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How to make a foundation for a stove - various options. How to make a foundation for a stove - all design options How to make a foundation for a stove in a bathhouse

The stove is truly the heart of the sauna; without it it is impossible to create a steam room. Previously, the stove in the bathhouse was installed directly on the floor, but today completely different rules and regulations apply. Heavy, massive stone stoves that retain heat for a long time require a foundation. And here a number of questions and nuances arise that require coverage: what kind of foundation for furnaces is needed, how it is done, why it is needed. Correct calculations and adherence to foundation installation technology will help protect against possible misalignment of the stove, destruction of the chimney, or the appearance of cracks in the masonry of the stove itself.

The very first questions that arise are whether a foundation for the stove is really necessary and, if so, why.

First of all, whether a stove needs a foundation depends on its weight. For example, under a metal stove, the weight of which is usually no higher than 200 - 250 kg, does not require a personal foundation. It can be placed on a solid floor base. The exception is a wooden floor - sometimes it is preferable to make a simple foundation for a metal stove. This will reduce the fire hazard and also reduce the impact of the stove on the wood floor.

Brick oven can have different weights: from 500 kg to 8 - 10 tons. The most common option is a stove weighing 1200 - 1500 kg. Brick kilns weighing more than 750 kg require a separate foundation. This is primarily due to soil movements and settlement of the structure.

The structure of the bathhouse and the design of the furnace are subject to settlement, which depends on the distribution of mass over the area. Taking into account the design, a heavy massive stove will influence the foundation of the bathhouse unevenly with its weight and will press at the point of contact. As a result, the foundation will sag unevenly, and the structure of the bathhouse may become askew. To prevent this from happening, a personal separate foundation is built under the brick oven.

Important! The requirement to equip a separate foundation for the furnace is specified in SNiPs. However, there are exceptions. When these SNiPs were written, slab foundations had not yet been made everywhere, mostly only strip foundations. If a reinforced concrete slab is poured under the entire structure of the bathhouse, then a personal foundation for the stove is not needed.

When choosing the type of foundation, it is necessary to take into account the properties of the soil. For example, another reason why it is necessary to make a separate foundation for a stove in a bathhouse is the heaving of the soil during frost. The bathhouse is not always heated; quite often it is unheated. During this time, the soil under the bathhouse freezes and either expands or contracts, which is called heaving. As a result of heaving, the foundation under the stove can rise above the level of the foundation under the bathhouse itself. If the foundations were connected to each other and did not have a gap, then destruction and distortion of both the furnace and the building would inevitably occur.

How to make a foundation for a brick oven

The most important requirement for the foundation for a stove in a bathhouse is reliability and non-susceptibility to soil movement. To ensure this, you need to know exactly what type of soil the bathhouse is on and to what depth it freezes. If you do not have such information, then you should contact the geological service of your region, they have all the data.

Before making a foundation for the stove, you need to calculate its weight. The size of the foundation and its depth will depend on this. 1 m3 of brickwork weighs 1350 kg, this already includes the weight of the bricks and the weight of the cement mortar. To calculate the weight of the furnace structure, it is necessary to multiply the total volume of the masonry (furnace) by 1350 kg. A stove weighing 750 kg does not require a separate foundation. The base for such a stove can be an asbestos sheet. A sheet of asbestos must be laid on top of the floor on the clay mortar; a sheet of roofing iron must be laid on top of the asbestos sheet. This will be enough to insulate the floor and ensure fire safety. The dimensions of asbestos and iron sheets must exceed the dimensions of the stove by 25 cm on each side.

If the weight of a brick kiln exceeds 2 tons, then a buried concrete foundation must be installed under it. Also, the basis for arranging such a foundation can be the type of soil - porous clay or loess soil. Porous clay, saturated with water, expands greatly, especially when freezing. And loess soil, when wet, simply turns into slurry. Therefore, a foundation is built on such soils with a depth below the freezing point of the soil in winter.

Stages of work:

We dig a pit for the foundation. The dimensions of the pit should exceed the dimensions of the furnace by 10 - 15 cm on each side. The depth of the pit should be greater than the freezing level of the soil. For many regions, a depth of 1.5 m is sufficient.
We compact the bottom of the pit.
Add a layer of crushed stone and compact it as well. After compaction, the height of the crushed stone layer should be at least 15 cm.
We pour a 20-30 cm layer of sand on top. We spill it with water and wait until it seeps into the voids between the crushed stone fractions.

When the sand dries, pour another layer of crushed stone 15 - 20 cm thick. Compact it.
We install wooden formwork in the pit. We lubricate the inner surface of the formwork with hot bitumen or waterproof it in another way.
Inside we lower a reinforcing frame made of steel rod 8 - 12 mm thick.

