How to make a columnar foundation yourself. Types and stages of construction of columnar foundations. Columnar type base device

Among all the types of concrete foundations used today, the columnar strip foundation deserves special attention. Most often, this design is used when arranging heavy and massive construction projects.

Subject to proper construction, the column-and-tape structure will have the highest performance indicators. At the same time, relatively little time and money are spent on arranging such a foundation, and all the required work can be done on your own.

Read the general information about column-and-strip foundations, study the manual for arranging such structures and get to work.

The use of such a design will be justified when performing construction work in areas with a large depth of soil freezing.

In such situations, the construction of an ordinary buried strip foundation will require irrational financial investments, and a shallow structure simply cannot cope with the tasks assigned to it.

In such conditions, a columnar strip foundation is an excellent option. Even a beginner can cope with the arrangement of such a structure.

An additional advantage of the foundation in question is the possibility of its arrangement on sloping areas. But if the underground aquifer is located too close to the ground surface, it is recommended to refrain from such a decision.

In the design under consideration, the largest part of the load falls on the base of pillars. In this case, the pillars must be placed in the ground at least 200 mm below the freezing point of the soil. Thanks to this, maximum durability and reliability of the structure will be ensured.

To prevent the tape from rising in the future under the influence of natural changes in the structure of the soil, its lower part must be made somewhat wider.

In a column-and-tape type structure, the tape functions exclusively as an upper grillage, which is necessary to connect the pillars into a single structure and further increase the strength of the base. At the same time, the tape does not exert any load on the ground.

Using the tape, the most even distribution of the load on the main foundation pillars is ensured.

The foundation must be designed so that after complete completion of the structure, at least 150-200 mm of free space remains between the lower edge of the grillage and the top layer of soil. Thanks to the presence of such a gap, the foundation will not receive any significant damage even with severe swelling of the earth.

What are the pillars made of?

Before you begin to independently arrange a columnar-strip base, you must choose the optimal material for making supports. Available solutions include: wood, concrete blocks, brick, asbestos cement and metal pipes. Familiarize yourself with the features of each option and choose the most suitable solution for your situation.

They are used extremely rarely due to their relatively low durability. Wooden pillars are only suitable for arranging a foundation intended for installing a terrace or other similar structure.

The optimal diameter of wooden posts is 150-200 cm.

Before burying pillars of the material in question into the ground, they must be treated with antiseptic and fire-retardant impregnation. Thanks to this treatment, the resistance of the material to rot, pest damage and fire will be significantly increased.

Bitumen-based mastics are optimal for waterproofing wood.

Iron brick is well suited for arranging a column-and-strip structure. It is also used to build shallow columnar foundations.

Supports in the form of concrete pillars, additionally strengthened with reinforcement, are considered the most reliable. Because of this, these types of supports are the most popular.

Concrete pillars can have either a solid (monolithic) structure or consist of several blocks.

It is important that the width of the pillars is at least 40 cm.

Pipes made of asbestos cement or metal are very easy to install. Installation boils down to placing hollow pipes in pre-prepared recesses, installing reinforcement rods inside the pipes and finishing filling the cavity with concrete mortar.

The work is done extremely quickly and simply. The optimal pipe diameter is selected individually, taking into account the expected load on the foundation being built.

Stages of foundation construction

The construction of the foundation of this type is carried out in two stages. First you will need to create the base of the structure from pillars, and then arrange a shallow concrete strip.

Pillars

Before starting work, determine the optimal depth of the columnar-strip base. At this stage, consider the following parameters:

• type and features of soil structure;
• ground freezing level;
• depth of groundwater passage.

There are shallow and buried foundation structures. When constructing a shallow foundation, the pillars are usually immersed 40 cm into the ground, but in the case of constructing a buried foundation, the supports are deepened 10-50 cm below the freezing point of the soil.

Maintain the installation step of the supports within 100-250 cm in accordance with the future load. The higher the load on the base, the smaller the space between the installed supports should be. Professional builders strongly do not recommend placing supports at intervals of more than 250 cm, because this will lead to a significant reduction in the strength of the finished structure.

Proceed to install the support posts. This is a fairly simple job done in a few steps.

