The foundation for the house is columnar. Do-it-yourself column-strip foundation

Not so difficult to build, inexpensive, and most importantly, a strong and durable columnar foundation with your own hands can be erected under a building of any type. Usually, of course, such a solution is provided for small wooden buildings, frame houses or foam blocks. Nevertheless, it sometimes occurs during the construction of rather massive brick structures. In particular, this occurs when it is necessary to lay a fairly deep foundation, which in the case of c will cost at least 1.5-2 times more.

In some cases, for a rather modest light building, it becomes a kind of synonym for the phrase “unnecessary luxury”. And in fact, this is so, because it is quite expensive, and in most cases it is possible to equip a columnar foundation, which will be no less strong and durable.

First you need to figure out what a columnar foundation is. By itself, it is a support, which is significantly deepened into the surface of the soil, and protrudes somewhat above the ground. It should also be noted that without fail the upper level must be ideally the same for all supports. In addition, grillage equipment, which contributes to an even distribution of the load, becomes a prerequisite.

It should be noted a fairly extensive variation of the materials used when making the pillars, these can be:

1. Tree
2. Concrete
3. asbestos cement
4. rubble stone
5. Brick
6. Metal

Let's consider in more detail each of the types.

Wooden poles for the foundation

Today, such material as wood is quite rarely used for the manufacture of a columnar foundation, due to its low durability.

In particular, it finds application in the arrangement of small wooden buildings or in the construction of terraces. In this case, the diameter of each column should be 15-20 centimeters. Additionally, each support is treated with protective compounds before immersion in the ground, which contribute to increased resistance to moisture, corrosion and combustion. Additional waterproofing of the material is also provided; bitumen-based mastics are often used for it.

Pillar foundation made of bricks

The next type is the arrangement of supporting pillars made of bricks. In particular, brick-iron ore is widely used.

From such material, shallow and shallow foundations are equipped, which are used in the construction of light buildings on hard rock soils. A prerequisite is the implementation of pillars with a width of at least 38 centimeters (the column itself is square in shape).

Reinforced concrete poles

This option becomes the most common when arranging a columnar foundation, which is due to its reliability. When considering the type of such pillars, it should be noted that they can be either monolithic structures or made from already prepared concrete blocks. The width of such a column is equipped with at least 40 centimeters.

Pipe poles

And the last option is poles made of metal or asbestos-cement pipes. For the most part, the pipes themselves in this situation play the role of fixed formwork. Since the inner part is reinforced, after which it is poured with concrete.

Depth of the column foundation

The calculation of the laying depth itself depends directly on the type of soil, in addition to the level of its freezing. Thus, it can be divided into two types:

1. Shallow, the depth of which is 40 centimeters.
2. Buried, which plunges into the soil 20-25 centimeters below the freezing level.

It should be noted that the buried foundation is quite often used in areas where the level of soil freezing reaches two meters, since the provision of other types of foundations in this situation is not possible. In this case, a columnar foundation is arranged in a standard way with a laying 15-25 centimeters below the freezing level.

In this case, the optimal distance between the supports should also be taken into account, which also depends on the characteristics of the soil, and ranges from one to two and a half meters.

Grillage

Considering the arrangement of the grillage, which is carried out after a full-fledged installation of supports, in the case of using concrete, it is strictly a month after the completion of the pouring. It should be noted that either wooden beams or metal beams are used for it, which in the future will act as a mortgage screw.

Quite often recently, there is also a monolithic concrete grillage, which is poured over the pillars into a wooden formwork.

By itself, the grillage of the columnar foundation can be of two types:

1. Low, i.e. be placed directly on the ground.
2. High, which protrudes above ground level by at least 35 centimeters.

Arrangement of basements

It also becomes a rather important factor, in turn, the lack of the possibility of arranging basements becomes a disadvantage. In some individual cases, fences are provided between the posts to organize the fencing of the space. They are made of bricks, while a rather important condition is the lack of connection with the supporting structures, in order to avoid damage to their integrity.

It is also necessary to equip high-quality insulation and ventilation to ventilate the basement. But such an implementation is possible only in individual cases, since quite often the construction of buildings on this type of foundation is carried out with the building being raised to a height of 1-2 meters.

Calculation of the columnar foundation, diagrams and drawings

Initially, it is necessary to carry out a full calculation and draw up project documentation. The best solution is not to do it yourself, but to entrust this issue to specialists.

An approximate scheme of the columnar foundation is as follows:

Initially, a full-fledged calculation of the foundation is carried out, which will ultimately allow you to calculate the number of required pillars, their dimensions, depth, as well as installation locations.

To obtain the most accurate data, you need to fully explore the soil, finding out its type, level of freezing and its other characteristics. In the case of carrying out such a calculation on your own, it is recommended to use online calculators.

All data obtained during the study and calculations are entered into the project documentation.

So, it's time to consider directly the technology of erecting a columnar foundation

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

This type of foundation is a purely columnar structure with a grillage. The arrangement of such a bearing element is most appropriate for the construction of light structures on sandy soils.

All work is divided into several stages, including:

1. Carrying out earthworks.
2. Construction of foundation pillars.
3. Arrangement grillage.

Let's go directly to the beginning of work.

Excavation

The first step is earthworks. First you need to prepare the area. To do this, excess soil is removed and the surface is leveled.

Particular attention is paid to clay soils, in this situation it will be necessary to remove a fairly large layer of soil, and then arrange a lining of sand.

