Thermal insulation of a metal fireplace from a wooden wall. Thermal insulation materials for fireplaces. Requirements for thermal insulation materials
The basis of the device of the majority modern fireplaces and stoves - metal firebox and chimney. And the role of a spectacular decoration is played by the outer duct and chimney. Let's talk about materials that will protect these and other structures located in close proximity to hot surfaces.
A fireplace is an indoor stove with a wide open firebox and a straight chimney. It is curious that initially it not only performed heating functions, but also effectively ventilated the rooms. However, even today most consumers do not consider the fireplace as the main heating equipment. Rather, it is perceived as an element of the interior decoration of a living room or office, serving to effectively frame the fire.
The heat generator in popular types of fireplaces is a metal firebox like a potbelly stove and a pipe coming out of it. This simple device can become an accent element of the interior - just build a decorative portal and box around it, which can imitate a brick or masonry and chimney. One of the most simple ways box execution - frame made of metal profiles, covered with plasterboard.
We isolate heat
In solid fuel fireplaces, the temperature of gases removed from the fireplace does not exceed 400-450 °C. The temperature inside the decorative structure (box) is noticeably lower, but can reach 100 °C. And this circumstance must not be overlooked. So as not to damage the drywall. prevent it from overheating, and also so that, in turn, it does not heat up and deteriorate finishing(plaster, paint, etc.). An insulation circuit is installed inside the decorative Noro-6a. It provides reliable heat insulation (the external parts of the fireplace can be touched without fear), and warm air from the inside of the box it enters the room through the holes provided for this purpose. Besides, non-combustible insulation plays the role of an additional fire screen. For example, when a fragment of a pipe connection burns out and fiery sparks come out of the combustion chamber (which, by the way, often happens when the rules for operating fireplaces are violated and the firebox is constantly overfilled) or in any other place Decoration Materials will not light up.
If the fireplace is supposed to be installed near a wall or in the corner of the room, then thermal insulation boards are also installed on all adjacent surfaces. They will protect the structure of the house from overheating, accidental sparks and ignition. At the same time large quantity hot air will be retained inside the firebox and then distributed throughout the room, increasing the efficiency of the fireplace.
Thermal insulation of the fireplace - avoid overheating!
To insulate fireplaces, highly specialized materials from stone wool in the form of slabs, say. Fire Batts (Rockwool), price 1 pack. (8 pcs. size 1000 x 600 x 30 mm) - from 2760 rub.; PS17 (Ragos), price 1 pack. (7 pcs. 1200 x 600 x x 30 mm) - 1930 rub.; “TECHNO T 80” (“Tech-noNIKOL”), price 1 pack. (6 pcs. size 1200 x 600 x 50 mm) - 3580 rub. Their main feature- wide range of operating temperatures: from -180 to +750 °C. They produce two types of slabs: regular and covered on one side with reinforced aluminum foil, glued
special heat-resistant glue. The foil layer increases thermal insulation properties structures due to the reflection of radiant heat.
If you choose the right material, when arranging fireplace area follow the recommendations of manufacturers of fireplaces and insulating materials, and during operation adhere to basic safety measures (do not leave a working fireplace unattended, do not place flammable objects near it), then you for a long time You will enjoy the warmth of a living and safe fire.
Warmth or heat insulation?
Many private developers often overlook the fact that the product line of each major stone wool thermal insulation manufacturer includes materials for different purposes.
Despite their external similarity, they have a different composition of raw materials and have different characteristics.
If for general building insulation the operating temperature range varies from approximately -50 to +100 ° C, then specialized products, say, intended for work in high-temperature environments (in close proximity to fireplaces, stoves, heating equipment), are designed for other loads, and the temperature of the insulated their surfaces can vary from -180 to +750 “C. The choice of such materials should be approached more thoughtfully, since conventional insulation elevated temperatures will be ineffective.
On a note:
There are two types of specialized high-temperature thermal insulation boards: without foil and with aluminum foil glued on one side with a special heat-resistant adhesive. The maximum permissible temperature on the foil side is 500 °C, on the stone wool side - 750 °C. In order not to deteriorate the properties of the product, the packaging should be stored indoors or under a canopy (horizontally, on a dry, flat surface), covered with polyethylene.
The stone doesn't burn
Stone wool is produced from non-flammable raw materials - rocks of the gabbro-basalt group with the addition of a small amount of binder to give shape, and in high-temperature insulation there is very little of it (less than 2% by mass fraction).