First step. Prepare the area for upcoming events. To do this, remove the fertile ball of soil and level the area. If the top layer of soil on your site is clay, remove more of it and fill the resulting base with a small layer of sand.

Second step. Mark the area. Any suitable pegs and visible rope will do for this. Pull the thread at a distance corresponding to the width of the future concrete strip.

Watch the angle at which the cords intersect. It is important that the threads intersect strictly perpendicularly.

Mark the intersections and junctions of internal partitions and external walls of the building, the corners of the future structure and areas that will be subject to the most severe loads.

Third step. Dig a trench where the strip part of the foundation is installed. A hole about 400 mm deep will be enough. The width of the trench should be 70-100 mm greater than the width of the tape. This gap is necessary for the installation of formwork boards.

Fourth step. Make recesses in the places where the support pillars will be installed. A drill or other suitable device will help you with this. Select the diameter of the recesses individually in accordance with the expected loads on the foundation. The higher the load, the larger the diameter of the support pillars should be.

If, according to the project, the pillars will lie more than 100 cm, be sure to install supports made of strong boards. They will prevent the soil from crumbling. If the pits are up to 100 cm deep, you can refuse to install supports.

Fifth step. Fill the bottom of each depression with a 100mm layer of sifted sand.

Sixth step. Start arranging the pillars. In the example under consideration, the supports are made of asbestos-cement pipes.

Pre-waterproof the supports. To do this, cover them with a double layer of roofing felt or other similar material. Insert the pipe with waterproofing into the recess until it stops.

Tie a reinforcing frame from steel rods and knitting wire. Use rods with a diameter of 12-14 mm. The fittings must be such a length that its upper ends protrude from the pipes by 150-250 mm.

Start pouring. First you need to fill the free space in the holes around the supports with concrete to about 20 cm of the height of the recesses, and then pour the pipes directly.

Leave the finished posts to dry and gain strength.

Ribbon

Proceed to arranging the ribbon part of the structure.

First step. Tie the frame from reinforcing bars and steel tying wire. Weld the structure and screw it to the reinforcing bars protruding from the concrete support pillars.

Second step. Install the formwork to fill the tape. Assemble the formwork from boards 40 mm thick and about 150 mm wide. Boards can be replaced with chipboards, plywood or sheet metal.

Third step. Cover the inner surface of the formwork with moisture-proofing material. Polyethylene is suitable for waterproofing; more modern membrane materials can also be used.

Fourth step. Fill the formwork with concrete mortar. To save time and effort, you can order ready-made concrete. If desired, you can prepare the solution yourself. Perform the filling in one go. Pour the solution horizontally. Vertical joints are strictly prohibited - they will crack even before the concrete has completely hardened.

Treat the poured concrete with a special vibrator. This treatment will eliminate voids and excess air. If you don't have a vibrator, at least pierce the concrete with rebar in several places, and then carefully seal the holes with concrete.

The filling will dry within a month. It is recommended to dismantle the formwork only after the filling has completely hardened. For some time (usually 1-1.5 weeks), the poured concrete must be additionally moistened, otherwise it will crack.

Determine the frequency and duration of moistening individually in accordance with the “behavior” of concrete and weather conditions.

Waterproof the hardened and strengthened concrete, fill the remaining trenches with earth and proceed with the planned construction activities.

Good luck!

Video - DIY columnar strip foundation

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. It is quite simple to build a columnar foundation with your own hands, which in some respects is not inferior to the listed foundation 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 a monolithic structure to a 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 excellent for cases where the upper layers of the soil have a high degree of 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 territory. 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 area. 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. The 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 has gained a sufficient measure of strength, the formwork can be dismantled and the foundation can be cleared of 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 placed 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.

The issue of marking for a 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.

At first glance, it may seem that building a columnar foundation for a house with your own hands is an almost impossible task. However, this statement is not true.

Features of a columnar foundation

First you need to understand the definition of a columnar foundation. To put it simply, it is a set of supports that bear the weight of the structure being built. The racks are installed in places of maximum load - these are the corner points of the building, wall connection points and spans longer than 2.5 meters.