The next step is to mark the area. Pegs and building thread are used. With its help, in accordance with the working drawings, markup is carried out. The thread is pulled in two strips parallel to each other, while the distance between them should be the size of the supports and, accordingly, the grillage. Particular attention must be paid to the corners, they must be absolutely even (i.e. 90 degrees). In addition, the marking of the walls, their intersections and junctions is carried out.

Based on the working drawings, in places where poles should be equipped, wells are equipped with a drill. Its diameter can be from 15 to 40 centimeters. At the same time, if the depth of the pillars is more than a meter, then it is necessary to carry out additional fixation of the soil in order to avoid shedding. In our case, in addition to arranging the pits manually with a drill, it will be necessary to bring them to a square shape, for laying pillars.

After that, the bottom of the well is covered with sand, its layer should be approximately 10 centimeters. Next, a control reconciliation of the location of the wells relative to the axes, and their evenness, is carried out.

The last step of such preparation will be pouring concrete with a layer of 10-15 centimeters, which will serve as a solid foundation for arranging this type of foundation. You can start work immediately after the full drying of the concrete, which takes place within 28-30 days.

Construction of a column foundation

Now let's move on to construction. In this case, brick will be used to equip the pillars.

So, we lay out the basis on which we will be equal. It is made in the form of a square with parameters 38 * 38 centimeters. After that, we lay out the pillar itself along it, up to 50 centimeters high above the ground.

We form the pillar itself with a contour, so that there is free space inside. Further, reinforcement is carried out, while at least 1-2 rods are connected to each other and inserted inside (ideally, these are 3-4 rods). After installing the frame, the space is poured with concrete.

After the concrete center has completely dried, it is necessary to carry out waterproofing of the supporting structure. It is also necessary to check that all the pillars are on the same level. After that, the trenches are covered with soil.

In addition, thanks to its unique technology, the arrangement of a columnar foundation can be carried out using asbestos-cement pipes. Installation is carried out as follows:

1. The pipe is lowered into the prepared well, after which it is poured with concrete.
2. The next step is to raise the pipe a little so that the concrete can spread. This gives a good foundation and fixation.
3. The next step, not reaching 10-15 centimeters to the edge, the pipe is poured with an additional portion of concrete.

Arrangement grillage

Now we turn to the arrangement of the grillage. It can be done using wooden beams. In this case, each of them should rest on a pole with an edge, in addition, be linked to another beam.

In addition, the implementation of a reinforced concrete grillage is often found. In this case, a wooden formwork is arranged on top of the pillars, reinforcement is provided inside it, of the same type as for a strip foundation. Then it is poured with concrete.

Do-it-yourself column foundation: video instruction

Conclusion

First of all, it should be noted significant savings in the construction of this type of foundation. Since you can complete it yourself in a few days, you will need fewer materials than when building other types of foundations. In addition, there is no need to hire construction crews.

A little advice, it is better to finish the construction before the start of frost, or to provide for concrete slabs, since it is unacceptable to leave the foundation unloaded for the winter. This may entail pushing the pillars out of the ground, as a result of which the foundation will need to be completely redone.

As for buildings, this type of foundation is suitable for building garages, terraces, small and light houses. That's all, you can also get acquainted with the technology of building other foundations, and deal with their types in our other articles.

The foundation of the pillars is a universal option. Such a foundation is built without taking into account the type of soil, and it does not require serious work on waterproofing and insulation. Therefore, they decide to build a columnar foundation without a doubt, even without having the knowledge of a builder.

Unique foundation of "rods"

To understand what a columnar foundation is, it is worth considering in detail its pros and cons, tasks and device.

The column foundation differs significantly from the strip foundation, since it is not built around the entire perimeter of the building

Advantages and disadvantages of a columnar base

The indisputable advantages of the foundation of the supporting pillars are:

The disadvantages of the columnar foundation are attributed to:

All the minuses of the base of the pillars can not be considered as something important if you build this structure, taking into account its purpose.

The tasks of the construction of supporting pillars

It is advisable to build a columnar foundation for objects such as:

• a house without a basement with walls made of light materials;
• a brick building, which, for economic reasons, cannot be placed on a strip foundation and therefore is built on pillars sunk into the ground by 2 meters;
• a building erected in an area with soil prone to heaving due to low temperatures and, as a result, adversely affecting any foundation other than a columnar one.

It is reasonable to put only small houses made of light materials on the pillars, because the weight of other structures of the support will not withstand

It is better to abandon the construction of a structure from supporting pillars in the following cases:

• the soil on the construction site is weak or mobile, which can cause an insufficiently stable foundation to overturn;
• the land on the site contains a large amount of peat, sedimentary rocks or clay saturated with water;
• the house is planned to be built from heavy raw materials, for example, bricks more than 5 cm thick or reinforced concrete standard slabs;
• finances and time for arranging the basement are significantly reduced (when creating a columnar foundation, the basement does not form by itself, as happens during the construction of a strip base);
• the soil on the site for the construction of the house is characterized by a sharp difference in height (from 2 meters).

A columnar foundation can only be built on firm and even ground, since it is not perfectly stable.

View of the foundation from individual supports

The columnar support structure under the house is a system of pillars placed in the corners, in the areas where the walls cross and where the load-bearing walls or beams are located, which bear the weight of the entire building. In order for the pillars to function as a single structure and be as stable as possible, they are combined by means of a grillage - strapping beams.

The columnar foundation, constructed most often, is considered to be a structure made of monolithic reinforced concrete blocks.

The foundation can be made of concrete blocks, and the grillage can be made of wood

Usually the pillars are placed, leaving between them from 2 to 2.5 meters of empty space. But in some cases, builders go beyond the traditional option for arranging supports.

