Thermal insulation of the fireplace from the walls of the house. Thermal insulation of the fireplace insert. Other thermal insulation materials

Installing a fireplace indoors and organizing it efficiently and safe work is not limited to just the construction of the foundation, frame and chimney. To complete all the work yourself, you need to apply knowledge of several branches of physics, including thermal phenomena. One of the most important stages construction is the thermal insulation of the fireplace, this is a set of measures to ensure the protection of the surface from heat leakage. Several fireplace blocks are insulated at once: the firebox, the body and the chimney.

Fireplace design drawing

Why is thermal insulation needed?

The role of the thermal insulation material is that, due to its poor thermal conductivity, the transfer of energy through the layer of material is difficult. Thus, you can not only preserve the heat that the fireplace produces, but also protect the structural elements of the house from high temperatures.

Chimney insulation serves several purposes.

• At the external location of the pipe, intense heat exchange occurs with the cold air of the street space. A huge part of the amount of heat is released into the atmosphere, but could be used to heat the room. If you reduce this share, you will achieve more high performance Efficiency The solution to this issue will be insulation, which is applied on top of the walls of the chimney.
• Combustion products that are thrown out through the chimney contain carbon dioxide and water vapor. The temperature of all this gas exceeds a hundred degrees. Upon contact with cooled external environment the walls of the chimney form condensation on the surface of the latter. Acids, which are a combustion product, are mixed into it. The result is a chemically active environment, leading to the destruction of the walls. The appearance of condensation can only be avoided by increasing the temperature of the pipe itself, that is, by providing it with high-quality insulation.
• In places where the chimney pipe passes through the ceiling or roof, contact of materials necessarily occurs. In the case of wooden buildings, this situation is a fire hazard. But additional function insulation will be to protect the ceiling surfaces.

Corner placement option

Internal insulation of fireplaces involves the localization of energy inside the firebox for the purpose of its directed transmission. The fireplace should not emit heat in all directions, especially if it is installed near a wall. It should warm those sitting directly in front of the fireplace. Special reflectors for fireplaces are installed inside the firebox and serve as a screen from infrared radiation. As a result, all the heat escapes through the combustion hole into the room.

Reliable thermal insulation for stoves and fireplaces means protecting the walls of the building from the negative effects of temperature. When the fireplace is located close to the wall, a heat-protective layer is installed, since high temperatures can lead to destruction brickwork walls or fire if the building is wooden.

What material is used

All building materials that provide insulation and are suitable for use in a fireplace can be divided into separate groups. These include stone fibers and silica, superisol, mineralite, gypsum fiber, supersil and vermiculite.

• Stone fibers are obtained by pressing crumbs of gabbrodolerite and limestone. The resulting fibrous structure is formed into plates. One side of the plate is covered with foil, which is capable of reflecting radiation, because this type of heat propagation accounts for about half of the total energy. Such foil can withstand temperatures of several thousand degrees. This material is quite durable and moisture resistant. Able to provide all possible assistance in maintaining the integrity of the structure in the event of a fire. The most popular fiber brands: PAROC FPS 17, TECHNO T80, Rockwool.

Rockwool brand insulation

• The technology for using silica involves melting alumina and quartz sand. The resulting glassy mass is blown into fiber form. Fiber is already a heat-insulating material, but for ease of use it is produced in the form of slabs or rolls. This substance is flexible, which makes it easy to insulate surfaces that are not perfectly flat.
• Products based on calcium silicate have good thermal insulation properties. Superizol is one of the representatives of this class. Its porous structure not only improves technical specifications, but also facilitates easy processing. Super-insulated slabs are used to insulate fireplace casings and chimneys. They are mounted with glue or self-tapping screws. Operating temperature material should not exceed 1200 °C degrees.
• Vermiculite slabs represent a pressed grain structure of the substance. This is a fairly rigid structure, thanks to which the surface of the slab is ready for decoration. They have relatively high density, but at the same time they are perfectly sawn and processed. Characterized by their durability. Buyers are showing increased interest in the Thermax, GRENAR-ISOL and Scamol brands.

Panels made of fire-resistant material Superizol

Thermal insulation not only improves the efficiency of the fireplace, but also provides fire protection. It is important that the material remains safe for humans when heated. The requirements for building insulating materials are technical performance, environmental friendliness and ease of processing.

