How to make a columnar foundation yourself. How to make a columnar foundation with your own hands. Columnar base in terms of laying depth

Depending on what kind of soil is on the construction site, you have to choose the right foundation structure. If the soil is soft, mobile, with flooding or with a high level of groundwater, then a columnar foundation is indispensable. With the seeming simplicity of installation work, the process of building a columnar structure requires an accurate calculation of the bearing capacity of each support post.

But among all types of foundations for a house, this one is the cheapest in terms of material consumption, moreover, it is possible to use various building materials for it. Let's look at step-by-step instructions for building a columnar foundation with your own hands.

Advantages and disadvantages

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

quick construction of the foundation;
there is no need to use construction equipment;
the simplicity of the work carried out, so making a columnar foundation with your own hands is not a problem;
the absence of additional measures related to the thermal insulation of the foundation;
columnar foundation is easy to repair;
you can build this species on frozen soils;
the service life of the poles with strict adherence to technology is up to 100 years.

As for the shortcomings, there are not so many of them:

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

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

General scheme of the device

The general scheme of construction work can be identified by several main stages. They, in principle, do not differ from the construction of any type of foundation.

The bearing capacity is calculated taking into account the number of supporting pillars and the weight of the building.
A general drawing of a columnar foundation is made with an exact indication of the distance between the posts, the cross section of the supports and the height of the protrusion above the ground.
Preparatory work is underway. This is marking exactly according to the plan, earthen with digging holes - wells, making reinforcing frames, pouring pillows into holes, waterproofing and installing frames. If there is a need, then the formwork of the basement is assembled.
Making a concrete solution and pouring it into prepared wells, followed by the removal of air by baying the mixture. If bricks or blocks are used as the material for the columnar foundation, then they are laid.

The entire node of the columnar foundation is the union of the columns with a horizontal tape, which is called a grillage. It can be concrete, metal, wood or be the lower crown of a log cabin.

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

Material classification

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

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

Monolithic reinforced concrete pillars

This is the strongest and most reliable design. Such a foundation for pillars has high tensile and compressive strength. Of course, if you take into account the correct reinforcement.

At the same time, if you correctly distribute the racks around the entire perimeter of the house, taking into account the required section of the supports, then multi-storey buildings can be erected on such a foundation.

We add that the columnar reinforced concrete foundation is constructed in cases where it is necessary to fill it to a sufficient depth, and more often below the level of soil freezing. It perfectly withstands heaving of the soil, but is afraid of contact with groundwater. Therefore, it is necessary to take care of the waterproofing of the supports.

Asbestos cement pipes for the construction of pillars for the foundation are not often used. Although they feel great in any soil.

Their bearing capacity is not high, but it is not required, because the pipes in the foundation structure act as formwork.

Pillars made of plastic pipes

Here the situation is the same as with asbestos-cement. That is, plastic pipes act as a formwork. They do not corrode, do not collapse under the influence of water, so they do not need waterproofing. The only thing is that it is necessary to correctly pour the supports under the foundation. Namely: install a reinforcing frame in them and pour concrete mortar.

Of bricks or blocks

Brick pillars for the foundation should be treated as the most long-known structures. From the history of European and Russian architecture, they are "long-livers".

Until now, brick pillars stand under huge buildings, and, apparently, they will stand for more than one century.

Because the attitude towards the choice of bricks in those ancient times was serious. Be sure to use burnt bricks of the highest quality. Therefore, when building a house on a columnar foundation, this requirement must be taken into account.

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

Pillars built of stone can be attributed to block structures. A good option, strong enough, but such supports cannot withstand the exploits of the soil. Therefore, when a house is being built on a slope, it is better to refuse stone pillars. As a replacement for them - the foundations of rubble concrete. This is when stones are poured into the prepared formwork, and then they are poured with concrete mortar.

Such a columnar foundation, like a brick one, has been used in Russia for a long time.

Today it is not so in demand, but, for example, under baths installed by a river or lake, they are often found.

Gotta give credit right choice wood. The stronger it is, the longer the life of the pillars. At the same time, protective measures must be taken very carefully.

Treatment of the entire column with antiseptic compounds.
Processing of the part deepened into the ground with bituminous mastics with gluing a layer or two roofing material.

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

Mostly wooden racks are used for light structures, although even a hundred years ago, boyar mansions of several floors were built on them.

Frost heaving is the force that is taken into account in the first place when designing a columnar foundation.

This is very dangerous pressure, which, if not bookmarked correctly, can break the foundation of the house.