When the pillars are mounted in the ground every 2–2.5 meters, the grillage is created as a standard reinforced jumper. At the same time, the veranda, porch and terrace attached to the house are not combined into a single ensemble.

For places like the porch, separate bases are organized, separated by an expansion joint. This is a necessary measure, because the weight of additional premises is always different from the weight of the house, which is why the shrinkage of these buildings cannot be the same.

Usually the poles are placed at a distance of 2-2.5 m from each other

The distance between the posts is made large (from 2.5 to 3 meters), referring to the significant power of the strapping beams. The most reliable grillage is created in the form of a single or prefabricated beam. And a simple structure connecting the supports can be made of metal parts, such as channels or profiles.

Pillar base variations

What will be the columnar foundation, they decide, based on the amount of finance and the ability to independently engage in construction.

Block supports

The columnar foundation can be made up of concrete or reinforced concrete blocks, manufactured separately and mounted directly during the arrangement of the supporting structure for the building.

Each pillar of the structure can be assembled from separate blocks - a very reliable material

The GOST states that the blocks that will be used for the construction of the foundation must be made from concrete of a grade not lower than M-100. As for the size of the blocks, private developers are used to taking raw materials with parameters of 20 * 20 * 40 cm and a weight of 32 kg. Relatively light are considered foundation blocks made of expanded clay concrete - a material that is resistant to thermal effects.

Large block structures made of reinforced concrete can only be laid with a construction crane, because their weight can even be equal to two tons. Such blocks are reinforced with special reinforcement with a diameter of 9 to 15 mm and are used exclusively for the construction of tape and slab bases for huge brick buildings.

Most often, light small blocks are taken for the independent construction of a columnar foundation, since it will be possible to build supports from large raw materials only with the use of technology

The best depth for fixing a column of blocks in the ground is from 50 cm to 1 meter. If the type of soil and the weight of the building dictate other requirements, then it is more reasonable to build not a block foundation, but a foundation of asbestos-cement pipes filled with concrete. It is too difficult to lay blocks to a depth of more than 1 meter.

brick pillars

Having decided to build a columnar foundation of brick, it is necessary to purchase only red full-bodied ceramic building materials. This material meets all the necessary requirements: it is waterproof, extremely durable and frost-resistant.

Such a characteristic of a brick as frost resistance is considered extremely important. The higher the resistance to low temperature, the longer the building material lasts. For example, a frost resistance of 70 indicates that a brick will deteriorate no sooner than after 70 years.

For the construction of the foundation, it is customary to use red full-bodied ceramic bricks, because it is the most durable

Bricks can be used to build both shallow and deep columnar foundations. The depth of the first version of the foundation varies between 40 and 70 cm. And the deepened foundation is always set below the freezing level of the soil by 30–50 cm.

It is decided to locate the supporting structure at a considerable distance from the surface of the earth when the soil on the construction site is heaving and the groundwater level is unstable.

To make the base reliable, the brick supports of the columnar foundation must be created in 2 bricks

The main foundation pillars (supports standing at the corners of the outer walls and at the intersections of the inner partitions) are usually made in 2 or 2.5 bricks. In other cases, the pillars are allowed to be one and a half bricks and placed at a distance of one and a half or two meters from each other.

"Legs" made of wood

The base of wooden "legs" is the most economical option. Logs suitable for the foundation are easy to cut and process on your own.

It is customary to build a columnar foundation of wooden supports for a house for living during the summer or a tiny building made of wood.

Wooden poles are only intended for the lightest temporary structures, as they can break under excessive pressure.

The best raw material for creating wooden supports is pine, oak or larch wood."Rods" are cut out from the butt of a log with a diameter of 2 to 40 cm. Putting in holes, wooden pillars are fixed on the sides with bricks, stones or a compacted mound of rubble.

Sometimes wooden poles are fixed in place with concrete mortar. In this case, the pillars are immersed in liquid concrete by 10 cm. Another good fixator for wooden supports can be a cross, made of two plates 0.8 meters long, arranged in a crosswise position.

To fix the pole on the crosspiece, a spike is cut out in its lower part. It is inserted into a groove made in the central zone of the cross. Then the pillar is fixed on a kind of platform with scarves.

For reliable fixing of the post in the ground, a cross and jibs are used.

Wooden supports are supposed to be protected in a special way from decay. First, they are covered with clay so that a layer 1 cm thick is formed, then they are fired with hot coals. The last task is carried out slowly, making sure that literally 1.5 cm of wood is charred. Burnt pillars are treated with heated bitumen or tar and dried.

Under the outer walls, wooden supports are immersed in the ground to a depth of 70 to 120 cm. And the pillars to support the partitions inside the house are placed at a depth of 50 cm.

The main pillars of the wooden foundation are supposed to be immersed to a depth of 70–120 cm

Monolith

Buildings with 2 or 3 floors are preferably built on a columnar monolithic base. Such a foundation will not sag even under significant pressure.

The columnar monolithic foundation has been serving without problems for more than 100 years. Each pillar of this supporting structure is capable of supporting an object weighing 100 tons.

A monolithic foundation is considered the most popular design compared to other columnar foundations.

A monolithic base of pillars is made of concrete, reinforced with metal rods and poured into special forms - pipes or formwork. This foundation turns out to be unusually durable, as it is completely devoid of seams.

Do-it-yourself column foundation: step by step instructions

The construction of a columnar structure under the house is started only after the calculations have been completed and the construction site has been prepared.

Necessary Calculations

The calculation is needed to find out how many pillars are needed, and what they should be in size.

