The foundation pillars are sticking out, what should I do? In winter, the foundation moves, why, what to do? Strengthening the base depending on materials

Construction of the foundation- the most important and responsible stage of building a house. The reliability and durability of a building are determined by the choice of foundation type and its parameters, as well as the quality of workmanship. Mistakes made can lead the house to disrepair already at the stage of its construction.

But what to do if the house has already been built, and the builders saved money, hoping for the traditional “maybe”. Most foundation problems arise when building on heaving soils. Soil heaving is a very insidious and powerful phenomenon, which is very difficult to combat after construction is completed. Why is this happening?

If the foundation (strip or pillars) was laid above the freezing depth, then the wet foundation under the support, freezing, expands and squeezes out the structure. This process occurs most actively in the spring on the south side of the house, which freezes at night and warms up during the day. With each passage of the “thawing-freezing” boundary through the lower support platform of the foundation, the latter rises higher and higher. Extrusion forces exceed tens of tons. At the same time, cracks appear in the stone walls. Wooden and panel houses receive noticeable distortions, walls crack, collapse, doors and window sashes do not close. What to do?

Owners of stone houses have several options for improving the performance of their foundation. In places with difficult terrain, it is possible to lower the groundwater level by organizing its drainage using an effective drainage system (Fig. 1). Dry soil is not heaving and “warm”. Considering that in heaving soils with a dusty structure, moisture rises upward, drainage should be located below the freezing depth by 0.5 m. The literature on construction speaks quite well about the technology of creating a drainage system, but it must be borne in mind that this is complex and expensive Job.

You can also take the path of artificially reducing the freezing depth. To do this, add a layer of soil around the house, bringing the depth of the foundation to the freezing depth (Fig. 2). By the way, the visual image of the house will benefit somewhat; it will be on some elevation.

The freezing depth can be increased by replacing part of the soil with a heat-insulating layer, made, for example, in the form of a mixture of expanded clay and coarse sand in a volume ratio of 1.5:1. A layer 20-30 cm thick and about 2 m wide, laid at a depth of 20-40 cm on top of a layer of coarse sand 20-30 cm thick, will insulate the soil and reduce its freezing depth by 60-80 cm. A heat-insulating layer can be made and from polystyrene foam boards 8 cm thick, wrapped in plastic film (Fig. 3). Plates laid at a depth of 20 cm on a layer of coarse sand 20-30 cm thick are a very effective remedy. The width of laying slabs around the house is about 2 m. The gap between the slabs is no more than 5 cm.

A thick layer of snow around the house will also reduce the depth of freezing. If closed for the winter ventilation windows in the basement of the building, then the degree of soil freezing can be somewhat reduced. All options can be combined. Thus, when insulating the soil, it is possible to reduce the depth of the drainage system. Insulating the soil can also be combined with raising its level around the house. Now about light houses (wooden, panel). Heaving phenomena affect them to a greater extent, since such houses themselves are lighter.

Sometimes pillars rise even when they are laid below the freezing depth, if the house turns out to be too light, or too many pillars were installed, which is the same thing. This occurs due to the adhesion of the side surface of the pillars to the ground, if a layer of waterproofing is not laid between them (glassine, roofing felt, polyethylene, bitumen coating, etc.) or the side surface of the pillar is uneven, rough. Then it turns out that the adhesion forces of the soil with the pillars are greater than the weight of the house. By the way, it is for this reason that when laying a conventional columnar foundation, it must be loaded with a house in the same season.

If such a foundation “walks,” then it is necessary to evaluate the real weight of the house and the bearing capacity of the soil. With a large margin of bearing capacity, you can reduce the number of pillars by eliminating some of them from work. To do this, it is enough to dig up extra pillars or destroy their upper part.

Sometimes for wooden and panel houses it is possible to recommend the techniques proposed for stone houses (for example, insulating the soil around the house reduces the adhesion area of frozen soil to the supports). But it is better to replace the previous supports with pillars (Fig. 4), made using TISE technology using the TISE-F foundation drill. How to do it?

