Thermal insulation materials for stoves and fireplaces

The use of thermal insulation materials for stoves has several goals: to ensure 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 warm up the entire stove mass. When carrying out work, it is recommended to use existing standards to avoid mistakes and prevent the risk of fire in building structures.

Materials for thermal insulation of fireplaces

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 efficiency of heating equipment. Insulation of different parts of the fireplace has the following goals:

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.
Where the pipe passes through the ceiling, special care should be taken to comply with fire safety standards. If wooden building materials are used, special care should be taken to protect the surface of the ceiling.
High-temperature insulation in fireplaces is used to create a directed flow of thermal energy to warm people sitting across from it. For these purposes, infrared reflectors are used, which are installed in the firebox itself.
Protection of wall structures using a heat-protective layer. Otherwise, a brick wall can quickly become unusable due to a sharp temperature change, and a wooden wall can 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 make sure that they are environmentally safe so that they do not release toxic substances into the environment when heated.

What are the criteria for choosing fireproof materials for walls?

When selecting material, you should consider the following features:

type of premises - residential or non-residential, in the first case it is better to buy “fine” samples;
fuel for a stove or fireplace - the temperature to which the firebox will heat up depends on it;
cost - the price of materials also matters, you should familiarize yourself with it in advance;
manufacturer - it is better to choose branded products that meet all GOST standards.

When selecting, it is advisable to be guided by all points, this will help you make a rational decision. High-quality refractories for stoves or fireplaces undergo careful production control, which ensures their reliability. The sheathing of the area is carried out strictly before installation or assembly, which ensures compliance with safety regulations.

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. Protective screens for fireplaces, as well as for sauna stoves, are ideally suited for these purposes. 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 designs 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 of furnace protective screens.

Brick protective screen

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. The use of cement mortar is considered as a last resort. When lining the stove with brick, it is necessary to provide a gap of 3 to 10 cm, as well as ventilation holes at the bottom and top 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.

Technology for installing fire-resistant materialheat-resistant materials for finishing walls near the stove

Multilayer protective technology, using the example of wall cladding near a heater in a bathhouse, consists of a sequence of actions:

A layer of vapor barrier and waterproofing is attached to a wall made of combustible material. As a vapor barrier, you can use a three-layer film consisting of foil, polyethylene, and kraft paper for strength. It is attached using a metal profile (wooden blocks can be used instead of a metal profile).
Next, insulation is installed, for example, foiled mineral wool. It is placed inside the sheathing so that the foil layer is on top. The joints of mineral wool slabs must be sealed with aluminum tape.
Using self-tapping screws, fire-resistant boards, for example, made of fiber cement, are attached to the sheathing. An alternative to fastening a multilayer structure is to install the plates with self-tapping screws through a sleeve. This creates a space between the slab and the wall.
After fixing the slabs, they can be faced with ceramic tiles for aesthetics. To do this, a metal mesh is screwed onto the self-tapping screws onto the slabs, onto which heat-resistant adhesive is subsequently applied and the tiles are glued.

If the installation is carried out in compliance with the technology and ventilation gaps, the wall near the stove will not heat up and will not create a fire hazard.

A budget-friendly way to protect between a stove and a wooden wall is to use profile metal used for the roof. To do this, you will need two sheets of such metal and hollow tubes. Hollow metal tubes are attached to the wall, and a metal profile is mounted to them. The distance to the floor and ceiling should be at least 10 cm. The tubes are attached to the sheet in the same place as the first ones and covered again with the sheet. Hot air moves in the gaps between the wall and the floor, while the wall remains unheated.

Stainless steel casing

Thermal insulation of the furnace using stainless steel casing has several options. Based on orientation in space, front and side screens . The recommended distance from the oven to the screen is from 1 to 5 cm . Thanks to such structures, it is possible to reduce the intensity of thermal radiation from a metal furnace, since the outer surface of the protective screens warms up to 1000 C. In this case, it is possible to reduce the distance from the furnace 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.

Tips from the pros

In order to increase the fire safety of the ceiling that crosses the chimney or chimney, install a decompression chamber by installing a heat-insulating board in a horizontal position.

It is preferable to provide 2 fan grilles in the box : one for the purpose of cooling the decompression chamber, and through the other, warm air will be transmitted throughout the room. Sheets of plasterboard are attached to the iron guides using self-tapping screws: they will be the basis for the decorative finishing of the fireplace.

Basalt with cladding

Basalt facing slabs look aesthetically pleasing and provide good fire protection. 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. The modern building materials market allows you to choose an option according to your means and taste, while providing reliable protection against fire.

How to do it yourself?

First, the required number of thermal insulation boards is taken, which are cut to the size of the fireplace insert.
After this, a special heat-resistant glue (mineral, cement-based) is applied, and the application should be carried out pointwise.
When installing foil material, glue is applied to the non-foil part.
After this, the slabs are mounted on the walls. Joints and other openings must be sealed with special heat-resistant aluminum tape, which can also be reinforced.

Heat resistant sealants

This type of sealing materials is produced on a silicate basis, which makes them stable at temperatures close to 1300-1500 °C. Some of them can even withstand temperatures of 1600 °C for a certain time.

In this case, they are dark gray or black in color and are called fire-resistant pipe sealants (the word “fire-resistant” is on the outside of the tube or package).

Some important rules when using heat-resistant sealants:

Work with silicate sealing materials is carried out in the temperature range of +5 - +40 °C.
The required sealing effect is achieved only in the case of rough and uneven surfaces. For this purpose, if necessary, the areas where the composition is applied are treated with abrasive materials.
In addition, the surfaces should be degreased with acetone and then allowed to dry for 15-20 minutes.
When the paste hardens in places where the sealant is applied, very strong and hard seams are obtained, so it is not recommended to use heat-resistant compounds for structures operating in vibration conditions.
Traces of sealing material can be removed with a wet cloth or rag, but only before the material hardens. After hardening, this will require the use of mechanical force and some simple tools.