Before the computational steps, it is required to test the soil at the construction site - to drill a well with a depth of 60 cm below the level at which it is planned to install the foundation pillars. In the event that soil is found under the bearing soil, soaked with water and therefore weak, it is better to cancel the decision to build a columnar foundation. Poles under load in unstable ground are unlikely to be able to stand still.

The first well at the construction site should be a test one - to check the condition of the soil

Determining the load on the soil

After making sure that it is possible to build a columnar foundation on the site, you should find out what pressure the earth will experience. To do this, you need to determine the weight of the future home.

Calculating how the pressure on the ground will become after the construction of the house, the weight of the foundation should be added to the weight of the structure. To do this, it is necessary to determine the approximate volume of the structure and multiply the resulting figure by the specific gravity of the material. For example, for reinforced concrete, this figure is 2500 kg / m³.

Table: approximate values ​​of the specific gravity for building elements

Constructions	Specific weight, kg/m²
Walls
Brick walls (half a brick thick)	200–250
Walls made of foam concrete or aerated concrete blocks 30 cm thick	180
Walls made of logs with a diameter of 24 cm	135
Walls made of timber 15 cm thick	120
Frame insulated walls 15 cm thick	50
Overlappings
Basement and between floors on wooden beams (insulated with material with a density of up to 200 kg / m³)	100
Attic on wooden beams (insulated with material with a density of up to 200 kg / m³)	150
Concrete hollow slabs	350
Monolithic (from reinforced concrete)	500
Operating load for basement and interfloor ceilings	210
105
Roof including rafters, lathing and roofing material
With a roof made of sheet steel, metal tiles or corrugated board	30
With a roofing roof in 2 layers	40
With slate roof	50
Roofed with natural ceramic tiles	80
100
50
190

*When the roof slope is more than 60 degrees, the snow load is reduced to zero.

The total area of ​​the bases of the pillars

As soon as it becomes known how much the future house will weigh, they will find out the minimum required total area of ​​\u200b\u200bthe bases of all pillars. To determine this parameter, use the formula S \u003d 1, 3 * P / R 0. The number 1, 3 indicates the safety factor, P is the total weight of the building in kg (including the foundation), and R 0 is the calculated resistance of the bearing soil in kg / cm².

Table: approximate values ​​​​of the resistance of the bearing soil at a depth of 1.5 meters

An example of determining the number of base pillars

Let's try to calculate how many round supports will be needed to build a columnar base for a small frame-panel house with dimensions of 5x6 meters. At the same time, we take into account that the height of the first floor is 2.7 m, and the same parameter at the gable is 2.5 m. Also, do not forget to use data such as roofing material (slate), type of bearing soil (loam) and freezing depth ( 1.3 m).

The frame house can be installed on 10 pillars

The calculation of the weight of the building is performed as follows:

1. The area of ​​​​all walls is determined, taking into account the gables (72 m²) and their weight (72 × 50 = 3600 kg).
2. There is a total area and a mass of floors. Since the house has a basement and interfloor floors, their area is 60 m², and their weight is 6000 kg (60 × 100 = 6000 kg).
3. The operating load is also available on the 1st and on the attic floor. Its value will be equal to 12600 kg (60 × 210 = 12600 kg).
4. The roof area in our example is about 46 m². Its weight with a slate roof is 2300 kg (46 × 50 = 2300 kg).
5. We take the snow load equal to zero, since the angle of inclination of the roof slopes is more than 60˚.
6. Determine the preliminary mass of the foundation. To do this, we conditionally select the diameter of future pillars and their number. Let's say we have a drill with a diameter of 400 mm, and we will take this value. The number of pillars is preliminarily taken based on the condition - one pillar per 2 meters of the foundation perimeter. We get 22/2 = 11 pieces. Now we calculate the volume of one column 2 meters high (we deepen 0.2 m below the freezing depth + 0.5 meters rises above the ground): π × 0.2² × 2 = 0.24 m³. The mass of one pillar is 600 kg (0.24 × 2500 = 600 kg), and the mass of the entire foundation is 6600 kg (600 × 11 = 6600 kg).
7. We summarize all the obtained values ​​​​and determine the total weight of the house: P \u003d 31100 kg.
8. The minimum required total area of ​​\u200b\u200bthe bases of all pillars will be 11550 cm² (S = 1.3 × 31100 / 3.5 = 11550 cm²).
9. The area of ​​the base of one column with a diameter of 400 mm will be equal to 1250 cm². Therefore, our foundation must have at least 10 pillars (11550/1250 = 10).

If you reduce the diameter of the base supports, then their number will increase. For example, armed with a drill that creates wells 30 cm in size, you will need to install at least 16 pillars.

Preparation for construction

Before pouring the columnar foundation on the site, you need to take care of the following:

1. Clear the site of debris and remove a fertile layer of soil 30 cm thick.
2. Coarse or medium sand found under the removed soil should be taken as the foundation for the foundation, and clay soil, which is found no less than sandy, should be strengthened by filling it with a layer of two materials - sand and gravel.
3. Level the site for construction, eliminating bumps and pits, and check its horizontalness using a level set on a two-meter flat board.

   The evenness of the prepared area is checked with a rail

4. Bring building materials to the site and install a cast-off around the perimeter of the future building (pillars at a distance of 2 m from the building and boards nailed to them with marks for the size of pits and supports). The correctness of the breakdown of the center lines must be controlled by measuring the distance with a tape measure. In addition, it is supposed to check whether the corners of the foundation turned out to be straight in the form of a rectangle or square.
5. Break the plan of the future house on the site, that is, mark its parameters with the help of pegs.
6. Create holes for installing pillars (if necessary, make holes for wooden supports, you can use a drill, and in the case of installing reinforced concrete pillars, you should arm yourself with a shovel).
7. Fill the bottom of the pits with gravel and sand and moisten. Ready "pillows" need to be compacted and covered with polyethylene or roofing material.