Pour the concrete to a level 6 cm below the floor level in the bathhouse. We use the same solution as for the foundation of the bathhouse.
After pouring, check the horizontalness of the foundation surface.
Cover the concrete with film or roofing felt and leave to dry. It will take from 15 to 30 days.
After the concrete has completely hardened, remove the formwork.
We coat the foundation walls with waterproofing material - tar or any other. It is better to do this in 2 - 3 layers.
The space between the foundation and the soil walls, as well as between the foundation of the bathhouse, must be filled with sand.

Waterproofing the foundation surface can be carried out from above, before laying the furnace. Or maybe at the stage of building the foundation. For example, appropriate additives can be added to the solution. Or, at the stage of the last crushed stone filling, make a concrete preparation on top with a layer of only 2 cm of liquid mortar. When it dries, you can spread roofing felt or other rolled material on top in 2 - 3 layers. Concrete is poured on top of the waterproofing.

For a furnace weighing from 1 to 1.5 tons, you can get by with a shallow foundation. Especially if the soil on the site is continental or sedimentary, and the groundwater level is very low. If the region does not suffer from severe floods, then this type of foundation, as described below, will be quite sufficient.

Stages of work on arranging a shallow foundation for a furnace:

We are digging a pit for the foundation: the dimensions are 20 cm larger than the size of the furnace, the depth of the pit is 70 cm.
At the base of the pit we make an extension - a heel. On each side we expand the pit by 10 cm. This will make it possible to avoid soil movement.
Pour the sand in a layer of 15 cm. We spill it with water and wait until the water is absorbed and the sand settles.
Then add sand so that the total layer is still 15 cm. And fill it with water again and wait until the water is absorbed.
Pour broken brick, stone and crushed stone in a layer of 20 cm. Carefully level and compact.
Pour sand on top and spill with water. We wait for the sand to settle in the cracks between the stones. Add sand and fill it with water until the entire space between the stones is filled with sand.
Fill in a 10 cm layer of crushed stone and compact it.
Then we install the formwork inside so that there is a free space of 10 cm between the formwork and the walls of the pit.
We insert a reinforcing frame made of 8 mm rod inside the pit.
Pour concrete to the floor level in the bathhouse.
We check the horizontalness of the foundation surface.
Cover the concrete with film and wait for it to dry, about 2 - 3 weeks.

After the concrete has completely hardened, remove the formwork and coat the foundation walls with waterproofing mastic.

We fill the free space between the walls of the foundation and the walls of the pit with sand or fine gravel. Sand is preferable.

For highly heaving soils, a foundation in the form of a concrete monolithic slab on piles or pillars is also suitable. If you bury the pillars to a depth below freezing of the soil, little ground movement will be felt in winter. This option for arranging a foundation for a furnace is suitable for those regions where the soil freezes very deeply and making a full-fledged foundation to such a depth is simply not profitable.

On non-heaving soils, you can make a monolithic slab without columnar supports. After all, if the soil is subject to heaving, then the concrete slab will move along with the soil. And if it is also connected with the structure of the floor, then destruction inside the bathhouse cannot be avoided. It is to minimize the movement of the slab that pile or columnar supports are made.

Arrangement of a slab foundation on columnar supports:

The height of the concrete slab will be 15 cm. Therefore, we remove the top layer of soil to this depth. The dimensions of the pit should exceed the dimensions of the furnace by 15 - 20 cm on each side.
At the four corners of the pit, at a distance of 15 - 20 cm from the edge, we drill holes for the pillars. The depth of the holes is below the soil freezing level, diameter 20 cm.
Place 10 cm of crushed stone on the bottom and compact it.
We insert rolled roofing material into the hole. It will serve as both formwork and waterproofing of the columnar foundation.

We insert a frame made of reinforcement 8 mm thick inside.
We arrange formwork throughout the pit for pouring the slab. We also lower the reinforcing frame inside.
We fill everything with concrete. First the pillars, compacting the concrete with a vibrator, and then the slab.

Important! It is advisable not to take breaks between pouring the pillars and pouring the slab. Otherwise, the structure will turn out to be disconnected, but it needs to be monolithic.

After the concrete has dried, about a month later, we cover the surface of the slab with waterproofing material. After which you can safely equip the oven.

Slabs on screw piles:

Screw piles can be used instead of concrete pillars. They are screwed into the ground using threads. As a result, the soil is compacted and foundation settlement will be minimal.

The foundation on screw piles is stronger and more durable than on pillar supports. But more expensive. The concrete slab is poured on top of the screw supports using conventional technology. The height of the slab is 15 cm. Accordingly, the top of the screw piles must be buried to a sufficient depth.

Foundation for a sauna stove made of rubble concrete

The most common type of foundation for a furnace is rubble concrete. It is more economical than a concrete foundation, especially if there is a lot of construction waste left in the form of fragments of bricks or stones. Such a foundation can be installed instead of a buried concrete foundation.

