Often, owners of private houses are faced with the problem of the destruction of the foundation. Most often this applies to old log or timber buildings. But sometimes strengthening is also required for the foundation of a new house, if the technology was not observed during the construction and natural factors were taken into account, for example, how deep the soil freezes in the territory. In some cases, the foundation is destroyed if any objects are built near the house. And, finally, the foundation needs to be strengthened if it is planned to add additional premises or add floors to an already finished building. If this is neglected, then an increase in the mass of the building can lead to subsidence, distortion of the entrance and window structures, the formation of cracks in the base, and even complete destruction.

Causes of partial destruction of the foundation

The foundation is the platform on which the structure is based. It distributes the mass of the building over the entire area and reduces the specific pressure on the soil. The performance and durability of the structure depend on its condition, since it is on the base that all the load from higher structures falls.

Deep cracks in the foundation indicate the beginning of destruction

But during the operation of the building, the foundation is often subjected to partial destruction. This may be due to the following reasons:

• the location of the house on sloping terrain, in a seismically unstable area or next to the railway;
• incorrectly drawn up project;
• errors at the stage of calculating the planned load;
• non-compliance with construction technologies during the construction of the platform;
• the use of low-quality building materials;
• improper arrangement of waterproofing;
• a decrease in the quality characteristics of the base;
• natural phenomena - flooding, oversaturation of the soil with moisture, freezing of the soil;
• human economic activity - improper operation of the house, for example, lack of seasonal heating, construction or laying of communications in the immediate vicinity of the foundation, repair or completion of the house.

Since at the initial stage of construction it is not always possible to accurately predict what kind of load and natural factors the foundation will be exposed to, subsequently it will be necessary to resort to strengthening it. Strengthening the foundation ensures the reliability and safety of the operation of a private house, since it is suburban households that are most exposed to natural factors. If you ignore the problem, you may have to completely change the foundation, and this costs a lot of money.

Before starting work on strengthening the foundation, it is necessary to conduct a thorough analysis of the reasons that caused its partial destruction. As a rule, professionals with special equipment are invited for this. They evaluate the factors that cause foundation deformation and make recommendations to eliminate or minimize them.

Preparing to strengthen the foundation

Before strengthening the foundation, its external and internal inspection is carried out. During the external examination, the following parameters are determined:

• building dimensions;
• condition of supporting structures;
• the presence of cracks and bevels.

During underground research, indicators are determined:

• device and dimensions of the platform;
• strength properties of the material used;
• the depth of its bookmark.

Before starting work on strengthening the foundation, it is necessary to make sure that its shrinkage is over. It usually lasts at least a month. To understand that the shrinkage is over, gypsum beacons are installed across the identified cracks. Their condition will allow you to determine when you can start strengthening the base.

At the final stage of preparation for strengthening, the platform is unloaded. It may be complete or partial. An important factor is the prevention of distortions that will adversely affect during the restoration of the foundation.

To further strengthen the foundation, the building is raised with jacks

Partial unloading of the platform of the house is carried out using wooden or metal supports and struts.

1. In the basement, install support pads, stepping back from the wall 2 m.
2. Place a support bar on top.
3. Fasten the stands.
4. Then connect them with a beam to the ceiling, and then to the support beam using wedges.

For capital unloading of the platform, steel strapping beams are mounted.

1. Under the row of masonry, in which the bricks are laid with short edges to the wall, punch the strobes on both sides, keeping a distance of 2 m between them.
2. Place the tie beams in them and secure with 25mm bolts.
3. Using overlays, weld the joints of the beams, and fill in the gaps from the wall to the beam with a sand-cement mortar.
4. Punch holes in the lower part of the walls, keeping the distance between them no more than 3 m, insert beams into the holes.
5. Install the crossbeams on the support pads on both sides of the wall.

Base strengthening methods

In modern construction, different methods of strengthening the foundation are used, due to the rapid development of the building materials market:

• widening of the sole;
• piles;
• reinforced concrete pillow;
• basement replacement;
• reinforcing belt;
• reinforced concrete shirt;
• cementation;
• ebbs;
• summing up new grounds;
• clips;
• shotcrete.

Various methods are used to strengthen the foundation.

Each of these methods has both advantages and disadvantages. Consider the most popular technologies.

Outsole widening

In practice, home owners most often resort to the classic, proven method of strengthening the foundation - the method of widening the sole. The sole is a reinforced concrete pillow on which the foundation rests. This method is the simplest, most reliable and relatively inexpensive. Several people with certain skills can handle the job.

