DIY concrete pillar foundation. How to make a columnar foundation with your own hands. Arrangement of basements

Depending on the type of soil located on the construction site, you have to choose the right type of foundation structure. If the soil is soft, mobile, with flooding or with a high level of groundwater, then a columnar foundation cannot be avoided. Despite the apparent simplicity of installation work, the process of constructing a columnar structure requires an accurate calculation of the load-bearing capacity of each support post. But among all types of foundations for a house, this is the cheapest in terms of material consumption, especially since it is possible to use various building materials for it. Let's look at step-by-step instructions for building a columnar foundation with your own hands.

Advantages and disadvantages of a columnar foundation

One of the advantages has already been mentioned; it is low-cost construction. You can also add to the advantages:

quick construction of the foundation;
there is no need to use construction equipment;
simplicity of the work carried out, so making a columnar foundation with your own hands is not a problem;
lack of additional measures related to thermal insulation of the foundation;
a columnar foundation can be easily repaired;
this type can be erected on frozen soils;
The service life of the pillars, if the technology is strictly followed, is up to 100 years.

As for the disadvantages, there are not many of them:

the load-bearing capacity is not very high, so it is recommended to build lightweight buildings on poles: wooden, frame, panel;
the stability of supports is reduced if they are erected on moving soils;
there is no possibility to organize a basement or subfloor.

Before you start making a columnar foundation with your own hands, you need to familiarize yourself with its classification, materials and carry out calculations.

General diagram of a columnar foundation

The general scheme of construction work can be outlined in several main stages. They are, in principle, no different from the construction of any type of foundation.

The load-bearing capacity is calculated taking into account the number of support pillars and the weight of the building.
A general drawing of a columnar foundation is made with an exact indication of the distance between the racks, the cross-section of the supports and the height of the protrusion above the ground level.
Preparatory work is being carried out: marking exactly according to plan, excavation with digging holes - wells, manufacturing reinforcing frames, adding cushions to the pits, waterproofing and installing frames. If there is a need, then the formwork of the base part is assembled.
Making a concrete solution and pouring it into prepared wells, followed by removing air by baying the mixture. If bricks or blocks are used as the material for the columnar foundation, then they are laid.

The entire assembly of a columnar foundation is a combination of pillars with a horizontal strip, which is called a grillage. It can be concrete, metal, wood, or be the lower crown of a log house.

As you can see, there are not many positions according to the diagram, which is why it is believed that it is not difficult to build a columnar foundation with your own hands.

Classification of columnar foundations by material

Like any foundation for a house, a columnar foundation must be strong and reliable. Therefore, for its construction, building materials are used that can provide the necessary strength and reliability. These include concrete, concrete blocks, bricks, stone, metal and some types of wood, which are used in the form of logs or timber installed vertically.

The choice of material is actually a crucial moment on which the quality of the final result depends. And if the task is to build a columnar foundation with your own hands, then you need to choose the right material for its construction. For example, it is believed that it is better to build monolithic structures on water-unsaturated soils, and prefabricated block structures on damp ones.

Monolithic reinforced concrete pillars

This is the most durable and reliable design. Such a foundation for pillars has high tensile and compressive strength. Of course, if you take into account the correct reinforcement. Moreover, if you correctly distribute the racks along the entire perimeter of the house, taking into account the required cross-section of the supports, then multi-story buildings can be built on such a foundation.

Let us add that a columnar reinforced concrete foundation is constructed in cases where it is necessary to pour it to a sufficient depth, and more often than not, below the freezing level of the soil. It perfectly withstands soil heaving, but is afraid of contact with groundwater. Therefore, care must be taken to waterproof the supports.

Asbestos cement pillars

Asbestos cement pipes are not often used for the construction of foundation pillars. Although they feel great in any soil. Their load-bearing capacity is not high, but it is not required, because the pipes in the foundation structure act as formwork.

Pole made of plastic pipes

The situation here is the same as with asbestos-cement. That is, plastic pipes act as formwork. They do not corrode and are not destroyed by water, so they do not require waterproofing. The only thing is that the supports need to be properly poured under the foundation. Namely: install a reinforcing frame in them and pour concrete mortar.

Made from bricks or blocks

Brick foundation pillars should be treated as the oldest known structures. From the history of European and Russian architecture, they are “long-livers”. Until now, brick pillars stand under huge buildings, and, apparently, they will stand for many more centuries. Because the choice of bricks was taken seriously in those ancient times. The highest quality burnt bricks were always used. Therefore, when building a house on a columnar foundation, this requirement must be taken into account.

As for block pillars, they are not inferior in strength to brick ones, of course, depending on the material from which the blocks are made. It is better to give preference to concrete blocks; cinder blocks in this regard cannot bear heavy loads, although they are used for light buildings such as a veranda, a bathhouse, and so on.

Block structures include pillars built from stone. Not a bad option, quite strong, but such supports cannot withstand the movements of the soil. Therefore, when building a house on a slope, it is better to abandon stone racks. As a replacement for them - foundations made of rubble concrete. This is when stones are poured into the prepared formwork, and then they are filled with concrete mortar.

Wooden pillars

Such a columnar foundation, like a brick one, has been used in Russia for a long time. Today it is not so in demand, but, for example, for bathhouses installed near a river or lake, they are often found. We must pay tribute to the correct choice of wood. The stronger it is, the longer the service life of the pillars. In this case, it is necessary to carry out protective measures very carefully.

Treatment of the entire column with antiseptic compounds.
Treating the part buried in the ground with bitumen mastics and gluing a layer or two of roofing material.

