The choice of foundation for a house or other building is influenced by many factors. For each specific case, a different foundation design can be used. In first place in terms of frequency of use is the strip structure; for unstable soils, a pile foundation is common. Quite easy to build columnar foundation with your own hands, which in some respects is not inferior to the listed base options. This design has its own variations and nuances in the bookmark. Each of these points will be discussed in the article.

Benefits of the solution

During the use of this type of foundation design, users and builders managed to compile a certain list of positive qualities that were identified. Among them are:

• possibility of independent design;
• relative simplicity of calculations;
• possibility of use on various types of soils;
• Possibility of use in areas with level differences;
• the ability to avoid site planning;
• high construction speed;
• long service life;
• relatively low project cost.

Perhaps these nuances do not apply to all types of columnar foundation designs, but for a classic structure with a concrete grillage this is exactly the case. There are also disadvantages, of which there are significantly fewer. One of them is the impossibility of constructing heavy buildings whose walls are made of brick. The latter is capable of exerting significant pressure on the base, which often leads to destruction. This occurs due to shrinkage, although on an industrial scale this foundation design is used for brick buildings on soils with permafrost. Another unpleasant point is the inability to build a basement or garage directly under the house, since a foundation of this type does not provide for laying monolithic design to great depth.

Note! Columnar foundations are most often used for the construction of structures that use gas-filled blocks or are made using frame technology. Construction of buildings made of rounded logs is also allowed.

Types of designs

The design of a columnar foundation will largely depend on the specific building it will be used for. If we are talking about an ordinary gazebo, then its dimensions will be significantly smaller than those needed for a bathhouse or cottage. Based on the material used, the types of columnar foundations can be divided into:

• monolithic with a concrete grillage;
• monolithic with a wooden grillage;
• brick;
• bud-filled;
• rubble concrete;
• wood;
• monolithic from asbestos pipes;
• columnar-pile.

The first design option is the most durable. This is due to the fact that the pillars and grillage are a single structure that is capable of evenly distributing the load exerted on all pillars. This design is more expensive than others, but will last much longer. Such a columnar foundation allows the construction of houses of several floors using frame technology or from logs. The next version of a columnar foundation with a grillage is made using a similar technology. Its pillars are also filled with monolithic concrete with reinforcement, only wooden beams are laid on them, which are the basis for the walls of the structure.

Most often, when they talk about a columnar foundation, they mean the third design option, which is laid using bricks. Unlike previous options, a columnar brick foundation is quite simple to construct and requires relatively lower costs. With good soil quality, as well as the right approach to construction, a service life of several decades can be achieved. Many ancient buildings that have survived to this day were built precisely on this type of foundation. In some areas, it is possible to build a house with several floors on a foundation of this type.

Note! Other types of blocks can be used as the basis for a brick foundation. In this case, the strength and stability of the base will depend entirely on the quality and strength of the material used.

A rubble-filled columnar foundation is laid using brick or stone from old structures. This solution is suitable for stable soils and for areas where there are no level differences, since the stability of such a foundation is significantly lower than that of previous options. The base of the structure made of rubble concrete is also built using the materials mentioned above, but the connecting link in this case is cement mortar. The result is a monolithic, but not reinforced structure.

The wooden base of the structure is now practically not used, but it still remains relevant for areas where it is necessary to raise the structure to a considerable height in order to avoid flooding. This applies to warm parts of the world. A similar method was used in other areas, but proper implementation requires special treatment of the wood to prevent rotting and drying out. A wooden columnar foundation is an excellent solution for additional buildings near the house. This applies, for example, to terraces. In addition to antiseptic impregnations, wood is also coated with waterproofing material. As the latter, bitumen mastics are often used.

Another interesting design option is a foundation made of asbestos pipes. Most often, it is manufactured using a solution similar to a monolithic columnar solution. In this case, the pipes act as formwork, into which reinforcement rods are inserted and concrete solution is poured. Usually a pipe with a diameter of 20 cm or more is used. A column-pile foundation is made using screw or other types of piles. In the first case, no special equipment will be needed to build the foundation, except for a concrete mixer. Screw piles can be installed in place by a small crew of three people.

The advantage of this solution is the greater stability of the structure base. This is due to the fact that the pile is immersed to a considerable depth, which passes the freezing level and reaches dense layers of soil, where fixation is carried out. The design with screw piles can be used for a log house or a frame house. If we are talking about bored piles, which are intertwined with a metal frame with a concrete grillage, then such a foundation is used when constructing houses from blocks.

Varieties by depth

The difference between foundations is made not only by the materials that are used to lay them, but also by the depth to which the foundation is mounted. To put it simply, then, as with strip foundations, there are two types:

• shallow;
• buried.

In the first case, the immersion is usually 50 or 80 cm, which somewhat reduces the cost of equipment for the base itself. This support structure is used for buildings that are light in weight. A recessed structure involves the use of supports that go 150 or 200 cm into the ground. This depends on the level of freezing. This design is more preferable for areas where there is heaving soil or high instability of the upper layers. In addition to the depth of the foundation, the height at which the grillage is located also varies. In this regard, the following are distinguished:

• aboveground;
• ground;
• buried.

Above ground foundation design options are great for cases where the top layers of the soil are different high degree heaving. If the grillage is laid directly on the ground, there is a possibility of distortion or damage. In the case of constructing an above-ground version of the structure, the pillars are made of greater height in order to raise the grillage to a certain height. The disadvantage of this solution is the need for additional floor insulation. This is due to the free ventilation of the space under the house. Usually the sides are closed and only small openings are left for ventilation.

The ground version of the structure is built on a prepared bed of sand and gravel. It is placed so that it is flush with the surface. On the one hand, this eliminates strong blowing, as is the case with the above-ground version of the structure, but on the other hand, for such a structure there is a need for a correct approach to waterproofing. The shallow version of a columnar foundation is very similar to a similar strip foundation, but additionally, supporting elements in the form of pillars or piles are prepared in the trench, which are sunk to a considerable depth. The second and third options are most often implemented using a concrete grillage.

Basic Concepts

Almost all types of columnar foundations have one principle according to which they are constructed. Certain nuances are important to consider in order to achieve success. Among them:

• pillar pillow;
• heel support;
• column design;
• arrangement of columns;
• grillage device.

If we are not talking about pile supports, then preliminary backfilling must be done under the posts. For these purposes, medium-grained sand is usually used. The thickness of the pillow itself depends on the amount of moisture in the soil, as well as the expected weight. It can reach 30 cm, and the minimum permissible value is within 10 cm. If additional drainage is required, then an additional layer of crushed stone is laid under the columns, which allows water to pass through faster than sand. The functional purpose of such a pillow is to uniformly distribute pressure, as well as reduce the level of humidity under the posts.

For monolithic columns, which are made by pouring, soles are made, which are a small concrete slab with a thickness of up to 50 cm. It is wider and longer than the supporting column in order to increase the interaction area. The next nuance of such a foundation is the need for reinforcement. If we talk about a monolithic foundation, then there are no questions regarding reinforcement, but this also applies to other options. Only in this case is external reinforcement carried out, which eliminates the deformation of the columns. To prevent moisture from rising to the grillage and the building, it is necessary to approach the issue of waterproofing correctly.