Therefore, a large number of options for the construction of buildings are considered from the point of view of the impact on the foundation structure of frost heaving.

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

But often a light structure cannot exert enough pressure on the piers to contain the forces of frost heaving. That is, even when laying to a great depth, the foundation will be subjected to deformations. Therefore, when building a columnar foundation with your own hands, it must be borne in mind that there are two more positions: shallow and superficial.

Unburied

Non-buried columnar foundation or surface - these are all the same racks, only their laying depth does not exceed 30 - 40 cm. Often they are simply built on the surface of the soil, having previously made a pillow and waterproofing. Designers refer this variety to those foundations, the laying depth of which does not exceed a third of the level of soil freezing. From our example: 120: 3 = 40 cm.

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

Shallow

The shallow foundation from its name suggests that it is buried in the ground, but not to a great depth. In any case, not below the level of its freezing. Designers are laying the depth at the rate of 0.5 - 0.7 of the depth of freezing of the earth. Again - from our example: 120 x 0.5 \u003d 60 cm.The main requirement for this design is not to touch groundwater.

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

Do-it-yourself step-by-step construction instructions

We turn to the main question, how to properly make a columnar foundation with your own hands. The scheme of work has already been described above, where the first stage was to carry out calculations and draw up a project. If a house is being built on a columnar foundation, then this stage of construction is best left to specialists. Indeed, in order to accurately make all the calculations, it is necessary to take into account a large number of different indicators and nuances. For example:

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

Of course, you can use online calculators, but not for solid houses. For baths, verandas, sheds it can be used. And then no one gives a guarantee of one hundred percent correctness of the calculations.

Video

Video on how to make a columnar foundation yourself.

Marking and earthworks

So, if the project of the building is in hand, then the designers must have made the binding of the foundation to the terrain in it. This makes it easier to find its location on the plane. Usually, the binding is carried out to the boundaries of the site, indicating the distance from the foundation structure to these very boundaries. Therefore, before marking the pillars, it is necessary to postpone these same dimensions from the borders and determine the perimeter of the building.

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

sod is removed to a depth of 20 cm;
the installation sites of the pillars are marked: at the corners of the building and between them with the necessary distance, which is determined by the project;
wells are made in the ground with a garden or electric drill, the depth and section of which are also determined by the project.

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

A pillow is a layer of sand 20–30 cm thick. It is poured into wells and rammed with improvised means. It can be a beam, a wooden lath, a log of a small section. Often a pipe is used, to the end of which a metal plate is welded.

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

Formwork must be dealt with carefully. After all, much will depend on what kind of soil is located on the construction site.

If the soil is clayey, that is, strong, then there is no need to make formwork as such. Clay itself, like a monolith, does not collapse or collapse.
If the soil is weak sandy, then formwork will have to be installed in the well. At the same time, it is necessary to take into account what kind of section the designers have determined in terms of shape: rectangular or round. If the second, then pipes are used as formwork: plastic, asbestos-cement or metal. If the first option, then the well will have to be expanded, made of a rectangular section, and formwork made of boards or other flat materials should be installed in them. This is a large amount of earthworks, so this form for buried structures is rarely used.

As for the first position, usually a roofing material rolled into a tube is laid inside the shaft. It forms the walls of the foundation and will continue to perform the functions of waterproofing. Roofing material formwork is a must.

Regardless of whether the formwork will be installed in the well or not, it is necessary to form a pillar in the basement. So, here the formwork is going to be sure.

Reinforcement of pillars is carried out without fail, after all, it is the reinforcement laid in concrete that makes it possible to restrain loads from the forces of frost heaving.

In the project, the number of reinforcing bars, their form of connection to the frame and diameter must be indicated. Therefore, the reinforcement is simply cut into pieces of the desired length and into the frame.

Its cross-sectional shape can be triangular, square or round. The main task is to correctly fold the reinforcing bars relative to each other at the required distance. Then clearly tie them together with wire.

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

The length of the reinforcement bars is cut, taking into account that their ends will be attached to the grillage reinforcement cage. Therefore, the rods are cut 10 - 30 cm longer. So that they stick out this size above the basement of the pillars.

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

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

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

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

V = SxH, where S is the area of the pipe and H is its length or installation depth. The area can be found using the formula: S \u003d πD² / 4 \u003d (3.14 × 0.15²) / 4 \u003d 0.018 m³. If converted to liters, it will be 18 liters. In fact, these are two buckets of solution.