• Supersil is a flexible material. It comes in the form of a silica fabric with a foil-like layer. But such production is expensive in terms of cost, which affects final price rolls of fabric.
• Gypsum fiber sheets are produced by mixing cellulose with gypsum and then pressing them. Distinctive feature The advantage of such sheets is that they can be used as a building material. Gypsum fiber does not tolerate deformation, therefore it is used only for insulating the fireplace body, walls and floor.

Carrying out work

The technology for thermal insulation of a fireplace consists of a step-by-step solution to certain problems.

Setting tasks and solving them

• Calculation in progress required quantity material. For more rational use Take into account the cutting and processing ability of the insulation boards or fabric.
• If the fireplace is located at a distance not exceeding 50 cm from the wall, then sheets of insulating fiber are attached to its walls.
• The degree of insulation can be increased using a multilayer structure.
• The chimney is insulated, regardless of what material it is made of.

The characteristics of modern insulating materials will help answer the question, how to properly insulate a fireplace? To insulate walls, it is advisable to use slabs, one side of which is covered with foil. The foil creates a protective screen, and the effectiveness of such protection is quite high. Negative quality is the unaesthetic appearance of slabs made of insulating material.

IN wooden buildings It is recommended to insulate in several layers. To do this, a lathing is made of metal slats into which gypsum fiber boards are inserted. Top mounted wooden sheathing for fastening sheets of fire-resistant plasterboard. The outside surface must be finished with tiles or artificial stone.

Several technologies are used to perform chimney thermal insulation. One of them is making a sandwich pipe. A box is made of metal, which has a larger diameter compared to the diameter of the chimney pipe. Mineral wool is laid along the walls of the box. Then a pipe of smaller diameter is inserted inside. When manufacturing the structure, it is necessary to provide for the option of wrapping the pipe in parts.

The brick pipe is insulated with plaster, which is applied in several layers on all sides. After the fourth layer, the outside of the pipe is lined with mineral wool slabs. They are fastened with self-tapping screws with large washers. The outside must be made of brick; it will give an aesthetic appearance to the pipe and protect the material from precipitation.

A fireplace in your home is an opportunity to enjoy warmth around the clock. But it is not enough to establish a fireplace; it is important to create conditions for its safe and efficient work. For this purpose, thermal insulation of fireplaces is carried out: chimney, firebox, walls using high-quality materials.

Why insulate the stove?

When it comes to thermal insulation of fireplaces, the question arises about its necessity. If there is no time, money or desire to spend additional work with a stove, then insulation may not be necessary. But to increase efficiency and increase service life, the work is necessary and important. And why exactly you need to make insulation should be considered for each part separately.

Fireplace insulation

• to prevent heating of walls located near the pipe;
• to increase the cooling time of the pipe, the heat from which is evenly distributed in the room;
• to prevent condensation accumulation.

Thermal insulation is also required to protect the walls adjacent to the fireplace. It is important to strengthen the load-bearing and interior design to prevent fire and damage to the finish along with the base. Insulation also increases efficiency, helping to quickly distribute heat throughout the room.

Modern materials for insulation

Thermal insulation of fireplaces and walls to protect against hot fireboxes is carried out using several materials, many of them have been developed recently and are used mainly by professionals:

Chimney insulation with basalt wool

• • Basalt wool with a foil surface - can withstand high temperatures (up to +750 degrees). Goes well with other parts of the fireplace chimney.
  • Gypsum fiber sheet - obtained by pressing cellulose fiber and natural gypsum. It is characterized by high strength, the ability to retain properties under any operating conditions, and moisture resistance. It is used for thermal insulation of the firebox and furnace box, extending its service life. The disadvantage is that the sheet cannot be bent, so it is not used for a chimney.
  • Calcium silicate is a material with high thermal insulation properties. Used when arranging the firebox and fireplace box. Calcium silicate is suitable for stoves that will be decorated with shelves and niches. Thermal insulation prevents overheating of additional elements, as well as the fireplace itself. The material fits well on any surface and goes well with putty. The disadvantage is the high cost. But when arranging a fireplace in a private home, silicate is indispensable.
  • Supersil is a fabric heat-insulating material with an operating temperature of up to 1200 degrees. It is based on silicon oxide, which is environmentally friendly and safe. When heated, the material does not emit dangerous vapors and is suitable for insulating fireboxes, hoods and walls. The high cost prevents superpower from being used.