The distance between the posts, as well as the shape of the posts, are calculated values ​​that depend on a number of factors:

• type of racks;
• material of manufacture;
• building design;
• planned mass of the structure;

The standard distance is 1.5 - 2.5 m, the cross-sectional diameter for round supports is from 20 to 25 cm. The size for rectangular ones is from 25 by 25 to 40 by 40 cm. It is desirable that the ground part be at least 50 cm in height, length underground part depends on the depth of the backfill.

The upper support points must be at the same level, which must be carefully checked after installing the racks and adjusted if necessary.

Disadvantages and advantages

Before you build a columnar foundation with your own hands for a frame house, you need to understand in which cases its use is suitable and in which it does not make sense, as well as its pros and cons.

Flaws:

• it is impossible to arrange the basement of the future house;
• cannot be used on floating or water-saturated soils

Advantages:

• quick drying and ;
• minor costs;
• construction in any season;
• separate installation of each support;
• ease of installation;
• affordable replacement and repair.

Types of columnar foundations

There are different bases depending on the parameters, the cross-sectional shape of the supports, the materials and manufacturing processes of the pillars and the depth of the base. In cross-section, the racks are round, square, rectangular. It is possible to make supports in monolithic form from concrete, or in prefabricated form from bricks, blocks, rubble.

The classification according to the depth of the bookmark is as follows:

• for heaving soil, buried pillars are laid below the freezing point;
• for non-heaving and low-heaving soils with sand and gravel air embankment, use shallow racks with filling up to 70% of the soil freezing point;
• for non-buried for low-heaving or non-heaving soils using a dense sand cushion.

Base structure

In order to competently build a columnar foundation with your own hands for a frame house, it is important to clearly understand the structure and process of its construction.

Work with soil

• To begin work, it is necessary to prepare the site for the construction of the foundation.
• Complete removal of debris and removal of turf by approximately 15-20 cm.
• Leveling the ground surface.
• Marking the area with pegs according to the plan. The pegs are installed at the corner points of the future foundation, connected with a cord, after which the accuracy of the markings is checked along the perimeter.
• The installation points for the pillars are being marked.
• Digging holes.

Support arrangement

1. Brick supports . Some situations make it possible to make support posts from brick, which is advisable to do on stable soils and in places where groundwater is deep.

Laying is possible in two ways:

• laying on a sand bed;
• constructing a concrete shoe, then laying bricks on a hardened base.

The most commonly prepared supports are 25 by 25 cm (a row of 2 bricks). If you plan to build a large building, then you can lay 4 bricks - 38 by 38 cm with additional installation of reinforcement inside the pillar.

It is important to maintain an exclusively vertical position of the supports with regular checking with a plumb line or level.

2. Block . An alternative option is wall or shoe (cushion) rectangular concrete blocks measuring 20 by 20 by 40 cm. The latter should be mounted on top of a sand cushion at the base of the supports, the shape of the posts is trapezoidal. Most often they are erected as shallow or non-buried supports.

3. Monolithic . Such supports are made by pouring concrete mortar into pre-installed formwork, round or rectangular in cross-section, additionally reinforced with steel rods.

4. Rectangular supports . The formwork for such supports is constructed from plywood or edged boards. If construction takes place on stable ground, then the formwork is created naturally from the walls of the recesses. Before pouring the solution, it is necessary to cover the walls of the pit with waterproofing material.

When installing racks in loose soils, it is necessary to erect formwork along the entire height of the future pillar; recesses are dug in such a way that it can be installed and fixed without problems.

5. Round pillars . It is allowed to erect supports that are round in cross-section. For production, wells 20 - 25 cm in diameter are drilled. The construction technology coincides with the production of rectangular supports; instead of formwork, roofing felt, plastic or asbestos pipes are used.

In some cases, TISE technology is acceptable, when specialized drills with a plow are used for wells with expansion at the bottom in order to increase the support area.

6. Combined supports. In some cases, a do-it-yourself columnar foundation for a frame house is built not from one material, but from two. For example, first the buried part of the support is concreted, after which the above-ground part is erected, but using bricks.