It is important to correctly determine the number of columns in the foundation and distribute them throughout the area. This will determine how the load will be distributed. The projection of the posts above ground level will depend on the placement of the grillage, as well as the topography of the site. In some cases, owners of houses on columnar foundations prefer to make a fence. This is an additional concrete structure that is placed between the columns to cover the underground space. Reinforcement is also required for it. The fence for the columnar foundation further strengthens the entire structure.

Note! In areas where flooding is possible, the height of the pillars can reach up to 2.5 meters above ground level. The calculation is based on the maximum level to which the water rose in the area.

Self-calculation

The key to successful completion of the construction of the structure is the calculation of the columnar foundation and preparation of the project. They begin even before the process of preparing and planning the site for the foundation. It is better if a professional in his field provides assistance in drawing up the project. Thanks to this, it will be possible to take into account all the nuances that relate to the soil and the expected load. The wishes of the customer himself are also taken into account. The main initial parameter for drawing up a design project is the area allocated for the building. Next important indicator is the mass of the structure. To correctly draw up all the documents, you will need a geodetic survey of the area and linking the future structure to a specific site.

During the design, the following points will also be taken into account:

• soil specifics;
• proximity of aquifers;
• soil freezing level;
• number of floors;
• materials for construction;
• possible additional loads.

The first and second factors will determine the required depth of columns or piles for the foundation structure, as well as their level above the ground. The third factor is necessary to determine below what depth the supporting elements of the foundation should be located. The number of floors affects the number of supporting elements, as well as the choice of material for construction. Additional loads that may be caused by wind, changes in soil or precipitation are taken into account. All these factors give a clear understanding of the number and parameters for the pillars of the future foundation.

With sufficient experience, you can try to perform the design work for the structure yourself. To do this, you will need to collect all the data relating to a specific area. They can be found on the official websites of various services or obtained directly from the services. When taking readings, knowledge of many formulas will be required. But even the use of online assistants may not help, since important factors that can only be assessed while staying at a specific site will be missed. If you turn to specialists who have already performed dozens of calculations for a specific region, you can be sure that they have a good knowledge of all the nuances of the soil in the area. In addition, professional services involve the issuance of specific documents that will be required when obtaining the necessary permits for construction.

Construction process

Each foundation design option has its own construction nuances, so it’s worth considering step-by-step instructions for several options. The first of these will be a monolithic columnar foundation.

Monolithic option

After drawing up the design design, it’s time for practical work. The first step is to prepare and mark out the area for a monolithic columnar foundation.

As you can see in the photo above, it is necessary to pre-mark the area where the structure will be located. To do this, the corners of the building are marked with pegs. A clearly visible rope or twine is stretched between the latter. Particular precision of angles is not required, since the marking of the structure is carried out for preliminary preparation of the area for construction.

The next step is to remove the top layer of soil along with the vegetation that is located on it. To make work easier, you can compact the area to make it easier to move around.

When the preliminary stage is completed, you can move on to more precise marking of the foundation structure. To do this, the corner pegs are placed exactly in their places, and the distance between them is checked. It is also necessary to determine whether the diagonals of the resulting figure of the future foundation structure are equal. If they do not match, then it is worth finding out which of the corners has the wrong angle and moving one or more columns.

In accordance with the developed project, markings are applied to the columns that will be installed later. For these purposes, additional stakes and ropes are used. The latter are stretched in places where the rows of columns will pass. The photo shows that the string, which is stretched in the middle, marks the edge of the pillars of the foundation structure. Simultaneously with this procedure, notes are made on where exactly the columns for the foundation will be located.

If you pay attention to the photo above, you can see that the master specifically marks the boundaries of the pit for the post. To do this, four pieces of reinforcement are driven in along its edges, which makes orientation easier during digging. You can start with it immediately after marking a specific element of the foundation structure. This can be done mechanically or manually. Everything will depend on the quality of the soil that exists in a particular area. A square heel with a side size of 40 cm is considered standard, but in certain cases it can be increased to 80 cm. It is this size plus the gap for the formwork that the foundation pit for the column should be.

The distance between individual pillars of the structure can vary from one to three meters. When the pit for the foundation column is ready, it is necessary to waterproof the lower part, where the heel of the supporting element will be poured. In the photo above you can see that for this purpose a polyethylene oilcloth is laid on the bottom. The density of the oilcloth should be 200 microns. It is located with a twist on the walls. Additional waterproofing and at the same time formwork for the structure is bikrost, roofing felt or similar material that does not have powder. Waterproofing can be fixed to the wall using nails or other fasteners. Subsequently, it will be pressed down by concrete. The height of such formwork should be equal to the height of the heel, which will be poured under the column.

The next step in constructing a columnar foundation structure is the preparation of reinforcing elements that will be poured with concrete. For these purposes, rods with ribs that have a diameter of 10 mm or more are used. It is necessary to calculate the elements in such a way that the heel is larger in size, and the vertical reinforcement corresponds to the post. The height of the reinforcement must be sufficient to combine the pillars with the monolithic foundation grillage, which will be poured later.

To make it easier to bend the reinforcement, you can make a similar device to the one shown in the photo above. For this, two metal corners are used, which are screwed to the wall. Moreover, their length is equal to the length of the element that will bend. The distance between the two strips is equal to the diameter of the reinforcement that is used for the foundation. To make it easier to bend the rods, you can use a metal pipe as a lever.

To make it easier to assemble the sheathing, stands are made, as shown in the photo above. A support is screwed to the vertical plane, in which notches are made at a distance from the reinforcement bars that will be embedded in the column. Additionally, a stand is made that can be rearranged depending on the length of the reinforcement. She can be seen on the right.

After this, the horizontal structural elements are distributed at an equal distance. To do this, use a tape measure or other device. The next step is to lay two more vertical posts, as seen in the photo above. To fix the structural modules together, it is necessary to use a binding wire that securely clamps them in place. For knitting, you can make a small hook yourself, which will simplify the task.

Reinforcement under the heel is performed separately and is represented by a small square in which rods are laid perpendicularly, as shown in the photo above. They are tied at all intersection points to ensure reliable fixation.

Next, preparation of the support stands of the structure is carried out, which will raise the reinforcement under the heel and under the column a short distance from the ground. This is necessary so that the element is filled with concrete mortar and from below.

The reinforcement for the heel structure is installed on plastic legs, and the reinforcement for the posts is fixed on top. All elements are tied together with knitting wire. So that it turns out as shown in the photo below.

Once the reinforcing elements for the columnar foundation structure are ready, formwork is manufactured for each column. An OBS board with a thickness of more than 12 mm is perfect for this. If you take a material with a smaller thickness, it will bend under the pressure of the concrete solution. To properly reinforce a columnar foundation, concrete must cover the mesh by at least 5 cm on each side. This means that the length and width must be 10 cm greater than the reinforcing elements. The height can be 5 cm greater.

To fasten the walls of the formwork under the posts together, hangers for a plasterboard profile are suitable. In this case, the middle part of the structure is cut out and only perforated strips remain, which are bent into the corners, as shown in the photo below. They are screwed to the walls and combine them into the required structure.

When all the elements are ready, they are assembled into a common structure, which will ensure high-quality pouring of the foundation.

In order for the OSB structure under the foundation columns to have a sufficient water-repellent effect and not to swell under the influence of moisture from the solution, it must be covered with cold-prepared bitumen mastic. This is done both externally and internally.

The next step is to install the armored belt under the foundation structure in the prepared pits.

The frame must be placed exactly in the middle of the prepared pit so that the concrete solution can freely and evenly fill the space around the structure. In addition, the structure must be exactly vertical and level. To achieve this, you can resort to the trick shown in the photo below.