The thin fibers of this heat-insulating material can withstand temperatures up to 1000 °C without melting; they are not damaged, remain connected to each other, retain their strength, shape and do not collapse in the absence of mechanical stress on the material.
Stone wool products are classified as non-flammable building materials(NG according to GOST 302W), which are used both in low-rise cottages and in high-rise buildings. In addition, in the event of a fire, such thermal insulation delays the destruction process for some time. load-bearing structures building.
Since the operation of the fireplace and its chimney is associated with the combustion process and high temperatures, their installation requires an extremely careful and balanced approach. There is SP 7.13130.2013 “Heating, ventilation and air conditioning. Requirements fire safety", which clearly outlines the principles of constructing furnace chimneys, penetrations and installation of insulation from the point of view of fire safety. Ignoring these rules can lead to very sad consequences.
Based on our practice, the majority of private owners whose bathhouse or cottage burned down installed a fireplace or stove on their own and violated the rules for installing a chimney through the ceiling or did not maintain the fire-prevention distance between the heating equipment and the wall, although this parameter is indicated in the installation instructions.
Practical advice on fireplace insulation
To increase the fire safety of the ceiling that the chimney crosses, a decompression chamber is installed by horizontally installing a heat-insulating slab. It is advisable to provide two ventilation grilles in the box: one for cooling the decompression chamber, and through the other warm air will spread throughout the room. Drywall sheets are attached to the metal guides using self-tapping screws. They will become the basis for decorative finishing fireplace.
Fireplace insulation diagram
- Chamber cooling hole
- Decompression chamber
- Ventilation grill
- High temperature stone wool slabs
- Box made of plasterboard slabs
- Chimney
- Firebox body
Do-it-yourself fireplace insulation
Installation of Fire Batts when installing a fireplace - photo
First they prepare required amount thermal insulation boards, and their size must correspond to the dimensions of the fireplace insert (a). Heat-resistant cement-based mineral adhesive is applied pointwise to the slabs; if the insulation is foil, then to its non-foil surface (6). Then the slabs are glued to the wall (c). The joints of foil insulation are protected with heat-resistant aluminum tape (g).
A fireplace insert with a decorative portal is installed in the place prepared in this way, leaving an air gap of at least 4 cm (d) between the latter and the insulation layer. After this, metal guides are mounted above the decorative portal and thermal insulation slabs are also installed between them (e)
10/15/25 g Mystical tricks Colored Fire flame sachets fireplace...
Installing a stove is a complex process and requires a lot of attention to each stage, from preparing the installation site to the nuances of removing the chimney pipe from the roof. In this article we will talk about how to properly insulate a wooden wall from a steel one, cast iron stove. Any wood has a predisposition to ignition, so a constantly hot stove design can easily cause a fire. Any builder understands that insulation wooden wall behind the stove - this is a mandatory process. Let's look at an example of installing a Bavaria stove-fireplace on a wooden floor next to wooden wall. The stove does not have separate foundation, so a lightweight base is required metal structure. The base for the stove will be laid out with bricks in one layer. In this case, wall insulation can be done in two versions: asbestos cement sheets or flame sheets (non-hot composition). There are several opinions about asbestos - sometimes they say that they emit toxic fumes. But flames have their drawbacks: they have standard sizes sheets 600x1200 mm, which can be inconvenient when working, and also in price they do not beat asbestos cement at all.
Options for wall insulation
The width of a particular oven is 720 mm. As a result, it turns out that horizontal sheets need to be installed - you will need four sheets to the ceiling, it turns out that they can cover top part premises - there is a beautiful partition there. There are several other options on how to proceed: get rid of the existing partition, replace it with a fireproof one and cover it with tiles or stone. You can also place the screen and circular saw remove the wood on the partition completely. Next, finish with tiles, plaster or paint. There is no doubt that the tree needs to be removed. After all, if you cover it with non-flammable materials on top, there is still a chance of ignition wooden surface. In this case, it is better not to take risks and remove the partition from wood. Thermal radiation from the oven will not only be from the back wall. Lateral radiation will also emit radiation onto the wall at a distance of 0.8-1 meter. You should carefully read the installation instructions - the manufacturer describes everything very clearly there, including what concerns safety. For example, when a stove with a glass door is on, and there is a chair next to it, it is better to move it further away (more than 1 meter).