First you need to determine where to place the pillars. If the lower crown of the house is “powerful”, then new pillars can be placed near the previous supports at a distance of no more than 1 m. It is also necessary to take into account that the bearing capacity of each such pillar is very high - from 5 to 10 tons, that is, they can be installed less frequently . New supports are installed around the entire perimeter of the house and under its internal walls. After this, the house is raised a few centimeters, leveling pads are installed on the new supports through the waterproofing and then the house is lowered. You can lift the house using a jack and levers. Old supports are removed or their upper part is destroyed.

If the crown of the house is weak and can bear the full load only in the place of existing supports, then on both sides of it at a distance of about 1 m it is necessary to place reliable temporary supports (Fig. 5), which have developed upper and lower surfaces. The house in this place must be raised by 1-2 cm, freeing the old support. Then it should be dug out, and the hole should be filled with soil, thoroughly compacting it. To avoid the house falling off temporary supports, they are replaced sequentially.

To create foundation pillars using TISE technology, you first need to prepare formwork in the form of pipes. Their design depends on the capabilities of the developer, his funds or imagination. The main thing is that they must have a constant cross-section - 500...700 cm2 (square, rectangular or round). The length of the pillars should be taken in such a way that they are buried 30 cm below the freezing line, and from above - do not reach the crown of the house by 3-5 cm. Asbestos-cement pipes, boxes welded from steel sheets can be used as formwork (Fig. 6). At the top, they all must have a support crossbar located at ground level.

Before starting to drill an inclined well under a house, it is advisable to first draw a cross-section of the building on a reduced scale. Care should be taken to ensure that the bottom of the hole drilled below the freezing depth is in the middle of the wall and that the drill handle does not rest against the wall. For ease of work, you can make a template marking the distance from the wall to the drilling point and the angle of inclination of the well (Fig. 7).

Having identified the drilling point, they begin to work. After the inclined well is drilled below the freezing depth by 10-15 cm, we begin to expand it to vertically install the formwork of the foundation pillar. To do this, a drill is inserted into the well, the soil is cut with a shovel, and periodically, as the drill storage tank is filled with soil, it is raised to the surface and emptied. The well is expanded until the formwork can be freely placed in it in inclined and vertical positions. The lower part of the well (up to 30 cm from its bottom) is not expanded.

Having installed the plow on the foundation drill, they begin to expand the lower part of the well. First, they work with the drill rod fully extended. In this case, the bottom of the expanded part of the well turns out to be inclined, but it is easier to work. You can level the bottom of the well with the drill in a vertical position, for which you will have to fold the rod slightly so that the handle is located under the wall.

Installation of reinforcement and filling the well with concrete is carried out through the formwork, which is located at an angle and rests with its crossbar on two boards laid near the well. As concrete is laid, it must be compacted by bayoneting and tapping on the side wall of the formwork.

Immediately after filling the formwork with concrete, the upper part is shifted, placing the formwork in a vertical position (Fig.). This doesn't require much effort. The concrete in the lower part of the formwork should be further compacted by tapping on its side wall.

Concreting one well must be carried out continuously for 30-40 minutes until the concrete sets. The side gaps around the foundation pillar must be filled with soil, laying it in layers of 10-15 cm, compacting it with a tamper and slightly moistening it. Concrete is poured into the formwork and the upper surface of the foundation column being formed is leveled.

For normal setting of concrete during the first week, it is necessary to periodically moisten it, and to preserve moisture, wrap the top of the column with plastic film. The foundation pillar is loaded no earlier than after three weeks. The part of the wooden formwork protruding above the ground is carefully removed by sawing it off with a hacksaw.

When creating foundation pillars under the internal walls of the house, difficulties will arise: it is impossible to do without opening the floors.