A regular bubble level is used to ensure the structure is vertical. After this, the reinforcing base is tied to an additionally laid beam so that there is no displacement during pouring. The beam is fixed with weights in the form of bricks or other devices.

In this way, all elements that are responsible for the stability of the columnar foundation structure are installed.

Next, concrete is mixed for the foundation structure. The columns will be filled in stages. The first step is to fix the heel of the column under the foundation. It is enough to knead for each heel. The mortar for the foundation structure can be laid with a shovel. Its level will be equal to the height of the prepared waterproofing. To evenly distribute the concrete in the heel under the foundation, you will need an electric vibrator. It is lowered into the solution to fill any voids and remove air that could weaken the foundation post structure.

All that remains is to wait for the time during which the heel under the foundation column gains strength. As soon as this happens, you can begin installing the formwork for the column, which was prepared from OSB sheets. The formwork is placed in such a way that the reinforcement is located in the middle.

If you pour concrete into the formwork without fixing it, this will lead to displacement of the formwork and disruption of the foundation structure. Therefore, it is necessary to perform backfilling, which will fix the formwork under the foundation column. When performing backfill for the foundation structure, soil may get into the column form. To prevent this from happening, the upper part of the formwork structure under the foundation is covered with a thick film, as shown in the photo above.

Additionally, it is fixed to the formwork using a construction stapler so that the oilcloth does not move during operation.

For backfilling, you can use the soil that was removed when digging pits for the foundation columns. It is carefully poured between the pit wall and the formwork under the foundation column. After this, compaction can be done using a hand tamper, which can be easily made from a log and a small handle-shaped crossbar.

To protect everyone who will move around the construction site, it is necessary to cover the protruding rods with plastic bottles. The latter are easy to find and will do the job perfectly.

To make the backfill dense, you can additionally compact it with water, which will allow the soil to sink under its own weight.

The protective film is removed from the formwork under the foundation column. There are small pebbles and other debris left at the bottom of the structure that may interfere with good adhesion. To eliminate this, you can remove them using a regular or industrial vacuum cleaner, the tube of which will be tied to a pole, as shown in the photo above.

Before pouring the next portion of concrete under the foundation, it is necessary to wet the heel under the foundation, as well as the formwork. This is done for better interaction between the components of the foundation structure. After this, you can fill the column into the prepared formwork. The solution must be compacted with a vibrator to eliminate the presence of air in the structure. To ensure that the foundation column does not lose too much moisture during the process of gaining strength, it is necessary to put an oilcloth on the foundation reinforcement, which prevents soil from getting inside the column.

After pouring the foundation columns, you can begin digging a trench between the foundation columns. In this case, a trench will be needed to construct a grillage for the foundation. Its depth is calculated in such a way as to accommodate a cushion of gravel and sand. The second in this case will be 30 cm, and the first will be sufficient at 15 cm. In this case, it is also necessary to decide at what level the foundation grillage will be located. If it is a little deep, then you need to go deeper to this level.

The first to be laid is a sand cushion under the foundation structure, which is well compacted. Next, the second cushion is backfilled under the foundation in the form of fine crushed stone. It also needs to be compacted well in order to achieve uniform distribution of the load from the foundation to the ground. For this, a gasoline or electric vibrator is used. It is best to work by placing it perpendicular to the trench under the foundation, so as not to collect rubble along the edges.

When the backfill for the foundation structure is ready, you can proceed to the construction of formwork for the columnar foundation. Wooden beams will be needed. The length of such a beam for foundation formwork should be such that it can be 45 cm immersed in the ground and protrude to the full height of the foundation grillage. To make it easier to hammer the timber into the ground, it must be sharpened from below with an axe, as shown in the photo.

After this, the element is leveled and driven in with a sledgehammer to the required depth. It is necessary to periodically check the level of the structure, as it may go astray. In addition, this will be the key to the correct installation of formwork under the foundation.

A board is nailed to the installed supports under the formwork. It is necessary to arrange the individual elements for the foundation formwork in such a way that there are no gaps between them.

The foundation formwork board will deform from exposure to moisture, so it must be protected. The easiest way to do this is to use plastic film. It is fixed to the boards using a construction stapler.

To strengthen the formwork structure, jibs are installed that rest against another rack. The elements are mounted through one rack. The free racks are connected to each other using a knitting wire, as can be seen in the photo below.

Additionally, transverse elements are nailed on top of the structure, which tighten the walls of the foundation formwork together. It is first necessary to lay reinforcement inside, since this will be problematic later.

Note! To reinforce the foundation, reinforcement with a diameter of 14 mm is used. In this case, the clamps can be made from rods with a diameter of 8 or 10 mm.

The reinforcement that remains protruding from the foundation columns must be bent to intertwine it with the reinforcement for the grillage. It is tied to the rods, which are laid in the formwork using a knitting wire.

When everything is ready, you can pour the foundation with concrete. This is easier to do with a concrete pump, which can be directed along the entire perimeter of the foundation. After pouring, the foundation grillage is processed with a vibrator and leveled with a trowel.

When the foundation gains sufficient measure strength, you can dismantle the formwork and clean the foundation from soil residues. You can clearly see the process of installing the structure of this foundation in the video below.

With brick pillars

This design option is constructed somewhat simpler than the previous one, but it is worth understanding that a columnar foundation made of blocks cannot be used for serious buildings. It is perfect for sheds or gazebos where the weight will be minimal. Marking for this type of foundation structure is carried out in a similar way as for the previous option.

The pits for the foundation columns are constructed with a small margin so that the support pad is slightly larger than the area required to support the blocks. Crushed stone is laid on the bottom of the prepared pit. Its layer can reach 20 cm. It is important to compact the material well. It not only ensures proper distribution of the load, but is also responsible for drainage, which will eliminate the impact of liquid on the laid blocks.

After laying the crushed stone, sand is poured. Its layer will be ten or more centimeters. It is important to compact it well and level it in a horizontal plane.

After this, you can proceed to laying the blocks. They are leveled and secured with cement mortar. The second row is laid out perpendicular to the first to ensure ligation of the seams for greater structural strength. Foundation waterproofing in the form of roofing felt is laid on top of the blocks. It is necessary to prevent moisture from entering the grillage, which can rot from it. A wooden beam with a cross-section of 15 cm is most often used as a grillage for such foundation structures. It is laid along the entire perimeter of the foundation.

At the intersections of the structure, weaving is done using a tenon joint. The photo shows that two beams can also be connected using the half method. In this case, in each of the elements for the foundation grillage, a cut is made to half the thickness and width of the log. After this, the two foundation elements are fixed to each other using a pin or a self-tapping screw with a hex head.

Pile option

The next option for foundation design, which can also be classified as columnar, is a pile foundation with a grillage. For independent construction of the structure, screw piles are suitable, which are easiest to install without additional equipment. Such a foundation is sufficiently reliable and allows it to be anchored in strong layers of soil. This is done quite simply, since piles for such a foundation can be selected in a wide variety of lengths. The only question will be the convenience of screwing them in. In some cases, additional platforms will be required when work begins. But most often such a foundation is installed without them.

Question of marking for foundation design based on screw piles at the initial stage is relative. This is due to the fact that during work you should push off from the first pile. Its installation for the foundation is determined by the plan, which indicates exactly how the house should be located on the site. It is necessary to choose any corner of the foundation from which it will be convenient to start work. This pile will be the starting point from which it will be easy to make the rest of the measurements for the foundation.