We dig a pit for the foundation. Depth - 1 - 1.2 m. The dimensions on the sides are 15 - 20 cm larger than the dimensions of the stove.
Compact the base soil.
Pour crushed stone in a layer of 15 cm and tamp it down.
We install wooden formwork. We waterproof the internal walls.
We place large stones or bricks at the bottom, the maximum size of which is 15 cm. The total layer of stones is 20 - 30 cm.
We fill the voids with small crushed stone.
We prepare a concrete solution with a consistency like liquid sour cream and pour it over the stones. Concrete should fill all voids.

Important! If the foundation height is large, then the next layer of stones and concrete pouring can be done the next day. If the height of the foundation is such that 2 layers are enough, then everything can be done in one day.

The last layer of stones should end at such a level that there is 6 - 7 cm left to the finished floor.

We check the surface of the foundation for horizontalness. If there are deviations, then add concrete solution until the foundation is level and horizontal.
Cover the concrete with film and leave to dry for 2 - 3 weeks.
After the concrete has hardened, remove the formwork.

The surface of the foundation walls must be waterproofed with mastic material. We fill the space between the foundation and the walls of the pit with sand. In the future, the laying of the stove begins at a level 6 - 7 cm below the floor level.

Also, do not forget that between the foundation of the bathhouse and the foundation for the stove there must be a gap of 5 cm, which is best filled with sand.

How to make a foundation for a metal sauna stove

As already written above, sometimes a foundation is also made for an iron stove, although its weight is not that great. If the floor in the bathhouse is concrete, then there is no need to make a foundation for an iron stove. And if it’s wooden, then it’s not necessary, but it’s possible.

We dig a pit for the foundation of the furnace with a depth of 50 cm. The dimensions of the pit should be slightly larger than the size of the metal furnace - by 5 - 10 cm.
Pour crushed stone into the bottom of the pit and compact it thoroughly. After compaction, the height of the crushed stone layer should be at least 30 cm.
Pour the concrete preparation on top with a layer of 2 - 3 cm. Make the solution for concrete preparation as follows: 1 part cement, 4 parts sand, enough water to obtain a medium-thick consistency.
After the concrete preparation has dried, we lay a waterproofing layer in 2 - 3 layers.
Then we install the formwork.
We insert a reinforcing frame made of 8 mm steel rod inside.
Fill the concrete with a layer of 20 cm. Prepare the solution according to this recipe: 1 part cement, 2.5 parts sand, 4 parts small crushed stone.
We check the horizontalness of the foundation surface. If necessary, add and level the solution.
After the concrete has completely hardened, i.e. after 2 weeks, we carry out the laying of red burnt bricks, bringing the level of the foundation to the level of the floor.

Red brick can be laid both over the entire area of the foundation base, and only as support columns. Also, the entire foundation for a metal stove can be made of brick.

The foundation for a stove is a responsible task. If you plan to order the laying of the stove from a specialist, then you should not make the foundation yourself. First you need to consult with the stove maker, and only under his guidance begin to build the foundation. Please note that an incorrectly made foundation threatens you with the fact that during soil movements the chimney will break the floors and roof. All this can lead to unpleasant destruction. Think through everything in advance.

Depending on experience and knowledge of how to make a foundation for a stove in a bathhouse, the service life of the stove and the entire bathhouse as a whole depends. Therefore, it is important to be able to perform simple calculations on materials and choose the type of foundation depending on the size of the furnace, the type of soil and other factors.

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Why do you need a foundation for a stove in a bathhouse?

To answer this question, let’s look at the reasons that require installing a base for a stove in a bathhouse:

The size of the foundation for the stove in the bathhouse and its design directly depend on its dimensions and weight. A large stove, even made of metal, will require the building to be equipped with a base for it. Sizes increase, weight increases. According to the rules, if the mass of the heater is less than 200 kg, you can not make a separate pillow, but mount the heater on a ready-made foundation;
floor material. If it is made of flammable materials, you will need to make a non-flammable base for a solid fuel stove. In this option, you can simply lay out a brick cushion, making it larger than the dimensions of the stove by at least 1 m;
Definitely, a separate structure will need to be made for the brick heater even when laying the main foundation. Such a device will protect the heavy structure from destruction during shrinkage or soil movement;
the structure of the main base and the bathhouse building itself are affected by the force of gravity, shifted from the center. At the same time, the load is distributed unevenly, increasing at the place where the stove is installed. To this we can add that during operation a large amount of thermal energy is released. Concrete, when heated, transfers heat to the soil, it dries out, settles, and voids form under the foundation.

Therefore, it is important to make at least a pile or brick foundation for the stove in the bathhouse.