Initially, the base for the stove was supposed to be one brick thick, but such a thickness for a wooden floor is not very good. Regarding the non-combustible partition, you should also note the importance of the situation - where the chimney will go, at what distance from the beams, walls and rafters. In the area of this furnace, “Bavaria” is best used as a base. concrete slab- laying it along the beams, flush with the floors or a little more - it will turn out like a podium, reliable and ensuring safety. However, the bottom of this stove practically does not warm up; there is an additional part for firewood, which takes on the heat. Therefore, you can make it simpler - lay mineralite or DSP on the floor, then tiles or porcelain tiles on mastic or hot melt adhesive. In places where the chimney pipe is laid, you can use basalt, non-flammable or kaolin wool. Vata plays the role of additional insulation and is embedded in ceiling cutting. In this case, you should make an opening in the ceiling - in accordance with safety standards - from the contour of the two-layer sandwich pipe, 250 mm in different directions. The furnace cutting should be made of non-combustible materials - superizol, mineralite, calcium silicate, vermiculite. When passing through a chimney pipe, the groove should be filled with cotton wool.
It is, of course, very difficult to get rid of a beautiful partition, because it was built for aesthetics, a lot of time was spent on it, but if it was decided to install a metal stove against this wall, then you should get rid of the additional threat of fire of wooden parts.
Wall insulation material
Facing materials are often made from cement, the complete hardening of which can take several years. As a result, even after the work has been completed, changes in size, bends and deflections may be observed. Some manufacturing companies (for example, the Nitiha company) use effective and effective method keeping facing materials in an autoclave in a high-temperature oven high pressure. And it turns out that shrinkage due to drying and expansion by exposure to heat can be avoided, and reliable strength is also ensured.
Those same Nitikha panels are made from fiber cement, universal material, which consists of 90% cement and 10% fibers of cellulose material and various mineral fillers. In this case, technology without the use of asbestos is used by pressing the ingredients.
Panels of this type are environmentally friendly; their production does not use formaldehyde resins, chlorine compounds or asbestos. Fiber cement has excellent fire-resistant properties; it fully fits into the category of non-combustible materials. Fiber cement siding has many advantages, including - with its help you can easily select various variations design, and it is also easy to install. Instead of mineralite, you can also use glass magnetic sheets - this is a more budget option.
Examples of thermal insulation of a wooden wall
Here's another example of making a fire-resistant wall located behind the fireplace:
- treating the wall with fire protection (about 5 layers);
- fireproof mats are attached with a stapler;
- The plates are attached through ceramic bushings - there are gaps at the bottom and top.
Available in stock decorative panels are slightly flammable according to fire classification. It turns out that only a 5 mm layer of basalt cardboard really protects the wall from fire. However, the oven is convection in nature and its outer surface does not heat up much. If you follow the manufacturer's instructions, it will not heat up more than 60 degrees. But you can't help but worry about safety. For example, even in summer, on the facade of the stove on the south side, it is worth measuring the temperature of the outer surface, and its value may greatly surprise you.
You can pay attention to the color of the first mono-pipe; the most furnace heat emanates from it. From the floor to the sandwich pipe, the wall should be reliably covered with super-insulation, especially since the stove is installed close to the wooden partition. In this case, when thermally insulating the partition, you should also pay attention to the cutting.
You also need to be careful about fiber cement boards; they come in two types: moisture-resistant for the façade and for landscaping fire-resistant partitions (the second option has grey colour, no paint or drawing).
Minerite panels, painted with acrylic (sometimes even in several layers, 5-6), belong to the category of low flammability and low combustion support. Because of the acrylic, the entire slab cannot be classified as “non-flammable”, and this is very bad; such panels, supposedly resistant to fire, are often used just when it is necessary to insulate wooden walls behind the stove - mineralite panels coated with acrylic look It’s beautiful, but, unfortunately, it won’t reliably save you from a fire.
If it suddenly turns out that you bought mineralite coated with acrylic, then you need to get rid of such “protection” of the wall. You should dismantle the panels - this is not difficult, in their place you glue gray classic mineralite onto a galvanized profile, and then terracotta tiles are glued onto it using heat-resistant tile adhesive. With such reliable thermal insulation you can sleep peacefully.
It also happens that gypsum board is used as protection. If the gypsum board is not protected by anything, then it will not play a role high-quality thermal insulation. If the gypsum board is fixed to the wood with a metal profile, and the gypsum board is attached on top tile, then protection of such a plan takes place. Bare gypsum board should not be used for such purposes; its flammability class is G1, not NG (non-flammable). When installing, it is necessary to take into account the distance from the stove to the wall.