Pipes are filled with concrete, tapping on the formwork, punched to remove air. In this state, the poles must stand for 28 days. During this time, concrete will gain its branded strength.

grillage device

We will assume that the grillage will be monolithic according to the project. This means that under it it will be necessary to build a formwork from any flat materials.

It is made on weight, therefore, supports made of bricks, blocks, boards, logs and other materials are installed under the lower shields. The formwork is assembled into a rectangle with a complete and strong fastening of the panels to each other.

A reinforcing frame is placed in it. Usually these are two vertical gratings connected with 6 mm wire rod or 6 - 8 mm reinforcement. Be sure to fasten the reinforcing cage of the grillage with pieces of reinforcement sticking out of the pillars.

This node of the columnar foundation is subjected to serious loads. Therefore, the fastening of two reinforcing structures must be approached carefully. Concrete solution is poured with ramming and bayonet. After 7 days, the formwork is dismantled, after 28 days the foundation can be loaded.

Summarizing

You can not apply to the markup in large allowances. It is necessary to accurately drill wells to the required depth. Even a few centimeters can play a bearing role in extreme situations. The foundation device is A complex approach to its construction, where there is no place for mistakes and miscalculations.

In contact with

If a a private house is made using frame technology or from light building materials, then the most optimal foundation support for it is pillars with tape reinforced concrete or steel grillage. Such a base exerts minimal pressure on the ground and is quite simple in independent execution. Correctly according to all standards, it is not difficult to make a columnar foundation with your own hands, but such a design is relatively inexpensive.

What is a column foundation?

Pillar foundations are just perfect for light buildings (garages, garden houses, sheds, bathhouses). However, with the right calculation, frame or foam concrete cottages can also be placed on them. But for a brick house with thick walls, it is better to look for another option.

But much in this matter depends on the total weight of the building. After all, slate or ceramic for a roof is much heavier than roofing material or a light metal profile. In the project of the columnar foundation and the whole house, it is necessary to take into account all the materials used in the construction - from the floor and walls to the roof. And it is worth trusting only a qualified specialist to prepare calculations.

Structurally, such a base is a pile field of pillars made of various materials and connected on top with a grillage. If the soil on the site is unstable, then building a foundation for the house in the form of a recessed reinforced concrete monolith is not very rational. Columnar piles here greatly benefit in terms of cheapness of work. With proper design, they are not afraid of high groundwater and soil heaving.

Varieties of columnar foundation

The pillars of the foundation under consideration according to the technology of immersion in the ground can be hanging or retaining. In the first case, short supports are held in the ground due to friction forces, and in the second case, they are made longer so that the base rests on a solid soil layer. Due to the need to carry out complex calculations and immerse a large number of piles, the hanging option is practically not used in private housing construction.

According to the structural arrangement of the grillage, they are divided into:

Unburied - the grillage part hangs on poles above the ground at a height of up to half a meter;

Shallow - the grillage is immersed in the soil by 40–60 cm;

Buried - with the laying of a reinforced concrete tape on supports below the freezing depth at the construction site of the soil.

Shallow base scheme

The latter option provides little benefit in terms of savings on building materials. In the construction of country houses, such a foundation is used very rarely. Most often, for cottages, builders choose an unburied grillage, hanging along the entire length on columnar supports. This technology eliminates problems with heaving and makes it possible to make a grillage structure from a steel channel, which greatly simplifies and speeds up the process of building a foundation.

Advantages and disadvantages of the foundation on pillars

The list of advantages of a columnar foundation is quite extensive, it includes:

No need for lifting special equipment;

Possibility of arranging a pile field on slopes;

High construction speed;

No need for preparatory leveling of the construction site;

The simplicity of the technology that allows you to make it yourself;

Excellent resistance of posts to heaving;

Cheap construction.

If it is designed and done correctly at the construction stage, then it will quietly last more than half a century. He is not afraid of seasonal heaving of the soil, as long as the rise of the earth does not affect the grillage. And the technology of work is so simple that it is quite possible to do everything alone, without involving third-party highly professional and expensive installers.

Among the shortcomings of foundations on pillars for houses outside the city are:

Low resistance of supports to lateral loads;

Soil restrictions (for swampy areas you should not choose).

Restrictions on the bearing load (for heavy concrete or brick houses, such a base is not suitable by definition);

The impossibility of building a basement.