Cheap and practical material, suitable for self-installation, is stone mineral wool in slabs. She answers everyone necessary requirements: non-flammability, excellent thermal insulation, resistance to high temperatures, durability.

Thermal insulation of fireplaces and walls is carried out in several stages

• • 1. Preparation. Calculate in advance how many slabs you will need to minimize costs and reduce waste.
    2. Wall insulation mineral wool. The wall located next to the fireplace is exposed to high temperatures. As a result of strong heating, the structure is subject to fire and damage. To ensure that the heat is retained inside the firebox and does not go outside, mineral wool with a foil surface is used. Secure the boards with high-temperature adhesive or stainless steel dowels. This method of thermal insulation is suitable for fireplaces located at a distance of no more than 50 centimeters from the wall.
    3. Insulation with multilayer construction. If it is necessary to insulate walls located at a distance of more than 50 centimeters from the fireplace, then a multilayer structure is made, consisting of the following materials: metal lath for sheathing, wooden slats, mineral wool slabs, reflector (foil), heat-resistant plasterboard, facing material (tiles, stone). This method prevents the walls from overheating while maintaining their attractive appearance. appearance(which cannot be said about nailed mineral wool).
    4. Thermal insulation of wooden and stone elements. This is done to protect against overheating and further damage. To do this, pieces are cut from mineral wool the right size and glued to the parts on the side adjacent to the fireplace.
    5. Thermal insulation of the chimney. It is carried out depending on the type of structure.

Fireplace insulation

How to insulate a chimney

Having protected the walls from the hot fireplace insert, proceed to insulating the pipe. For this, one of the following materials is used:

Chimney insulation

• • • mineral wool is the most popular and sought-after material, which is convenient and inexpensive to work with;
    • glass wool - its properties are similar to mineral wool, but it is more difficult to work with;
    • brick - the use of whole and chipped specimens is allowed;
    • slag slabs - designed for insulation in unstable climatic zones.

If the fireplace and chimney are made of brick, then insulation is carried out quickly and with little financial loss. To do this, the surface is plastered using a reinforcing mesh. At the junction of the pipe and the roof, reinforce it - lay an additional layer of brick. This completes the thermal insulation.

It is much more difficult to work with round pipes made of metal and ceramics. These materials overheat strongly during operation of the fireplace, and accidental touching them will inevitably lead to severe burns. Therefore, be sure to take care of insulating such pipes. This is necessary to reduce heat loss and maintain the integrity of the pipe for a long time.

Thermal insulation is carried out with non-flammable materials of dense structure. Mineral wool is ideal and is used to wrap the pipe as the first layer. The second layer of insulation is reinforced on top - stainless steel sheets. They are wrapped around the chimney and sealed. Instead of stainless steel, plaster can be used.

The above method of thermal insulation increases the efficiency of the chimney, increases the service life of the structure and prevents overheating of nearby surfaces. If all the work is done correctly, then re-installation will be required after about 15 years with intensive use of the fireplace.

Video: Insulating fireplaces

IN Russian Federation The market for stoves and fireplaces continues to develop and new products and materials go on sale every year. Each manufacturer pulls the blanket over itself, claiming that its product is the best, unique and effective. Salespeople, having no practical experience, give rote answers to detailed questions from sales training. The consumer, if he still decides not to contact specialists, will have to spend a lot of time and effort studying all the nuances.

The most important aspect in the operation of fireplaces and stoves is fire safety. This is exactly the case when the desire to save money or simple negligence together with ignorance can lead to big trouble. The main structural element responsible for safety is high-temperature thermal insulation.

Theoretically, you can do the installation yourself, but since we are talking about human lives, it is better to entrust this work to specialists. There are many companies on the construction services market that are capable of performing this service efficiently, but the choice of contractor should also be approached with the utmost rigor - the company must have been on the market for a long time and have an excellent reputation. You shouldn’t involve migrant workers and coven workers; there will be no one to ask.