Formwork

Before erecting the formwork for both installation options, it is necessary to create a cushion of a mixture of sand and gravel 30 - 50 cm high for shallow and non-recessed racks and 10 - 20 cm for recessed racks.

The formwork is mounted strictly vertically on the cushion, secured with stops. The inside walls are covered with waterproofing.

The supports can be of uniform thickness along the entire length or with a thickened bottom - a “shoe”. In this case, the width of the support pit must correspond to its dimensions. The “shoe” can be installed separately with the reinforcement released from it; after its hardening, the support formwork is installed on top.

Four ribbed reinforcing bars with a diameter of 10 - 12 mm make up the frame, connected by clamps 6 - 10 mm in diameter made of ribbed or smooth reinforcement. The distance between the reinforcement and the formwork is more than 3 mm, a similar gap from the cushion for the purpose of anti-corrosion protection of the metal. You can ensure distance using plastic stands, which will also prevent the reinforcement from moving.

When constructing supports with a “shoe,” the rods are installed before the formwork is installed.

If a grillage is not planned, then the upper point of the end of the reinforcement is 5 - 6 cm down relative to the level of pouring the mortar. It is planned to install embedded studs with a diameter of 14 - 16 mm to connect the supports with the lower trim.

For foundations where the construction of a grillage is planned, the frame protrudes 15-25 cm above the pouring level in order to coordinate with the latter’s frame.

Next, a concrete solution is poured, either made independently or purchased from a brand no less. Filling in portions with compaction using a vibrator or other means. Removal of the formwork is permissible after final hardening.

Grillage

You can install a grillage, or you can do without its construction. This is a solid cast concrete structure, which serves to ensure uniform load on the supports. The lower surface of a high grillage is located at a distance of 10 - 20 cm from the ground surface, a low one is laid on a sand and gravel cushion buried 15 - 10 cm into the ground.

Formwork for grillage

To install a hanging grillage, you need to build formwork. Two installation methods are allowed here: place the bottom at the level of the supports’ heads, or build it to its full length to the ground level, and then fill the space between the ground and the grillage with sand. The formwork must be covered with waterproofing.

The height of the formwork is important; its top should end flush with the level of pouring the concrete solution, or exceed it by 5 - 6 cm. The height of the grillage depends on its type and the type of cross-section of the supports: for a hanging one from 25 to 30 cm, for a low base 50 cm , and width from 25 to 40 cm.

Reinforcement

The frame is made up of 1 - 2 rows of longitudinally located reinforcement, which is connected by transverse rods or clamps. The connection takes place using soft wire. The gap between the frame and the formwork is at least 3 - 5 cm, the same rule applies to the upper surface of the grillage.

The reinforcement must be linked to the outlets of the reinforcement cages of the supports. If the length of the support reinforcement outlets exceeds the height of the grillage, they must be bent at the highest points of the grillage surface at 90°.

Mortgages for vents are mounted at the stage of fastening the formwork along with studs to fix the lower trim. The diameter of the latter is 14 - 16 mm, and they are placed strictly parallel to the supports along the line of the bottom trim beam.

Concreting the grillage

Concrete is poured carefully, completely covering the reinforcement and without creating cavities. It is recommended to use tools to compact the solution. At the end of the pouring process, it is necessary to level the top layer so that the surface is even over the entire area. Removing the formwork is permissible only after the concrete has completely hardened.

Using waterproofing

For those parts that are the above-ground component of the supports, waterproofing is necessary, since they are vulnerable to the influence of the environment and the weight of the building. In order to protect against external sources of moisture (rain, snow), wind, physical and chemical influences, you can use roofing felt or solutions designed for such tasks.

Conclusion

In general, it is obvious that a do-it-yourself columnar foundation for a frame house is a completely feasible task. In addition, installing such a foundation makes it possible to build a truly reliable foundation for the future home.

The durability of each building directly depends on the strength of the foundation underneath it. But is it always justified to install a massive continuous foundation strip if you plan to build a light wooden or frame building? Increasingly, in this case, a columnar foundation that is less expensive and can fully withstand the expected load is installed. Support pillars are made from various materials, using different methods and technologies. Next we will talk about the foundation of the building, made of concrete pillars.