The main disadvantage of the pile-strip foundation under consideration is the possible destruction of the supports under strong lateral impacts. If the site has highly mobile soils in the horizontal plane, then the diameter of the piles will have to be greatly increased, which will affect the construction price. Or, in general, it will be necessary to select a different type of foundation for the house being built.

Cons - side loads

Instructions - how to equip the foundation yourself

Columnar foundations are being built according to technology in four stages:

Earthworks with drilling holes for supporting pillars and arranging sand cushions at their bottom.

Installation of fixed formwork for foundation supports, followed by pouring concrete or laying them out of brick or concrete blocks.

The device for this type of pile-grillage foundation of the upper distributing load of the part is made of reinforced concrete, steel channel or wood.

Waterproofing of the entire structure and sheathing of supports along the perimeter of the building with siding or corrugated board.

Everything is quite simple, but there are a number of nuances in this process. The first of them - regardless of the level of foundation of the grillage, the retaining piles of the columnar version of the foundation for a private low-rise building should be immersed deeper than the freezing point. To speed up the work, in some cases it would be best to involve specialized equipment with a drill.

The base supports themselves can be made of:

Reinforced concrete poured into an asbestos-cement pipe;

FBS (prefabricated reinforced concrete blocks for foundations);

natural stone.

Below is a step-by-step photo instruction for a columnar foundation on foam blocks:

We transfer the foundation plan to the area - we mark future borders with pegs

Digging holes

We measure the zero level of the foundation with a hydraulic level - its height

We expose the next levels of blocks of our foundation

By level we make all the other pillars

We spread the roofing material on the posts for waterproofing

It is also possible to use steel screw piles. But this will already be more than one of the variations of the pile-screw foundation. Previously, supports were made even from moisture-resistant larch. However, today most private developers prefer to put something more durable and concrete under their house.

Supports are placed at intervals of 1.5–2.5 meters so as to be at the corners of the building, at the intersection of internal walls and the laying of load-bearing beams, as well as under stoves and fireplaces. These are the main stress points. Some of them, the grillage is quite able to distribute throughout the structure. But ideally, the main weight should fall just on the supporting piles on which the column-strip foundation rests.

When choosing a brick, you should immediately exclude its silicate variety. And ceramic should be taken with the highest possible frost resistance. In general, if you do not want to knead and pour concrete, then it is best to prefer FBS. These blocks were originally intended for the construction of foundations for various buildings.

By design, a concrete grillage on top of the pillars is a small strip foundation. For him, a separate formwork is assembled with reinforcement made of steel bars of 10-12 mm in it. After they are bundled, the finished reinforcing belt will only need to be poured with concrete mortar with a grade of at least M-300. At the same time, for wooden buildings, the grillage part is often made entirely of timber. In many cases, it is quite enough to redistribute the loads.

For waterproofing the elements of the columnar base, you can use roofing material or liquid bituminous mastic. Even soft tiles will do, if it remains unused when covering the roof on an already built building.

Where is it better to use the foundation on pillars

It is not difficult to independently build a columnar foundation with a grillage on top of the supports with your own hands. The step-by-step instructions given and the nuances of manufacturing such a support described above will help even a novice builder cope with the task. Everything is done in just a few days. True, you will have to wait up to a month until the concrete in the grillage hardens, but there is no other way.

House example

If the building is planned to be erected light, then it will be most profitable to make such a foundation for it in terms of cost and timing of work. You can even prepare a project yourself. But it is better to order the calculations for the foundation under a massive cottage from a professional.

Only a professional builder can design and implement a support-column foundation with his own hands according to the recommendations of SP 50.100, 22.13330, 32.13330, 45.13330, 27.13330. These grounds are too unreliable; the results of geological surveys should be studied in as much detail as possible.

The technology of the grillage on the pillars depends on the construction technology of the building for which the foundation is being built. Columnar bases are made of structural materials:

reinforced concrete - pouring into the formwork in place, installation of the finished product in a glass 1F or 2F;
tree - logs with a widening sole;
brick - clinker, full-bodied ceramics;
blocks - wall, only with dense fillers, hollow;
rubble concrete - a stone is introduced into the formwork after partial filling with ready-mixed concrete.

In addition to the tape grillage, a slab construction can be used. This is the only option for a columnar foundation suitable for a brick cottage on sandy soils with a groundwater level (GWL) below 1 m. In all other cases, columnar foundations are created for log cabins, half-timbered houses, buildings from SIP panels, panel, frame buildings.