Based on materials from the magazine "DOM"

Any violation of the construction technology of load-bearing structures is fraught with the opening of cracks. In 90% of cases, the cause is the foundation of the house (soil) or the foundation, which can only be strengthened using one of the technologies below.

If the crack on the surface of the wall is horizontal (encircling, local), the foundation has nothing to do with it. The reason most often lies in the sagging of the lintels or rafter system. In the absence of tightening, the hanging rafters try to push the opposite walls apart.

There are several main reasons why the foundation has sunk and cracks have appeared in the house. The main ones are traditionally:

areas under the foundation consisting of subsidence soils - rupture of the foundation tape, change in the geometry of the structure;
swelling forces - uneven loads tear the foundation, walls warp;
violation of construction technologies - low grade of concrete, loading of the foundation to 70% strength, low reinforcement coefficient, corrosion of reinforcement, winter concreting without heating.

If the foundation has lost its integrity, restoration is necessary; in other cases, it is enough to strengthen the base under the sole of the tape in certain areas. There are several technologies for this.

Attention! A crack is a “pointer” that makes it easier to find the boundaries of subsidence or swelling soils. This makes it easier for specialists to localize repair work.

There are inclined and vertical cracks with divergence upward or downward, which most accurately indicate the nature of the deformation:

a vertical crack diverging upward in the middle part of the wall - swelling of this particular area;
vertical gap, divergence downwards - subsidence of soil in the middle of the house;
a similar defect with a divergence downwards is swelling on both sides of the wall due to lateral freezing;
an inclined crack from the corner to the center of the facade - the backfill of the adjacent wall has sagged;
inclined crack from the center to the corner - the shrinkage funnel is located directly under this crack;
cracks converging in the shape of an arch – soil subsidence in the central part of the foundation strip.

A crack on the wall extends upward.

After determining the cause, in any case, you will have to expose the foundation with a trench close to the tape to carry out measures to strengthen the soil, lay drainage, install “bulls”, make a clip and other work.

Soil strengthening

If the foundation has vertical movements on soils with low design resistance to loads from the weight of the building (embankment, peat bog, silty sand), it is necessary to strengthen the foundation using the following technology:

lifting the foundation with jacks - to the design level in compliance with safety measures (partial or complete unloading with supports), meaning the lifting of sagging parts;
drilling holes - for immersing injectors with a diameter of 20 - 40 mm;
filling voids - with liquid glass (silicatization), cement laitance (cementation), synthetic resins (smolization) or hot bitumen (bitumenization).

These substances reduce water permeability, stabilize unstable soils, and increase the design resistance (bearing capacity) of the foundation. The disadvantage of the method is the need to use professional equipment capable of injecting binders under a pressure of 5–10 atmospheres. Other methods are not available to individual developers; they are used by restoration teams for architectural monuments.

Attention! These actions may not be enough, since if the foundation subsides in a separate area, this means its destruction in 70% of cases. Instead of costly dismantling of the building, tape restoration methods are used.

Strengthening the foundation

There are several ways to strengthen the foundation strip depending on the condition of the reinforced concrete structure:

unloading – inserting beams into load-bearing walls to support the masonry;
restoration of bearing capacity - drainage for drainage of ground, soil, surface water, relocation, replacement, protection from mechanical destruction (weathering, corrosion);
increasing the load-bearing capacity - frames made of monolithic concrete, brickwork, reinforced concrete slabs;
hardening - epoxy, polymer resins, cement mortar, and penetrating compounds are introduced into the drilled holes;
special methods - screw piles, pressed piles, “bulls” in the corners, injection of cement mortar into the masonry.

If the foundation has non-through cracks caused by weathering, the surface is plastered or targeted, coated or impregnated with penetrating mixtures. Tarquetting is called pressure (0.4 - 0.6 MPa) spraying with cement laitance with a minimum amount of quartz sand.