Features of a columnar base

Such a foundation resembles a pile foundation, with the difference that the finished piles are driven (screwed) into the ground, and the pillars are poured or laid out in place in prepared recesses. A base made in this way makes the work much cheaper and less labor-intensive.

However, a columnar foundation is not always suitable. If the mass of the above-ground part of the building is significant (the walls are made of brick, concrete, cinder block or other heavy building material), a large area of ​​​​support on the ground is assumed. In this case, it is better to prefer the construction of a buried or shallow (depending on the soil structure) strip base with a sufficient base area.

If the house is supposed to be built from lightweight building materials (wood, foam concrete, materials for frame construction), a columnar foundation, or rather the area of ​​its support on the ground, is sufficient.

Important! The area of ​​the base of the columnar foundation is also calculated. This indicator is regulated by the number of vertical supports and their own transverse area.

A symbiosis between the strip version of the house foundation and the columnar one is the columnar-grillage foundation, when the vertical supports are additionally reinforced and connected to each other by a shallow reinforced concrete strip. This is done not only to strengthen the pillars, but also in situations where the usual shallow strip foundation of a building may be unreliable due to loose or heaving-prone soils on the site. In this case, the pillars, resting their soles on deeper and more reliable soil layers, act as piles that strengthen the main belt.

Advantages and disadvantages of a pillar foundation

The installation of concrete piles has a number of obvious advantages, such as:

• relatively low consumption of materials;
• much less labor intensive (compared to a strip base);
• greater efficiency and strength in waterlogged, loose soils and those prone to heaving;
• the ability to combine with other foundation structures.

However, there are also disadvantages that limit the construction of a columnar foundation in some cases:

• cannot be constructed in case of a large expected load on the foundation (heavy buildings);
• impossibility of constructing a basement;
• instability to horizontal movements of soil layers;
• void under the base floor (to cover it, a fence is constructed around the perimeter of the base).

That is, the construction of a foundation structure from pillars, including concrete ones, is not always permissible, but only under certain conditions. However, taking into account the trend towards accelerated construction of buildings from lightweight materials, the construction of inexpensive foundations from pillars is becoming more relevant every year.

Principles for calculating a columnar foundation

The construction of such a foundation for construction also requires calculations. It is necessary to calculate the number of support pillars, their location and the total area of ​​support on the ground.

The supports are arranged according to this principle. The pillars must be at the corners of the building and in places where the piers adjoin the external walls. The location of the remaining pillars depends on the calculations of the load on the base. However, regardless of the calculated area of ​​the sole, the distance between adjacent supports should not exceed 2-2.5 m (depending on the chosen grillage design). The minimum appropriate distance between pillars is 1 m.

If the calculation of the required total area of ​​the foundation base shows the need to further reduce the distance between the supporting structures, it means that a columnar foundation may be ineffective for the mass of a given building. In this case, it is better to choose a strip foundation for the building or its combination with pillars or piles (if the type of soil does not allow pouring a simple shallow concrete strip).

Methods for pouring concrete pillars

Before proceeding with the installation of concrete foundation supports, the site for construction is marked according to the project. With the help of stretched threads, external contours and right angles are formed. If it is planned to install a column-grillage foundation, the inner perimeter corresponding to the edge of the trench is also hammered out with threads, after which the latter is dug to the calculated depth.

The most common way to construct pillars is to pour concrete into pre-prepared forms. The process looks like this.

1. Along the perimeter of the future foundation of the building, the installation locations of the supports are marked according to the calculations performed.
2. The holes are prepared using a hand drill. Their depth depends on the degree of soil freezing in the region and the level of occurrence of stable soil layers. Even if the stable soil is shallow, the base of the pillar is 15-25 cm below the freezing level. The diameter of the supports must correspond to the calculated area of ​​each pillar.
3. A cylinder (2 layers) is formed from rolled waterproofing material (roofing felt, waterproofing), 3-4 cm deep into the already prepared recess. The longitudinal joint is secured with tape, and several fixing stitches are made around the prepared cylinder.
4. The form for pouring concrete is placed in a recess, and a sand and gravel cushion is poured onto the bottom. A reinforcing structure formed from several metal rods is welded or twisted with knitting wire. One reinforcement, usually the central one, is made 30-40 cm longer than the others so that it protrudes beyond the head of the cylinder. It will be connected into one structure with the reinforcing frame of the concrete strip.
5. The pipe formed from waterproofing material is gradually filled with liquid concrete. It is advisable to shake the cement mortar layer by layer using a vibrating device. The upper edges of the poured pillars must be located in the same horizontal direction, for which purpose the pipes are aligned using a water (laser) level before pouring. The poured pillars are allowed to stand until the concrete has completely set, after which they move on to constructing a grillage.