Standard scheme

Classification

By depth level

The grounds are divided:

Shallow. The depth of such a base is a maximum of 700 mm; they are capable of providing a reliable base for stoves weighing one and a half tons. For the cushion, a 150 mm layer of sand, crushed stone or gravel is poured.
For larger ovens. foundations are made taking into account freezing and soil types.

By type of design

When installing heaters of different materials, lay:

One of the most popular designs for small-sized stoves is a base made in the form of a tape. The trench for the strip foundation is made according to the dimensions of the furnace;
monolithic reinforced layer of concrete and reinforcement is widely used in capital construction. Using a monolithic slab, you can equip a foundation for a large sauna stove when installed on non-radiant soils;
foundation made of supports with a concrete base. Work can be done on sandy and radiant clay soils. A simple and reliable foundation of this type can be made on a finished base by drilling 4 large-diameter holes;
base with a concrete slab, which is installed on screw piles. In this case, there is no need to dig a pit and pour a large volume of concrete.

According to the material of manufacture

For work, 3 types of materials are used:

The most common, but expensive material is concrete. With its help, most types of foundations in capital construction are made. This is the optimal solution for an industrial furnace in a bathhouse plant.
Brick. It is used to create a base for most foundations for small homemade steel sauna heaters.
Rubble stone is used to make the foundations of bathhouses and stoves. The material is inexpensive and easy to work with.

How to calculate the amount of materials needed?

For calculations, it is important to take into account not only the size of the stove in the bathhouse, but also the depth level and the type of base itself. When calculating, first of all you need to know:

the thickness of the layer of sand and gravel cushion. You can calculate the amount of sand using the volume calculation formula. To do this, you will need to measure the length of the trench or pit, the width of the fill and the thickness of the layer. After multiplying, you get the required number of cubes of sand and crushed stone;
Concrete calculations are made using the same formula. Having calculated the number of cubes, you can order ready-made concrete; it must be purchased with a small reserve;
This formula will help you calculate the number of bricks. Knowing its dimensions, it is easy to determine the amount in 1 cube and calculate the required number when making a brick foundation for a metal heater;
To stock up on reinforcement, you will have to decide in advance on the design of the base and, based on this, determine the approximate footage of the rods. But here you should take into account the remaining unmeasured ends when cutting long lashes.

Calculation example

For clarity, let’s look at an example of calculations for a bathhouse with an area of 48 m2, for a monolithic slab for a total area combined with the base for the stove. To work, you need to decide on the cubic capacity of the base, the thickness of which is 20 cm. We multiply the length, width and thickness of the base - 6 m width, 8 m length and 0.2 m height of the foundation. We will need 9.6 m 3 of concrete.

But it is necessary to take into account the dimensions of the reinforcing layer. To lay it, 4 segments are used to place along the long side - 32 m of reinforcement and 3 lintels along the width - 18 m. Now you can determine the cubic capacity of the reinforcing layer, it is equal to 1.5 m 3.

As a result, for the base you will need to order 8 m3 of ready-made concrete and 48 m of reinforcement.

Making a foundation for a sauna stove with your own hands

The base for a stove in a bathhouse is a simple operation that does not require much experience. Any steam lover can do the job. How to pour a foundation for a stove in a bathhouse - for this it is important to determine the design of the base, calculate and order the required amount of materials, and prepare tools. You need to make a foundation for an iron stove in a bathhouse with your own hands - just lay several rows of refractory bricks on a ready-made foundation for the entire building.

General requirements

Several points can be highlighted here:

Large margin of safety and reliability of the design.
High level of resistance to ground movement.

In this case, the depth of soil freezing in your climate zone when digging a pit, as well as the structure and type of soil, must be taken into account. When following the recommendations, the foundation is not subject to cracking or damage throughout its service life.

For various soils, the minimum pit depth is accepted, regardless of the climate conditions in this place:

dry sandy soils - minimum pit depth 50 cm;
rocky soils – up to 400 mm;
clay soil, loam - you will need to make a pit up to 1000 mm deep. This also takes into account the soil freezing depth for your region;
wet marshy soils - the distance increases and becomes from 1000 mm.

It is not recommended to make strong foundations on bulk soils, especially if large fragments of soil were used during filling. The size of the foundation for the stove in the bathhouse is made taking into account the protrusion beyond the dimensions of the stove by at least 100 mm on all sides.

Monolithic

How to pour a monolithic foundation for a stove in a bathhouse, in what cases is it necessary to equip a heater with such a foundation? In a small individual bathhouse there is no need to make such a separate base.