To strengthen the prefabricated foundation with a cage, the following technology is used:

strip exposure - a trench along the wall to a depth just below the base;
reinforcement - own frame by analogy with a strip foundation, installation of rods in holes drilled in the foundation, tying them to the frame rods;
formwork - below the blind area or to the entire height of the basement;
concreting - standard laying of the mixture.

After stripping, the upper part of the cages, rising above ground level, is protected from moisture by ebbs.

Attention! Unlike the underlying layer created during the construction of the foundation, non-metallic materials under the expansion (cage) are compacted into the ground without laying geotextiles.

Reinforcing ring around the foundation.

When manufacturing a reinforced concrete cage, the following points should be taken into account:

width – from 15 cm on each side for reinforced concrete, from 20 cm for concrete;
thickness of the underlying layer - from 10 cm of crushed stone or sand;
anchoring with the existing tape - rods with a diameter of 20 mm to a depth of 12-25 cm, rod length 25-40 cm, step 1 - 1.5 m;
reinforcement of the cage - mesh with a cell of 15 x 15 cm for the lower belt, 10 x 10 cm for the upper belt;
concrete – class B10 – B15.

When restoring brick strip foundations, it is necessary to remove crumbled stone. When repairing reinforced concrete structures, the oxide film should be removed from the surface and the roughness should be increased by notching.

If it is not possible to increase the bearing capacity of the soil under the foundation (the thickness of the loose layer is significant), the technology of strengthening the underground structure with piles is used:

short driven ones - pipes with a diameter of 57 - 89 mm with a pointed tip made from their body (analogous to SBC, but without a blade) are driven in next to the foundation and embedded in the holder;
external screws - SHS are immersed around the perimeter, the building is raised, the ends are tied with a metal grillage, the house is lowered onto a new foundation (suitable for wooden houses);
“bulls” - the method is used when settling corners, screw piles are screwed in obliquely on both sides of the corner, a beam (I-beam, channel) is welded onto their heads, on which the corner of the foundation rests.

The advantage of the technology is the unloading of the existing foundation. The piles are guaranteed to penetrate through unstable horizons and rest on a bearing layer with high resistance.

These measures are usually carried out as a complex, since when individual sections settle, the integrity of a monolithic or prefabricated structure is violated. For example, if the foundation partially rests on subsidence soil, the base is first strengthened, after which a reinforced cage is poured. When using screw piles, there is no need to strengthen the foundation, however, after raising the foundation to the design level, it is necessary to fill the voids formed under it with concrete or cement mortar.

Another option for strengthening the foundation with piles.

When the casing is deepened by 0.7 meters or more, standard thermal insulation measures are taken. This is necessary to reduce the pulling forces during swelling:

vertical surface of the frame with high-density polystyrene polystyrene foam + horizontal thermal insulation of the blind area 0.6 - 1.2 m wide at a depth of 0.3 - 0.4 m;
sand, crushed stone in the sinuses of the trench + at the level of the base of the cage;
or crush-sliding thermal insulation - EPS rigidly fixed on the vertical surface of the casing, polyethylene film (attached only in the upper part), polystyrene foam PSB-S without attachment to the casing (pressed to the film with backfill material).

In some cases, it is possible to sufficiently strengthen the foundation in certain areas and strengthen the foundation using one of the indicated methods, but sometimes this may not be enough.

If you have a wooden house, we additionally recommend that you read the article:.

Advice! If you need contractors, there is a very convenient service for selecting them. Just send in the form below a detailed description of the work that needs to be performed and you will receive proposals with prices from construction teams and companies by email. You can see reviews about each of them and photographs with examples of work. It's FREE and there's no obligation.

If you have a cracked foundation, a crack in the wall of your house, or other problems with the foundation, don’t panic, you can always find a solution to this problem.