Doing all this yourself is not a problem, the main thing is not only to make protection, but also to install wooden supports under the pillars in the form of a board with a thickness of at least 50 mm and a width over the entire area twice as large as the cross-section of the pillar. The support boards also need to be protected from moisture and the negative effects of the soil.

Wooden racks are mainly used for light structures. although a hundred years ago boyar mansions of several floors were built on them.

Types of columnar foundation by depth

Frost heaving is the force that is taken into account first when designing a columnar foundation. This is a very dangerous pressure, which, if not installed correctly, can tear the foundation of the house. Therefore, a large number of options for building construction are considered from the point of view of the impact of frost heaving on the foundation structure.

The basic design rule states that the foundation should be laid below the soil freezing depth by 30 - 50 cm. And if this indicator is, for example, 1.2 m, then, accordingly, the laying depth will be equal to 1.5 - 1.8 m.

But often a light building cannot exert such pressure on the support posts to contain the forces of frost heaving. That is, even when laid to a great depth, the foundation will be subject to deformation. Therefore, when building a columnar foundation with your own hands, you must take into account that there are two more positions: shallow and surface.

Columnar non-buried foundation

A non-buried columnar foundation or a surface foundation are still the same racks, only their laying depth does not exceed 30 - 40 cm. Often they are simply built on the surface of the soil, having previously made a cushion and waterproofing. Designers classify this type as those foundations whose depth does not exceed a third of the soil freezing level. From our example: 120: 3 = 40 cm.

The construction of a columnar foundation of this type belongs to the category of the cheapest and most rapidly erected structures. As practice shows, they usually use a block modification using blocks, stones or bricks. But since the height of the pillars is not very large, which means their load-bearing capacity is also low, it is therefore recommended to increase the cross-sectional area of the supports. Minimum size – 40 x 40 cm.

Shallow columnar foundation

The name of a shallow foundation suggests that it is buried in the ground, but not to a great depth. In any case, not below the level of its freezing. Designers calculate the depth of their installation at the rate of 0.5-0.7 from the depth of freezing of the ground. Again from our example: 120 x 0.5 = 60 cm.

The main requirement for this design is not to touch groundwater.

Foundation with grillage

The columnar foundation unit - the grillage - has one single task - to distribute the load from the house evenly across all the pillars. As mentioned above, the grillage can be constructed of concrete, metal (channel or I-beam), wood (beam with a cross-section of 150 x 200 or 200 x 200 mm) or be a log from the first crown of a log house.

Attention! If the beam is a monolith with pillars, then during the construction of the latter, the ends of the reinforcing frame reinforcement are exposed, which are connected with a knitting wire to the reinforced belt of the grillage.

Step-by-step DIY construction instructions

Let's move on to the main question of how to properly make a columnar foundation with your own hands. The scheme of work has already been described above, where the first stage was carrying out calculations and drawing up a project. If a house is being built on a columnar foundation, then it is better to delegate this stage of construction to specialists. After all, in order to accurately make all the calculations, it is necessary to take into account a large number of different indicators and nuances. Eg:

type of soil on the site;
groundwater level;
soil freezing level;
the type of building, its number of storeys, what materials it is constructed from;
materials from which the foundation itself is supposed to be built;
additional loads.

Of course, you can use online calculators, but not for established homes. You can use it for baths, verandas, barns. And no one can guarantee that the calculations are 100% correct.

Marking and earthworks

So, if a building design is in hand, then the designers must link the foundation to the area. This makes it easier to find its location on the plane. Usually the reference is made to the boundaries of the site, indicating the distance from the foundation structure to these same boundaries. Therefore, before marking the pillars, it is necessary to set aside these same dimensions from the boundaries and determine the perimeter of the building.

To do this, two rows of strings are stretched along the boundaries of the building, which immediately determine the width of the foundation pillars. The rest is simple:

the turf is removed to a depth of 20 cm;
the installation locations of the pillars are marked: at the corners of the building and between them with the required distance, which is determined by the project;
Using a garden or electric drill, holes are made in the ground, the depth and cross-section of which are also determined by the project.

We must pay tribute that the drawing of the columnar foundation greatly helps in marking. Because it clearly indicates all the parameters of the future design.

Pillow device

The cushion is a layer of sand 20-30 cm thick, which is poured into the wells and compacted using improvised means. It can be a beam, a wooden slat, or a small section of log. Often a pipe is used, to the end of which a metal plate is welded.

The purpose of the sand cushion is to divert some of the water from the supports that gets into the ground. Next, concrete mortar is poured onto the sand, which will subsequently become a support for columnar structures. The thickness of the concrete layer is 10 - 30 cm.

The formwork must be dealt with carefully, because much will depend on what kind of soil is located on the construction site.

If the soil is clayey, that is, strong, then there is no need to make formwork as such, because the clay itself, like a monolith, does not collapse or collapse.
If the soil is weak and sandy, then formwork will have to be installed in the well. In this case, it is necessary to take into account what shape the designers have determined: rectangular or round. If the latter, then pipes are used as formwork: plastic, asbestos-cement or metal. If the first option, then the well will have to be expanded, made of a rectangular section, and formwork made of boards or other flat materials installed in them. This is a large volume of excavation work, so this form is used extremely rarely for buried structures.

As for the first position, usually a rolled-up roofing material is placed inside the shaft. It forms the walls of the foundation and will further serve as waterproofing. Formwork made of roofing felt is a mandatory attribute.

Attention! Regardless of whether the formwork will be installed in the well or not, it is necessary to form a pillar in the base part. This means that the formwork must be assembled here.