It will be easier to install the pile if you prepare a small pit for it. Typically, a depth of 30 cm is sufficient for these purposes. The diameter of the pit is made slightly larger than the diameter of the foundation pile. You can dig it out with a garden drill, if its diameter allows this, or with a regular shovel.

It will be easier to install such a foundation if you do not just screw in the pile using a lever that is inserted into the hole, but with a special device. You can rent a pile sleeve, as shown in the photo above. Thanks to the arcs that are located on the sides of the coupling, it is easier to transmit force from the lever, which is in any position. In this case, the immersion of the pile under the foundation proceeds smoothly. Rotating a pile under the foundation through a hole that is located on top is not always convenient, since there may be restrictions on the area of ​​movement around the pile.

As a lever that will be used to immerse the pile into the ground, one pipe will not be enough, since the direction of the force that will be applied with its help can change the position of the foundation pile, which is very inconvenient. To build the structure you will need at least two levers. The length of each is from three meters. In some cases, longer levers will be required to properly install the structure if the pile must lie quite deep.

To make installation of the structure easier, at least three people are required. Two of them act on levers. The third person’s task at the initial stage is to keep the pile in a vertical position. As long as the main part of the pile is on the surface, there is no point in using a bubble level for the structure. This is due to the fact that the pile still has a significant amplitude of movement.

Note! The wall thickness of the lever must be at least 3 mm in order to provide the required force for screwing in the pile.

Screwing occurs clockwise. This can be determined by the direction of the screw at the end of the pile structure. As you can see in the photo, the main load during screwing of the structure for the one who holds it in a vertical position falls not on the hands, but on the shoulder. Hands act as assistants, since it is almost impossible to grasp a pile of such diameter well. The emphasis is supported by half-bent legs and widely spaced legs.

As soon as most of the pile structure is in the ground, it is necessary to increase the force, since screwing will be more difficult. To do this, the levers are extended to their maximum distance so that only a small part engages the coupling arcs.

As soon as it becomes clear that the pile has taken a good position and is firmly held by the soil, you can proceed to the precise vertical positioning of the structure. To do this, you will need a level that can be fixed to the body of the pile with a magnet. The photo shows that the level is located on the pile for a reason. It is placed perpendicular to the two support arms. This is the only way to correctly track the position of the pile. To make monitoring easier, you can use another level, which is installed directly under the lever.

When the level is in place, you need to position the structure in a slightly different way. If in the previous version the pile was held by the shoulders, now it must be leveled with the weight of the body, directing it in the opposite direction from the one in which the pile is tilting. Support is also provided on legs widely spaced and bent at the knees.

The deeper the pile goes, the more effort will have to be made to guide and rotate it. You may have to enlist the help of a few more people, as can be seen in the photo.

When the installation of the first element of the foundation structure is completed, it is necessary to determine the point at which the second corner pile will be located, which is in line with the first. It is best to take measurements at the centers of the circles. This means that the end of the tape measure is installed on the central part of the pipe. The distance to the center of the second pile for the foundation is measured. It will be equal to the total length or width of the house, from which the width of one wall is subtracted. Once the distance is determined, it is necessary to position the foundation piles on the same line. The easiest way for these purposes is to find a common landmark, for example, a fence, and place the foundation structure at the same distance from it.

The second pile is screwed in in the same way as the first. But now it is necessary to monitor not only the vertical level of the foundation pile, but also the distance at which it is located from the first pile. If in the process there is a need to adjust the position of the structure, then you should not act by simply tilting it in the intended direction. The photo shows that the pile must be tilted in the opposite direction to the one in which it is necessary to align the pile. After this, two turns of the pile are made under the foundation, and it is leveled to a vertical position. If this fails to achieve the desired effect, then the operation must be repeated.

When two piles are already in place, you can proceed to the installation of the third. The point of its installation is calculated somewhat more complicated than in the first and second cases. To install the third pile of a columnar foundation structure, you must be guided by the Pythagorean theorem. The width of the building is known, the length is also known, now you need to calculate the diagonal or hypotenuse of the right triangle. To do this, the thickness of the wall is subtracted from the width and length, since the measurement is taken at the centers, and each figure is squared. The sum of the resulting numbers will be the size of the diagonal. The photo shows that one of the ways to mark the third point of the foundation structure is to use two tape measures. At the intersection of the required values, the location of the third pile is located.

Note! If you don’t have two long tape measures, then you can use twine on which the required size is marked.

After determining the location of the third pile under the columnar foundation, preliminary installation of the pile is carried out in the pit prepared for it. Once it is securely in place, it is necessary to re-measure to ensure that the foundation pile is in place. If there are certain errors, then it is necessary to level the foundation pile in the manner described above.

When the installation of the pile in place is completed, it is necessary to further secure it. To do this, the pit that was dug earlier is filled with soil. It is important to compact the latter well so that the upper part of the foundation pile does not become loose.

The fourth pile under the foundation is also mounted using the diagonal and wall dimensions. In this case, all the indicators are known, so you can use tape measures or twine and screw the pile into place under the foundation. Periodically, when screwing the pile into place, it is necessary to check whether the distances at which it should be in relation to other piles are maintained.

The support of the entire structure is ready, now it will be easier to install the remaining piles under the foundation. For these purposes, a string is stretched between all risers. It must be located as close to the ground as possible. It will be easier to operate if two strings are pulled between the foundation piles, which will mark the corridor in which the piles should be located. Each wall is divided into two halves. The resulting size is marked on a stretched string and a pit is dug under it for the pile of the future foundation. This must be done on all four sides of the house.

During screwing, you must ensure that the marked point is in the center of the pile pipe. All foundation piles are immersed to the required level.

Foundation piles will also be required for interior walls. To mark them, you can use the intersection points between the lines of existing piles. To do this, ropes are stretched between the piles, which are clearly visible. At the intersection points, where necessary, a pit is prepared and the pile is screwed in. At the same time, it should be positioned in such a way as not to strain the rope or deflect it. It is important to monitor the level of the foundation pile throughout the screwing process.

The pile should be located at the intersection of the stretched ropes as shown in the photo above. The ropes are tangential, so the center of the foundation pile does not coincide with the center of the pile that will be screwed in.

Once all the piles are in place, it is necessary to trim them horizontally. This will allow you to correctly position the foundation even on an inclined area. For this purpose, you can use two tools. One of them is a laser level. It's easier to use. It is enough to position the beam at the required height and project it onto the body of the piles. After that, markings are applied to the foundation piles and trimming is done with a grinder.

Another option is to use a water level. Before use, it must be well aligned to avoid any bends. Next, the container containing water for the hydraulic level is installed on one of the piles. One of the craftsmen lowers part of the tube into a container, and the second creates a vacuum so that water under its own pressure begins to fill the tube.

Next, the functionality of the hydraulic level is checked. Its two ends are connected together and a certain time is waited. After this, the liquid in the two pipes should reach the same common level. If this happens, then you can proceed to the process of measuring the height for the foundation piles. If not, then you should carefully examine it and identify kinks or places where airing has occurred.

Note! The longer the hydraulic level, the more time it takes for the liquid inside it to calm down.