1. An additional foundation is laid around the house, which plays the role of an auxiliary support.
2. The sole along the entire perimeter of the structure is fixed at several pre-marked base points, the number of which depends on the size of the building and the degree of destruction of the main foundation. Typically, the distance between the points is 2.5–3 m.
3. On the sides and under the foundation, excavation is carried out.
4. A reinforcing screed is laid under the foundation and evenly filled with mortar.
5. Air bubbles are removed using a concrete vibrator.
6. The side walls of the sole rise to the plinth by 15 cm.

The method of strengthening the foundation by widening the sole is the simplest, most reliable and relatively inexpensive.

Strengthening the foundation with piles

There are many types of piles with which you can strengthen the foundation.

Bored piles

Additional strength can be given to the structure with the help of bored injection piles. Recently, this technique has become very popular. But due to the use of innovative technologies, expensive materials, drilling equipment and the involvement of specialists, this method is considered quite expensive.

The essence of the technology is as follows:

After the solution dries, a new foundation of pile structures is formed, which, in terms of strength and reliability, resembles a monolith on which the structure is based.

Additional strength can be given to the structure with the help of bored injection piles.

Micropiles

In some cases, micropiles are used. Their diameter is 150–300 mm. In the process of drilling, it is possible to fill the wells with a solution. This method involves the use of drill rods. Remaining inside the pile, they provide more reliable reinforcement of the foundation.

With the help of micropiles, it is possible to strengthen not only the foundation, but also the soil

Video: strengthening the foundation with micropiles

Driven piles

Pressed piles are used to transfer the load to solid deep-seated soils. They are installed using special equipment. Beams mounted in the base provide a good connection between the foundation and piles.

Video: strengthening the foundation with pressed piles

The method of strengthening the foundation with remote piles is used at an increased level of groundwater. The foundation is taken out on piles. The connecting link between the piles and the foundation is a reinforced concrete beam passed through the foundation.

The foundation is carried out on piles

Metal tubular piles

Installation of metal tubular piles is carried out on both sides of the platform. For this, a welding method using special equipment is used. To install the piles, a reinforced concrete frame is mounted and connected to the beams supported by jacks.

Metal piles are connected with a reinforced concrete beam

Pouring reinforced concrete pad

The advantages of strengthening the platform by pouring a reinforced concrete pad are:

• reduced pressure on the soil due to the large footprint;
• additional ground insulation. This prevents frost heave, which is considered the most common cause of foundation failure.

The disadvantages of the technology include the impossibility of pouring the entire foundation, but only in sections of no more than 2 m, and the need to observe the drying time of each section before pouring the next one. Therefore, this method is used to strengthen one of the corners of the base, or in the event that the time and cost of pouring the foundation around is not fundamental.

Reinforced concrete cushion reduces the load on the ground and allows you to insulate it

Filling the pillow under the foundation takes place in several stages:

1. The repaired area is dug around outside and inside the building. At the same time, the blind area and the floor are removed, the earth is dug around the base in the form of two trenches with a length of 3.0 m to 3.5 m and a depth of ¾ of the depth of the foundation.
2. The condition of the foundation is assessed for the presence of cracks and destroyed areas.
3. If the base is in order, a hole is dug under the pillow up to 2 m long and 0.4–0.5 m deep relative to the foundation. The bottom of the pit should be level.
4. Geotextiles are laid in the pit, sand is poured in a layer of 3-5 cm and a 10-cm layer of crushed stone with a fraction of 30-40 mm.
5. To level the surface, clean sand is poured over the rubble, and then a 5-centimeter layer of foam is placed.
6. The reinforcing structure is laid on top and the formwork is installed.
7. The base is poured with concrete and compacted with a vibrator.
8. The formwork is removed after 2 days.
9. You can start repairing the next section no earlier than after 25-28 days.

It is important that the concrete contains as little water as possible. The optimal proportion of water to concrete is 1:4. But too thick concrete is difficult to pour into a trench, so it can be diluted with a plasticizer sold in hardware stores.

The height of the finished reinforced concrete pad should be at least 10 cm of the repaired section of the foundation. This will strengthen the base and reduce the pressure on the ground.

In winter, it is not recommended to repair the foundation by pouring a concrete cushion. If dug trenches remain, protect them from frost heaving: cover with earth and cover with foam.