If the oven is operating normally, nothing should happen in any way. But measures fire safety specified in the stove manufacturer’s passport must be observed. The distances to fireproof and combustible structures are clearly stated there. Gypsum is a good heat insulator, but its features should be taken into account. If the wall is wooden and gypsum board is attached close to it, therefore, when it is heated, dampness will form behind it, since the wall is cold. The wall itself also shakes - the tree always lives its own life at different humidity levels and temperature fluctuations in environment. A profile is necessary not only for creating behind it air channel ventilation, but also for the durability of the entire structure. The tile adhesive needed here is one that is suitable for heated floors.
It is imperative to take into account fire safety standards when installing important distances. If you calculate the distance from the metal firebox to the wall, then it is more logical to add another 65 mm to such offsets - this is the thickness of the brick, which any metal stove does not have.
It turns out that the open setback to the unprotected wooden part is 320 mm (+65 mm), resulting in 385 mm - this is the minimum value.
To the protected wooden part 260 mm (+65 mm), and a minimum of 325 mm is obtained.
WITH metal chimney things are much simpler. A sandwich with 50 mm insulation is already approaching the edge-on distance of a brick, that is, when passing the floor between the floors of such a pipe and without filling polyurethane foam with non-combustible materials and completely open for control, the following important distances must be maintained (from the outer wall of such a pipe):
To an unprotected wooden wall 320 mm (+ 15 mm), resulting in a minimum of 335 mm.
To a protected wooden wall 260 mm (+ 15 mm), resulting in a minimum of 275 mm.
Until unprotected wood panel 500 mm from smoke minimum;
Minimum 380 mm smoke protection to a protected wooden panel. That is, with a sandwich insulation thickness of 50 mm - 330 mm from the outer contour to the protected joist. As for the roof passage, the distance of 130 mm to the sheathing and rafter part is taken into account from the wall of the brick chimney of 120 mm. That is, there should be at least 250 mm from the smoke to the protected sheathing and rafters.
The simplest option for protecting wood is basalt cardboard and a metal sheet.
A fireplace in a home is not only a decoration that brings a pleasant atmosphere. It gives real heat that warms the house, especially during the necessary heating season those. in winter. What can be done so that the fireplace can be used effectively? In this article we'll talk about proper thermal insulation.
Step two - insulate the back wall
The back wall of the fireplace is often an external partition, and therefore also has contact with hot air, and therefore must be protected by plates with an aluminum screen. Due to this, more hot air will remain inside the fireplace body. The air will subsequently be distributed into the room. The slab is mounted mechanically using dowels made of of stainless steel or glued using a high temperature adhesive solution.
Step three - connecting the plates
To avoid cracks through which dirt can get outside and inside the fireplace, it is necessary to tightly fold and connect the slabs. For this purpose, high temperature adhesive tape with aluminum foil is used to maintain continuity of the joints of the aluminum foil covering the boards. The slabs are placed with foil inside the fireplace.
Step four - saving intervals
It is very important that the insulation does not lean against the fireplace or firebox. An air gap of at least 4 cm must be left between the fireplace and the stoves.
Step five - insulation of stone or wooden elements
Stone and wooden elements the fireplace should also be insulated. There is a high risk that the lack of insulation on these elements will lead to their damage.
Step six - installation of steel profiles
After installing the insulation, the plasterboard housing is made from steel profiles. The frame is built after installing the lower part of the fireplace.
Step seven - compaction
In order for thermal insulation to fulfill its function, it is necessary to pay special attention to two elements: accurate installation of the panels and sealing of all joints with aluminum tape.
Step eight - highlighting the pressure chamber
To reduce the unwanted effect of hot air from the fireplace on the ceiling, a decompression chamber is installed directly below the ceiling. Insulation is also installed in its interior. The next stage of work is installation plasterboard sheets to the grate.
Step nine - installation of ventilation grilles
The housing contains 2 ventilation grates made from materials resistant to high temperatures. The air supply grille is installed in the lower part of the housing, and for exhaust ventilation With opposite side at the top. The decompression chamber must also have 2 ventilation grilles to ensure cooling of the ceiling. Then all the necessary finishing work is carried out.
Note! Insulation material for fireplaces must be resistant to very high temperatures. The presented project uses FIREROCK plates that can withstand a constant temperature of 600°C, and aluminum foil itself - up to 500°C.
Video
Still have questions? In the video presented for this article you can see not only how to make insulation but also how to install a fireplace yourself.
Proper fireplace insulation step by step. Photo instructions
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 thermal insulation material is that, due to its poor thermal conductivity, the transfer of energy through a 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. When 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.