The most common method of arranging supports is described above. As an option, they often use ready-made pipes (PVC sewer pipes) or lay out pillars from ready-made concrete blocks. The second method is more labor-intensive, since you have to dig a hole under each post. With a large depth of placement of the base of the pillar, this is very inconvenient.

Options for grillage installation

One option is to pour a shallow concrete foundation tied and supported by columnar supports. To fill it, a trench is dug (as described above) and vertical wooden formwork is installed around the perimeter of the future building and under the internal walls.

Before pouring the tape, a reinforcing structure must be formed, which is connected to the protruding reinforcement of the pillars. This results in a monolithic structure, where a surface-constructed concrete strip rests on formed pillars. This achieves the following goals:

• cheaper design (compared to the installation of a buried belt);
• sufficient strength of the base;
• a solid base for the construction of walls (there is no need to make a fence between the supports).

After reinforcement, the formwork cavity is filled with concrete, and when it hardens, the wooden enclosing structure is dismantled. Before starting the construction of wall structures, the concrete is allowed to gain strength (mature), after which the foundation surface is waterproofed.

The second option for a grillage is to install wooden logs (beams) on top of the pillars. This design is prepared for lightweight frame, frame-panel type buildings or wooden houses. In this case, an empty space is formed between the bottom of the house and the ground surface. In order to protect the lower structures from weather influences and to improve the overall appearance of the building, a fence is made between the supports - a fence that covers the space between the ground surface and the bottom of the walls.

Collection device options

Nowadays, fencing the space between foundation pillars is done in several ways using various materials. Wood is often used to cover the base between the pillars under a wooden house. Also used as building materials:

• brick (masonry);
• concrete (pouring with reinforcement);
• sheet materials (corrugated sheets, flat slate, dense insulation (extruded polystyrene foam).

The peculiarity of the construction of the fence is that the structure should not be rigidly connected to the foundation supports and have ventilation holes. The first condition is met so that the enclosing structure does not collapse due to possible settlement of the foundation and ground movement. Ventilation holes prevent excess moisture from accumulating in the space under the building, which has a detrimental effect on building structures. One of the most popular options is to make a wooden fence like this.

1. Between the pillars along the perimeter, a trench is dug about 30 cm deep at the lowest point of the ground. The bottom of the ditch is covered with crushed stone and sand and a beam (log) is placed on the formed cushion after it has been compacted and leveled. The second beam is attached to the bottom of the building’s perimeter wall.
2. Boards are vertically attached to the beams and protected with waterproofing material from below to ground level. Afterwards, the trench is filled with crushed stone or expanded clay and concreted on top.
3. The above-ground part of the boardwalk is processed and painted or sheathed with some external finishing material. If cladding is intended, the boards are not attached continuously, but with a certain step, forming a sheathing for fixing the finishing material.

A columnar foundation made of concrete supports costs owners about half as much as a strip foundation, even taking into account the need for a back-up device. In terms of strength, the foundation of the building, made of pillars, is not inferior to a solid reinforced concrete strip.

The foundation is the most important element of any structure: from a light garden gazebo to a capital multi-story country mansion. This is the beginning of the building and its foundation in the literal sense. The strength, durability and operational safety of the building depend on how correctly the foundation is selected, calculated and executed. The question of what type of foundation to choose arises even at the construction planning stage. The optimal solution in many cases will be to build a columnar foundation with your own hands: step-by-step instructions for performing the work can give a complete understanding of the principles of its design and the intricacies of the arrangement process.