Video: strengthening the foundation by pouring a concrete pad

Plinth replacement

If shedding or destruction of the platform has occurred in the area of ​​\u200b\u200bthe base, this part must be replaced. It is easiest to replace under a wooden building, as it weighs less than stone or brick.

The easiest way to replace the plinth under a wooden building

Under a structure made of stone or brick, the plinth is changed in parts no longer than 1 m with intervals between sections of at least 3 m. To carry out the work, you will need:

• fittings;
• cement;
• sand;
• crushed stone;
• plasticizer;
• concrete mixer;
• chain saw for concrete for cutting the necessary sections of the base;
• perforator;
• welding machine for fastening reinforcing elements.

How to replace the base with your own hands

Video: replacing the basement with the rise of the house

Filling reinforcing belt

If the platform is covered with cracks, but their number does not increase over time, then the repair is carried out by pouring a reinforcing belt. This makes it possible to prevent further destruction of the base and protect it from deformation at low temperatures, but its strength does not increase significantly. The reinforcing belt is allowed to be poured both along the entire perimeter and along one wall.

1. First of all, the foundation is excavated outside the building. The outer part of the foundation should be completely free from the ground, but you should not dig deeper than a sand or gravel cushion. The optimal ditch width is 0.8–1.0 m.

   The outer part of the foundation must be completely free from the ground

2. Then it is necessary to compact the soil near the foundation by manual tamping and pour a layer of crushed stone with a fraction of 30–50 mm and a thickness of 10–15 cm. The crushed stone is also compacted. A thin layer of sand is poured over it to hide the sharp edges.
3. A dense foam 5 cm thick should be laid on top of the sand and covered with a tarpaulin to protect the material from sparks during the welding process.
4. Further, in the foundation, it is necessary to drill holes with a diameter of 18–25 mm at a distance of 60–90 cm and drive pieces of reinforcement into them, which will serve as anchors. Trimmings should protrude from the wall by 15–30 cm.
5. Weld external and internal meshes made of reinforcement 10–14 mm thick to them, which should recede from the base by 5–7 cm. The meshes are connected to each other using pieces of reinforcement.

   Reinforcing meshes are connected with reinforcement

6. In the lower part of the belt, an additional reinforcing mesh is arranged for a pillow with a thickness of 25–35 cm, and equal in size to the width of the ditch. The pillow reduces the load on the ground without the need to dig the foundation.
7. After creating a reinforcing mesh, remove the tarpaulin from the foam and install the formwork. Concrete is poured in two stages. After pouring the pillow, you should wait 2 days, and then proceed to fill the belt.

   Concrete pouring is carried out in two stages

8. After 2 days, you can remove the formwork, and after another 3-5 days, fill the ditch with earth.

Pouring a reinforced concrete jacket

A common way to strengthen the foundation is to pour a reinforced concrete jacket.

The foundation for pouring a concrete jacket is dug out, taking into account the length of the tabs no more than 3 m

This method is quite simple. A person with the slightest skills in construction can pour a reinforced concrete shirt alone. This will require the following materials:

• concrete grade M400;
• fittings for tying the frame with a thickness of 16–18 mm.

Work order

cementation method

The method of cementation is also called injection. This is due to the introduction of hollow tubes into the platform cracks. As a rule, it is used to give strength to a rubble foundation that has many voids. Mortar is poured into them, and small cracks are covered up. This method is considered quite affordable, but it is used only for foundations with preserved bearing capacity.

The cementing composition is introduced using special injectors

Strengthening the base with ebbs

Sometimes the foundation is reinforced with ebbs. This technology is used to strengthen platforms made of brick or rubble. Reinforced concrete sills are used instead of the reinforcing cage.

The order of work is as follows:

1. Reinforced concrete sills are installed on both sides and squeezed out, while the lower part should touch the wall, and the upper one should not.
2. The structure is fixed with jacks and ties.
3. Then trenches are dug with a 2-meter grip.
4. The ditches between the wall and the resulting structure are filled with mortar.

Reinforced concrete sills are used instead of the reinforcing cage

This technology provides for increasing the strength of the platform with double-sided reinforced concrete clips or tubes through which the solution is injected. It fills all the voids of the masonry, due to this, the base is strengthened throughout the entire thickness.