Reinforcement

Reinforcement of pillars is mandatory, because it is the reinforcement laid in concrete that makes it possible to restrain loads from the forces of frost heaving. In the project, the number of reinforcing bars, their shape of connection into the frame and diameter must be indicated. Therefore, the reinforcement is simply cut into pieces of the required length and tied into a frame. Its cross-sectional shape can be triangular, square or round. The main task of the assembly manufacturer is to correctly fold the reinforcing bars relative to each other at the required distance and clearly tie them together with wire.

After which the frame is lowered into the prepared well exactly in the middle. After which you can start pouring concrete.

Attention! The length of the reinforcement bars is trimmed taking into account that their ends will be attached to the reinforcement frame of the grillage. Therefore, the rods are cut 10-30 cm longer so that they stick out above the base of the pillars by this size.

Pouring concrete

The pouring of a columnar foundation must be approached from the standpoint of standard technology. The concrete solution is made using classical technology:

one part of cement grade M 400;
two parts of washed sand, without a large amount of clay impurities;
three parts of crushed stone with granules 5 - 40 mm.

The most interesting thing is that for a columnar foundation there is no need to prepare a large batch. And there is no need to fill all the pillars at once in one day, as is usually done when constructing a strip or slab structure. It is enough to calculate the volume for one column, make a batch and pour it.

For example, a pipe with a diameter of 150 mm is used as formwork, and it is installed to a depth of 1.2 m. It turns out that the volume of the empty pipe is equal to:

V = SxH, where S is the area of the pipe, and H is its length or installation depth. The area can be found using the formula: S = πD²/4=(3.14×0.15²)/4 = 0.018 m³. If converted to liters, it will be 18 liters. Essentially, these are two buckets of solution.

The pipes are filled with concrete, tapped on the formwork, and pinned to remove air. In this condition, the pillars should stand for 28 days. During this time, the concrete will gain its original strength.

Grillage arrangement

We will assume that the grillage will be monolithic according to the project. This means that under it you will have to construct formwork from any flat materials. It is done by weight, so supports made of bricks, blocks, boards, logs and other materials are installed under the lower panels. The formwork is assembled with a rectangular cross-section with complete and strong fastening of the panels to each other.

A reinforcing frame is placed inside it, usually these are two vertical gratings connected by 6 mm wire rod or 6 - 8 mm reinforcement. The reinforcement frame of the grillage must be fastened to the pieces of reinforcement protruding from the pillars. This unit of the columnar foundation is subject to serious loads, so the fastening of two reinforcement structures must be approached carefully. The concrete solution is poured with compaction and bayoneting. After 7 days the formwork is dismantled, after 28 days the foundation can be loaded.

Summarizing

As you can see, you need to approach the construction of a columnar foundation with your own hands with a thorough analysis of all stages of the construction processes being carried out. Miscalculations must not be allowed in the first place. Markings with large allowances cannot be applied. Wells must be accurately drilled to the required depth. Even a few centimeters can play a supporting role in extreme situations.

There is no need to talk about preparing concrete and pouring it. That is, the arrangement of the foundation is an integrated approach to its construction, where there is no room for mistakes and miscalculations.

Do-it-yourself columnar foundation step-by-step instructions

The technology for installing a columnar foundation with your own hands is not complicated, the main thing is to follow the step-by-step instructions, then you will have a reliable foundation

The secret to the popularity of a columnar foundation is that it is quite cheap and suitable for many types of buildings. It is quite easy to build a columnar foundation with your own hands.

This article tells you how to make a columnar foundation, the pros and cons of the foundation, which is better for a veranda, other wooden buildings or a house made of foam blocks.

More about columnar foundation

The basis of the house is the foundation, so you need to take the choice of its type very seriously. The pile foundation is one of the most popular.

Firstly, making a columnar foundation with your own hands is easier than any other type of foundation, and secondly, it is a less expensive option.

The support is made of concrete or wooden piles. They can be made of any material, depending on the weight of the house.

But you need to remember that the structure should not weigh very much, because the pile foundation is still not as strong as a monolithic or simple strip one. It is often built for wooden houses made of timber, since wood is a lightweight material.

This type may also be suitable for buildings made of foam blocks, but to a lesser extent, since this material is quite heavy.

But for a veranda and other small buildings, such a foundation is almost always suitable, you just need to check the type of soil - you cannot build a pile foundation on heaving soil.

Despite the fact that a pile foundation is suitable for almost all types of buildings, in some cases it is not recommended to use it.

For example, if the land on the site is very mobile and there is a lot of groundwater. It is still impossible to use these types of foundations if the total weight of the house is very large (if it is reinforced concrete).

If the site is located in a mountainous area, then the use of such a foundation is also impossible. A multi-storey building should not be built on such a foundation.

For all other types of buildings and soil, the construction of pile types of foundation is completely justified. It is especially good to use a pile foundation if a wooden building is planned.

When designing a building using a columnar base, the most important point is to determine the exact weight of the entire house (it includes furniture, residents, etc.) and the total load (pressure from the weight of the building, wind and snow).

It is also very important to know whether the support can withstand such pressure - then building a columnar foundation with your own hands will not be difficult. Calculation of a columnar foundation is a very important part of the design.

Pile foundations can be built from anything. For example, supports made of plastic pipes for sewerage are often used.

To build a columnar foundation with your own hands, step-by-step instructions are a necessary thing that it is advisable to have with you.

Conventional pile and support-column foundations

A simple pile type of foundation looks like several piles that stand in those places where the greatest load occurs (in the corners of the house, under load-bearing beams, etc.).

