Since ancient times, in the Russian hut, stoves were installed on the floor, for this the floor beams were strengthened or an additional one was laid. Today, a stove that does not have a foundation is a rarity; to save money, builders cut the floor beams into the first crown, while the previous installation method can no longer be called suitable. In addition, the foundation for the furnace is necessary to increase the stability of the structure and prevent destruction. Traditionally, the foundation is made of cement-based rubble or concrete, which is poured in such a way that the foundation extends 10 cm around the perimeter of the furnace.
The height of the base should be the same as the height of the foundation of the main building. Roofing material or roofing felt in two layers is laid on top of the finished structure, on which bricks and outlets from metal corners are laid to build fireproof cuts. But if you decide to install a foundation for the furnace, then you must follow some rules. For example, it is impossible to additionally concrete the previously laid foundations, as there will beuneven shrinkage of the furnace. Therefore, the foundation for it is not connected with the foundation of the house. But if both of them are located as close as possible, then between them it is recommended to lay a backfill of crushed stone, the thickness of which will be equal to 0.5 m.
The need for a foundation for the furnace and determining the dimensions
Some owners of country and private houses are wondering if a foundation is needed for a stove? To resolve this issue, it is necessary to determine the dimensions of the future structure. The weight of the furnace also determines the need for arranging the base. The newly laid structure will weigh approximately 8 tons, after the mortar dries, the mass will decrease by half. Sometimes a separate foundation is formed for the root chimney, this eliminates uneven shrinkage.
The depth of the foundation will depend on the strength of the ground, the heaving of the soil, the depth of freezing, the laying of the foundation of the main building, the level of the groundwater, and whether the construction of the main building is completed at the time the foundation for the furnace is erected. On dry sandy soils, the foundation for the furnace must be laid 80 cm. If we are talking about heaving soils, then the depth should be 1.5 m or less below the freezing line. In order to determine whether a foundation is needed for a furnace, its future mass should be calculated using a formula that looks like this:
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P=1350 x V, where V is the volume of masonry in meters;
1350 is the approximate weight of 1 m2 masonry in kg (mortar + about 200 bricks).
Building a foundation for a metal furnace
If you decide to build a foundation for an iron stove, then you should not think about the need for a foundation, even if you use thin ultra-light steel in your work. If the future structure will weigh about 150 kg or less, then you should first prepare the pit and fill it with rubble. The layer is well compacted, in the end its thickness should be equal to 30 cm. A cement solution of medium fluidity should be poured on top and left for a day to solidify.
The ratio of ingredients should be as follows: one part of cement, four parts of sand and liquid "by eye". From this solution, the sole of the foundation should be poured. Pieces of roofing material are laid on the dried layer to exclude the effects of water, and after that the pit is filled with a mixture prepared in the following proportion: one part of cement, fine gravel in the amount of four parts, 2.5 parts of sand and water. Using the level, the master must check the horizontalness of the base.
Expert advice
If you decide to build a foundation for a stove in a wooden house, then you can replace concrete with bricks. But the first option will be stronger and cheaper, however, if there is gravel and sand nearby. If necessary, the concrete foundation will be difficult to dismantle, but brickwork lends itself to such work much easier.
Brick oven foundation
If you decidelay the foundation for a brick oven, then you should prepare a pit, deepening below the soil freezing line. Its dimensions should be larger than the future foundation by 10 m along the perimeter. This will prevent the influence of soil movements. 15 cm of sand are poured to the depth of the pit, which is filled with water. As soon as the liquid leaves, the sand must be added to the desired level, and then again filled with water. After that, a brick battle or a 20 cm layer of stone is laid on the bottom. The preparation should be compacted and covered with sand, and then poured with water. This procedure must be repeated several times until the sand stops settling.
Before making a foundation for the oven, after all the above manipulations, it is necessary to pour a 10 cm layer of crushed stone, compact it, and make a formwork inside the pit so that 10 cm of free space remains between the boards and the sides of the foundation. There must be a reinforcing cage inside the formwork.
Master's recommendations
In order to choose the type of foundation, you should know the approximate mass of the future structure. For this, the weight of the bricks that will be used for construction is calculated. As a rule, heaters weigh more than 1200 kg, so they provide for a fairly massive foundation.
Method of work on the construction of the foundation for a brick kiln
Speaking of the above, it can be noted that concrete should be poured into the formwork. As soon as the solutiondry, the boards can be dismantled by applying tar in several layers to the sides of the foundation. The resulting free space should be covered with coarse sand or fine gravel.
Building a wooden foundation
Experts do not recommend building a wooden foundation for a furnace, but if you are interested in getting acquainted with the technology of its construction, then you should read the information below.
At the first stage, wooden poles are prepared and processed, which involves their antiseptic or firing. This will extend the period of their use, since soil moisture will affect the surface of the products. Next, the site is marked and cleaned, holes are dug, the diameter of which is 1.5 times the diameter of the prepared supports, and then a sand cushion is arranged.
This foundation does not do without waterproofing, after laying the layer of which the pillars are installed. To increase the bearing support area, such pillars should be placed on a concrete slab or cross. The next step will be backfilling, leveling the supports in a horizontal plane and waterproofing the ends of the pillars.
It is quite easy to build such a foundation for a furnace with your own hands, but the labor and time costs will be more impressive. This is also due to the fact that the wooden foundation will have to be additionally protected from moisture, as well as the increased influence of temperatures from the furnace.
Reinforced concrete slab on supports
The stove can also be installed on a reinforced concrete slab, the thickness of which varies from 15 to 20 cm. This design is laid on columnar or pile supports, which will depend on the depth of soil freezing. If the territory has clay soil with surface groundwater, then it is best to give preference to a slab foundation. Such a base should be arranged separately from the main foundation, and the gap between these structures should be approximately 5 cm.
Conclusion
If you prefer the columnar structure for the furnace foundation, then for its construction you will need four pillars, on which a reinforced concrete slab or a frame of steel profiles will be installed. Supports should be located at the edges. The pillars will help avoid seasonal ground movements that occur as a result of heaving of loamy and clay soils during severe frosts.
