How to make a foundation for a heavy brick furnace: step -by -step instructions

Our homes require a dependable and effective furnace to be heated, particularly in the winter months. In addition to being a sturdy choice, heavy brick furnaces also give homes a hint of traditional charm. To guarantee stability and safety, however, the foundation for a furnace of this kind needs to be built with great care and attention to detail. We’ll take you step-by-step through the process of building a sturdy foundation for your heavy brick furnace in this guide.

Prior to beginning construction, it is essential to comprehend the significance of a solid foundation. The foundation acts as the base on which the furnace’s whole weight is supported. Without a solid foundation, the furnace may eventually sink, shift, or even collapse, endangering the occupants’ safety as well as the integrity of the house.

Examine the area where you intend to install the furnace first and foremost. Pick a location that is easy to maintain, level, and well-drained. Steer clear of places where there is a high risk of flooding or soil erosion, as these can weaken the foundation. Check local building codes and regulations as well to make sure that any requirements pertaining to foundation construction are being followed.

After deciding on a location, the next step is to collect the equipment and supplies needed for the task. A number of materials are required, such as bricks, concrete blocks, mortar, rebar, gravel, sand, and cement. Your furnace’s weight and size will determine whether you also need additional reinforcements like support columns or steel beams.

After obtaining your materials, start by digging a trench for the foundation. The size and weight of your furnace, as well as the guidelines provided by regional building codes, will determine the trench’s depth and dimensions. In general, stability is ensured by recommending a depth of at least 18 inches.

Step 1: Determine the location and size of the foundation according to the dimensions of the brick furnace.
Step 2: Excavate the area to the required depth, ensuring a stable and level base for the foundation.
Step 3: Compact the soil thoroughly to prevent settling or shifting of the foundation.
Step 4: Install formwork around the excavated area to contain the concrete for the foundation.
Step 5: Mix and pour concrete into the formwork, ensuring it fills the entire space evenly.
Step 6: Smooth the surface of the concrete with a trowel to achieve a level finish.
Step 7: Allow the concrete to cure for the recommended time, typically several days, before proceeding.
Step 8: Once the foundation is fully cured, carefully remove the formwork to reveal the solid base.
Step 9: Check the levelness and stability of the foundation before proceeding with further construction.

Basic rules for laying the foundation

No matter what size you decide to use or the foundation option you select for the stove, there are a few fundamental guidelines that are important to follow:

  • The foundation for the furnace must be made independent, in no way related to the base of the whole house. Why? The fact is that during operation, the house can give a small shrinkage. Wow, he should not pull the furnace, as this can lead to its deformation, deterioration of traction and violation of the technical properties.

The general foundation and the furnace foundation are not connected.

It is possible to partially combine two bases in some situations by joining them with a single wall.

  • If both foundations (for the house and for the furnace) are located close to each other, you need to perform a sandy backfill between them with a thickness of 50 mm.
  • If the foundation for a common house is a strip, then the base under the stove should in no case with the walls in contact with this foundation.
  • When choosing a place under the stove and, accordingly, the 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 during the construction of the furnace does not fall into the ceilings and beams.
  • When calculating the size and depth of the foundation, be sure to take into account the severity of the overlaps and weight of the furnace with the chimney.

The density of the soil on which the furnace is built is influenced by the foundation’s dimensions in addition to the furnace’s actual size. Since the furnace’s primary load typically causes a chimney, it must be positioned closer to the base’s center when designing the furnace. This will lessen the likelihood of an uneven load and premature furnace shrinkage.

Stovers occasionally create a separate base for the pipe when designing a very large, massive stove with a stone chimney.

The material of the furnace affects the foundation selection as well. The depth will differ for a metal structure and stone; a brick furnace’s total mass is at least 400–500 kg, whereas a metal furnace weighs about 150 kg.

How to determine a stone furnace’s weight

In theory, a small metal stove can be installed independently without the need for foundational support, particularly if it is housed in a building with a tile monolithic base.

Crucial! The type of soil at the location must be ascertained prior to equipping the foundation beneath the furnace.

The size of the foundation is largely dependent on the soil’s density and the level of freezing. Nearly all of Russia experiences winters that are sufficiently harsh due to the country’s climate. As a result, the furnace’s foundation should be set down to the depth at which the soil freezes.

Another very important factor is the type of soil.