Columnar-type foundations are built for structures that do not have basements or cellars. This type of base is especially often made for wooden buildings made of timber. The supporting beams for such a foundation are laid on supports - piles or pillars.

The structure of such a base can be made of wood or stone. To build such a foundation for a house, use the butt part of a tree pillar (the part next to the root). Typically, the diameter of the butt part varies from 18 to 25 cm.

For verandas and houses made of timber, a wooden foundation is most often used.

In addition to the usual columnar foundation, there are several other types of foundations for a house. Among them, a monolithic pile base is distinguished.

Externally, it is a concrete base without seams. It is very durable, and this is its main advantage.

The second type is a prefabricated columnar base. It is built from stones, bricks and reinforced concrete blocks. The main advantage is that construction proceeds very quickly. But due to the not very reliable seams, this design is not particularly durable.

Columnar foundations differ not only in the principle of construction, but also in their depth. There is a shallow columnar foundation and a recessed one.

The first type involves deepening the supports from 40 to 70 cm. Typically, a shallow columnar foundation is made in an area with rocky or sandy soil.

At a recessed base, the supports go to a depth of 0.5 to 1 m, i.e. below the soil freezing zone. Often this type of foundation is made on clay soil, which has a lot of water.

There are other types of pile foundations, which will be discussed in more detail below.

The general construction technology is basically the same, as is the construction of a columnar foundation of any type.

One of the most popular types is the support-column foundation. Most often it is used for the construction of wooden houses from timber.

Its cost is quite low, so the support-column foundation is popular. Often, a support-column foundation is used to build a bathhouse or veranda.

The supports are installed at the corners of the building and under the walls into which windows and doors are built. The distance between the base pillars should be from 1.5 to 2 m.

If a bathhouse is being built, then a cushion of sand is formed, and then a support-column foundation is built directly on it.

The supports are dug into the ground, and then the next ones are attached to them to the desired height. The same method is used to construct wooden buildings from timber.

A columnar foundation is not suitable for a brick house. You can try to make such a foundation for a house from foam blocks, but you need to carefully calculate the columnar foundation so that the piles can withstand the load of the structure.

If the construction of a house is carried out from foam blocks, then everything needs to be calculated correctly so that the construction goes faster.

Sometimes a pile foundation is built from plastic pipes. It is usually made for external sewerage. Such a foundation is not suitable for a veranda or bathhouse.

Even though the supports are made of plastic pipes, they can last about 50 years.

In addition, they withstand frost well, and the base made of plastic pipes is quite strong, but at the same time light. The cost of plastic pipes can be different - gray ones are cheaper, orange ones are more expensive.

Features of a base made of pipes and with a grillage

A foundation with a grillage is often used for brick buildings. The advantages of this design are reliability and stability; such a base is less susceptible to any displacement.

In order for the base supports to hold better, a grillage is made between them (a sole that evenly transfers the load of the structure to the soil).

Quite often, a grillage is used for a shallow foundation.

There are low and high grillages. The first type is located above the soil level, and the second is done at some depth. However, both of these structures distribute the load of the structure well, so the house becomes stronger.

The most commonly used grillage is made of concrete or reinforced concrete. Wooden and metal grillages are used much less frequently and less often.

A foundation with a grillage is more suitable for foam blocks at home, since for this type of structure it is very important to correctly distribute the load. For a veranda this type will be too complex, although it depends on the type of structure.

Another popular type of foundation is a columnar foundation made of asbestos pipes. This type is one of the cheapest, like the columnar foundation.

The foundation using asbestos or steel pipes is erected using permanent formwork. This type of base is used for wooden houses made of timber. If you plan to have an attic in the house, then it is better to take asbestos pipes with a diameter of about 20 cm.

The technology for constructing such a base is not very complicated. To begin with, cylindrical holes are made in the ground, after which a frame of reinforcement and asbestos pipes are inserted into them.

Then, one third of the concrete mass must be poured into the hole, during which a hydraulic cushion is obtained. At the same time, the concrete mixture is leveled (using vibrocompression) and its remains are poured.

At the final stage of construction, it is necessary to treat the pipes with various waterproofing solutions, since the pipe can retain moisture that has fallen on it for a very long time.

It is advisable to immediately load such a foundation, otherwise the pipes may crawl out of the ground a little. It's not scary, but it's still better to put a load on them right away so that you don't have to level them later.

Such a base may be better suited for a foam block house. But first you need to make sure that the load will be optimal.

Otherwise, a house made of foam blocks may warp. But for wooden houses made of timber, such a foundation is more suitable, there are fewer risks. This base may also be suitable for a veranda.

Block foundation and strip base

The next type is a columnar foundation made of blocks. Making such a foundation with your own hands is not very difficult.

Most often, this type of foundation is used for wooden buildings - bathhouses, verandas or houses made of timber.

For a house made of foam blocks, this option may not be very suitable due to the fact that the supports are designed for small, lightweight buildings. But a columnar foundation made of blocks is much easier to build than a columnar foundation.

Most often, a columnar block foundation is made from reinforced concrete components. Such construction can be carried out very quickly, since the construction of the base is carried out according to the type of brickwork.

First, the area is properly prepared for construction, then a sand cushion is formed.

After this, waterproofing work is carried out so that the base does not deteriorate from water. Then the water supply is laid.

It should be remembered that this type of base is best secured with thick concrete mortar. Under no circumstances should it be diluted with water.

To make it stand even more firmly, you need to coat the seams that were formed during the construction process with a concrete solution.

It is especially good to make such a columnar foundation with your own hands for a frame house. For a house made of timber, this type may also be suitable, but here you need to know all the possible disadvantages.