Causes of foundation deformations

The main reasons for changing the subwall design can be divided into:

Consequences of human activity (for example: if for some reason the foundation was flooded with water, freezing may occur, and as a result, destruction of the structure);
Errors when creating a project and during the construction of the foundation (use of low quality cement, incorrect calculation of the load on the foundation of the house, and so on);
Natural factor (high groundwater level, heaving soil, etc.).

Destruction of the foundation of a building often occurs due to uneven shrinkage. In this case, damage to the walls of the building may occur.

Ways to check the foundation of a house

Before starting work on restoring the foundation, you need to find out the cause of the cracks and determine the speed of their spread.

An analysis of the reasons for the appearance of cracks in the foundation or walls of a house will be carried out most efficiently by a special expert group, but this work can be done yourself, saving a large amount of money.

Diagnostic methods:

Installing plaster beacons is the easiest way to diagnose a crack. Using beacons you can find out whether the crack continues to expand. 3 beacons are applied to the crack: if the crack expands, then cracks also appear on the beacons. If the beacon does not crack for a long time, then it is possible that the appearance of a crack is an isolated phenomenon (no work to restore the base is necessary). After using the beacons, you can determine the rate of deformation of the base and whether it is shrinking. Any composition that becomes brittle after drying can be used as a beacon. It is applied with a spatula 5 centimeters in height and 10 centimeters in length.
Foundation diagnostics are also carried out using a hole (approximately 1 meter deep) dug to the full depth of the foundation. By looking at the exposed subwall, you can understand the condition of the waterproofing and the entire structure as a whole.

After identifying the causes of destruction of the subwall, restoration work can begin.

Strengthening the base depending on materials

After inspecting the damaged base and observing the increase in cracks, you need to move on to repairing it.

Subwalls made of rubble stone or brick, after identifying the causes of deformation, can be strengthened by pouring cement mortar or resin. The repair process is carried out as follows: after 30 centimeters of the base, wells are drilled (radius 15 millimeters), then the process of filling with a solution under high pressure begins;
Shallow foundations can be strengthened by strengthening using work on: deepening, strengthening the cushion with reinforced concrete with reinforcement, expansion;
Pile foundations are converted into strip foundations. To carry out restoration, a reinforcement screed filled with mortar is made between the piles.

Also, the process of strengthening the subwall depends on: the purpose of the building, loads on the foundation, soil type, construction features.

Methods for repairing the base

If the entire foundation of your house has given way or a large crack has appeared along it, you need to dig a channel around the entire building, to the depth of a sand cushion. Afterwards, the surface of the foundation is cleaned of dirt. At a short distance from the walls of the house, a mesh with reinforcement is mounted on the foundation, and the mesh is tied to the foundation.

Then the structure is concreted layer by layer. The compaction of each layer must be done as carefully as possible.

If rubble concrete or monolithic concrete was used to construct the base of the building, then it is strengthened by pouring a reinforced concrete cage, which is firmly connected to the previous masonry using anchor bolts. The screed is carried out taking into account that the new foundation will distribute the load from the building along with the old areas.

Scheme of strengthening a rubble foundation with reinforcement and the process of pouring the foundation with concrete mixture.

Methods for replacing a base that has become unusable

If after diagnostic checks you realize that the subwall cannot be restored, it will need to be replaced. To carry out a complete replacement, it is necessary to unload the old foundation so that not a single wall of the building is damaged.

To preserve the integrity of houses, the following is used:

Installation of supports, the fixation of which is carried out perpendicular to the old foundation;
Installation of stone pillars on which the walls of the building are placed;
A system of braces that transfers the load from the house to the soil.

If the foundation is being deepened, the walls of the building must be strengthened with struts. After strengthening with struts, a dig is made under the base. The walls of the dug trench are reinforced with formwork. The old sole is cleaned of dirt and concrete. Afterwards, a hard cement mortar enriched with fine crushed stone is poured.

Repair of a subwall that has become unusable due to flooding

If the cause of cracks is flooding, then you first need to drain the water from the base. To do this, a barrier barrier is installed, thanks to which water moves away from the house through drainage channels. If groundwater flows too high, a drainage system must be installed.