There are three possible kinds:

In areas with a high concentration of rivers, lakes, and reservoirs, sedimentary soil types are typically found. Here, it is preferable to entrust professionals with the construction of the furnace and house foundation, so the water passage point calculations should be completed.

Loam soil, which is a sand and clay mixture, is a common type in central Russia. Because clay predominates there, the soil is less malleable.

When building a foundation on such soil, difficulties and extra issues are typically involved because, in the dry state of loopy loamy, the sediment becomes viscous due to large amounts of frost and causes the soil to "go down" when it occurs.

As a result, in this instance, the foundation’s depth beneath the furnace needs to be greater than the freezing point.

On the other hand, in areas of forest, you must equip the base of the stove with a 60–90 cm thick sand pillow and lay the foundation beneath it below the freezing point of the soil.

Sadly, there are instances when you must build a house and stove on unstable ground despite the fact that rocky and engraved soil are among the most dependable types for foundation construction. To level this fact, competent construction of a solid foundation is necessary.

Types of the foundation

For a brick furnace, there are three primary types of foundations:

  • cement;
  • bottle;
  • On stilts.

Which foundation is better for the furnace, and what are their main differences?

We will thoroughly examine a number of construction options so you can select the one that best suits your needs.

The question of how much it is worth choosing to tear up the foundation is one that interests a lot of people.

You shouldn’t go overboard, but it all depends on the soil’s density and the heating structure’s weight. The pit’s depth of 80–100 cm is the best choice. Certain artisans choose the less-resisting route, excavating solely the earth’s vegetative layer, constructing a 20-cm-tall formwork, and then pouring concrete mixture into it. However, this is a poor choice.

Several hundred kilograms of pressure are applied to the foundation; this load is particularly high in the winter when the soil freezes. As a result, you shouldn’t be stingy and put off paying for the foundation’s arrangement, since this is what determines the furnace’s strength and dependability.

Tools and materials for the construction of the foundation

Purchasing the required equipment is the first step towards beginning construction work.

The following tools should be ready because the work will require both carpentry and earthwork:

  • Bayonet shovel (will need to dig the main pit).
  • Sutual shovel (it is convenient to prepare a sand-cement mortar).
  • Hammer.
  • Hacksaw or saw.
  • Sieve for sifting cement (cell size 1*1 mm).
  • Sieve for sifting sand (cell size 2*2 mm).
  • Water bucket (for the preparation of cement-sand mortar).
  • Metal trough in which we will prepare the solution.
  • Building level.
  • Roulette and pencil.
  • Stapler.
  • Concrete mixer.

Of the supplies that are required:

  • Boards (for the manufacture of formwork).
  • Polyethylene (for waterproofing formwork).
  • Sand.
  • Cement.
  • Gravel.
  • Reinforcing mesh or rods.

We begin to fill the foundation for a brick stove with our own hands

Foundation for a brick stove

Step 1. Marking for the foundation and pit

  • After you have decided on the location of the future furnace, it is necessary to correctly calculate its size, based on the power. It depends on the area of the room, the number of doors, the window, etc.D.

Marking the foundation’s location on the ground

Excavating the well

Step 2. Installation of formwork and reinforcement

    We proceed to the construction of formwork from the boards. For formwork, in principle, any old boards or plywoods that are in the household are suitable. This does not affect the technical properties of the foundation.

Penciling beneath the range

Ruberid for water-proofing

Tools for reinforcement

Reinforcement and formwork

Step 3. Preparing a concrete mixture for filling the foundation

In order to prepare the mixture, we take one part cement and three parts middle fraction crushed stone for every four parts sand.

Using a bayonet, thoroughly mix a dry mixture before adding water. Use a concrete mixer to thoroughly knead the mixture. It should have a consistency similar to thick sour cream.

Preparing a concrete solution

Pour this mixture into the pit, making sure it is not 8 cm above the base floor. Within a day, these tasks must be completed. Concrete solutions should be integrated rather than layered.

Pour and bide your time. two weeks

You must check the horizontal coating level by the construction level once more after filling the foundation pit completely with concrete. It will be more challenging to fix your mistakes once the solution has fully dried.

Verify the horizontal foundation’s construction level.

Lay a layer of roofing material or polyethylene over the foundation and let it dry completely for two weeks.

Only after the formwork has completely dried can the upper portion be removed, using a hammer to repel the boards. Fill the resulting hole with crushed stone and sand, then compact thoroughly.