The next type is a column-and-strip foundation. This type is monolithic and is most often used to build wooden houses.

To make a columnar strip foundation with your own hands, you use TISE technology (a special drilling rig for making wells).

To build a column-and-strip foundation, reinforcement is placed into the holes and then filled with concrete mortar.

The result is a pole that can withstand heavy loads (up to 15 tons). This type is called strip, because the construction technology is similar to the construction of a simple strip foundation.

Typically, wells are made 15 cm below the freezing area of the ground. This type of construction may take longer than other types because drilling is a difficult process.

In addition, the ease of work also depends on the type of soil and what time of year the laying is carried out. In winter, such work is almost impossible to do.

Another disadvantage of this type is that the lower part of each hole will have to be further expanded in order for everything to be correct.

After the wells are ready, reinforcement is placed in them and concrete is poured. But not completely, but by one third, in order to insert a piece of roofing felt (tar paper jacket) for greater strength of the base. When the concrete solution dries a little, you can pour the rest.

The advantages of such a base are that the supports can withstand a load of more than 10 tons, and they also tolerate low temperatures.

After this, a grillage tape is made, it is reinforced and secured 15 cm above ground level.

In addition to these types of foundation, you can make a columnar brick foundation with your own hands. This type is not used often because it is expensive.

However, brick supports can last much longer than wooden ones. This type can be used for wooden buildings or buildings made of foam blocks. However, the structure should not have more than two floors.

A pile foundation with a shallow depth is also quite popular. Its use is most advisable on slightly heaving or non-heaving soil.

If the house is built on rocky ground, then it is better that it be made of timber. Verandas are also sometimes built using this type of foundation.

This option is not very suitable for a house made of foam blocks, but you can always consult with specialists to make the right choice.

In the family of point-support foundations, the columnar structure looks like the black sheep. Unlike pile-screw schemes or options on bored piles, a columnar foundation cannot ensure the stability of a building on a slope or on decrepit peat soil. Even the most desperate amateur house-builders do not try to install columnar structures on a swamp or heaving foundation.

How to install a columnar foundation

But in fact, the columnar version has two remarkable features. Building a columnar foundation with your own hands is accessible even to beginners in construction, and the cost is approximately half the estimate for a shallow-depth tape. If you need to build a hut on a sandy area, near a pine forest or on hard calcareous soils, the easiest way to solve the problem of arranging the foundation is in one of the following ways:

From the above list, the first two options will require the use of construction equipment and handling equipment; for a brick scheme, the skill of a mason is required. The last method from the list above requires only time and a little patience in working with your own hands and following the recommendations of the practical guide.

Important! A cast columnar foundation can be safely called universal; if there is drainage and drainage on the site, it can be placed even on small slopes without the need to work with a grader to level the horizon on the site plan.

In fact, a columnar foundation is the best option for building a small summer kitchen, gazebo or bathhouse on a country plot with your own hands. For large and heavy buildings, a columnar foundation is weak and dangerous.

How to make a columnar foundation with your own hands quickly and easily

Casting concrete columnar structures will require lengthy and rather dirty work with mixing cement mortar, installing and strengthening columnar formwork, leveling and cleaning working surfaces. You can take a simpler route and buy ready-made blocks with a length of 40 cm and a cross-section of 20x20 cm. A foam concrete block of the structural grade D1200 or heavy expanded clay concrete grades are best suited.

For heavier versions of the house, granite blocks can be made. To do this, blocks are cast on a manual machine for pressing cinder blocks filled with heavy rock. Such a block will be able to withstand a load of 300-400 kg, which corresponds to the weight of the walls of a timber house. If you have experience working with your own hands with laying stone on cement mortar, then you can build 6-8 columnar supports in half a work shift.

In addition to standard rectangular blocks, massive hollow blocks in the form of a truncated pyramid with a reinforcing frame are cast on the machine. A pin or threaded rod is placed in the upper base of the pyramidal columnar support, which allows you to tie the installed pillars with a wooden beam or steel profile. It is enough to compact and fill the horizontal platform in order to install a finished foundation field of columnar supports along stretched cords.

Do-it-yourself columnar foundation step-by-step instructions

Casting foundation supports from cement is no more difficult than working with a shallow-depth tape, but the volume of concrete and earthworks is three times less. Most of the time is spent on the first columnar support, made with your own hands. From practice, it turns out that the next two columnar supports take the same amount of time as the previous one. The entire technology for arranging a columnar foundation comes down to five simple operations:

Preparation of the cushion and pit at the site of marking the columnar support;
Assembling the formwork to be poured with concrete;
Installing reinforcement into the formwork and pouring concrete into the form;
Assembling and tying the foundation.

Advice! To make a foundation field, it will take at least three days and three to four sets of split formwork. If we assume that one columnar support will require three days to cure the concrete, then in a week you can make a columnar foundation of 8 supports with your own hands.

The optimal option for arranging the base of a columnar block

The most serious problem with columnar foundations is not the weak load-bearing capacity of the supports, but their tendency to tip over when the lateral component of the load increases. Strong winds and uneven subsidence of the foundation, when some supports sink into the ground, while others are torn off by beams from the cushion, leads to tilting and overturning of the foundation pillars, as in the photo.

Therefore, when preparing a cushion for a columnar foundation, it is necessary to pay attention to the presence of reinforcement in the form of a backfill of gravel and soil. For columnar supports installed on the surface or in a slight recess, it is recommended to strengthen the base by expanding the support spot or use fungal types of pillars. In the latter case, the foundation structure can be made in the form of two independent elements: in the form of a round concrete platform, buried 10-15 cm into the ground, and a vertical support of a round or rectangular cross-section, connected to the platform by one reinforcement cage.