On one of the corner piles of the foundation, a point is drawn where all foundation piles should be located. One part of the hydraulic level is applied to it, and the second is brought to the next corner pile. Once the water level has calmed down, you can make a mark on the pile to guide the cutting. This way the mark is transferred to all corner piles of the foundation.

To mark a line over the entire area of ​​the foundation pile, it is necessary to make a pattern from a plastic pipe, which will be cut on one side for ease of installation on the pipe. Using a marker, draw a circle.

To transfer the marking line to the remaining piles, which are located in the middle of the foundation structure, it is necessary to pull a strong fishing line along the marks on the outer piles. It will be the indicator of the required line. After this, marking is carried out with a marker at the selected point. Using the prepared pattern, a line is drawn over the entire area of ​​the piles.

Once the marking of the piles for the foundation is completed, you can proceed to cutting all the elements along the drawn lines.

The next step is to fill the installed screw piles for the foundation. This is not done with concrete, but with an ordinary cement-sand mortar in a ratio of three to one. The solution must be liquid enough to fill the pile cavity. The purpose of this procedure is not to impart additional rigidity to the foundation, but to prevent the exposure of the internal walls of the pile to oxygen, which could lead to corrosion and destruction of the foundation. Filling is not done to the very top. It is necessary to leave a gap of 10 cm. It is filled with a dry mixture, which can be purchased ready-made.

The next step is to install the head on the pile. It must be located on a horizontal surface. The purpose of the head is to hold the grillage on which the walls will be fixed. The head is welded to the pile so that the fixation is as reliable as possible.

Welding seams are cleaned and coated with paint, which will protect them from corrosion. A video of the complete process of constructing this type of foundation is below.

Summary

As you can see, a columnar foundation is a fairly common design. It is an indispensable option when it is planned to build a small lightweight building. The last one can be a rounded log or frame. When laying the foundation, it is important to take into account all the features of the soil, as well as other parameters that were discussed in the article.

Nowadays frame houses are created in almost all climate zones. Due to the light weight of the structure, a foundation with low load-bearing capacity is used during its construction. A simple option is a columnar foundation.

Advantages and possible disadvantages of a columnar foundation

A columnar foundation is a simplified version of a pile foundation. The structure is a network of supports installed around the perimeter of the walls and in places of greatest load. The maximum step between supports is 2.5 m. All pillars are connected to each other by a grillage (horizontal strapping). Columnar foundations for frame buildings are used in 2 types: monolithic concrete (made by pouring into supports) and prefabricated (constructed from ready-made blocks or stones). Despite the fact that the structure is constructed without completely pouring concrete over the entire perimeter, such foundations have a number of advantages that make the structure reliable and durable.

Columnar foundation for frame house

Advantages of a columnar foundation:

• Costs less than tape analogues;
• Can be made by yourself;
• Quickly erected;
• Its construction does not require heavy equipment;
• Easy to repair;
• The poles can be installed at any time of the year, including winter.

The disadvantages of the design include a large amount of manual work (if there is no drilling equipment) and the need for additional insulation of the floors, since the frame structure practically hangs in the air.

Preparation for production

At the preparatory stage, you should find out the dimensions of the future structure, the load on the foundation of higher structures and bearing capacity soil. Before building a frame house, you can do a soil test yourself. To do this, you need to drill several holes in the area. The depth of the well is below 50 cm of the base of the foundation. In this way, the type of soil and the absence of aquifers are determined.

Soil characteristics:

• Rocky - soils with a high content of stone or gravel, have a strong foundation, hold the load well, and do not collect water.
• Coarse sands are a strong base with low heaving.
• Fine sand - not suitable for construction, as they are characterized by high heaving. They collect water in the upper layers and act as a buoyant force on the foundation.

Calculations of depth and number of pillars

Columnar foundations can be recessed (for water-saturated and clay soils) and shallowly recessed (for rocky and sandy soils with a low level of occurrence groundwater). The height of the buried foundation depends on the average depth of soil freezing in your area. The base of such a foundation should be located 30–50 cm below this level. Before starting work, you should calculate the load of the house; for this, the weight of the walls, ceilings, roof and the weight of the foundation are summed up.

If the slope is more than 60 degrees, the snow load is 0.

To determine the weight of a reinforced concrete columnar foundation, its volume must be multiplied by the specific weight of reinforced concrete (2500 kg/m³). To calculate the weight of one column, the following formula is used: V=3.14*G²*h. V is the volume of the column, G is the radius of the column, h is the height of the column. All values ​​are indicated in meters. The resulting value must be multiplied by the number of pillars, and we will get the total volume of the foundation.

Bearing capacity of different soils (in kg/cm²):

If the load on the soil exceeds the bearing capacity of the soil on the site, you need to increase the number of columns.

Material selection and quantity calculation

Different materials are used to construct a columnar foundation:

• Wood is a very short-lived material; even when treated with protective compounds, it will last no more than 20 years.
• Stone pillars - usually constructed from rubble or granite stones. They are distinguished by durability and reliability. The disadvantage is its massiveness and labor-intensive construction.
• Monolithic concrete pillars.

The number from the table must be multiplied by the length of the pole (in meters) and the number of supports.

The reinforcement for the columnar base is corrugated, class A, with a diameter of 10–12 mm. Metal rods are needed the same length as the supports. For a post with a diameter of 10–14 mm you will need 4 bars of reinforcement. They are placed at a distance of 10 cm from each other and tied every half meter with smooth and thinner reinforcement with a diameter of 6 mm. Thus, for a two-meter pole you will need 8 m of thick and 1.2 m of thin reinforcement. We multiply the resulting figures by the number of supports and obtain the footage of the reinforcement required for the columnar base.

Required Tools

Before starting construction, you need to prepare the following tools:

• Concrete mixer;
• Shovel;
• Roulette;
• Level;
• Nails and screws;
• Hammer;
• Cord;
• Pegs;
• Hand drill;
• Master OK;
• Pipes or boards for formwork.

Step-by-step instructions for creating a foundation with your own hands

Site marking

Before starting work, markings are made - pegs are driven into the corners of the future building and a cord is pulled. At this stage, it is imperative to check the diagonals. They should be the same. Next, debris and vegetation are removed from the entire area and the installation locations for the pillars are marked.

Digging holes and waterproofing

Drilling holes for a columnar foundation

For foundations made of monolithic concrete or asbestos pipes, it is convenient to use a motor drill. The pits can be either straight or widened at the bottom. A wider sole will increase the load-bearing capacity of the base and increase its resistance to heaving. Now you need to waterproof the foundation. To do this, a pipe made of roofing felt or polyethylene should be lowered into each hole. The upper edges of the waterproofing must be pressed to the soil with stones or sprinkled with earth.

Creation of formwork and installation of reinforcement

Opalwood from pipes for a columnar foundation

Formwork of asbestos or metal pipes (fixed) or boards (removable) is installed in finished wells. Then reinforcement with a diameter of 10–14 mm (at least 4 pieces) is inserted into each pit. Horizontal jumpers are made from thinner rods of 6 mm.

Installation of reinforcement in boreholes for poles

All pillars must be installed in such a way that the grillage is strictly horizontal. To do this, select a starting point and then use a level to mark the height of each support.

Concrete pouring and grillage

Installation of formwork for grillage

For the construction of columnar foundations, M200 concrete can be used. Filling is done in layers of 20–30 cm, each section is carefully compacted. Concrete is poured without interruptions to prevent the formation of transverse seams. After the pillars have dried, a grillage is installed. To make it, horizontal formwork is installed on top of the pillars along the entire perimeter of the foundation. Then the reinforcement frame is laid and concrete is poured. Standard grillage dimensions are 2.5–2.5 m (width and height).