Advantages and disadvantages of a columnar foundation

Self-calculated and self-equipped columnar foundations for frame houses and buildings without basements that do not exert strong pressure on the ground are easy to implement and relatively cheap.

According to reviews, columnar foundations have a fairly impressive list of advantages:

At the same time, columnar foundations have only two disadvantages:

Types of columnar foundation

Before proceeding with the detailed design and calculation of a columnar foundation, you should decide on what site, what type and using what technology the building will be erected on it. The choice of material for the columnar foundations and the depth of their placement depend on these factors.

Materials for building the foundation

The following materials can be used for foundation foundations:

• reinforced concrete;
• rubble concrete;
• blocks;
• brick;
• a natural stone;
• tree;
• pipes: asbestos or plastic.

Foundation depth

The depth of a columnar foundation is determined by its design, technological parameters of the structure and geological characteristics of the soil in the building area.

Based on their depth, columnar foundations are divided into three main types:

To build a columnar foundation with your own hands, step-by-step instructions are needed as the most detailed and visual aid.

In general, the design of a support-column foundation is a system of supports of the minimum possible cross-section, located at points of load concentration: in the corners of the building, at the intersection of walls, under load-bearing beams, partitions, under the furnace. To determine the number of free-standing columns, the distance between them is taken to be 1.5–2.5 m. To connect the foundation supports into a single structure, a grillage is made between them.

The height of the pillars above the zero mark is individual and depends on the design features of the grillage.

Calculation of a columnar foundation

The construction of a columnar foundation begins with calculations. Most likely, to perform the calculations yourself, you will need a program like “Foundation” or some other that can be found on the Internet and downloaded for free. To work with such programs you will need the following parameters:

The technology for constructing a foundation with columnar supports also requires additional data:

As a result of the calculations made, the following values ​​​​necessary for installing a columnar foundation will be obtained:

Columnar non-buried foundation

A columnar, non-buried foundation on supports spaced at intervals of 1.5-2.5 m is used quite often. Such foundations can be erected on non-heaving and slightly heaving soils, despite the fact that the building (wooden or panel house, bathhouse, outbuilding, outbuilding or summer kitchen) has a small area and, accordingly, light weight. Moreover, if construction is carried out on rocky, coarse-grained or non-moving soil, this type of foundation can be installed under a fairly large house made of logs or timber. It is also possible to build a foundation on non-buried supports, provided that the influence of heaving forces on the structure is reduced. To do this, the soil under the supports is replaced with a sand cushion.

As a material for pillars, it is possible to use concrete, rubble concrete, sand concrete or concrete blocks for the foundation, the sizes and prices of which are very diverse. However, most often they take foundation blocks measuring 20x20x40. The price of such a foundation, as well as the number of blocks required for its construction, can be calculated independently or using an online “foundation” calculator. You can also make a columnar foundation from brick with your own hands, but it must be taken into account that the use of silicate or ceramic bricks with low frost resistance is unacceptable.

Work on the construction of a non-buried columnar foundation from ready-made blocks can be divided into several main stages:

When building a foundation using 20x20x40 blocks with your own hands, video clips and step-by-step instructions will help you understand the technology of work, understand the process and more accurately estimate financial costs.

Shallow columnar foundation

A shallow foundation is one of the most popular types of columnar foundation. The funds and effort that its device requires are minimal, and the range of applications for frame-type buildings is very wide.

As a basis for a frame house or a light bathhouse, a columnar foundation is often made using pipes as formwork for the concrete mixture. Since the reinforced concrete pillar will take the entire load, the material of the pipes does not matter much: both plastic and asbestos pipes, usually used for installing sewer networks, are suitable.

The diameter of the pipes depends on the load. For light buildings such as gazebos or extensions, 10 cm is enough; for log buildings, pipes of 25-30 cm are needed. The amount of concrete is ultimately determined by the diameter of the pipe. For 10 m of a pipe 10 cm in diameter, you will need 0.1 m3 of concrete, a 20 cm pipe will require 0.5 cubic meters, and a 30 cm pipe will require 1 cubic meter. The calculation was made taking into account the concrete base pad.