   The bottom of the drilled pits is reinforced with hard material, for example, gravel.

Creating formwork for pillars

An excellent option for formwork for supports under the house can be a temporary structure made of planed on one side (the planed part is installed facing concrete) boards of any kind of wood, 25 to 40 mm thick, 12 to 15 cm wide and with a moisture content of not more than 25%.

Instead of boards, when constructing formwork, you can use chipboard, waterproof plywood or metal sheets. However, it is preferable to choose exactly the boards, since they adhere less to the concrete solution.

Wooden formwork of the columnar foundation is the standard option

The temporary auxiliary structure must be installed close to the walls of the dug well and perpendicular to the sole of the base. It is recommended to check the correctness of the completed task with a plumb line.

If boards were chosen as the material for the construction of the formwork, then it must be borne in mind that they must be thoroughly moistened with water. By ignoring this condition, you can get fragile pillars, because dry wood absorbs moisture like a sponge, and because of this, worsens the properties of concrete.

Roofing material formwork is an innovation

An auxiliary structure in the construction of a columnar foundation can also be a fixed roofing material formwork. This material performs several tasks at once: it serves as a form for pouring concrete and protects the supports from moisture.

Roofing material formwork is a good solution if the soil in the created well is dense and not crumbling.

To make an auxiliary structure of roofing felt, proceed as follows:

Features of pouring the foundation

If the home craftsman is a supporter of the traditional way of pouring the foundation, then in order to fulfill this mission, he must do the following:

Anyone who is not averse to alternative methods of building a foundation for a house can make a foundation using a TISE drill. The tool will allow you to create a column structure with a broadening at the base, which will provide a unique opportunity to support a heavier building or reduce the number of columns.

A pillar with broadening (according to TISE technology) is formed in stages:

Video: an example of the construction of a columnar foundation using TISE technology

Even one person can cope with the construction of a columnar foundation. For this work, you do not need to look for either equipment, or hired workers, or a large amount of materials.

A columnar foundation is a variant of a non-solid structure, which is used for the construction of light buildings, frame and panel houses. Its main advantage is the speed and simplicity of construction, the minimum cost of building materials. A step-by-step instruction for building a columnar foundation with your own hands consists of several main steps: calculating the number of pillars, breaking down the site, earthworks and building the foundation.

Table No. 1 Calculation of the number of pillars

The calculation is based on two indicators:

• ground resistance,
• bearing capacity of supports.

The first value is tabular, therefore it is selected taking into account the type of soil at the construction site (see table No. 1). It depends on it what section the pillars will have. The second is calculated, where the weight of the building is mainly taken into account. But since the support-columnar foundation is being built for light one-story buildings, the calculations can be simplified by taking the location of the supports as a basis. They must be erected at the corners of the building, as well as at the junction of partitions and external walls. Intermediate pillars are located in the range of 1-2 m between each other, depending on their cross section.

For example, if a solid concrete block measuring 390x180x190 mm is used for the construction of supports, laid in pairs, then the distance between the posts can be left 2 m. If one and a half bricks are used, then the spacing should be reduced to 1.5 m.

Materials for column foundation

The foundation structure of the pillars is built on dense soils, on heaving soils it is necessary to use a pile variety, tape or slab. Therefore, a columnar foundation is either a shallow structure, or laid 20-30 cm below the freezing of the soil.

It is erected from block materials (brick, concrete or gas silicate blocks, logs or timber) or in the form of a monolithic element by pouring concrete mortar into the formwork. The formwork can be collapsible or non-collapsible from pipes (plastic, steel, asbestos-cement).

Marking the locations of pillars, for example, a rectangular foundation, is an accurate drawing of the perimeter of the structure on the plane of the construction site. The main thing here is to set the corners of the structure at 90 °. Make it simple. It is necessary to take as a basis the rule of the "golden triangle", it is also the Pythagorean theorem. That is, one side of the angle should be 3 m, the other 4 m, and the distance between the ends of the sides, which is also the hypotenuse of a right triangle, should be 5 m.

The perimeter of the building is indicated by a strong string or twine, which is stretched between wedges driven into the ground at the corners of the building. You can finally check the correctness of the applied markup by measuring the diagonals. They should be equal in length.

Excavation

It all depends on what material the columnar foundation is decided to build from:

1. If these are block materials, then a rectangular hole is dug under them with a shovel. The depth is determined at the stage of calculations. Usually a block variety is a shallow or surface design.
2. If it is a concrete solution, then round wells are drilled under the pillars, for which you can use a garden drill. For example, a monolithic support with a cross section of 200 mm² and a depth of 1 m can withstand 3-7.5 tons of load, depending on the type of soil.
3. A monolithic structure can also be of rectangular section, for which it is necessary to construct a formwork of the appropriate shape for each pillar. The volume of excavation in this case increases greatly, because space is needed to install the formwork. Therefore, the size of the pits is increased by 40-50 cm on each side.

Construction of a columnar foundation

Consider all varieties separately, taking into account the building materials used.

Pits of square section are dug out, in them it is necessary to make a rammed pillow of sand 30 cm thick. This size is not chosen in vain. Sand of this thickness additionally performs the function of waterproofing. Through such a layer, water from below will not reach the foundation pillars.