Video: pouring a columnar foundation with concrete

A columnar foundation is one of the simplest and most economical solutions for frame buildings, which is quite feasible to implement on your own. Use our advice and good luck with your work!

Main advantages:

• Reliability, strength, wear resistance, long service life;
• A universal material applicable for any type of construction, on any landscape;
• Cost savings - considered one of the cheapest;
• No extensive preparatory work is required, waterproofing is minimal;
• Installation can be carried out by one person;
• Speed ​​of work.

Columnar foundations are economically justified - much cheaper than strip foundations. But the geological features of the soil should allow it to be installed.

• it is impossible to make a cellar or basement;
• Suitable only for simple, light buildings.

Foundation types

Before we start building a columnar foundation for a frame house, we decide on the material for the pillars: bricks, wood, concrete, stone, flagstone. The choice depends on the construction budget and type of structure:

• Lightweight structures on a frame;
• Buildings with 1-2 floors;
• Outbuildings, bathhouse, terrace.

Wood is a durable material, but capricious; it needs to be burned and treated with antiseptics to prevent rotting. Wood requires additional use of waterproofing materials.

• Main types of columnar foundation

A monolithic columnar foundation has maximum compressive strength, and with a reinforced base - tensile strength. Best material for the foundation, therefore popular. It is wear-resistant, durable and easy to install.

Brick is considered one of the most affordable and durable. Unlike wood, it is stable, has the simplest technology, and will last for about a century. This type can be used to build a two-story building.

Among the disadvantages of a brick foundation are high labor costs, excavation work, and poor resistance to moving soil. The result: displacement of the structure. The main disadvantage: for masonry you need a special burnt brick, which is expensive. Minimum size brick pillars - 500x500 mm.

The foundation is also created from flagstone and rubble stones. The minimum size of pillars is 600x600 mm.

A columnar foundation with a grillage is created to evenly distribute the load. Uniform distribution of forces by the grillage is the basis of construction.

We carry out calculations

The calculation of a columnar foundation can be performed independently under the supervision of specialists. We take into account the type of house, the weight of the structure and materials. We take into account the costs of a grillage to bundle materials and properly distribute loads. The technology ensures the safety and reliability of the frame.

There are 2 types based on depth:

• Shallow depth (40-70 cm) – used in rocky, sandy soil with low groundwater.
• Recessed (below half a meter - the depth of soil freezing) - it can be installed at a depth of up to 2 meters, below the groundwater level. Apply on clayey, water-saturated soil.

The exact calculation of the pillar parameters depends on the characteristics of the soil and construction features, but a reliable supporting foundation cannot be less than 500x500 mm. If the starting material is flagstone or stone, we make a foundation of at least 600x600 mm. When drawing up drawings, we take into account the fence - the wall between the columns. The fence protects the house from cold, rain and snow.

Phased construction of a reliable foundation

The first stage is preparing the site for construction. We don’t just clean the site (remove debris, fill up uneven areas), but also backfill if the soil is clayey and damp. The second stage is marking: we fix the axis according to the drawings, control the angle and diagonal. Work on the ground can be done manually or with an excavator. The main thing is to accurately position the holes along the axes.

• Digging holes for a columnar foundation

If the depth of the pillar is less than 1 m, then strengthening the walls is not needed; if it is more, we dig a pit with slopes and install fortifications with board slopes. We make the pits wider than the pillars, since it is possible to install supports and formwork. We make a reinforced concrete cushion under the pillar to protect against subsidence.

• Formwork

We arrange the formwork. We take boards 10-15 cm, 4 cm wide and about. Chipboard, plywood, iron sheets are suitable. If permanent formwork is needed, we use pipes made of asbestos, concrete, iron, 100 mm wide.

We reinforce the columnar foundation with rods 10-15 cm long. We make wire horizontal jumpers of 6 cm each. The rods should rise 15 cm on the foundation to connect the grillage to the frame.

• Reinforcement

We pour the concrete in layers of 20 cm. The finished mixture is compacted with a manual deep vibrator and waterproofing is performed. If the soil is wet, we make a double layer, for the rest - a single layer of roofing material.

We install the grillage. We connect the lintels with scraps of reinforcement, weld mounting loops, install the formwork and make a reinforcement base. We make a monolithic belt, or using reinforced concrete beams. After the concrete is poured, we take a break so that it settles and becomes strong and acquires its basic characteristics, then we do waterproofing and fill the hole.

Concrete columnar block foundation is another popular option.

Block foundation

The main advantage is ease of assembly: the base is made of crushed stone, a sand cushion is poured, blocks are placed and bonded with cement mortar. There are restrictions when choosing blocks:

• Do not use on horizontal soil prone to movement;
• Not used for the construction of large buildings;
• Do not use on weak-bearing surfaces - peat, permeable to water.

When choosing, we fix the concrete blocks with a rigid grillage made of reinforced concrete, which makes the construction process expensive, and if we take into account the cladding of the base, even more labor-intensive and complex

If we are planning a pipe With columnar foundation, then we make holes in the ground, tamp the base, insert pillars and sprinkle on the outside. Next, fill a third of the concrete, raise the pipe and fill it again, leaving 15 centimeters at the top unfilled. We tamp the concrete and install a reinforcement rod in the center, leave it to set, insert metal anchors into the left cavity to connect the foundation to the wall, then concrete it to the end.

Calculation of the cost of foundation construction

The main elements for the construction of a columnar foundation do not differ from the strip version: you will need concrete, reinforcement, sand, gravel and waterproofing. For the construction of industrial buildings, a special reinforced concrete foundation is used, manufactured by professionals. All types differ only in construction technology. The cost of materials varies throughout the country and the average figures are presented below:

Cost of materials:

• Heavy concrete class B15-B20 - from 800 to 1500 rubles per cubic meter. m.
• River sand - from 80 to 200 rubles per ton
• Expanded clay - from 800 to 1000 rubles per ton
• The glass type of industrial columnar foundations costs from 1000 rubles per piece. It all depends on the purpose, condition and class
• Fittings with a diameter of 6 - 14 class A400 from 10 to 15 thousand rubles per ton
• Cement 50 – 100 rubles per bag.

Cost of work:

• Digging – 250 rubles per cubic meter
• Installation of a monolithic foundation – 2700 – 4000 rubles per cubic meter. m.
• Waterproofing of a columnar foundation – 40 – 60 rubles per square meter
• Truck crane (rental for mounting main parts and supplying concrete) – from 3,000 rubles per day
• Rental of equipment for delivery of elements and materials – from 270 rubles per hour.

How to avoid mistakes during construction

During construction, it is important to ensure that all pillars operate simultaneously by distributing the load using a grillage. A professional design engineer will be required to draw up the correct project based on engineering and geological calculations. A project consists of drawings and materials consumption sheets.

The main mistakes in the construction and design of columnar foundations:

• Incorrect assessment of the geological features of the soil. If during the design it was not taken into account that the soil can freeze and subsidence, this will lead to cracks in the grillage;
• Poor quality concreting. For concrete to gain basic characteristics and strength, it must be kept for almost a month and moistened on hot days;
• Excessive savings on materials. To save money, the wrong grade of concrete was used during construction. Saving can lead to destruction and high level precipitation;
• During construction, the engineers did not take into account the differences in relief (during construction on a slope) and did not maintain the depth;
• The main documents were not reviewed - the Project and the Work Agreement - with their help it is easy to control the correctness of the work, the savings in materials, and the completion time.