In any case, to install the supports of a columnar foundation, you will need to dig a pit to a depth of immersion plus 20 cm of sand and gravel cushion and 20-25 cm of a layer of large rubble or crushed stone material. The filling mass is placed on the bottom of the pit in layers of no more than 10 cm, with compaction of each layer using a hand or electric tool.

It is clear that for the manufacture of supports, formwork boxes of exactly the same size are most often used. This makes it possible to obtain columnar foundation supports of the same height, but only under one condition - if the crushed stone cushion in all pits has the same height. Therefore, it would be correct to do the following:

Dig the required number of mini-pits for the foundation supports, trim and level the walls so that the soil and fertile layer do not fall on the gravel bed;
Drive a reinforcement rod into the center of the bottom of the foundation pit for the future column, align it with the stretched foundation marking cords;
Pour the gravel-sand mixture onto the pillow using a compactor. The compaction of the cushion must be done with the utmost care, the main thing is to prevent the centering rod from moving or deflecting. We constantly check the height of the pillow by the distance from the cord to the backfill plane using a clogged piece of reinforcement.

Installation of formwork and reinforcing frame

To obtain a homogeneous, defect-free concrete casting, you will need to make collapsible, reusable formwork of a box-shaped or tubular structure. The inner surface of such a box is covered with plastic film, or materials with a laminated surface are used. Thus, a support with smooth and even walls is obtained. In addition, the internal coating of the formwork significantly reduces the swelling of the wooden structure and helps maintain the original shape of the foundation pillars.

Before installing the formwork, it is recommended to tighten the dimensional cords, which can be used to align and fix the wooden frame of the form with a minimum error. In addition to the horizontal supports of the walls, it will be necessary to install additional fixing wedges to prevent the formwork from floating under the influence of concrete pressure on the lower part of the wooden form.

At the next stage, a reinforcing frame is installed inside the wooden form, welded from 4 or 6 rods with a diameter of 8-10 mm, photo. Like formwork, the reinforcement is aligned inside the form and fixed in a vertical position, after which you can proceed to pouring the concrete mixture inside the support.

Leveling and pouring concrete

Filling the formwork with concrete must be done as carefully as possible to prevent displacement of the installed support elements. Long foundation columns are poured in several portions, with each layer being “punched” inside the support using a vibrator or manual tamper for 10-15 minutes. In total, it will take 35-40 minutes to fill out one support form. 2-4 studs are embedded in the concrete surface of the upper part of the post, allowing the strapping beam to be subsequently secured to the concrete surface of the support. The poured formwork is covered with a plastic bag to reduce moisture loss and prevent the foundation concrete from being washed away by rainwater.

Important! If you have made the formwork boxes high, but not rigid and strong enough, especially in the central or bottom part, then a situation may arise where the concrete mass crushes and expands the lower part of the foundation form.

The result is not a rectangular shape of the support, but a barrel-shaped one. Everything would be fine, but the volume of the form increases, and the level of concrete drops, which means the height of the foundation column will decrease. Therefore, the formwork has to be poured several millimeters higher than the calculated one. After about a couple of hours, the surface can be sprinkled with damp sand to reduce cracking and shrinkage of the foundation columns.

After the concrete mass has set, the formwork is disassembled and removed, after which that part of the support surface that will be under the soil layer must be treated with waterproofing bitumen coating. After 7-8 hours, the space around the columnar base can be covered with layers of a mixture of gravel, expanded clay and sand.

Conclusion

No matter how hard you try, a columnar base does not have a perfectly flat and horizontal top surface. After about a couple of days, until the concrete reaches the design strength, the plane of each support must be trimmed horizontally and vertically with a grinder or grinder. Before tying the columnar foundation supports, treat them with mastic and lay roll waterproofing. Next, you can lay a wooden beam and tie it to the supports of the columnar foundation, but the construction of walls and further construction is permitted no earlier than a month later.

A durable and inexpensive columnar foundation is usually built under buildings whose walls can be called lightweight - and these are wooden and panel baths, framed and made of foam blocks. But it happens that a zero level of this type is also laid under a heavy brick bath - when a deep foundation is needed and the strip foundation in this case can ruin. After all, columnar ones cost at least one and a half times cheaper than the last option, which, in fact, are good.

For a usually light and small bath, massive strip foundations are often akin to unnecessary luxury - but columnar foundations are much more suitable for such construction: both in price and in strength. Yes, the traditional structure of a columnar foundation does not require the presence of a basement - but the Russian steam room does not need one.

Budget column foundation with grillage

If you build a columnar foundation with your own hands, then the first thing you need to do is make an accurate calculation. For this purpose, it is necessary to calculate the mass of the bathhouse, and here it is important to take into account its snow load - in the Moscow region this is approximately 100 kg for each square meter of area. As well as the weight of the internal filling of the bathhouse: furniture, stove and people - that’s another 100 kg for the same meter.

By the way, if it is difficult to calculate the bearing capacity of the soil in a certain area, then it is better to proceed from this calculation: 0.5-0.6 kg per cm2. In fact, these are the parameters of a peat bog or an old drained swamp. In all other cases, things are much better.

Stage I. Making pits

The easiest way is to take a drill with a diameter of 25 cm and drill small holes in the ground - 15-20 cm. This will be the basis for making the lower part of the pillars. It must be reinforced with a fine mesh and filled with 200 grade sand concrete.