Now about the assembly of blocks:

1. In the pits located at the corners of the building, one concrete block is laid. They are placed closer to the outer wall.
2. With the help of a string stretched between the blocks and a level, the blocks are set in the same horizontal plane. Usually, sand is poured under those that are lower, raising it to the required level (to the laces).
3. Next to the already laid blocks, one more is laid so that both elements form a single upper plane located exactly along the horizon.
4. Intermediate poles are laid and exposed along the stretched laces.
5. After that, the second row of blocks is laid on the masonry mortar on top of the first row, only across, so that a bandage is formed. Here the sequence is exactly the same: corner elements are assembled, a cord is pulled between them with horizontal alignment, and intermediate pillars are built up.

If the columnar foundation is built of brick, then the assembly technology is no different from the previous one.

Stone laying should be carried out with a bandage not only vertically, but also horizontally.

There are two methods of pouring, which differ from each other by the presence of formwork or the absence. If the soil on the site is dense clayey, then there is no need to install pipes in prepared wells. A piece of pipe is required only to form the basement (above the ground). It is important to line up the pipes with each other horizontally.

This must be done in exactly the same way as when placing pillars from block materials:

1. To do this, sand is poured into the well and rammed.
2. A piece of roofing material is twisted into a tube with a diameter equal to the diameter of the well, where it is inserted.
3. A pipe with a height equal to the height of the outer part of the support column is installed on top of the well.
4. Inside, you can install a reinforcing frame made of reinforcement. If the structure is light, for example, a gazebo or a summer terrace, then the armored frame can be omitted.
5. Concrete mortar is poured with tamping.
6. After 28 days, the foundation can be loaded.

If the soil on the site is soft (loose), for example, with a lot of sand, then it is better to install pipes in the wells. Their installation, exposure in a horizontal plane, pouring of concrete mortar are carried out in the same way as in the previous case.

This is a more complicated process, because it involves the assembly of the formwork, which must be dismantled and removed 7 days after the concrete has been poured.

1. A sand cushion is poured into the prepared pits.
2. Square formwork is assembled from boards or flat durable materials: plywood, OSB, metal sheet, corrugated board, etc. The main requirement for the design is strength, because the concrete mortar poured inside will press on the walls of the formwork with its weight.
3. A reinforcing frame of steel reinforcement is installed, which in shape is a cage with a step between the rods within 10-20 cm.
4. Concrete is poured and rammed.
5. After a week, the formwork can be dismantled, and the supporting pillars can be loaded after 28 days. During this time, concrete will gain its branded strength.
6. After stripping, the pillars are covered with soil with a rammer.

stone pillars

Natural stone, as a material for the construction of a columnar foundation, is often used. Its structures are durable and reliable. Purely technologically, stone pillars are cocked according to two technologies:

Masonry technology is considered difficult, because you have to select pieces of material according to size. Large stones are laid down. As the column rises, their dimensions can be reduced, but it is better that all blocks are the same. At the same time, the chipped surface of the stones makes it difficult to fit one element to another. The foreman must have experience in laying stones in poles.

In this regard, the rubble-concrete method is simpler, but in terms of the consumption of concrete mortar, it is unprofitable, because the mixture itself must fill all the voids between the stones. And this is a large volume. Concrete pillars are constructed using the following technology:

• formwork is going;
• a sand cushion is poured into it;
• stones are laid in one row;
• concrete is poured, which should fill the voids;
• the second row of stones is laid;
• concrete is poured;
• And thus up to the required height of the supporting column, or rather, to the upper edges of the formwork.

Any formwork method of constructing supporting pillars requires precise alignment of the formwork, both along the height of each element, and horizontally between all. To adjust the height of the pillars, the last layer of stones can be laid out from pieces of small sizes or by pouring concrete in a thick layer.

Video: Installing the formwork of the column, armo-frame and pouring the heel of the column foundation

Video 2: Backfilling and pouring the post

In the family of point-support foundations, the columnar structure looks like a black sheep. Unlike pile-screw schemes or variants 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 heads of amateur housing construction do not try to install columnar structures on a swamp or heaving base.

How to install a column foundation

But in fact, the columnar version has two remarkable features. The construction of a columnar foundation with your own hands is available even to beginners in construction, and the cost is about half the estimate for a shallow tape. If you have a need to build a hut on a sandy site, near a pine forest or on hard limestone 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, a bricklayer skill is needed. The last method from the listed list requires only time and a little patience in doing it yourself 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 for 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 in a suburban area with your own hands. For large and heavy buildings, the 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 a long and rather dirty job with mixing cement mortar, installing and strengthening columnar formwork, leveling and cleaning work surfaces. You can go the simpler way and buy ready-made blocks 40 cm long and 20x20 cm in section. A foam concrete block of the D1200 structural grade or heavy expanded clay concrete grades are best suited.

For heavier house options, granite blocks can be made. To do this, the blocks are cast on a manual machine for pressing cinder blocks with a filler of heavy rock. Such a block can withstand a load of 300-400 kg, which corresponds to the weight of the walls of a log house. If you have experience with do-it-yourself work 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, hollow massive blocks are cast on the machine in the form of a truncated pyramid with a reinforcing frame. A pin or threaded pin is laid in the upper base of the pyramidal columnar support, which makes it possible to tie the installed columns with a wooden bar or steel profile. It is enough to tamp and pour out a horizontal platform in order to install a finished foundation field of columnar supports along the stretched cords.

Do-it-yourself column foundation step by step instructions

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

• Preparation of a pillow and a pit at the place of marking a columnar support;
• Assembling the formwork to be poured with concrete;
• Installation of reinforcement into the formwork and pouring the form with concrete;
• Assembly and binding of the foundation.