Types of columnar foundations according to the depth of laying

Depending on the geological characteristics in the building spot, wall materials, columnar foundations are:

buried - below the freezing mark, GWL, but may not reach the bearing layer;
shallow - 40 - 70 cm below ground level;
not deepened - instead of the removed fertile layer, non-metallic material is filled up, the underground part is absent.

The height of the pillars above the zero mark depends on the design of the grillage and the technological solutions used in the project. The head is embedded in a monolithic grillage by 20 cm, the beams of the prefabricated grillage are installed on top of the piles. Therefore, the height above the surface is always individual. The construction of buried pillars is justified if there is a bearing layer at this mark. A shallow foundation of this type is stabilized by soil against lateral shear. Unburied has a minimum construction budget.

Column foundation design

The fundamental difference between columnar foundations and piles is the occurrence of the sole, as a rule, above the freezing mark, the level of groundwater level, layers with a bearing capacity. Therefore, in any case, the supporting-columnar foundation is protected from heaving forces and movements in several ways:

sand cushion under the base plate, if the base of the foundation is located below the freezing depth, a sand cushion is not required;
draining the soil with a drainage system;
insulation of the blind area and basement.

For the last two activities, open excavation is required in the building spot.

Even with a slight deepening of the pillar itself, it will be necessary to take into account the thickness of the broadening (20 - 40 cm plate), the underlying layer (pillow of 20 cm sand + 20 cm crushed stone). In addition, you will need an annular ditch for laying drains, access for workers to the lower level. Therefore, the size of the well and trench increases several times, it is inconvenient to work from the ground at a depth.

The manufacture of columnar foundations, by analogy with bored piles, is a gross violation of technology. The sole is difficult to widen, there are heaving forces under it. On the side walls without backfilling with sand, the tangential forces of the same processes act.

Thus, the correct design of the columnar foundation is:

preparation - sand (layer thickness 20-40 cm) with layer-by-layer compaction with a vibrating plate, pouring;
footing - serves exclusively for laying waterproofing, is a 5 cm screed;
stepped plate (sole) - distributes the load due to the increased surface of the sole;
column - a vertical stand made of monolithic or prefabricated concrete;
grillage - reinforced concrete products, monolithic structure, timber or rolled metal (channel, I-beam).

Unlike piles, pillars do not have spatial rigidity, therefore grillage beams must not only rest on their heads, but be attached to each pillar for tying into a single structure.

Step-by-step instruction

Due to the variety of construction operations of the grillage on the pillars, a step-by-step instruction is necessary for an individual developer as a guide. If you skip a stage, you will have to redo the work later or return to it, spending more effort and money.

For example, the instruction recommends laying drains at the excavation stage. If you forget about them at the beginning, remember when landscaping the territory, the trenches will have to be dug again, the construction will be delayed, the site will again be clogged with soil. The height of the pillars is selected 20 cm above the bottom of the grillage for immuring in concrete.

Below we will tell you how to make a columnar foundation with your own hands correctly.

Geological surveys and calculation

The technology for constructing a columnar foundation depends on the results of geotechnical surveys, wall material, and construction technology. For example, it is forbidden to leave unloaded poles in the winter even when tied with a grillage.

Prefabricated loads (the weight of the building, residents, furniture, belongings, wind, snow loads) may not be enough to compensate for the extrusion forces, or the building will gradually sink into unstable ground with excess weight.

In contrast to the test screwing of screw piles in the technology of the same name to find the depth of the bearing layer, full-scale surveys are required here, costing at least 30 thousand rubles. The designer needs the following information:

layered arrangement of layers;
composition and characteristics of the top three layers;
GWL level;
freezing mark.

The cross section of the pillars should be more than 40 x 40 cm for concrete or brickwork, 20 x 20 cm or 20 cm in diameter for a monolithic reinforced structure.

Marking and earthworks

Unlike bored piles that reach the bearing layers, it is much more difficult to pour the pillars into the wells. The main problem will be the lack of sand backfilling of the sinuses:

after a few years, the soil near the pile body will self-compact;
pick up moisture, freeze in winter;
heaving forces will pull out the pillar, like a carrot from a garden;
in the presence of a lower broadening, the column will rise up by heaving forces, the soil will crumble under the sole;
the plate will not allow you to pull out the entire column, but it will no longer be able to stand in place.

We dig holes for the widening of the columnar foundation.

Therefore, the only correct way would be to mark the trenches, taking into account the width of the sole, the drainage contour, and the work on the construction of the formwork. Instead of a square shaft of 40 x 40 cm, you will have to take out much more soil of 1 x 1 m at least. This takes into account the thickness of all layers of the foundation cake, the height of the groundwater level. If the last characteristic is slightly lower than a meter, you need to go deep by 0.6 m, no more.

