from its unique properties:

• Impermeability to gases and vapors. Even a sheet 0.009 mm thick allows water vapor to pass through in an amount of only 0.01 g per 1 square meter. m of surface during the day, and starting from a thickness of 0.025 mm, gas-vapor permeability is practically zero. The metal atoms are arranged so tightly that only hydrogen penetrates through the network. Compared to foil, any polymer material, then its permeability will be the smallest.
• High resistance to corrosion. When exposed to air, the foil becomes coated with oxide, which protects it from exposure to chemicals and greatly prevents corrosion.
• Excellent fireproof characteristics. Withstands temperatures up to 145 degrees.
• Environmental Safety. Foil is non-toxic, does not absorb odors, and is not attractive for the growth of microorganisms.
• High reflectance coefficient - from 95 to 98%. This is a screen that both retains heat inside the room and serves as a barrier to the penetration of heated or cold air from the outside.
• Not susceptible to deformation. The canvas can take any shape.
• Good ductility, maintained at high temperatures.
• Resistance to ultraviolet rays, rotting, and the proliferation of pathogenic organisms.
• No harmful fumes.
• Easy to install.

Foil with mineral wool

The advantages of foil for baths and saunas are much greater than the disadvantages, but they cannot be ignored. The following properties can be attributed to the disadvantages:

1. Tendency to gradual corrosion, as a result of which the reflective layer becomes cloudy and the quality of protection decreases. Therefore, when choosing a foil heat insulator for a steam room, pay attention to the presence of a metallized film layer.
2. Limited temperature range, which is why it is necessary to install a ventilation hole to prevent overheating.

Installation of foil on the ceiling

To buy high-quality bath foil, you need to choose certified products from manufacturers with a good reputation in the market.

Paper-based sauna foil

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	A fairly 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.

Product range of possible foil insulating products

Knowing the basic requirements for foil materials, you should consider in detail the types of thermal insulation products. Finishing a bathhouse with foil will take less time if you study all the diversity of the insulation market in advance. Below is a list of the most common ones:

• Aluminum foil for the bath. This thermal insulation product is sold in rolls. Rolls in the markets are presented in a wide range. Rolls can be of different widths and lengths. The thickness of the layer can also be different.

Foil in rolls does not have a base. Used for installation on top of an existing mineral insulator. You can use aluminum foil for a bath up to 650 degrees

The owner himself can choose the thickness of the thermal insulation; it is important to remember that the final strength depends on this. The reflectivity of aluminum sheet is usually at least 95%

Installation is carried out with an overlap, with mandatory gluing of the joints with metallized tape. The use of foil for insulation is absolutely safe for human health, since it does not emit toxic substances when heated.

• Kraft foil. This thermal insulation material is made on the basis of cellulose; it can also be found in a three-layer design consisting of foil, polyethylene and kraft paper.

The main properties include high strength, environmental friendliness, and tightness. Kraft foil has a small thickness, which may not exceed 1mm. The surface of the foil has a reflectivity of 95%. Despite the fact that the operating temperature of kraft foil is noticeably lower than that of rolled aluminum sheets, and is only 100 degrees, it is much more convenient to install, since it is less susceptible to mechanical damage and has greater flexibility.

• "Folgoizolon". Baths whose walls are lined with this material, if all technology requirements are met, do not require additional insulation measures. In addition to all the main functions, Folgoizolon has soundproofing properties. This product is usually sold in rolls, but you can also find sheet packaging when it is thick. Its base is foamed polyethylene.

In sheets "Folgoizolon" has standard sizes 600*1200mm with a thickness from 20 to 110 mm. In rolls, the thickness does not exceed 10 mm with a width of 1000 to 1200 mm.

“Folgoizolon” ​​is easy to process during installation, it is not subject to deformation, and can withstand temperatures up to 125 degrees in operation.

• The most popular thermal insulation product on the Russian market is foiled mineral wool. Products based on mineral raw materials have traditionally been used in insulating any premises for many years. In the markets it can be purchased both in rolls and sheets, with a thickness from 30mm to 100mm. The main disadvantage is the presence of an unpleasant installation procedure. Cheap thermal insulation causes irritant reactions in human mucous membranes.

• "Penofol". For a bathhouse, this foil thermal insulation can be an excellent product with vapor barrier properties. Being a vapor barrier-based fabric, Penofol not only does not let heat out, but also helps the walls to “breathe.” The reflectivity of the material is about 97%. With such indicators, we can safely say that the thermal insulation of bathhouse walls using Penofol will be better. The thickness of the main heat-insulating layer, as a rule, does not exceed 10 mm. The vapor barrier material can withstand temperatures up to 300 degrees.