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

Unique foundation made of “rods”

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

A column foundation is significantly different from a strip foundation, since it is not built along the entire perimeter of the building

Advantages and disadvantages of a columnar base

The indisputable advantages of a foundation made of support pillars are:

The disadvantages of a columnar foundation are attributed to:

All the disadvantages of a foundation made of pillars can not be considered as something important if you build this structure taking into account its purpose.

Challenges of Pillar Construction

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

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

It is wise to place only small houses made of lightweight materials on poles, because the supports will not withstand the weight of other buildings

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

• the soil at 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 standard reinforced concrete slabs;
• finances and time for arranging the base are significantly reduced (when creating a columnar foundation, the base does not form by itself, as happens during the construction of a strip base);
• The soil on the site for building a house is characterized by a sharp difference in height (from 2 meters).

A columnar foundation can only be built on solid and level soil, since it is not ideally stable

View of a foundation made from individual supports

A columnar support structure for a house is a system of pillars placed in corners, areas where walls intersect and where load-bearing partitions 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 most commonly constructed columnar foundation is a structure made of monolithic reinforced concrete blocks.

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

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

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

For places like a 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 pillars are placed at a distance of 2–2.5 m from each other

The distance between the pillars is 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. A simple structure connecting the supports can be made of metal parts, for example, channels or profiles.

Variations of the pillar base

What the columnar foundation will be like is decided based on the amount of finances and the ability to independently engage in construction.

Block supports

A columnar foundation can be made up of concrete or reinforced concrete blocks, manufactured separately and installed directly when arranging the supporting structure for the building.

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

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 accustomed to taking raw materials with parameters of 20*20*40 cm and a weight of 32 kg. Foundation blocks made of expanded clay concrete, a material that is resistant to thermal effects, are considered relatively light.

Large block structures made of reinforced concrete can only be laid by 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 strip and slab foundations for huge brick buildings.

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

The best depth for fixing a pillar 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 made of asbestos-cement pipes filled with concrete. Laying blocks to a depth of more than 1 meter is too difficult.

Brick pillars

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

This characteristic of brick, such as frost resistance, is considered extremely important. The higher the indicator of immunity to low temperature, the longer the construction raw material lasts. For example, frost resistance 70 indicates that the brick will deteriorate no sooner than after 70 years.

To build the foundation, it is customary to use red solid ceramic brick, because it is the most durable

Bricks can be used to construct both a shallow and recessed columnar foundation. The depth of the first version of the foundation varies between 40 and 70 cm. And the buried foundation is always installed 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 foundation reliable, the brick supports of a columnar foundation need to be created in 2 bricks

The main foundation pillars (supports located in the corners of external walls and at the intersection of internal partitions) are usually made of 2 or 2.5 bricks. In other cases, the pillars are allowed to be made of 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

A base made of wooden “legs” is the most economical option. Logs suitable for the foundation can be easily cut down and processed 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 structure made of wood.

Wooden poles are intended only 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 from the butt part of a log with a diameter of 2 to 40 cm. When placed in holes, the wood posts are secured on the sides with bricks, stones or a compacted embankment of crushed stone.

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

To secure the post to the crosspiece, a spike is cut out in its lower part. It is inserted into a groove made in the central area of ​​the cross. Then the pole is fixed on a kind of platform with scarves.

To securely fasten the pole in the ground, use a cross and jibs.

Wooden supports must be protected in a special way from rotting. First, they are covered with clay to form a layer 1 cm thick, then burned with hot coals. The last task is performed slowly, making sure that literally 1.5 cm of wood is charred. The burned 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 a wooden foundation should be immersed to a depth of 70–120 cm

Monolith

It is preferable to construct buildings with 2 or 3 floors on a columnar monolithic foundation. Such a foundation will not sag even under significant pressure.

A columnar monolithic foundation can serve for more than 100 years without problems. Each pillar of this support structure is capable of supporting an object weighing 100 tons.

Monolithic foundation is considered the most popular design compared to other columnar foundations

A monolithic base of pillars is created from 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 columnar foundation: step-by-step instructions

The construction of a columnar structure for a house begins only after calculations have been completed and the construction site has been prepared.

Necessary calculations

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

Before computational actions, it is necessary to test the soil at the construction site - drill a well with a depth of 60 cm below the level at which it is planned to install the foundation pillars. If soil is found under the load-bearing soil, saturated with water and therefore weak, it is better to cancel the decision to build a columnar foundation. Posts under load are unlikely to be able to stand still in unstable soil.

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

Determination of soil load

After making sure that a columnar foundation can be built 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 house.

When calculating what the pressure on the ground will be after building a house, you should add the weight of the foundation 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 specific gravity values ​​for building elements

Constructions	Specific gravity, 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
Floors
Basement and between floors on wooden beams (insulated with material with a density of up to 200 kg/m³)	100
Attics on wooden beams (insulated with material with a density of up to 200 kg/m³)	150
Concrete hollow core slabs	350
Monolithic (made of reinforced concrete)	500
Operational load for basement and interfloor slabs	210
105
Roof including rafters, sheathing and roofing material
With a roof made of sheet steel, metal tiles or corrugated sheets	30
With roofing felt in 2 layers	40
With slate roof	50
With a roof made of natural ceramic tiles	80
100
50
190

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

Total area of ​​pillar bases

As soon as it becomes known how much the future house will weigh, they find out the minimum required total area of ​​​​the bases of all pillars. To determine this parameter, use the formula S = 1.3 * P/R 0. The number 1, 3 denotes the safety factor, P is the total weight of the building in kg (including the foundation), and R0 is the calculated resistance of the load-bearing soil in kg/cm².

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

An example of determining the number of foundation pillars

Let's try to calculate how many round supports will be needed to construct a columnar foundation 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 pediment is 2.5 m. We also do not forget to use data such as roofing material (slate), type of load-bearing soil (loam) and freezing depth ( 1.3 m).

The frame house can be installed on 10 pillars

The weight of the building is calculated as follows:

1. The area of ​​all walls is determined, taking into account the pediments (72 m²) and their mass (72 × 50 = 3600 kg).
2. The total area and mass of floors are found. Since the house has a basement and intermediate floors, their area is 60 m² and their weight is 6000 kg (60 × 100 = 6000 kg).
3. The operating load is also present on the 1st and on 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 accept the snow load equal to zero, since the angle of inclination of the roof slopes is greater than 60˚.
6. Let's 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, let's take this value. The number of pillars is preliminarily taken based on the condition - one pillar per 2 meters of the perimeter of the foundation. We get 22/2 = 11 pieces. Now we calculate the volume of one column 2 meters high (buried 0.2 m below the freezing depth + 0.5 meters 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 sum up all the obtained values ​​and determine the total weight of the house: P = 31100 kg.
8. The minimum required total area of ​​the bases of all pillars will be equal to 11550 cm² (S = 1.3 × 31100/3.5 = 11550 cm²).
9. The base area 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, their number will increase. For example, armed with a drill that creates holes measuring 30 cm, you will need to install at least 16 pillars.