Training

The construction of a monolithic foundation of a dwelling by default should provide protection against corrosion and destruction. In the absence of oxygen, the only aggressive environment underground remains moisture, which should be removed from the sole by drains, stopped at the surface of concrete structures along the entire height with a waterproofing carpet.

Construction is carried out in stages:

layered backfill - 20 cm of sand with moisture, vibrocompaction twice (total height 40 cm);
footing - screed height 5 cm, no reinforcement;
waterproofing - 2-3-layer carpet of rolled material on a fiberglass basis;

Reinforcement

The technology of the armo-belt device of a column with an expanded sole has the form:

knitting a reinforcing mesh to the size of the slab, taking into account the side protective layers (40 mm from the formwork to the metal) with a cell of 15 x 15 cm or 20 x 20 cm with a thickness of 12 - 16 mm;
docking to the grid of rods bent at a right angle 12 - 16 mm, protruding above the sole of the grillage by 20 - 30 cm (usually 4 pieces in the corners, one in the middle of each side);
vertical bars are reinforced with horizontal square clamps from reinforcement 6 - 8 mm;
the design is installed on a waterproofing carpet, which is produced beyond the dimensions of the sole by 10-15 cm, for subsequent bending onto the side edges of the sole.

It is forbidden to lift the reinforcing structure with metal scraps, bricks, crushed stone to provide a protective layer.

Post widening

The construction of the sole is the pouring of the slab into the formwork. The broadening area is twice the section of the column, the height of all elements is a multiple of 30 cm. The formwork is simple - four boards fastened with screws, corners or bars at the bottom of the pit, trench.

Reinforcement of broadening and column.

The sides of the formwork should be slightly above the design level in order to qualitatively level the surface of the concrete. The permissible error in the horizontal plane is 1 cm. The pouring is carried out after the installation of the reinforcing structure.

formwork

We install and strengthen the formwork for the columnar foundation.

Drainage and waterproofing

From the perimeter of the building can be made at any stage, from the pit to the backfill. For the installation of drains, an annular trench is required with a single slope to the underground tank. Dornite or geotextiles are spread at the bottom, 10 cm of crushed stone are backfilled. Perforated pipes in the filter are laid in it, manholes are installed. After that, the communication is covered with another 10 cm of rubble, covered with the remains of geotextiles.

Waterproofing device - several technologies with different materials:

impregnations - contain penetrating additives, change the molecular structure of concrete, making it waterproof throughout the depth;
rolled materials - Bikrost, TechnoNIKOL and other analogues on a fiberglass basis, laid in two layers;
coatings - mastics on an epoxy, bituminous basis;
paints - enamels based on bitumen resins.

Most often, combined methods are used to achieve a 50-70 year resource. Roll, coating materials will have to be updated every 15 years.

Ready columnar foundation with reinforced concrete grillage.

backfilling

After the drainage device, a continuous waterproofing layer on the concrete surface, it is necessary to protect the side surfaces from heaving forces. The sinuses are covered with sand, compaction is necessary, since loose soils are extremely unstable. The chernozem of the fertile layer is saturated with organic matter, sits down after it rots. In the rest of the soils there is clay that swells in frost. Therefore, only non-metallic materials are used, in which heaving is less.

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Depending on what kind of soil is on the construction site, you have to choose the right type of foundation structure. If the soil is soft, mobile, with flooding or with a high level of groundwater, then a columnar foundation is indispensable. With the seeming simplicity of installation work, the process of building a columnar structure requires an accurate calculation of the bearing capacity of each support post. But among all types of foundations for a house, this one is the cheapest in terms of material consumption, moreover, it is possible to use various building materials for it. Let's look at step-by-step instructions for building a columnar foundation with your own hands.

Advantages and disadvantages of a columnar foundation

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

quick construction of the foundation;
there is no need to use construction equipment;
the simplicity of the work carried out, so making a columnar foundation with your own hands is not a problem;
the absence of additional measures related to the thermal insulation of the foundation;
columnar foundation is easy to repair;
you can build this species on frozen soils;
the service life of the poles with strict adherence to technology is up to 100 years.

As for the shortcomings, there are not so many of them:

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

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

General scheme of the column foundation device

The general scheme of construction work can be identified by several main stages. They, in principle, do not differ from the construction of any type of foundation.