The best material for insulating a bath

Since the cost of energy is constantly rising, owners of baths and saunas are forced to look for ways to save costs on operating a steam room. When constructing a new building, it is necessary to use materials that have heat-saving characteristics. Baths built from bricks, foam concrete, cinder blocks and other building materials, except natural wood, need additional protection from heat loss.

When arranging a steam room, you should be especially careful when deciding which foil is best for a bath, since the material must be environmentally friendly and reflect heat well. All these requirements are met by insulation materials with aluminum foil coating.

Advantages of foil insulation:

1. The material is universal because it is used for walls, ceilings and bath floors.
2. Insulation with foil coating has good light reflection.
3. Products are produced in a wide range.
4. They are used in wet areas, and they do not need to be treated with fungicidal compounds.
5. They have high hygienic indicators. The properties inherent in aluminum do not create a breeding ground for the growth of fungus and mold.
6. They do not deform and do not melt in the steam room at elevated temperatures.
7. The material is convenient to work with. It is easy to mount and fix on different planes: vertical, horizontal and inclined.

Tips for insulating baths:

1. If the bathhouse building does not have a commercial purpose, finishing the walls with 3 mm foil in rolls will be sufficient.
2. For commercial enterprises, the solution to the problem of which foil to choose for a bath is the use of laminated products on a basalt mineral base.

When insulating a bathhouse located inside a permanent building, you need to take into account the functioning central heating, since it warms up the air additionally.

How to attach foil

Simple cladding

Another advantage of aluminum foil is that it is convenient to attach it at any time, on any surface. No need for this major renovation, the work will take very little time and effort.

Simple sheathing of walls and ceilings with foil

To protect wooden walls, you first need to make sure that the surface is smooth enough and there are no sharp protrusions that will tear the foil. If such defects are found, they should be cleaned sandpaper. Then everything is simple: take a roll of foil, unwind a strip along the height of the wall, cut it off, and fix it in the upper part with a stapler. Straighten the canvas downwards, fix it again so that it does not move, then attach the next strip with an overlap of 5-7 cm over the first. The joints must be secured with aluminum tape. The usual one cannot be used for these purposes.

Aluminum tape

The foil strips can also be positioned horizontally, if it is more convenient for you to mount it that way. The main thing is that there are no gaps left anywhere. Around the windows and doorways the foil is also attached close to the ends, and fixed with a stapler around the perimeter.

An example of fixing foil around a window opening

Example of fixing foil around a doorway

Foil around the window

If the entire steam room is being sheathed, first the foil is fixed to the ceiling, leaving overhangs at the edges 10 cm wide. When sheathing the walls, the material will be overlapped so that there is not the slightest gap between the ceiling and the walls.

Finally, wooden slats are stuffed over the vapor barrier, onto which the lining is attached. The thickness of the slats should not be less than 20 mm. The presence of an air gap between the foil and the finishing is a prerequisite for effective thermal insulation.

Fastening the lining - photo

Sheathing over insulation

Very often, foil is attached on top of the insulation. To do this, 20x40 mm thick slats are placed on the walls, in increments of 40-50 cm.

Attaching foil over insulation

The slats can be positioned both vertically and horizontally.

Slats for insulation placement

Roll or slab insulation is inserted between the slats as tightly as possible, and then everything is covered with aluminum foil. The joints are carefully sealed with tape, the vapor barrier is straightened so that no folds remain, then a slatted frame is mounted on top to secure the lining.

Lathing over foil for attaching lining

This time the slats should be perpendicular to those under the foil. The final stage is clapboard covering.

The corner adjacent to the stove does not need to be covered with foil if it is planned to be covered with decorative material. Then the thermal insulation is cut around the perimeter of the masonry and reinforced with additional strips that will ensure tight fit to Wall.

Fixing foil next to decorative tiles behind the stove space

If laminated foil is used instead of regular foil, everything is done in exactly the same way. When choosing foil fabric, the only difference is in the laying of the material: the strips are laid end-to-end, not overlapping.

This is how you can efficiently insulate a steam room in a bathhouse using aluminum foil. Of course, this material is suitable for other rooms, but it is in the steam room that it gives the greatest effect

The most important thing is to properly secure the vapor barrier layer, otherwise heat will escape through the gaps in the seams.

In order to always have a healthy atmosphere in the bathhouse, it must be properly insulated. Hygienic and therapeutic procedures are carried out in it at high temperature and humidity. Therefore, not every heat-insulating material can be used there. High-quality and reliable insulation will extend the life of the bathhouse or sauna and the equipment located there, and reduce fuel consumption.