Advice! It will take at least three days and three or four sets of detachable formwork to make the foundation field. If we proceed from the calculation that for one columnar support it will take three days to cure the concrete, then in a week you can make a columnar foundation of 8 supports with your own hands.

The best option for arranging the sole of a columnar block

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

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

In any case, to install the supports of the columnar foundation, it will be necessary 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 dumping mass is laid on the bottom of the pit in layers of no more than 10 cm, with each layer compacted with a hand or electric tool.

It is clear that for the manufacture of supports, formwork boxes of the same size are most often used. This allows you to get the pillars of the column foundation of the same height, but only under one condition - if the crushed stone pillow has the same height in all the pits. So the correct thing to do would be:

1. Dig the required number of mini-pits for the foundation supports, cut and level the walls so that the earth and the fertile layer do not fall on the gravel pad;
2. Drive a reinforcement bar into the center of the bottom part of the excavation of the future column, align it with the stretched marking cords of the foundation;
3. Pour the gravel-sand mixture of the pillow with the tamper of the mass. Sealing the cushion must be done with the utmost care, the main thing is to prevent displacement or deflection of the centering rod. We constantly check the height of the pillow by the distance from the cord to the plane of the filling along the clogged piece of reinforcement.

Installation of formwork and reinforcing cage

To obtain a homogeneous, defect-free concrete casting, it will be necessary to make a collapsible reusable box-shaped or tubular formwork. The inner surface of such a box is glued with a 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 to maintain the original shape of the foundation pillars.

Before installing the formwork, it is recommended to stretch the dimensional cords, along which you can 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 that 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 the formwork, the reinforcement is leveled inside the mold and fixed in a vertical position, after which it is possible to proceed to pouring the concrete mix inside the support.

Leveling and pouring concrete

Filling the formwork with concrete must be carried out as carefully as possible to prevent displacement of the installed support elements. The long columns of the foundation are poured in several portions, with the "punching" of each layer inside the support with a vibrator or manual rammer 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 column, which later allow fixing the strapping beam on the concrete surface of the support. The poured formwork is covered with a plastic bag to reduce moisture loss and prevent rainwater from washing out the foundation concrete.

Important! If you have made the formwork box high, but not rigid enough and strong enough, especially in the central or bottom part, then a situation may arise when 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 falls, which means that the height of the foundation column will decrease. Therefore, the shape of the formwork has to be poured a few millimeters higher than the calculated one. After about a couple of hours, the surface can be sprinkled with wet 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 a waterproofing bituminous 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 upper surface. After about a couple of days, until the concrete is of design strength, the plane of each support must be cut with a grinder or grinder along the horizon and height. Before starting the tying of the support of the columnar foundation, treat it with mastic and lay the rolled waterproofing. Then you can lay a wooden beam and knit it with the supports of the columnar foundation, but the erection of walls and further construction is allowed no earlier than a month later.

If you know how to build a columnar foundation with your own hands, you can safely start building any building on your suburban area, from a small greenhouse or gazebo to a huge wooden house.

Column foundation - features and varieties

When it is planned to build a wooden house, any outbuilding, a bathhouse or a garage, the question arises of what type of foundation to choose for them. Any person wants to spend less money on such an event and at the same time get a truly reliable foundation for future construction. The best option in this case is the arrangement of the foundation of a columnar type. It is the simplest to implement and relatively inexpensive.

The base we are interested in is suitable for any other object that does not exert strong pressure on the ground and does not have basements.

It is not recommended to erect heavy concrete or brick structures on such a basis.

The device of this foundation is quite simple - a certain number of supporting pillars are placed on the ground in places where the main load will be directed at the end of the construction of a house or other object. Such places include:

• piers;
• building corners;
• sections of the intersection of walls;
• heavy load-bearing beams.

Do-it-yourself columnar foundations can be made from natural stone and wood, rubble concrete, brick, concrete, steel and asbestos pipes, bored piles. It is prefabricated and monolithic. In the first case, the raw material for its construction is a "mixture" of stones, bricks and reinforced concrete blocks. The monolithic base is made of reinforced concrete, which provides increased strength of the foundation.

It is customary to divide columnar structures into two types, taking into account the degree of freezing of the ground on which it is installed, and the type of soil itself. From this point of view, the foundation is:

• Shallow - the pillars are mounted in the ground at 0.4–0.7 m. Experts advise making such a foundation when building buildings on rocky or sandy soil.
• Buried - the laying of supports is carried out to a depth that is 0.5–1 m lower than the soil freezing mark in a particular area. The pouring and installation of such a foundation is recommended for watery and clayey soils, where there is always a risk of erosion of the foundation.

Note that the do-it-yourself columnar foundation is built using the same technology. Next, we will look at how to independently make a columnar base using various materials.

Preparing for arranging a columnar base - important tips

First you need to decide on the type of soil that is available on your site where construction work is planned. After analyzing it, you can choose the type of foundation and the installation depth of the support pillars (see above). For a light gazebo, it will be enough to deepen the foundation by 0.4–0.5 m and make it from wood or asbestos tubular products. But a relatively large wooden house will need to be placed on a deeper (about 1 m) and powerful foundation, for example, made of concrete.

After that, you need to calculate the number of pillars that will go to the foundation device. They must be present in the center and at all corners of any building (even if, in your opinion, it is very small). A truly reliable foundation for the building will be guaranteed to you when the pillars are located every 2 m (vertically and horizontally) of the structure. The height of the supports is usually taken 0.3–0.5 m above the soil level. It can be increased when there is a possibility of a large amount of precipitation and flooding.