Requirements for thermal insulation materials

At its core, a fireplace is the same stove with an open firebox and chimney, equipped with decorations. Others design features these products do not have, therefore the approach to their installation and equipment is the same. Thermal insulation, accordingly, is carried out separately for the firebox and for the chimney and must meet the following requirements:

• Low thermal conductivity
• Environmental friendliness
• High fire resistance
• Durability
• Maximum permissible temperature heating

Materials must retain the listed properties in full throughout the entire service life.

Classification by composition

High temperature insulating materials are divided into the following types:

1. Packed and filled: zirconium oxide, quartz sand, various mortars, kaolin. Used mainly in industry, labor-intensive to manufacture
2. Fiber insulators: fire-resistant wool, felt, felt, are essentially mineral wool and its derivatives. They have the lowest thermal conductivity coefficient, are resistant to thermal shock, but can be susceptible to mechanical damage
3. Solid materials: fireproof cardboard, fireclay brick, fireproof ceramic slabs. Retains original shape and can bear mechanical loads

In everyday life, the fireboxes of stoves and fireplaces, as well as metal and asbestos-cement chimneys, are insulated mainly with mineral wool. Brick chimneys are insulated with solid materials with cladding, or simply plastered in three layers.

Overview of the thermal insulation materials market

Due to its attractive price and high availability, it is the most popular product in the field of application in question. Composition - 100% stone (gabbro-basalt) wool. Available in two types: without coating and with aluminum foil On the one side. The maximum permissible temperature on the foil side is +500°C, on the cotton side +750°C. Slab size 1000*600*30 mm, density 100 kg/m3.

The thermal conductivity coefficient at +300°C is 0.088 W/m*K. The option without foil is not flammable, with foil the flammability class is G1. When choosing this material, it is very important to calculate the peak temperature of the firebox, since if it overheats, the foil may peel off and spread throughout the room. bad smell together with microparticles of cotton wool fibers. Insulator slabs are highly flexible and therefore are mounted in a rigid metal frame.

Vermiculite

A natural mineral from the hydromica group, the layered structure of which forms multi-colored threads when heated. Fire retardant materials produced from it by pressing. In addition to fireboxes, it is used in the aviation and automotive industries, as well as in nuclear energy as a reflector and absorber of gamma radiation. The material is presented in two products on the market:

• VermixFireproof. Country of origin - Russia, thermal conductivity coefficient at +300°C - 0.18 W/m*K, plate size 600*600*30 mm, density 300 kg/m3, permissible temperature +800°C. Among the advantages are ease of processing and installation; a rigid frame is not required. There are also disadvantages - the material is afraid of moisture.
• Skamolex is a vermiculite thermal insulator imported from Denmark. It is a symbiosis of refractory and decorative panel with various design solutions. Thermal conductivity at +200°C is 0.16 W/m*K, plate size 1000*610*25 mm, density 600 kg/m3, peak temperature +1100°C. Advantages: does not require follow-up finishing- according to the “set it and forget it” principle, it is used for lining fireboxes. The downside is the high cost; depending on the region of the Russian Federation, the price of a slab can be 5 times higher than a slab of the same area Vermix Ogneupor.

Based on calcium silicate

The next row of thermal insulators is calcium silicate - inorganic substance in the form of calcium salt and metasilicic acid. The mineral is presented on the market in the following versions:

1. Silca 250km. Imported from Germany. Slabs with dimensions 1000*625*40 are designed for use in stoves, fireplaces and brick chimneys. Density 250 kg/m3, thermal conductivity coefficient 0.09 W/m*K at +200°C, application temperature +1100°C. The structure of the board is not fibrous; it can act as both an insulator and facing material, is absolutely harmless to human health. Installation features metal frame is not executed. Suitable for thermal insulation of wooden walls in places where the firebox is installed.
2. Promasil 950 ks is another product from Germany with a size of 1000*500*30 mm and a density of 245 kg/m3. Peak load is 900°C, thermal conductivity at +200°C is 0.10 W/m*K, which is insignificantly inferior to the previous insulator at half the cost. It is easy to install without a frame, the manufacturer guarantees environmental safety. The material is relatively new, there are very few practical reviews on its use and it confuses construction specialists low price compared to analogues.
3. Scamotec 225 - sample from Denmark. Slab size 1000*610*30 mm, thermal conductivity coefficient 0.08 at +200°C, maximum application temperature +1000°C, easy to install without a frame, harmless to health, combines thermal insulation and decorative qualities, it can be coated with any fire-resistant paint. The cost is in the middle price segment.
4. Isolrath 1000. Country of origin - Austria. Size 1000*610*30 mm, density 240 kg/m3, thermal conductivity 0.06 W/m*K at +200°C. Operating temperature up to +900°C, a frame for installation is also not needed. The manufacturer guarantees environmental and fire safety against the backdrop of high structural strength. It also belongs to the middle price segment.