To work you will need:

dig a pit according to the size of the stove, to the depth required for your region;
make a sand cushion, 150-200 mm thick, compact the layer;
fill the pit with expanded clay for a thermal insulation layer and cover it with film or roofing felt for waterproofing;
make formwork along the contour of the slab from boards or other available material. In the case of a large base, the formwork is secured with several stiffening ribs, which also serve as beacons for pouring an even layer of concrete;
make a reinforcement layer from reinforcement with a thickness of 10 mm. It is better to knit the reinforcement with wire; for welding you will need to prepare or buy couplings;
We gradually fill the base with concrete and stretch its excess with a rule of a flat board or steel profile;
the layer needs to be compacted. For this it is better to use a vibrator.
While the concrete hardens, it must be watered with water, in this case the top layer will not crack.

The monolithic foundation is ready, the surface can be strengthened by ironing it with a layer of cement

Columnar with base plate

The foundation for a stove in a bathhouse of this design can be installed on top of the main one. In this option, use a reinforced concrete slab of a suitable size or you will have to fill it, making permanent formwork for it from corners or channels. This design protects the stove and the building from damage due to shifts in the layers of the earth in different seasons. It is recommended to install on loams and clay. All work is carried out in several stages:

Having marked 4 installation points for the pillars, we drill holes in the ground for them to the required depth. The minimum size of pillars for large stoves is 200 mm; for small steel heaters, use a section of 80-100 mm;
the bottom is filled up and compacted with crushed stone. Layer size 15-20 cm;
We make permanent formwork from roofing felt or other durable material, roll it into a roll of the required size and insert it into the hole;
we fill the cavities with concrete and compact the layer;
after a week, we lay several layers of waterproofing on top of the pillars. To do this, you can use polyethylene or roofing felt, the main thing is that the edges extend beyond the dimensions of the oven;
we lay the finished one or fill the area with mortar, making a homemade monolithic slab.

Work is done. This type of foundation is most suitable for a metal stove in a bathhouse.

On stilts

This foundation for the stove in the bathhouse is made in the same way as the previous one. With its help, steam rooms are equipped on marshy soils and bulk soil. For piles, concrete or steel rods of the required size are used. For installation, smaller diameter holes are drilled to the main soil and then the piles are driven into the ground.

A monolithic reinforced concrete slab larger than the stove by at least 200 mm is poured on top.

With the help of such a foundation, those who like to cool off after a steam room in an ice hole can set up a bathhouse not far from the river bank, the main thing is that the environmental prosecutor’s office agrees with this.

From rubble stone

The foundation for a stove in a bathhouse with a base of rubble stone is carried out in the following sequence:

make the pit larger in size by at least 15-20 cm;
make a sand cushion;
We make formwork along the contour and place several spacers - beacons;
We lay a layer of film from the inside to waterproof the foundation;
lay out 1 layer of rubble and fill the voids with crushed stone. Layer thickness 150-200 mm;
fill a thin layer with cement mortar;
After the cement has hardened, lay out the 2nd layer of rubble and apply a layer of mortar. We repeat the operation several times;
Having checked with a level that the installation is correct, we level the layer, adding solution to the required areas;
the foundation should not reach the top of the formwork by 70-80 mm. We cover the entire area with a layer of roofing material with melted bitumen.

The foundation for a small iron sauna stove is best made of brick, laid out in rows on the finished concrete base of the sauna.

Brick

Making such a foundation for an iron stove in a bathhouse with your own hands is not difficult. Let's look at the option of making a base for a heater from a barrel.

For this:

we mark the area for the stove, making it 300 mm larger;
Lay out the first layer of brick longitudinally on the cement mortar and clay;
the second row is laid out across. This is done to connect the layers.
in the middle part of the foundation from the middle of the front part we make a niche for the ash pan and the blower. We close this cavity with a door.

For metal furnace

The foundation for a metal stove in a bathhouse is made at the stage of the main work on making the base for the room.

For this:

We deepen a separate pit to a depth of 500 mm at the location where the furnace is installed. At the same time, we take into account an increase in the dimensions of the pit by 20 - 1000 mm, depending on the material of the future floor in the bathhouse. If wood is to be used, the foundation must extend at least 500 mm on each side;
Having leveled the bottom and removed the soil, we fill the base with an even 200-300 mm layer of slag;
We compact the layer using a manual tamper. Then expanded clay is poured on top for thermal insulation;
fill the base with a solution of cement and sand and let it harden;
lay out a layer of roofing material, fill it with ready-made or homemade concrete;
Having laid the flooring, we proceed to the final operations. We lay out several rows of refractory or ordinary building bricks. The first row can be laid on edge to increase the gap to wooden floors.

Remember - if the walls and ceiling of the bathhouse are made of wooden parts, in this case the foundation for a metal bathhouse stove must be planned taking into account the required minimum distances:

to walls – from 700 mm;
ceiling – 1000 mm;
floor - 140 mm.