1. At the initial stage, you need to dig out a part of the foundation to be repaired. Its length should be approximately 3 m, width - 1 m, depth - 0.5 m.
2. Then, on both sides, drill through holes in a checkerboard pattern and insert 20 mm reinforcement bars into them.
3. After that, it is necessary to attach a frame with cells measuring 150x150 mm to the reinforcement.
4. At the final stage, the formwork is installed and the resulting space is poured with concrete.

The method of reinforcement with clips allows you to strengthen the foundation throughout the thickness

Shotcrete reinforcement method

This technique is suitable for reinforcing a platform that is not too damaged or when planning to build additional floors. Reinforcement with shotcrete will reduce the pressure on the platform.

With this method, a concrete gun is used, so it is better to entrust the work to specialists. Strengthening the foundation is carried out in several stages.

Video: strengthening the foundation by shotcrete

Strengthening the strip foundation is carried out using a special technology and includes the following steps:

Video: strengthening the strip foundation

The most common cause of platform damage is ground heaving due to heavy rains, floods and freezing water. In this case, the building, as it were, is pushed out of the ground and warps. If the house is located in an area with close groundwater and an unstable climate, during construction it is necessary to think over the drainage system and arrange waterproofing of the foundation. The decision on how best to strengthen the foundation is made after studying the land and analyzing the damage.

Owners of private houses from time to time are faced with the appearance of cracks on the walls and base. The reasons are different for everyone. In any case, the consequence is the same: the foundation simply cannot withstand the load and sags or bursts. If you leave the problem, sooner or later the house will simply collapse.

Therefore, at the first sign of subsidence of the foundation, it is necessary to take the necessary measures. As a rule, the problem is eliminated by strengthening the base. True, in each individual case, you need to select a separate method. We will talk further about how the foundation of a private house is strengthened with our own hands and with the help of specialists.

Causes of destruction

The foundation cracks and crumbles for various reasons:

1. Errors in the project.
2. Incorrect foundation laying technology.
3. Use of cheap and low-quality building materials.
4. Changes in the soil that have occurred over several years after construction.
5. Construction of buildings in the surrounding area.
6. Reconstruction and redevelopment of the house (for example, completion of the attic, replacement of the wooden floor with a bulk one).
7. Sloping landscape.
8. bad
9. Violation of the rules for the operation of housing (for example, a room without heating).
10. Great age of the house.

It is worth mentioning natural factors, which use the above reasons and lead to sad consequences.

1. Washing out the bases.
2. wind erosion.
3. Weathering of rocks that make up base materials.
4. Soil thawing (this applies to permafrost soils).

Monolithic bases cause almost no problems. If problems still exist, as a rule, groundwater is drained.

Preliminary work

To decide how to strengthen the foundation, you need to inspect it. You can do it yourself, but only if you know what to do. In other cases, it is better to invite specialists.

The base is viewed from two sides:

1. Outdoor(the dimensions of the house are analyzed, the load on the base, the condition of the bearing walls are determined, cracks and chips are examined).
2. Underground(the design features of the foundation, material and other characteristics are determined).

Only after that, the design of strengthening the foundations is carried out. It is also necessary to unload the base - partially or completely, after which you can begin to strengthen.

At this stage, you need to ensure that there are no distortions.

For partial unloading, you can take supports and struts (made of wood or metal), and for full unloading, you need to purchase metal beams - strapping.

Amplification methods

There are different ways to strengthen all kinds of foundations. For example:

1. Sole enlargement.
2. Laying new foundations.
3. Cementation.
4. The use of piles, ebbs, clips, shotcrete.

Methods for strengthening foundations are chosen based on:

1. Foundation type and design.
2. Degrees of destruction.
3. The material from which the house is built (wood, brick, concrete).
4. The reasons that led to the destruction.

Strengthening the foundation of a wooden house is easier to carry out. The material is easier to carry loads due to its structural features.

But with houses made of brick or concrete, you need to be much more careful, because here a mistake can destroy the wall.

cementation and injection

Reliable, but at the same time rather complicated methods, one of which requires the involvement of specialists and equipment. Strengthening the foundation by grouting is carried out as follows:

1. Holes are being dug. Their depth should be slightly less than the depth of the base.
2. Wells are drilled in the foundation at a distance of 25 cm to half a meter. The drill should not reach the sole by 30 centimeters.
3. A liquid solution is being prepared (the ratio of water and cement is 0.9 to 1), which fills the channels under a pressure of 0.2 MPa to failure.
4. Further, thicker solutions are prepared, with which the wells are again filled to failure. Thus cement fills cracks and cavities.
5. After two days, the base is considered reinforced.