Another group of thermal insulators is represented by a single cement-based material. Minerite LV is imported from Denmark. The product size is 1200*630*9 mm, density 1150 kg/m3, that is, the material is quite heavy, but thin - it saves useful living space. The thermal conductivity coefficient is 0.25 W/m*K, which is significantly inferior to the previously considered samples.

The application temperature for Minerit LV is up to +150°C. It is an easily accessible material due to its low cost. Based on the parameters, it can be used as an additional element in an already thermally insulated firebox of a fireplace or stove, or in highly specialized products.

The most important factor determining the choice of thermal insulation for fireboxes is correct calculation peak temperature. The temperature depends on the type of fuel, the volume of the firebox and other parameters, so it is better to entrust the determination of this key parameter to a specialist.

The use of thermal insulation materials for furnaces has several purposes: provide fire safety and reduce heat loss. The latter option is most often used in the construction of fireplaces, since in this case it is necessary to create a directed flow of heat, and not to heat the entire stove array. During work recommended to use existing standards to avoid mistakes and prevent the risk of fire in building structures.

Special thermal insulation for fireplaces is used to minimize heat loss in all parts of the fireplace: the chimney, the stove mass and the firebox itself. This allows you to increase the coefficient useful action heating equipment. Insulation different parts fireplace has the following purposes:

1. Protects the chimney from the destructive effects of condensation that forms during a sudden change in temperature. The aggressive effect of condensate is due to the moisture content, various acids formed during combustion and carbon dioxide.
2. Where the pipe passes through the ceiling, special care should be taken to comply with fire safety standards. If used wooden building materials, then special care should be taken when protecting the ceiling surface.
3. High-temperature insulation in fireplaces is used to create a directed flow of thermal energy to warm those sitting across from it. For these purposes, infrared reflectors are used, which are installed in the firebox itself.
4. Protection wall structures using a heat-protective layer. Otherwise brick wall can quickly become unusable from sharp drop temperatures, and the wood will catch fire.

The building materials used for thermal insulation of the fireplace are represented by the following groups:

• containing stone fibers (Rockwool, TEXHO T80, PAROC FPS 17) – are produced in the form of slabs and have a foil coating on one of their sides, which allows them to withstand temperatures of several thousand degrees;
• based on silica obtained from quartz sand and alumina, produced in the form of flexible plates;
• Superizol - is made using calcium silicate and has good thermal insulation qualities, suitable for insulating fireplace bodies and their chimneys, attached with glue or self-tapping screws;
• Vermiculite – presented in the form of slabs (Scamol, Thermax), consists of compressed grains of the substance, is rigid, easy to saw, and has a surface suitable for finishing;
• Supersil - is a fabric made of silica with a layer of foil, has a high cost;
• gypsum fiber - obtained by mixing and pressing gypsum and cellulose, suitable only for insulating solid fireplaces, floors and walls, does not withstand loads and is deformed.

When choosing materials, it is important to ensure they are environmental safety so that they do not highlight in environment toxic substances when heated.

Fireproof wall coverings

To prevent spontaneous combustion of the walls adjacent to the furnaces, it is necessary to install special cladding made of non-combustible materials with thermal insulation properties.

Thermal insulation for furnaces in this case is carried out in two ways:

1. For cladding, materials are used that have reflective properties and are resistant to high temperatures.
2. The heat-insulating furnace casing is covered with a lining of heat-resistant tiles.