To protect the walls you will need to make screens. It is better to make them covered with foil on the front side. In this case, the heat will be reflected from the screen, spreading throughout the room.

Which option is best to choose?

Several factors influence the choice here. To equip a large public bathhouse, you will need to make a monolithic foundation or a pile foundation when building on swampy or bulk soils.

In this case, you will not need to make a base at all if you are installing a small heater for a steam room made of steel or lay 2-3 rows of refractory bricks on top of the finished concrete floor. It will speed up the production of a foundation for a large stove on poles. This design can be used to equip a steam room in an old bathhouse by removing the wooden floor along the contour of the future base and drilling 4 holes in the ground.

Conclusion

It is better to make a reliable foundation for your stove, enjoy fragrant steam and leisurely conversation with friends, than to end up with a rickety or even burnt-out sauna that did not have a reliable and durable foundation for the sauna stove. You should not be lazy and skimp on your own safety.

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Despite technological progress in the heating equipment industry, home furnaces continue to enjoy continued popularity. They allow you to heat houses in areas remote from civilization. Where electricity and gasification are not provided. The construction of any furnace begins with the construction of the foundation. We will talk about how to make a foundation for a stove correctly in this article.

Making a stove, of course, requires a lot of labor, experience and knowledge of technology. When thinking about building a stove at your dacha and building a foundation, you can, of course, hire specialists. But in fact, arranging the foundation for a furnace can be easily done on your own.

This is not such a costly or complicated matter, but the pleasure from a self-built structure will more than pay for all the trouble.

Whatever option you choose for the foundation for the stove, and whatever size you decide to implement, there are a number of basic rules that you should not ignore:

The foundation for the stove must be made independent, in no way connected with the foundation of the entire house. Why? The fact is that during operation, the house may shrink slightly. When lowering, it should not pull the stove along with it, as this can lead to its deformation, deterioration of draft and disruption of technical properties.

In some cases, it is possible to partially combine two bases by connecting them with one wall.

If both foundations (for the house and for the stove) are located close to each other, you need to fill them with sand 50 mm thick.
If the foundation for a common house is strip, then the base for the stove should in no case be in contact with this foundation.
When choosing a place for a stove and, accordingly, a foundation, you should not only rely on wishes, but also on factors such as: the location of doors, windows and roof beams. The location of the chimney should be taken into account so that the pipe does not fall into the ceilings and beams during the construction of the stove.
When calculating the size and depth of the foundation, be sure to take into account the weight of the floors and the weight of the stove along with the chimney.

The size of the foundation is influenced not only by the dimensions of the furnace, but also by the density of the soil on which it is built. The main load in the furnace is usually created by the chimney, so when designing the furnace, it is necessary to place it closer to the center of the base. This will help avoid asymmetrical loading and premature incorrect shrinkage of the oven.

Sometimes, when designing a very large and massive stove with a stone chimney, stove makers create a separate base for the chimney.

Also, the choice of foundation depends on the material of the furnace. For a metal structure and a stone one, it will be different in depth; the entire mass of a brick oven is at least 400-500 kg, while a metal oven weighs approximately 150 kg.

In principle, for a small metal stove you don’t have to build a separate foundation, especially if it is being built in a house that stands on a tiled monolithic foundation.

Important! Before laying out the foundation for the furnace, it is necessary to determine the type of soil on the site.

The density of the soil and the degree of its freezing play an important role in determining the size of the foundation. The climate in Russia is accompanied by fairly harsh winters throughout almost its entire territory. Therefore, the foundation for the furnace must be laid to the entire depth of soil freezing.

The type of soil is also of great importance.

It comes in three types:

clay;
sandy loam;
loam.

In places where a large number of rivers, reservoirs, and lakes predominate, sedimentary types of soil are usually found. Here, it is better to entrust the construction of the foundation for the stove and the house to professionals, so calculations of the water passage point must be carried out.

In Central Russia, the most common type of soil is loam, which is a mixture of sand and clay. It is clay that predominates in it, so this soil is less plastic.

Building a foundation on such soil is usually associated with hassle and additional problems, since when dry the loam is crumbly, when frost sets in it begins to “heave”, and when there is a large amount of sediment it becomes viscous.

Therefore, in this case, the depth of laying the foundation for the furnace must be made above the freezing point.

But in forested areas, on the contrary, it is necessary to lay the foundation for the stove below the freezing point of the soil and the foundation must be built on a sand cushion 60-90 cm thick.

One of the most reliable types of soil for building a foundation is gravelly and rocky, but, unfortunately, sometimes you have to build a house and stove on an unstable one. Proper construction of a reliable foundation will help offset this fact.

Types of foundation

There are three main types of foundation for a brick kiln:

cement;
rubble concrete;
on stilts.

What is their main difference, and which foundation is better to choose for a furnace?