A crack in the subwall may appear due to laying the foundation above the soil freezing level. If this factor is the cause of cracks, then insulation of the foundation is required. To do this, a hole is dug along the base and filled with crushed stone, because it does not expand when it freezes. Afterwards, waterproofing and thermal insulation are installed on top of the backfill, and then the blind area.

Work to prevent the appearance of cracks in the base of the building

The main measures to prevent the appearance of cracks in the foundation are the selection of high-quality materials and the preparation of a well-thought-out foundation design.

In addition, it is important to consider that:

If a strip subwall is used as the sub-wall of the house, then it can be covered with brick;
In the absence of soil heaving and the use of a columnar type of foundation, the walls and pillars should be extremely light.
If soil heaving is strong, it is recommended to use wood for walls, because it can withstand deformation.
When using heavy building materials, the optimal solution would be a strip base buried below the soil freezing level, then the likelihood of deformation of the subwall and the building as a whole is minimized.

What to do if the foundation is cracked? updated: February 26, 2018 by: zoomfund

Every person who owns his own home will sooner or later encounter problems with cracks in the walls of the building, curvature of the foundation, and distortions. First of all, these problems come from damage to the base of the foundation, which, even with proper construction, can significantly decrease over a long period of time.

Of course, these problems must be solved without the slightest delay. This will save your time and money, and will prevent your home from deteriorating further. Therefore, the main ways to fix it will be described below.

There are 3 main options for solving this problem: the foundation can be strengthened, raised, or replaced in whole or in part.

Method one: strengthening the foundation

Let's start with the simplest: . Typically, reinforcement is carried out when the foundation begins to subsidence. If you cannot correct the foundation of your house in time with the help of reinforcement, then it can result in a large amount of money with the complete replacement of expensive parts of both the foundation itself and the entire building.

First, you will need to dig a trench around the entire perimeter of the house. It is better to make the trench as deep as possible. Its width should be such that it is as comfortable as possible for you to work with the underground part of the foundation while in the trench.

Now, using a trowel, carefully clean the surface of the foundation of the entire house from dirt and debris, after which you can begin strengthening. To be reliable, you will need rigid reinforcing wire. Take it and nail it firmly to the foundation to its full possible height. The other end of the wire is lowered and secured on the other side to the ground.

In order for this entire structure to remain strong, you need to make formwork along the width of the trench and fill the whole thing with concrete. The solution must be made as thick as possible. It is also advisable to add small pieces of reinforcement to it.

Fill the trench with the solution so that about 15 cm remains to the surface of the earth. After the concrete hardens to this height, you will need to add earth and sand and compact everything well. If there are places on your foundation with very large cracks, it is necessary to make through anchoring on them and connect it with an additionally laid row of brick or cinder block. This will subsequently ensure an even load on all parts of the building.

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Method two: raising the foundation

The next option is to raise the base of the foundation. This is an ideal option for how to correct the foundation of a house if it has sunk too much, thereby causing large cracks in the walls of the house and distortions in the openings of doors and windows.

To raise the foundation, you will need a very strong pad to support the foundation on, and two fairly strong jacks. Start by lifting the most damaged corner of the house using jacks. Carefully place a spacer under the raised part and immediately begin working on the next corners.

When lifting corners with a jack, it is very important to consider two main points. The first is the lift height. The most damaged area should be raised first and above the other corners. But with all this, the maximum lifting height should not exceed two cm. The second is the possible distortion of the frame. Therefore, in the process of raising the corners, it is necessary to carefully ensure that the frame does not warp. Otherwise, it may lead to even greater destruction.

After raising all the corners, check that in the end all the corners are raised exactly the same distance. If you have checked and all the lifting heights are the same, proceed directly to the process of correcting the foundation. To do this, near the corners and in the middle of each wall we make recesses for pillars, the height of which is approximately 1 m.