The scheme for carrying out work on constructing a columnar foundation from asbestos pipes with your own hands (a video of the process can be found on the Internet) is generally as follows:

• preparation of the construction site - removing debris, removing foreign objects, removing turf and leveling. Marking the perimeter of the future building, corners, internal walls and their intersections. Places for installing foundation supports are marked with pegs;
• Then, holes are made in the ground using a hand-held post drill. The depth of the well should be 20 cm greater than calculated: for the installation of a sand cushion;
• installation of a sand cushion with mandatory compaction and spilling of sand with water. After the final absorption of water, pieces of roofing material should be laid on the bottom in order to prevent moisture from the concrete mixture from escaping into the sand;
• installation of pipes in wells with a height reserve of at least 10 cm. Leveling pipes and securing them in wells using wooden blocks. If groundwater is close to the ground, the pipes must be coated with bitumen mastic to the ground level for waterproofing;

• then the base of the pipe, 40-50 cm deep, is filled with a thoroughly mixed concrete-gravel mixture (1 part cement and 2 parts sand, diluted with water to form a batter, combined with 2 parts fine gravel). Immediately after pouring, the pipe is raised to a height of 15-20 cm and left in this position until the cement has completely hardened. This is necessary to create a foundation that resists pushing out during soil heaving;
• after the concrete has hardened, the pipe should be waterproofed from the outside with roofing material and the well should be filled with sand, gradually poured and compacted;

• Reinforcement is placed inside the pipes, after which the remaining part of the pipe is poured with concrete;
• after the concrete has completely hardened - 2-3 weeks later - construction work continues. It should be added that it would be useful to waterproof the foundation with polymer or bitumen solutions.

Using the same scheme, it is possible to install a columnar foundation made of plastic pipes with your own hands. Videos and photos will help you navigate the intricacies of the work process, which is generally simple.

Columnar foundation with grillage

The grillage is a system of rand beams and strapping beams. It rigidly fixes the foundation, preventing it from moving in the horizontal plane or overturning the entire structure. In the presence of a grillage, the load from the structure is distributed evenly across all installed columnar supports, resulting in increased stability and resistance to destruction.

To facilitate understanding of the process, the necessary work is outlined in stages.

Preparation and installation of supports:

• In any case, the initial stage of preparation for the construction of the foundation is the arrangement of the construction site. After removing debris, etc. the turf and top layer of soil are removed along the perimeter of the future foundation;
• for supports it is necessary to dig holes 20 cm deep than the freezing level of the soil. The width of the pit should be 40 cm greater than the width of the wall, since 20 cm are added on each side for formwork and spacers;
• at the bottom of each pit, a 20 cm high cushion of sand-crushed stone mixture, spilled with water and well compacted, is made. The cushion is lined with roofing felt or polyethylene so that moisture from the concrete poured into the pit does not go into the ground;

• boxes for formwork are assembled from boards 20 mm thick;

• It is recommended to thoroughly moisten the formwork installed in the pits to prevent the absorption of moisture from the cement mortar and facilitate removal;
• After installing the formwork, a frame made of reinforcement is placed in the pits. The frame is assembled separately, from a rod 10-14 mm in diameter. The length of the rods is selected in such a way that when the concrete hardens, their ends protrude 30-40 cm above the ground level;
• the concrete mixture is poured continuously, in layers of 20-30 cm, leveling with a vibrator to avoid the formation of air bubbles;
• the formwork is removed after 3-4 days, the surface of the supports is treated with any suitable waterproofing mixture and the remaining part of the pit is covered with sand. Before backfilling, it is also possible to insulate the foundation with extruded polystyrene foam.

Grillage arrangement:

There are two options for installing the grillage: laying it on the ground or raising it above its surface. The advantage of the second method is the elimination of the effects of heaving forces:

Cost of work on installing a columnar foundation

The total cost of a columnar foundation is the sum of the cost of materials and the cost of the work itself. In most cases, it is significantly lower than the cost of other types of foundations, since almost all types of columnar foundations can be built with your own hands. Videos and photos, instructions and guides found on the Internet are also usually cheap or free.

You can calculate the cost of most types of columnar foundations yourself using special online calculators or programs. Many of them are quite easy to find on the Internet, free and have an intuitive interface.