Strengthening the foundation by injection looks a little different. Here, wells are drilled from different sides of the building up to solid layers of soil. The channels are filled with mortar, and then reinforcing bored injection piles are introduced into them, into which concrete or a mixture of cement is supplied under pressure. Thus, the soil under the foundation is strengthened, and the foundation itself is reinforced with reinforced concrete piles.

Shotcrete

Another very good way to strengthen the base. But here also you can not do without specialists, since special equipment is required to perform the work.

Strengthening the foundations by shotcrete is carried out using a special gun, which applies the solution to the base under pressure. For greater strength, it is recommended to first create a reinforced structure. The advantage is that the concrete applied in this way is very durable.

Shotcrete can be dry or wet. In the first case, it is possible to apply a thick layer with the same density and consistency in one go.

This result is explained by the fact that the composition is not closed with water, but is mixed with it in the nozzle. But this approach has significant drawbacks: for example, high consumption of material and dustiness of the area.

In addition, the workers must be highly skilled as the mixture must be prepared on site. Therefore, many resort to the wet method, when the material prepared at the enterprise is brought to the place by special machines. So the consumption of concrete is significantly reduced, and the loss of rebound particles is also small.

Reinforced concrete shirt

This method is suitable for those who wish to strengthen their foundation with their own hands. No technicians or assistants are needed here. Everything can be done by yourself. So let's start with the corners. It is necessary to dig near them and clean the foundation: from above - from the cladding, from below - from the soil. The depth of the pit should be half a meter deeper than the base.

Next, a frame is made from. Someone uses a knitting someone - a welding machine. Saving on fittings is not worth it. The finished structure is lowered into a pit, which is filled with concrete. Thus the corners are protected.

Now that the corners are protected, you need to divide the entire perimeter near the base into segments of a meter and a half. Then the first such section is dug to a width of half a meter. Holes are drilled in the base into which reinforcing bars are installed.

As in the case of corners, a frame is made. Finished parts are placed in a trench and tied to the reinforcement with wire. The trench is then filled with concrete. Having finished with one segment, proceed to the next and so on the entire perimeter.

The complexity of the work (as well as the choice of method) also depends on the type of foundation.

For example, amplification is easier. For example, one column can be replaced with bored or remote piles. But it will not be so easy to strengthen the old tape-type foundation. Here they resort to shotcrete, reinforced concrete clips, piles: bored, bored-injection, etc. It is also used to strengthen the foundations with grouting.

Dependence on the material of manufacture of the house

When strengthening the foundation of an old house, one must also take into account what it was built from. This factor affects both the choice of method and other features. Let's take a closer look at them.

Tree

In fact, the easiest situation. The fact is that a wooden house can be raised above the base with the help of jacks. In this position, you can easily carry out the necessary work. How to strengthen the foundation of a wooden house, you need to decide in each individual case in different ways.

Somewhere you need to replace, somewhere - create an additional monolithic belt. You can sheathe the base with a reinforced concrete shirt. And all this is made easier if the building is in an elevated state. As you can see, it is relatively easy to strengthen the foundation of a private house made of wood.

Brick

But here everything looks more complicated. The fact is that you cannot raise such a building, and you need to be more careful with the material itself. Therefore, strengthening the foundation of a brick house in the majority is fundamentally different from a wooden one.. Which method should be chosen in this case? It all depends on many factors, such as the degree of destruction, the type of foundation, and others. All this must be taken into account before reinforcing the foundation under a brick house.

One of the most reliable methods is shotcrete. In this case, the masonry is achieved not only strength, but also water resistance. Also, many resort to cementation, since this method is more economical both in time and in finance. Those who are thinking about how to strengthen the foundation of a brick house with their own hands can be offered the creation of a reinforced concrete pillow - this option is used quite often.

You can go on to describe possible methods, such as using piles or widening the sole. All these methods can be used to prevent the occurrence of cracks on the walls. So strengthening the foundation of an old brick house is quite possible, and in some cases even simple.

In conclusion

Now you know how to strengthen the foundation of your private home. For greater understanding, let's briefly go through the above:

1. First you need to establish the cause and degree of destruction.
2. Before starting work, everything must be designed.
3. The method is chosen based on many factors, such as the level of the problem, the type of foundation, the material from which the house is made, and others.
4. Some methods require specialists and equipment.
5. The base of a wooden house is easier to repair, but you should not expect big problems with a brick one either.