Preparation for construction

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

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

   The evenness of the prepared area is checked with a rack

4. Bring construction materials to the site and install cast-offs around the perimeter of the future structure (pillars at a distance of 2 m from the building and boards nailed to them with marks for the size of holes and supports). The correctness of the center lines must be monitored by measuring distances with a tape measure. In addition, you need to check whether the corners of the foundation in the shape of a rectangle or square are straight.
5. Lay out a plan for the future house on the site, that is, mark its parameters using pegs.
6. Create holes for installing pillars (if necessary, you can use a drill to make holes for wooden supports, and if installing reinforced concrete pillars, you should arm yourself with a shovel).
7. Fill the bottom of the holes with gravel and sand and moisten. The finished “pillows” need to be compacted and covered with polyethylene or roofing felt.

   The bottom of the drilled holes is reinforced with hard material, for example, Proce gravel

Creating formwork for pillars

An excellent option for formwork for supports under a house can be a temporary structure made from planed on one side (the planed part is installed facing the concrete) boards of any type of wood, with a thickness of 25 to 40 mm, a width of 12 to 15 cm and a humidity of no more than 25%.

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

Wooden columnar foundation formwork is a standard option

The temporary auxiliary structure must be installed close to the walls of the dug well and perpendicular to 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 constructing the formwork, then it must be borne in mind that they must be thoroughly moistened with water. If you ignore this condition, you can get weak pillars, because dry wood absorbs moisture like a sponge, and because of this, it worsens the properties of concrete.

Roofing felt formwork is an innovation

An auxiliary structure during the construction of a columnar foundation can also be permanent formwork made of roofing felt. This material simultaneously performs several tasks: it serves as a form for pouring concrete and protects the supports from moisture.

Formwork made from roofing felt is a good solution if the soil in the created well is dense and non-crumbling.

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

Features of pouring the foundation

If a home craftsman is a supporter of the traditional method of pouring a foundation, then to accomplish this mission he must do the following:

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

A column with widening (using TISE technology) is formed in stages:

Video: example of constructing 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 equipment, hired workers, or a large amount of materials.

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

Columnar foundation - features and varieties

When you plan to build a residential house made of wood, any outbuilding, bathhouse or garage, the question arises of what type of foundation to choose for them. Anyone 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, the arrangement of a columnar type foundation is considered. It is the simplest to implement and relatively inexpensive.

The foundation we are interested in is suitable for another 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 foundation.

The structure of this foundation is quite simple - a number of support pillars are placed on the ground in places where the main load will be directed upon completion of the construction of a house or other object. Such places include:

• piers;
• corners of the structure;
• sections of wall intersections;
• 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 can be prefabricated or 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 foundation strength.

Columnar structures are also usually divided 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 into the ground at a depth of 0.4–0.7 m. Experts advise using such a foundation when constructing buildings on rocky or sandy soil.
• Recessed - laying of supports is carried out to a depth that is 0.5–1 m below the freezing mark of the soil in a particular area. Pouring and installing such a foundation is recommended for watery and clayey soils, where there is always a danger of the foundation being washed out.

Note that a columnar foundation is built with your own hands using the same technology. Next, we will look at how to make a columnar base yourself using various materials.

Preparing for arranging a columnar foundation - 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 base and 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 pipe products. But it's relatively big wooden house you will need to place it on a deeper (about 1 m) and powerful foundation, for example, made of concrete.

After this, you need to calculate the number of pillars that will go to construct the foundation. They must be present in the center and at all corners of any building (even if, in your opinion, it is very small). You will be guaranteed a truly reliable foundation for the building if you place pillars 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 likelihood of large amounts of precipitation and flooding.

Next, we begin to clean the area of ​​land where the foundation is planned to be poured. We carry out these works as carefully as possible - we remove all unevenness in the ground, remove debris, add gravel to the clay soil. Then we create a point plan of the planned foundation and mark on it the locations of all the pillars.

You should also move 2 m away from the perimeter of the future building on four sides to mark the area from which the surface earthen layer needs to be completely removed (20–30 centimeters). This is done to eliminate the danger of vegetation growing under the structure. And at the place chosen for construction, it is necessary to pour gravel or, after which you can start digging holes for installing the supports of the columnar foundation.

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

The most common and economical is roofing felt formwork. This is what is most often installed on private farmsteads during the construction of various structures. It's done simply:

1. We take a piece of roofing felt of the required length (we focus on the length of the post, and also add a little length to the scraps according to the level) and twist it in two layers into a tube. It is best to wind the material onto a template, for example, onto 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 material blank is additionally wrapped with 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 felt 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 from wooden panels consisting of boards 15 cm wide and 4 cm thick. It turns out to be reliable and of high quality, but its cost, of course, is much higher than a structure made of roofing felt. Permanent formwork can be made of asbestos-cement or steel pipes. Their diameter should be 10–20 cm.

After this, we begin the process of strengthening the columnar base. For reinforcement, you need 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 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 to the columnar supports.

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

In this case, permanent formwork made from pipe products of a suitable cross-section is required. The construction of such a foundation is recommended for any buildings, including wooden houses. For the 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).

Step-by-step instructions for building a foundation are as follows:

1. We clear the site.
2. We prepare cylindrical pits in which we install a reinforcement cage or pipes and fill them with earth, ensuring the fixation of the supports.
3. We fill the pipe structures used with concrete solution to one third of their length. This procedure is mandatory; it creates the required hydraulic cushion for the base.
4. Raise the pipes to a third of the height and fill again concrete mixture, leaving about 15 cm of empty space at the top.
5. We completely remove the pipes, and compact the concrete solution that remains in the hole and place a reinforced rod in its center.
6. We are waiting for the concrete to harden.

The connection between the base and the erected walls of the structure is carried out using metal anchors. They should be attached to the lower wall beams and sunk into the 15cm cavity left. You have made a reliable and durable foundation out of pipes. All that is required is to finally concrete the structure.

Construction of a foundation made 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 support-column foundation is made with your own hands from concrete elements with geometric parameters of 20x20x40 cm.

The block base device includes the following stages:

1. Site preparation.
2. Digging holes, covering them with crushed stone and creating a sand cushion at the bottom.
3. Installation (using cement-based mortar) of concrete blocks.
4. Carrying out waterproofing measures (using ordinary roofing felt laid on the surface of concrete pillars).
5. Plastering the surface of the blocks.

Block foundations cannot be constructed on horizontally moving soils, water-saturated and peaty soils. It is also undesirable to place overly massive buildings and structures on them.

You can also make a wooden foundation. But the service life of such a foundation will be objectively short. It can be increased by impregnating the 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 larger - from 20 cm. 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 to be 1.5 times the diameter of the wood supports used.
3. We install wooden poles at the corners of the planned building, along its perimeter (every 2 meters) and at the points of intersection of the walls of the structure.
4. Place a layer (15–20 cm) of sand on the bottom and compact it as thoroughly as possible.
5. We carry out waterproofing of the lower part of the wooden supports (impregnation with oil, “wrapping” in 2-3 layers of roofing felt or ordinary roofing felt, which it is advisable to glue with bitumen-based mastic).
6. We mount and align the pillars vertically (use a building level).
7. We fill the voids between the pit and the pillar with broken bricks, large crushed stone and sand. These materials should be poured in layers and compacted constantly. The thickness of each layer is at least 10 cm.
8. We level (now in height) the installed supports - we cut off their tops to achieve a completely horizontal plane. This procedure is easy to do if you stretch a cord over the posts.
9. We apply roofing material or a special waterproofing film to the ends of the columnar supports.

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