In the central part of the pit, you need to insert several rods of reinforcement so that they protrude no more than 10 cm from the pit. These can be old and unnecessary pieces of pipes, pieces of iron and debris.

And to prevent the cement lait from being absorbed into the soil, pieces of roofing felt or even ordinary plastic bags will help.

Stage II. Installation of pillars

A piece of asbestos-cement pipe with a diameter of 10 cm is taken, two reinforcing rods with a diameter of 1.2 cm are placed in it and the whole thing is placed on the “shoe”. You need to fill it with the same sand concrete, simultaneously compacting everything with another rod. On top is either a bolt or another piece of reinforcement.

Stage III. Second drilling

It takes about 4-5 days for the concrete to harden after the last steps. Next, you can begin the second drilling. To do this, you will need a drill - it makes a hole with a diameter of 30 cm and always below the calculated freezing depth. You need to quickly insert the resulting pillar into this opening so that it does not crumble. Its strength can reach up to 11 tons of load.

Stage IV. Construction of the grillage

The grillage for such a columnar foundation can be made from metal, concrete and even wood - here it’s up to you to choose what you like best. The only important thing is that the grillage itself hangs above the ground by more than 10 cm.

The main advantage of this type of foundation is that it is suitable for almost any bathhouse that is not very heavy - log, timber and frame. And it serves for a long time - at least a hundred years, and even when it stands in a swamp.

Solid support-column foundation

Of course, foundation pillars can be of very different materials - concrete, brick or stone. But the most popular today for individual construction is affordable and practical reinforced concrete.

So, this is how a standard columnar foundation for a bathhouse is built:

Stage I. Site preparation

It all starts with cleaning the area - for this, the entire top layer of soil is cut off, right along with the plants. Its thickness is usually a little more than 30 cm, and it cannot be left under the foundation.

If there is clay on the site, then you need to make additional gravel and sand backfill. Its thickness depends on the geological features of the soil.

Now all the unevenness in the landscape is removed, soil is poured into the holes and with the help of pegs and ropes you can begin marking for the future foundation.

Stage II. Foundation plan

Next, from the drawings to the land plot, you need to transfer the plan of the future bathhouse - where and what will happen. This can be done using standard materials, securing the axes and marking the main dimensions of the future foundation. How accurately everything is marked, the easier it will be to work later.

Stage III. Pit preparation

Pits for a reinforced concrete columnar foundation are dug either manually or using an excavator - which, of course, is both easier and more expensive. They will be located along the axes.

If the depth of the pit does not exceed a meter, its walls do not need to be strengthened. If it is more, you will have to dig with slopes and install fastenings from boards with special spacers.

The holes should be 30 cm greater than the calculated depth of the foundation - so that gravel and sand backfill can be used. The width is taken a little more than it will be - so that the formwork and spacers become free.

Stage IV. Installation of formwork

To make good formwork for a columnar foundation of a bathhouse, you will need planed boards up to 40 mm thick and 150 mm wide. Alternatively, you can use chipboard, metal sheets and moisture-resistant plywood instead of wood. The boards need to be placed against the concrete.

Stage V. Foundation reinforcement

Foundation pillars need to be reinforced in the longitudinal direction with A3 rods with a diameter of 12-14 mm. Horizontal jumpers need to be installed in increments of 20 cm - for this, wire with a diameter of 6 mm is quite suitable.

In order to then connect the pillars with a grillage through the reinforcement frame, it is necessary that the rods extend above the edge of the foundation by at least 10-15 cm. By the way, something more solid can also serve as a grillage - this is how a columnar-strip foundation is built, which has its own advantages, but, however, not always justified for a bath.

Stage VI. Pouring foundation pillars

Concrete must be poured into already installed pipes, which will then remain in the ground with the foundation.

It must be laid in layers - 20-30 cm, using hand vibrators for the convenience of the process. This will ensure the homogeneity of the mixture and remove all the air from the solution.

Stage V. Waterproofing a columnar foundation

The future foundation can be protected from moisture using the same materials as a strip foundation. These are cold and hot prepared mastics, adhesive membranes, roofing felt on bitumen - and all new and well-proven materials.

Stage VI. Construction of a grillage

A monolithic belt makes both a solid foundation and a columnar foundation made of blocks more rigid and stable. And it can be made from prefabricated reinforced concrete rand beams or immediately monolithic.

So, if a prefabricated belt is being made, then the jumpers need to be well connected to each other with scraps of reinforcement - by welding them with mounting loops. Next, the formwork and reinforcement cage are installed and everything is filled with M200 concrete.

As soon as the concrete hardens and becomes strong, and waterproofing is carried out, the sinuses of the pits can be filled with soil and the installation of floor slabs can begin.

By the way, in order to protect the underground space under such a bathhouse from snow and cold air, a fence is usually made between the pillars - a special wall, most often made of brick. There is no need to tie it to the pillars - after all, the bathhouse will still settle, and cracks may appear. And already in the intake itself technological holes are made for communications. Externally, all this is beautifully decorated with false panels and siding - that’s all.

For light small buildings, a columnar foundation is built. This is one of the cheapest types of foundation, which, in addition to minimal financial costs, does not require the involvement of specialists. It is easy to construct with basic construction skills. How to make a columnar foundation with your own hands? More on this a little later, first let’s look at what structures it is intended for.

Types of buildings

This type of foundation is installed for the following buildings:

gazebos;
terraces;
utility blocks;
garden houses;
summer kitchens;
garages and other similar structures.

A pillar foundation can support even frame one-story houses. As for high-rise buildings or buildings made of heavy materials, it is not suitable for them.