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

The entire node of the columnar foundation is the union of the pillars with a horizontal tape, which is called a grillage. It can be concrete, metal, wood or be the lower crown of a log cabin.

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

Classification of columnar foundations by material

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

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

Monolithic reinforced concrete pillars

This is the strongest and most reliable design. Such a foundation for pillars has high tensile and compressive strength. Of course, if you take into account the correct reinforcement. At the same time, if you correctly distribute the racks around the entire perimeter of the house, taking into account the required section of the supports, then multi-storey buildings can be erected on such a foundation.

Asbestos-cement pillars

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

Pillars made of plastic pipes

Here the situation is the same as with asbestos-cement. That is, plastic pipes act as formwork. They do not corrode, do not collapse under the influence of water, so they do not need waterproofing. The only thing is that it is necessary to correctly pour the supports under the foundation. Namely: install a reinforcing frame in them and pour concrete mortar.

Of bricks or blocks

Brick pillars for the foundation should be treated as the most long-known structures. From the history of European and Russian architecture, they are "long-livers". Until now, brick pillars stand under huge buildings, and, apparently, they will stand for more than one century. Because the attitude towards the choice of bricks in those ancient times was serious. Be sure to use burnt bricks of the highest quality. Therefore, when building a house on a columnar foundation, this requirement must be taken into account.

Pillars built of stone can be attributed to block structures. A good option, strong enough, but such supports cannot withstand the exploits of the soil. Therefore, when a house is being built on a slope, it is better to refuse stone pillars. As a replacement for them - the foundations of rubble concrete. This is when stones are poured into the prepared formwork, and then they are poured with concrete mortar.

wooden poles

Such a columnar foundation, like a brick one, has been used in Russia for a long time. Today it is not so in demand, but, for example, under baths installed by a river or lake, they are often found. We must pay tribute to the correct choice of wood. The stronger it is, the longer the life of the pillars. At the same time, protective measures must be taken very carefully.

Treatment of the entire column with antiseptic compounds.
Processing of the part deepened into the ground with bituminous mastics with gluing a layer or two roofing material.

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

Mostly wooden racks are used for light structures. although even a hundred years ago, boyar mansions of several floors were built on them.

Types of columnar foundations according to the depth of laying

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

Columnar non-buried foundation

Non-buried column foundation or surface - these are all the same racks, only their laying depth does not exceed 30 - 40 cm. Often they are simply built on the surface of the soil, having previously made a pillow and waterproofing. Designers refer this variety to those foundations, the laying depth of which does not exceed a third of the level of soil freezing. From our example: 120: 3 = 40 cm.

Shallow columnar foundation

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

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

Foundation with grillage

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

Do-it-yourself step-by-step construction instructions

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

Marking and earthworks

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

sod is removed to a depth of 20 cm;
the installation sites of the pillars are marked: at the corners of the building and between them with the necessary distance, which is determined by the project;
wells are made in the ground with a garden or electric drill, the depth and section of which are also determined by the project.

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

Pillow device

A pillow is a layer of sand 20 - 30 cm thick, which is poured into wells and tamped with improvised means. It can be a beam, a wooden lath, a log of a small section. Often a pipe is used, to the end of which a metal plate is welded.

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

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

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

Attention! Regardless of whether the formwork will be installed in the well or not, it is necessary to form a pillar in the basement. So, here the formwork is going to be sure.

Reinforcement

The reinforcement of the pillars is carried out without fail, because it is the reinforcement laid in concrete that makes it possible to restrain the loads from the forces of frost heaving. In the project, the number of reinforcing bars, their form of connection to the frame and diameter must be indicated. Therefore, the reinforcement is simply cut into pieces of the desired length and tied into a frame. Its cross-sectional shape can be triangular, square or round. The main task of the assembly manufacturer is to correctly fold the reinforcing bars relative to each other at the required distance and clearly tie them together with wire.

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

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

Pouring concrete

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

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

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

Pipes are filled with concrete, tapping on the formwork, punched to remove air. In this state, the poles must stand for 28 days. During this time, concrete will gain its branded strength.

grillage device

We will assume that the grillage will be monolithic according to the project. This means that under it it will be necessary to build a formwork from any flat materials. It is made on weight, therefore, supports made of bricks, blocks, boards, logs and other materials are installed under the lower shields. The formwork is assembled into a rectangle with a complete and strong fastening of the panels to each other.