After this, very strong reinforcement is inserted into the recesses. Try to squeeze the reinforcement so that it rests well on the walls of the recesses. When you are done with the reinforcement, install the formwork. But after this, mix a thick solution with pieces of reinforcing wire and fill the recesses with reinforcement with it. As a result, you should get so-called reinforcement columns, which will prevent the foundation from sagging in the future. After the solution has hardened, you can sprinkle the flooded areas on top with soil, compacting it well with a roller.

During the entire work process, it is very important not to forget about safety precautions. To avoid damage, be sure to install the jack securely so that it is well supported. And between the log house and the support for the jack it is necessary to place non-slip boards.

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Method three: replacing the foundation

And now as for partial or complete. In the case of a complete replacement, everything is crystal clear. This is equivalent to rebuilding a building with large financial investments and significant time costs. Therefore, it is undesirable to allow this to happen. It is better to correct individual parts of the foundation in time.

To partially replace the foundation, it is most convenient to use the old, but well-tested method. This is a partial replacement of the base. To do this, the sole should not be deepened. For this purpose, it is best to make holes in the ground approximately 1 m deep in places where the foundation and walls of the house are damaged. Opposite each of the cells in the foundation wall, notches are made with a hammer drill for future fastening.

Now, using a powerful jet of water, wash the foundation near the dug cells and place reinforcement beams under them, which need to be hooked with anchors to the notches made in the wall. Then mix a thick solution and pour it into all the cells.

After this, it is imperative to strengthen the openings for doors and windows. To do this, tap the openings in loose places and check them with a level. Only they must first be carefully aligned, if even minor distortions have already formed.

This method will make it possible not only to partially restore individual parts of your foundation, but also to increase the overall load-bearing capacity of the foundation for the entire house. In this regard, the risk of new cracks appearing will be greatly reduced.

Thus, three main ways to improve the foundation of a house were considered. These methods are the simplest and most effective if the deformation of the foundation has not yet reached too significant a scale. Corrected defects in a timely manner will prevent the problem from developing into a more serious scale.

The foundation subsided: what to do in this case and how to save the house from destruction?

In order to repair the foundation of an old house, it must be raised using jacks: automobile, hydraulic and mechanical.

Restoring sagging corners and supporting walls is a task that requires a lot of effort and experience. There are several methods, which depend on the types of foundations and materials from which the buildings are made. The situation with cracked walls due to sagging foundations most often occurs with old houses built in areas of deep freezing of the soil, in swampy areas. The foundation may sag if, when building a house, you chose a type of foundation that does not suit the given area. Typically, the question of how to fix a foundation that has subsided arises when buying an old house or receiving an inheritance.

Problems with subsiding foundations arise due to the action of groundwater, which literally washes away the soil from under the foundation, which leads to its subsidence. Under the influence of high humidity, the monolith loses its strength characteristics and begins to collapse.

Columnar foundation and its restoration

Columnar foundations were often built from red brick, which is very hygroscopic and deteriorates over time. You can often observe that the supports of the foundation of the house have sunk into the ground over time, the crowns of the house have become excessively moist, and the house itself has become warped. This leads to cracks and jamming of doors and windows. Depending on the degree of destruction of the columnar foundation, the supports are restored or replaced. Typically, columnar concrete supports under the house, the crown of which is located above the ground surface, are replaced.

To make a replacement column from concrete, formwork is made with a cross-section of 20 to 30 cm. It must be equipped with a support beam in the upper part. The depth of the hole should be made with the calculation of a deepening of 30 cm above the depth of soil freezing. The hole is made with a drill so that the support can first pass at an acute angle and then fall into place. After installing the post, the hole is filled up, carefully tamped every 10 cm, and tapped for better soil settlement. You can install the supports using a jack. The column is ready for use 2 weeks after pouring the solution.