We will consider in detail several construction options, which will allow you to choose the best option for yourself.

Many are also interested in the question: how deep should one go when digging a foundation pit?

It all depends on the density of the soil and the weight of the heating structure, but you shouldn’t overdo it. The optimal option is a hole depth of 80-100 cm. Some craftsmen take the path of less resistance and remove only the plant layer of soil, build formwork 20 cm high and fill it with concrete mixture. But this is a bad option.

The foundation experiences pressure of several hundred kilograms, the load will especially increase in winter, when the soil freezes. Therefore, you should not be lazy and save money on arranging the foundation, on which the strength and reliability of the stove’s operation entirely depends.

Tools and materials for building a foundation

The first thing you need to do before starting construction work is to stock up on the necessary set of tools.

The work will have to be carried out not only in excavation, but also in carpentry, so prepare the following tools:

Bayonet shovel (needed for digging the main pit).
Scoop shovel (convenient to prepare sand-cement mortar).
Hammer.
Hacksaw or saw.
Sieve for sifting cement (mesh size 1*1 mm).
Sieve for sifting sand (mesh size 2*2 mm).
Bucket for water (for preparing cement-sand mortar).
A metal trough in which we will prepare the solution.
Building level.
Tape measure and pencil.
Stapler.

Materials you will need:

Boards (for making formwork).
Polyethylene (for waterproofing formwork).
Sand.
Cement.
Gravel.
Reinforcing mesh or bars.

We begin to pour the foundation for a brick oven with our own hands

Step 1. Marking for the foundation and pit

Step 2. Installation of formwork and reinforcement

Step 3. Prepare the concrete mixture for pouring the foundation

We prepare a mixture of the following proportion: for 4 parts sand, take 1 part cement + 3 parts crushed stone of the middle fraction.

Stir the dry mixture well with a bayonet shovel and add water. Mix the solution well using a concrete mixer. In consistency, it should resemble thick sour cream.

We fill part of the pit with this mixture, not reaching the level of the base floor by 8 cm. This work must be completed within 24 hours. The concrete solution should be complete and not layered.

After you fill the entire pit with concrete, you need to once again check the horizontalness of the coating with a building level. After the solution has completely dried, it will be more difficult to correct your mistakes.

Cover the foundation with a layer of polyethylene or roofing felt and leave for 2 weeks until completely dry.

We remove the upper part of the formwork only after complete drying, beating the boards with a hammer. Pour crushed stone and sand into the resulting gap and compact it well.

Making a foundation for a metal stove with your own hands

If the stove is installed in an already finished house, where this device was not previously intended and wooden floors are already laid, then the construction of the foundation will have to begin with partial dismantling of the floor covering.

As you can see, this is a simpler way to build a foundation, which does not require such careful preparation and laying of reinforcing mesh. The low weight of the metal structure of 150-170 kg does not require such a powerful foundation.

To avoid critical mistakes when building a foundation for a furnace, we recommend watching this video.

Video: Foundation for a stove, basic rules

Option for creating a rubble concrete foundation for a furnace

Installation of a pile foundation with a slab

One of the types of foundation for a furnace is a pile structure, which is characterized by good reliability and ease of installation.

We make markings on the ground according to the dimensions of the future oven and measure 10 cm in each direction - this will be the size of the foundation.
We remove 20 cm of the plant layer of soil using a bayonet shovel.
We put pegs and pull the rope.
In each part of the peg we drill holes with a diameter of 20 cm to a depth of 50 cm.
We make formwork from wooden boards, fastening them together with nails, and set them according to the size of these holes. The formwork is a wooden box without a bottom.
We make waterproofing using polyethylene, which we staple along the perimeter to the walls of the formwork.
Pour sand onto the bottom, compact it well and fill it with gravel to a depth of 15 cm. Fill with water.
We knit the reinforcing bars using 0.8 mm wire and twist them well.
We install a reinforced frame.
We roll up dense sleeves of roofing felt and insert such piles into the pits. Asbestos pipes can be used as piles.
We fill the finished piles and inserted into the hole with concrete mixture.
We take a technological break for 2 weeks.
Now you can fill the entire foundation with concrete mixture.
Cover with polyethylene and let the foundation harden for at least 2-3 weeks.

Video: How to make a foundation for a stove

Stove and foundation for the furnace– two inseparable conditions for safe use of the steam room. How to properly make a foundation for a sauna stove? This and other questions related to the construction of a heater foundation will be answered in this article.

After the construction of the main structures of the bathhouse, you can begin the construction phase of the foundation for the heater stove. However, it can be done simultaneously with the main foundation for the building. In many cases this is even more convenient and expedient.

The main rule that must be followed when building a heater foundation is that it must be made independent from the main foundation. Then the weight of the entire structure will not affect the stability of the foundation for the sauna stove.