A reinforcing frame is placed in it, usually these are two vertical gratings connected by a 6 mm wire rod or a 6 - 8 mm reinforcement. Be sure to fasten the reinforcing cage of the grillage with pieces of reinforcement sticking out of the pillars. This node of the columnar foundation is subjected to serious loads, therefore, the fastening of two reinforcing structures must be approached carefully. Concrete solution is poured with ramming and bayonet. After 7 days, the formwork is dismantled, after 28 days the foundation can be loaded.

Summarizing

As you can see, it is necessary to approach the construction of a columnar foundation with your own hands with a thorough analysis of all stages of the ongoing construction processes. You can't make mistakes in the first place. You can not apply to the markup in large allowances. It is necessary to accurately drill wells to the required depth. Even a few centimeters can play a bearing role in extreme situations.

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

Do-it-yourself column foundation step by step instructions

The technology of mounting a columnar foundation with your own hands is not difficult, the main thing is to follow step by step instructions then you will have a solid foundation

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

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

Budget columnar foundation with grillage

If you build a columnar foundation with your own hands, then the first step is to make its exact calculation. Why is it necessary to calculate the mass of the bath, and here it is important to take into account its snow load - in the Moscow region it is about 100 kg per square meter of area. As well as the weight of the internal filling of the bath: furniture, stove and people - that is another 100 kg per meter.

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

Stage I. Making pits

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

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

And so that the cement milk is not absorbed into the soil, pieces of roofing material or even ordinary plastic bags will help.

Stage II. Pole installation

A piece of asbestos-cement pipe is taken, with a diameter of 10 cm, two reinforcing bars with a diameter of 1.2 cm are placed in it, and all this is placed on the “shoe”. You need to fill it with the same sand concrete, simultaneously tamping everything with another rod. From above - either a bolt, or another piece of reinforcement.

Stage III. Second drilling

To harden concrete after recent actions– it takes about 4-5 days. Next, you can start the second drilling. To do this, you need a drill - they make a hole with a diameter of 30 cm and always below the estimated freezing depth. In this opening, you need to quickly insert the resulting pillar - so that it does not crumble. Its strength can reach up to 11 tons of load.

Stage IV. Construction of a grillage

A grillage for such a columnar foundation can be made of metal, concrete and even wood - here is what anyone likes more. The main thing is only that the grillage itself hangs above the ground by more than 10 cm.

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

Solid support-columnar foundation

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

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

Stage I. Site preparation

It all starts with cleaning the site - for this, the entire upper layer soil, right along with the plants. Its thickness is usually a little over 30 cm, and it cannot be left under the foundation.

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

Now all irregularities are removed on the landscape, soil is poured into the pits, and with the help of pegs and ropes, you can start marking for the future foundation.

Stage II. foundation plan

Next, from the drawings to the land plot, you need to transfer the plan of the future bath - where and what will be. This can be done with standard materials, fixing the axes and noting the main dimensions of the future foundation. How accurately everything will be marked up - it will be so much easier to work later.

Stage III. Pit preparation

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

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

The pits should turn out 30 cm more than the calculated depth of the foundation - so that gravel-sand bedding can be done. The width is taken a little more than it will be - so that the formwork and spacers become free.

Stage IV. Formwork installation

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

Stage V. Foundation reinforcement

It is necessary to reinforce the foundation pillars in the longitudinal direction with A3 rods and a diameter of 12-14 mm. Horizontal jumpers should be placed in increments of 20 cm - a wire of 6 mm in diameter is quite suitable for this.

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

Stage VI. Pouring foundation pillars

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

It is necessary to lay it in layers - 20-30 cm each, using manual vibrators for the convenience of the process. This will ensure the homogeneity of the mixture and all the air will leave the solution.

Stage V. Waterproofing of the columnar foundation

You can protect the future foundation from moisture with the same materials as the tape one. These are mastics of cold and hot preparation, gluing membranes, roofing material on bitumen - and all new and well-proven materials.

Stage VI. Construction of a grillage

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

So, if a prefabricated belt is being made, then the jumpers must be well connected to each other with trimmings of reinforcement - welding them by welding with mounting loops. Further, the formwork, the reinforcing cage are already installed and everything is poured with M200 concrete.

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

By the way, in order to protect the underground space under such a bath from snow and cold air, a fence is usually made between the pillars - a special wall, most often made of brick. It is not necessary to tie it to the poles - after all, the bath will still settle, and so cracks may appear. And already in the pick-up itself, technological holes are made for communications. Outwardly, all this is beautifully decorated with false panels and siding - that's all.