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Strip foundation and wooden house

The strip foundation is restored depending on the material from which the house is made. If the house is wooden, then it can be raised with jacks and completely sagged. To do this, a monolithic belt is poured, connecting the old and new monolith into a single whole. First, preparatory work is carried out:

remove furniture and belongings;
disassemble the stove;
The floors are removed, leaving only the walls and roof.

The house will be lifted using jacks: automobile, mechanical, hydraulic. With a columnar foundation, platforms of 0.5x0.5 m are prepared, on which jacks are installed. With linear, they usually knock out the bricks of the base or hammer out the monolith in order to bring the jack under the house. When lifting a house, the force of the jack must be transmitted through a steel plate with a thickness of at least 5 mm.

To prevent the house from falling apart due to movement and lifting, each log is secured vertically with nailed boards, which create additional rigidity. Raising the house occurs in several stages. At each of them, the house is raised only 1.5 cm. After each lift, the position is additionally fixed with timber supports, and the house is checked for damage. The process of raising a house to the required height takes a long time and requires caution in everything. After raising the house to the required height, it is firmly secured and work begins to update the foundation.

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Replacing the bottom crown of a wooden house

Repair work to restore the sagging foundation of an old wooden house also requires replacing the lower crowns. As a rule, a settled foundation leads to the development of wood destruction due to strong moisture. To do this, 2 layers of roofing material are laid on the foundation. Old crowns are removed and replaced with new ones impregnated with antifungal compounds. Then the house is lowered on one side and raised on the other, repeating all the steps.

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Features of repairing a linear foundation without raising the house

A brick or stone house cannot be lifted and requires a careful professional approach.

If the monolith is cracked in several places and this does not lead to a violation of the integrity of the building, and the cracks that appear do not increase in size, then they are rubbed down with cement mortar. If the house is deformed, then it is carried out completely or partially, or it is strengthened - it all depends on the degree of damage.

To fix a damaged section of a monolithic strip, first dig a trench, the length of which should not exceed 2 m. If the damaged section is larger, then first repair one part of the foundation, wait until the concrete stands, and only then continue. In the old foundation, holes are drilled horizontally, 60 cm long, vertically in 3-4 rows. The diameter of the drill is 2-3 mm smaller than the diameter of the reinforcement used.

This is necessary to fully strengthen the rods after installation. They are driven in to form the reinforcement tape frame. Afterwards, horizontal reinforcement is welded using welding, the voids, previously cleaned and washed of dirt, are filled with thick concrete, and a plaster mesh with large cells is installed. Afterwards, the formwork is placed and poured to a height of up to 0.5 m and the required thickness of at least 15 cm.

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Repair of the foundation of a slag-filled house

The main goal of repairing the settled foundation of a stone, brick or slag house is preventive action aimed at preventing further shrinkage of the weakened foundation. carried out through the creation of a monolithic enclosing and reinforcing belt - an overlay - on the inside and outside. This allows you to correct subsidence of the base, which leads to through cracks in the ceiling, walls, and corners of the building.

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Procedure

Strengthening should be done as follows:

dig a trench around the perimeter 40-50 cm wide, at an angle of 35°. The base of the foundation is not disturbed;
the monolith cleared of dirt is cleaned of dirt, old plaster, and destroyed parts of the foundation and base are removed;
the surface is treated with a deep penetration primer;
drill the entire foundation every 60-120 cm horizontally and in 3-4 rows in height;
drive in reinforcement 2 mm larger than the drill, total diameter 10-14 mm;
horizontal reinforcement is secured by welding;
fill deep cracks and damaged areas with concrete;
a metal mesh for plastering work with a large cell pitch is attached over the reinforcement;
if the foundation is generally strong and has just begun to settle, it is plastered;
if there is significant destruction and sedimentation, then install the formwork at a distance of 5-15 cm from the foundation and fill it with concrete;
after the concrete has hardened, waterproofing is applied;
The trench is filled in and each layer of 15-20 cm is carefully compacted.