Good reflective qualities are shown by metal sheets covering non-flammable heat-insulating sheets. It is best to use stainless steel, since galvanized steel releases toxic substances when heated.

The following materials are used as thermal insulation:

• basalt cardboard;
• basalt wool;
• minerite;
• asbestos cardboard.

In accordance with SNiP 41-01-2003, installation of the casing is carried out in the following sequence:

1. Installation of insulation in compliance ventilation gap from 2 to 3 cm. The thickness of the insulating material is no more than 2 cm and no less than 1 cm.
2. Installation metal sheet.
3. Maintain a distance between the stove and the casing of at least 38 cm.

Ceramic bushings are used to attach materials to the wall: they allow the required gap to be maintained and are resistant to fire. If it is not possible to maintain the specified distance between the stove and the casing, then two layers of thermal insulation sheets should be used. For example, two sheets of mineralite are attached using ceramic bushings. The distance between them is 2-3 cm. The outer sheet is covered with stainless steel.

The design of a room or bathhouse does not always allow the installation of metal cladding. Often it will not fit into the interior of the room. In this case, you can resort to sheathing with heat-resistant tiles, which are attached using a special adhesive that is resistant to high temperatures. Let's list suitable materials for cladding:

• terracotta tiles;
• porcelain stoneware;
• tiles;
• clinker tiles;
• Soapstone chlorite

When installing, follow the following rules:

1. The ventilation gap between the wall and the fireproof sheet should be 2-3 cm.
2. Fire-resistant tiles are attached to the installed sheet using special adhesive mixtures.
3. The oven should be located no closer than 15 cm from the surface of the tile.

The following are suitable sheet fire-resistant materials for cladding with cladding:

• minerite;
• fireproof plasterboard containing fiberglass;
• glass-magnesium sheet.

The cladding will help not only to complement the design of the room and maintain a unified style, but also to reduce the permissible distance between the stove and the wall.

Protective screens for furnaces

The thermal insulation material used for stoves must not only prevent the possibility of fire, but also protect people from too harsh infrared radiation. For these purposes, protective screens for fireplaces, as well as for sauna stoves. They can be made of metal or using brick or decorative stone.

The peculiarity of fireplace screens is that they are made exclusively of metal and can be built-in or mobile. Such structures prevent sparks and hot coals from entering the room, and also, when heated, contribute to the rapid and uniform heating of the air in the room. You can purchase a protective fence or make it yourself. Let's take a closer look at the features protective screens ovens.

Along with insulation, the furnace is insulated using bricks. There are two options: constructing a protective wall and lining the furnace with bricks. In both cases, the brick is laid using an adhesive mixture or clay. Usage cement mortar is considered as an extreme case. When lining the stove with bricks, it is necessary to provide a gap of 3 to 10 cm, as well as ventilation holes from below and from above to ensure better convection and quick heating of the room.

If you decide to build a protective wall, you should remember that the masonry is half a brick thick (120 mm); the height of the wall should be slightly higher than the stove itself. Thanks to this structure, a uniform and soft heat is created in the bathhouse, which eliminates the need for continuous heating and allows you to steam for several hours.

Stainless steel casing

Thermal insulation of the furnace using stainless steel casing has several options. By orientation in space they distinguish front and side screens. Recommended distance from oven to screen – from 1 to 5 cm. Thanks to such structures, it is possible to reduce the intensity of thermal radiation metal furnace, since the outer surface of the protective screens warms up to 1000 C. In this case, you can reduce the distance from the stove to the wall to half a meter. Ease of installation and the presence of special legs that allow you to securely fasten the screens make their use especially attractive.

For finishing walls under a boiler

If the walls of the boiler room are wooden, then they need pre-treatment fire retardant compounds. The wall behind the boiler must be covered with sheet metal. The remaining area is finished with sheets of plasterboard or glass-magnesium. Then the surface is plastered or covered ceramic tiles.

Basalt with cladding

Facing basalt slabs look aesthetically pleasing and provide good protection from fire. In addition, this material gives off heat for a long time after heating. You can use this material to cover both a brick screen and the wall itself on top of insulating sheets.

Fire safety cannot be treated negligently - the consequences of carelessness can be tragic. Modern market building materials allows you to choose an option according to your means and taste, while ensuring reliable protection from fire.