Advantages and disadvantages

The advantages of a columnar foundation include the ease of construction and the absence of the need to use special equipment. It is suitable for any type of soil, except for soil where underground waters lie close. To build such a foundation, complex landscaping work and large material costs are not required. The advantages include the high speed of construction, as well as the strength of the structure.

The disadvantages are the inability to withstand heavy loads and the inability to create a basement.

To build a pillar foundation with your own hands, you can use several different options for building materials, which is also a nice plus. Among them it is worth highlighting:

asbestos pipes are a convenient material, easy to use;
brick is durable and strong, but expensive, difficult to lay in a pit and can be deformed as a result of soil heaving;
wood is an economical option, easy to install, but has a short service life and requires a complex waterproofing system;
reinforced concrete is strong and durable, but difficulties arise in constructing the removable formwork required for the posts.

Thus, the columnar foundation can be prefabricated or monolithic. Experts recommend giving preference to a monolithic base. When constructing it, reinforcement must be used that can withstand heavy loads.

When using brick (prefabricated base type), repeated freezing and thawing of the soil will cause the posts to be pushed out. As a result, the seams will come apart, cracks will appear, and misalignment will occur. Based on this, it is recommended to build a columnar foundation using asbestos pipes and reinforced concrete.

Calculations

When calculating a pillar foundation, indicators such as the type of soil, the depth of soil freezing, and the weight of the structure are taken as a basis. They influence the strength of the future building.

Depending on the type of soil on which it is planned to build the structure, the design of the columns is selected. If groundwater is located close to the surface of the earth, additional measures are carried out with the involvement of specialists. If the groundwater is deep, there is no need to undertake any preliminary preparation, but can safely begin the construction process.

Much also depends on the level of freezing of the ground. The columns are buried below it. If you do not adhere to this recommendation, the foundation will deform in winter during frosts. Thus, if the soil freezing level is at a depth of 1 meter, the pillars are buried 1.2 or 1.5 meters.

The distance between the columns and their depth also depends on the type of foundation and the weight of the future structure. Under normal conditions, a distance of 2 meters should be maintained between them.

There is one more nuance. The posts must be installed at the most important nodes, which include external corners, junctions of internal walls and various intersections. This will increase the strength of the entire structure. The average installation depth of pillars in places of important nodes is 1.5-2 meters, but this value may vary depending on the site.

Preparatory work

Regardless of what material will be used, the preparatory work involves almost the same steps. It is necessary to create a drawing diagram, which indicates the exact distance between the pillars and the shape of the base.

Before starting construction, it is necessary to prepare the area. Do-it-yourself marking of a columnar foundation is done using a rope and several pegs. A turf layer up to 30 cm thick is removed from the area of land allocated for construction. Thanks to this, it will be possible to make a cushion of crushed stone and sand for drainage and protection from the germination of vegetation. Then you need to dig the required number of holes, for which a hand drill is used.

It is also worth considering another nuance. The cross-section of the pits is 10-15 cm larger than that of the columns themselves. This is done to provide space for various technological activities (brick laying, creating waterproofing).

The use of asbestos pipes: instructions for the construction of the foundation

After the preparatory measures, it is worth starting the installation of the columns. Sand and gravel are poured into the pits, which are subsequently compacted. Then asbestos pipes are used, the diameter of which is from 20 cm. They are installed at the bottom of the dug holes. 2-3 metal rods are necessarily placed in each pipe. They are pressed tightly into the ground by 15 cm. Ribbed rods with a diameter of 12-14 cm are used. This will ensure reliable adhesion to the concrete mixture. Every 50 cm of reinforcement should be tied with wire.

You should also indicate the required wire length. When calculating, you need to take into account 20 cm of reinforcement, add the depth of the hole and provide an additional 20 cm (for connecting vertical rods with horizontal ones installed along the perimeter of the base). These activities are carried out before pouring the columnar foundation with your own hands.

Then a concrete solution is poured inside the pipes and around them.

Before it has time to set, it is necessary to correct the evenness of the base using a building level. During hardening, the columns must not be touched. When the concrete has hardened, you can begin to create a horizontal component called a grillage. It uses prefabricated concrete blocks or solid structures made of reinforcement and concrete, as well as contoured with removable formwork (wood).

Monolithic pillar foundation: instructions

This method of constructing a pillar foundation differs little from the previous version. The difference is that vertical formwork should be provided in the dug holes.

They are removable type and burst between the walls. And only after this can you start making columns, for which a concrete solution is used. It is advisable to use cement grade not lower than M200. A mandatory requirement is the creation of reinforcement strapping inside the formwork. After that, the concrete solution is poured. It must be recalled once again that the length of the rods above the ground should be at least 20 cm.

When the concrete solution hardens, the formwork is knocked down, and measures are taken to waterproof the supports. In this case, it is advisable to use roofing felt, which is used to wrap the columns in 2 or 3 layers.

As mentioned above, the second component of a foundation of this type is a grillage. After installing the formwork, the horizontal and vertical rods are tied together, then the concrete solution is poured. When the grillages have hardened, it is worth starting to create waterproofing using roofing felt. Floor slabs are installed on top.

In the end, it is worth pointing out some nuances that you need to know before constructing a columnar foundation with your own hands:

to obtain a uniform consistency of the concrete solution and ensure greater structural strength, it is recommended to mix it in a concrete mixer;
the foundation must be equipped with a fence that can provide protection from gusty winds and snow drifts under the structure (it is created from rubble stone or brick);

The formwork is made from planed boards, the thickness of which is 3 cm or more.