Even if you decide to use a metal stove-heater weighing 150-200 kg, having bought it in a store, you still need a base for it. And even more so for a brick stove. After all, its weight can be 500-700 kg or more, depending on the design. To approximately calculate the weight of brickwork, you can use the following formula:

P = 1350 x V, Where

1350 – weight of one cubic meter. meters of masonry, kg;
V – total volume of masonry, m³.

By calculating the weight of the entire heater, you can easily calculate the necessary parameters of the load-bearing base.

There is no need to say once again that all work must be done carefully and correctly. Only then will there be a 100% guarantee that the bathhouse will last a long time and reliably, delivering true pleasure from visiting it.

Construction of a foundation for a stove

In general, the construction of a foundation for a stove comes down to the following work:

removing the top layer of soil;
digging a pit and preparing it;
production of formwork (for concrete foundation);
concreting or laying a brick base.

The dimensions of the pit in plan should be 10-15 cm larger on each side of the foundation. After pouring concrete and removing the formwork, the space between the foundation walls and the soil is filled with gravel or coarse sand. In the future, this backfill will prevent the movement of soil layers from affecting the foundation of the sauna stove.

For heavy stoves, and even those with a brick chimney, the depth of the foundation should be made to the level of seasonal freezing of the soil. For example, for Moscow and the region it is 120-140 cm. For other regions you can look. For more information about foundations and concrete preparation, see .

For metal furnace

Let's assume that we need to install a metal wood-burning stove of one of the brands "Harvia", "Kastor", "Helo" or the domestic analogue "Ermak" with base dimensions of 500x1000 mm. The process of making a foundation for it will look like this:

We dig a rectangular hole with dimensions of 600x1000 mm to a depth of half a meter.
We pour crushed stone into the open hole and compact it thoroughly so that its thickness is at least 25 cm.
We prepare a liquid cement mortar in the ratio of one part M200 cement and four parts sand. Pour liquid cement mortar on top of the compacted layer of crushed stone so that it completely covers its top layer. After this, leave it to set for a day.
The next day, we lay waterproofing made of rolled roofing felt in two layers on top of the cement screed.
We prepare M200 grade concrete and pour it into the pit directly onto the roofing felt. The concrete layer should be 250 mm thick. We level it from above with a wooden block to a horizontal level.
After the concrete has set, after 5-6 days you can begin laying a brick base to bring it above the level of the finished floor (zero level) by 100-150 mm. In the example given - 100 mm. For this purpose we use burnt red brick.
Instead of brick, you can use concrete. Then you will have to make formwork from boards (see the next chapter).

For brick heater

In this example, we will use the same overall dimensions of the foundation in plan, namely 600x1000 mm. It will differ from the previous one both in its size and its structure. Yes, this is understandable, because the weight of a brick stove for a bathhouse is incomparably greater. In addition, if previously we did not take into account the depth of soil freezing, now we will have to do so. No one will be happy when, after some time, cracks in the masonry, deviations from the vertical or other deformations of the bathhouse structures are discovered.

The traditional Russian bathhouse and the stove in it are often considered as a single whole. But in order for the furnace to operate successfully for a long time, it is necessary to install it correctly on a foundation specially prepared for this. It is necessary for any type of stove used - both metal and brick. Moreover, if done correctly, it not only plays the role of a supporting structure, but also provides an additional level of fire safety.

Types of foundation for a furnace and requirements for it

Before installing a stove in a bathhouse, it is necessary to check the presence and compliance with the requirements of the foundation for it. In most cases, it is recommended to carry out work on laying the foundation for the furnace simultaneously with other similar work. This leads to approximately the same shrinkage of all structures. But if this does not happen, it is quite possible to perform them in a ready-made bathhouse.

You should pay attention to an important point - under no circumstances should you install a stove in a bathhouse on a wooden floor. A sauna stove without a foundation is a potentially weak point of the structure, and also does not meet fire safety requirements. Before installing the stove in a wooden bathhouse, it is necessary to carry out work on the foundation.

When installing a foundation for a stove in a bathhouse, the following factors must be taken into account:

the dimensions in the horizontal plane should be at least 5-10 cm on each side greater than the dimensions of the stove that will be subsequently installed;
the height of the structure should generally be at the same level as the rest of the bathhouse foundation;
the depth is determined by analogy with the same indicator for the rest of the foundation, but taking into account the expected load from the furnace.

The most common foundation options for a sauna stove are concrete or rubble. We should not forget the mandatory rule that 2-3 layers of waterproofing are required on top of the foundation, which is necessary for the normal and long-term operation of the structure.

As a conclusion, we can say that before correctly installing the stove, as well as installing the pipe coming from it, it is necessary to build the foundation correctly and in accordance with the requirements of the technology.