We make the foundation for a metal stove with our own hands

If the furnace is installed in a pre-built home where this appliance was not anticipated beforehand and the wooden floors have already been fixed, some flooring will need to be partially disassembled before foundation construction can begin.

The metal stove’s foundation

  1. Make markings on the floor with a construction marker, depending on the size of the furnace. The base should exceed the oven by 7-10 cm on each side.
  2. Using a grinder, cut a rectangle in the floor.
  3. Swarm with a bayonet shovel with a depth of 50 cm.
  4. We pour gravel and sand to the bottom of the pit, tightly tamp and pour a little water.
  5. Create a formwork of boards or plywood sheets and lay 1 layer of roofing material around the perimeter.


As you can see, this is a less complicated method of laying a foundation that doesn’t need to be as meticulously prepared or reinforced with a grid. Given that a metal structure weighs only 150–170 kg, a strong foundation is not necessary.

Watch this video to prevent serious mistakes when building the foundation beneath the furnace.

Video: the foundation for the stove, basic rules

Option to create a bottle -concrete foundation for the furnace

  • The first steps are performed similarly to the previous method: the foundation pit breaks out, formwork is installed and waterproofed with polyethylene (or roofing material).

The button foundation’s scheme

An illustration of a concrete and bottle foundation

Taking out the formwork

Installation of a pile foundation with a stove

A pile structure is one type of furnace foundation that is popular because it is simple to install and has good reliability.

The stilt-based foundation

  1. We make markings on the ground according to the size of the future furnace and measure 10 cm in each direction – this will be the size of the foundation.
  2. Remove 20 cm of a plant layer of earth with a bayonet shovel.

The earth’s vegetation layer was eliminated.

Stove foundation made of piles

Creating an armature by knitting

The foundation’s reinforcement

Gilses made of roofing materials

For a heavy brick furnace to be stable and safe, building a foundation is an essential first step. You can build a sturdy foundation that can bear the weight of the furnace and endure over time by according to these detailed instructions.

Priority one should be given to selecting the ideal site for your furnace foundation. To avoid any problems with settling or water damage, choose a location that is level and has good drainage. Consider things like accessibility for maintenance and proximity to combustible materials.

Preparing the ground comes next after you’ve chosen the spot. Remove any debris, rocks, or vegetation from the area. Using a shovel, dig a hole deep enough to hold the foundation while keeping the frost line and regional building codes in mind.

Now that the hole has been dug, the foundation’s concrete can be poured. Pour the concrete into the hole after mixing it in accordance with the manufacturer’s instructions. Make sure the surface is level and smooth with a trowel. Before moving on to the following step, let the concrete cure completely.

The furnace base bricks can be laid once the concrete has hardened. Make sure the bricks are level and spaced evenly before cementing them together with a mortar mixture. To guarantee a strong and stable foundation for the furnace, take your time with this step.

After the base is finished, you can start constructing the furnace walls with thick bricks. Once more, join the bricks with mortar, being careful to leave gaps for ventilation and airflow. To make sure the walls are sturdy and safe, pay close attention to the details.

After the furnace walls are installed, you can add any last details, like decorative pieces or insulation. For your furnace to operate as efficiently as possible and to retain heat, insulation is extremely crucial.

Your heavy brick furnace is prepared for installation and years of use now that the foundation has been completed. Your home can have a reliable, efficient, and safe heating source if you pay close attention to detail and follow these step-by-step instructions.

The purpose of this article is to walk you through the process of building a sturdy foundation for a heavy brick furnace so that it is safe and stable for your house. We’ll cover every aspect, from site preparation to foundation installation and brick securing. Regardless of your level of experience with do-it-yourself projects, following our instructions will enable you to build a stable foundation that adequately supports your furnace. You’ll be well on your way to having a warm and comfortable house with an effective heating system if you adhere to these simple and understandable instructions.

Video on the topic

The correct foundation for the stove

The foundation for a brick furnace – how to prevent errors when laying

The foundation for the stove

The foundation for the stove/fireplace, the recommendations of the stove, which should be taken into account when laying the foundation 2024

1. The foundation under the stove.

What type of heating you would like to have in your home?
Share to friends
Michael Kuznetsov

I love to create beauty and comfort with my own hands. In my articles I share tips on warming the house and repairing with my own hands.

Rate author
Add a comment