Next, we proceed to clean up the plot of land on which it is planned to fill the foundation. We carry out these works as carefully as possible - we remove all irregularities on the ground, remove debris, make gravel bedding of clay soil. Then we create a point plan of the planned foundation and mark on it the locations of all the pillars.

From the perimeter of the future building, you should also move away from four sides by 2 m to mark the territory from which you need to completely remove the surface earth layer (20–30 centimeters). This is done to eliminate the danger of germination under the construction of vegetation. And on the place chosen for construction, it is imperative to pour gravel or, after which you can start digging holes for mounting the supports of the columnar foundation.

Formwork for the foundation - how to do it quickly and correctly?

The most common and economical formwork is roofing material. It is she who is most often equipped in private courtyards during the construction of various structures. It is done simply:

1. We take a piece of roofing material of the required length (we are guided by the length of the column, and also add a little length to trimming by level) and twist it into two layers into a tube. It is best to wind the material on a template, for example, on a metal pipe (its cross section should be about 20 cm).
2. We securely fasten the resulting twist with wide packing tape. Sometimes, before this, the roofing felt blank is additionally wrapped with a stretch film, which increases the amount of rigidity that the formwork will have.
3. We take out the template from the resulting tube. In fact, the roofing material formwork is ready!

Instead of roofing felt, you can use glassine. The sequence of operations in this case will be similar to that described above. Also, formwork is often made of wooden panels, consisting of boards 15 wide and 4 cm thick. It turns out to be reliable and of high quality, but its cost, of course, is much higher than the design of roofing material. Fixed formwork can be made of asbestos-cement or steel pipes. Their diameter should be 10–20 cm.

After that, we proceed to the process of strengthening the columnar base. For reinforcement, it is necessary to use reinforcement with a diameter of 1.2–1.4 cm. It must be installed longitudinally. The function of horizontal jumpers will be performed by a metal wire.

If the foundation is made with a grillage (special slabs or beams - the supports of the future building), about 20 cm of reinforcing bars are left above the pillars. With their help, after pouring the concrete mixture, you can easily connect the grillage with columnar supports.

We make a columnar foundation from asbestos or steel pipes - you can do it!

In this case, a fixed formwork made of tubular products of a suitable section is required. The device of such a foundation is recommended for any buildings, including wooden houses. For work, you will need pipes with a cross section of about 200 mm or more if the building is heavily loaded (several floors, large area).

The step-by-step instructions for building the base are as follows:

1. We clean up the site.
2. We prepare cylindrical pits in which we install a reinforcing cage or pipes and fill them with earth, ensuring the fixation of the supports.
3. We fill the used pipe structures with a solution of concrete for one third of their length. This procedure is mandatory, it creates the required hydraulic cushion for the base.
4. We raise the pipes to a third of the height and pour the concrete mixture again, leaving about 15 cm of empty space on top.
5. We completely take out the pipes, and we compact the concrete mortar that remains in the pit and place a reinforced rod in its center.
6. Waiting for the concrete to harden.

We carry out a bunch of the base and the erected walls of the structure with the help of metal anchors. They should be attached to the lower wall beams and immersed in the left 15 cm cavity. You have made a reliable and solid foundation out of pipes. It is only required to finally concrete the structure.

Construction of the foundation of concrete blocks and wood - instructions

For frame private houses, various gazebos in suburban areas, saunas and outbuildings, you can make a base from blocks. In this case, the do-it-yourself support-columnar foundation is made of concrete elements with geometric parameters of 20x20x40 cm.

The block base device includes the following stages:

1. Site preparation.
2. Digging holes, sprinkling them with rubble and creating a sand cushion at the bottom.
3. Installation (by cement-based mortar) of concrete blocks.
4. Implementation of waterproofing measures (using a conventional roofing material laid on the surface of concrete pillars).
5. Plastering the surface of the blocks.

Block foundations cannot be built on horizontally mobile soils, water-saturated and peaty soils. It is also undesirable to put too massive buildings and structures on them.

You can also make a wooden base. But the service life of such a foundation will be objectively short. It can be increased by impregnating wood with special antiseptic solutions. But even in this case, the foundation will last a maximum of a couple of decades.

For such a foundation, it would be correct to use coniferous wood or oak piles. The pillars are immersed in the soil by 0.5–1.5 m. The cross section of the piles should be chosen more - from 20 cm. The construction is carried out according to a simple scheme:

1. We clear the area for laying the foundation.
2. We dig holes. Their cross section is taken 1.5 times the diameter of the wood supports used.
3. We mount wooden poles at the corners of the planned building, along its perimeter (every 2 meters) and at the intersection points of the walls of the structure.
4. We lay a layer (15–20 cm) of sand on the bottom and tamp it as carefully as possible.
5. We perform waterproofing of the lower part of the wooden supports (impregnation with oil, “wrapping” in 2-3 layers of roofing material or ordinary roofing felt, which it is desirable to glue with bitumen-based mastic).
6. We mount and align the posts vertically (use the building level).
7. We fill the voids between the pit and the pillar with broken bricks, large gravel and sand. These materials should be poured in layers and constantly rammed. The thickness of each layer is at least 10 cm.
8. We align (now in height) the installed supports - we cut off their tops in order to achieve a completely horizontal plane. This procedure is easy to do if you pull a cord over the posts.
9. We impose roofing material or a special waterproofing film on the ends of the columnar supports.

Your wooden foundation is ready! Feel free to install a wooden structure on it.