Requirements

Building materials used at all stages of bathhouse construction are subject to particularly “harmful” influences. Therefore, special requirements are imposed on the properties of insulation and its installation:

• resistance to high humidity and temperature, temperature changes;
• stable strength;
• good compatibility with the materials from which the bathhouse is made, the ability to increase their thermal properties, and not turn advantages into disadvantages;
• protecting the premises from the formation of mold and mildew;
• low level of moisture absorption (prevents the formation and accumulation of condensation), heat transfer;
• high degree of thermal insulation;
• environmental safety (under the influence of high temperature values, high-quality insulation should not emit toxins);
• fire safety;
• simplicity and ease of installation;
• affordable price.

Insulation that meets all requirements must have certificates that confirm its compliance with sanitary, hygienic and fire safety standards.

Materials

Almost all known types of insulation can be used to insulate a bath or sauna. High-quality thermal insulation involves a combination of several materials.

Natural heat insulators

Since ancient times in Rus', bathhouses have been insulated with hemp, flax tow, moss, and wool. Thanks to them, there was excellent air exchange in the rooms. Today, connoisseurs of a real Russian bathhouse still choose these materials. They have a high level of thermal insulation.

Red moss, flax, sphagnum moss, used for caulking inter-crown joints, are not subject to rotting, have an antibactericidal effect, and are completely environmentally friendly.

To the disadvantages natural materials relate enough high cost, the duration of insulation work, the possibility of damage by rodents, moths, birds (as a result of which the heat insulator will have to be regularly updated).

Organic insulation

Thermal insulating materials of this type are made from peat, wood waste, and reeds. They are supplied to store shelves in the form of slabs. Despite the processing fire retardant compounds, these materials are recommended to be used for insulating locker rooms and rest rooms.

They can only be used as external thermal insulation in those regions where the winter temperature does not drop below -17 °C.

Mineral compositions

Such heat insulators are considered the most economical and practical. This is an ideal material for insulating a bath or sauna. There are basalt, diabase, limestone, dolomite and slag mineral wool. They insulate any surfaces in the bathhouse.

In addition to the affordable price, their advantages include fire safety (they do not support combustion, they self-extinguish), a high level of thermal insulation, durability, ease and speed of installation. Stone and slag mineral wool will not be damaged by rodents.

Basalt wool is a material that requires mandatory hydro- and vapor barrier, since when water gets in, it loses its thermal insulation properties.

Mineral wool insulation is similar in characteristics to glass wool. But the latter is more flexible and easier to install. Although, unlike mineral wool slabs, it is less resistant to high temperatures. But it’s unlikely that anyone will want to test glass wool at a temperature of +450 °C.

Polymers

The undoubted advantages of polymer insulation for baths or saunas include light weight, simplicity and ease of installation, moisture resistance, resistance to temperature changes, high thermal insulation properties, durability, and strength.

Polymer-based materials are polyurethane foam, pressed and extruded polystyrene foam. For thermal insulation, it is necessary to choose insulation that contains fire retardants. Such material does not support the combustion process, does not allow fire to spread, and self-extinguishes when a spark hits. With its help, floors and external walls in the bathhouse are insulated.

Foam glass is classified as a polymer heat insulator. It combines all the advantages of stone wool and polystyrene foam. This material is easy to work with (it can be cut with a saw or knife), does not burn, and has a high degree of water resistance.

The use of polymer insulation is impossible without a vapor barrier layer.

Please note that polystyrene foam cannot be used for internal thermal insulation: when exposed to high temperatures, it can release toxins.

When purchasing such material, you should carefully study the documentation supplied with it.

Most innovative material for thermal insulation of baths - insulation with foil. It can be used to protect all surfaces of the steam room from heat loss.

Foil insulation consists of a foam or paper base on which reflective foil is applied. The thickness of such material does not exceed 1 cm.

Principle of operation

The principle of operation of insulation with foil is to reflect radiant heat from the surface. Thermal insulation efficiency increases by at least 70%. A steam room with such insulation heats up much faster. You can save on heating steam room, installing heater stoves of lower power.

Features of application

Foil insulation plays the role of a hydro- and vapor barrier layer for walls, ceilings, and steam room floors. With their help, washing rooms or relaxation rooms in a bathhouse or sauna are protected from heat loss.

The steam room uses reflective thermal insulation based on kraft paper. This material can be used at higher temperatures.

Installation

Install directly on a beam or log with the foil surface inside the room. The joints of the sheets must be taped with aluminum tape. An air gap (no more than 15 mm) must be left between the insulation and the interior finishing of the walls and ceiling.

To remove condensation, leave a small sheet exit at the junction of the wall and floor.
carried out using high-quality materials and in compliance with all technological nuances, will provide comfortable conditions for medical and hygienic procedures, reduce fuel costs, and protect all internal structures from premature wear.