Of course, it's good if you can do all the necessary work yourself. But, if you do not have the necessary skills, or you need special units, it is better to turn to professionals, otherwise, all the work will go down the drain along with the costs.

In contact with

They are high bearing capacity, strength, resistance to all loads with a minimum amount of building materials.

This combination of qualities rightfully makes the tape a leader among all other types of support structures.

At the same time, the tape is constantly subjected to multidirectional loads from the soil and the effects of the weight of the building, snow, wind loads, etc.

Often there are situations when the strength of the tape is at the limit, especially when seasonal ground movements appear.

Such cases necessitate reinforcement of the tape, which must be discussed in detail.

The strip foundation constantly experiences destructive influences.

These include:

• Frosty heaving of the soil.
• Soil subsidence.
• Construction or earthworks in progress nearby.
• Seasonal ground movements.
• Floods, changes in groundwater levels.
• Presence of slope.

In addition, negative consequences can cause:

• Low quality building materials.
• Failure to comply with technological requirements during construction.
• A change in the weight of a building caused by the construction of an additional floor or otherwise.
• Violations of house rules.

These impacts can occur both individually and in combination, which creates extremely difficult conditions for the operation of the foundation.

Concrete begins to lose its strength over time, and additional stresses greatly accelerate the destructive processes. The solution to the problem may be to strengthen the strip foundation.

When is reinforcement required and what is it?

The need to strengthen the foundation arises in different situations:

• When planning an additional floor, extension, or other change in the size of the home.
• When cracks appear on the walls or foundation tape.
• If the waterproofing of the tape is broken, causing shedding.
• Mechanical damage to the tape.
• Rise in groundwater level destroying the tape.
• Aggressive environment.

All these cases require immediate intervention. Reinforcement is an increase in the bearing capacity of the strip base by installing additional elements, increasing the section of the strip, injecting special substances or other measures.

The choice of a particular method depends on the condition of the tape, the causes of the problem and the amount of intervention required. In any case, before starting work, it is necessary to carefully examine the structure and make a decision with the participation of experienced specialists.

NOTE!

Self-activity in such cases is absolutely excluded, since instead of the expected results, you can get directly opposite consequences.

Problem Diagnosis

Diagnostics is a set of measures aimed at obtaining complete information about the state of the supporting structure, the presence of mechanical damage, cracks or deformations.

A survey of the state of the underlying soil, sandy and other elements that perceive the load from the weight of the house is carried out.

The procedure is carried out in stages:

• External examination of the visible parts of the tape. Visual detection of damage to the tape is made from the outside, from (if possible). Visible signs of problems with adjacent soil layers are being looked for - subsidence, gullies, etc.
• Underground Inspection. The tape is dug around the perimeter, the condition of the trench is checked, the surface of the tape is inspected and any damage that has occurred is detected. The immersion of the tape and the foundation material are evaluated.

A defect list is compiled, which includes all detected damage. Foundation plan being drawn up, which marks the points of damage, cracks, deformed areas.

Based on the documentation drawn up, a decision is made on measures to solve the problems that have arisen.

During these works, a monthly check of the immobility of the tape is carried out.. Special control beacons are installed on the surface, their condition is recorded.

A month later, their status is checked. If there are no changes, then the tape subsidence is over.

To perform complex work, unloading of the foundation is required. Its purpose is to transfer the weight of the house to an auxiliary support system that allows you to remove the soil under the tape to replace it or.

How to strengthen the strip foundation

The actions that need to be taken to reinforce the tape are determined by the size and causes of the damage. In some cases, it may be enough to update the waterproofing, in other situations, a complex of complex technical measures is required, to install additional supports or expand the tape.

Let's take a closer look at these methods:

Strengthening a shallow foundation with a concrete jacket

A concrete jacket is a reinforcing concrete casting installed on a problematic section of the wall.

To create it, the following steps are performed:

• The surface of the tape is exposed, all the soil in the problem area is removed from the trench.
• A layer of waterproofing is removed from the concrete tape. The surface of the material must be absolutely clean, as after pouring.
• Transverse holes are drilled through the tape, into which reinforcing bars are inserted.
• , which is welded to the rods inserted into the holes of the tape.
• Installed.
• Concrete is poured, the allotted time is maintained.
• After the end of the exposure period, the formwork is removed, the concrete surface is waterproofed and further actions are taken.

The dimensions of the reinforced concrete jacket depend on the size of the damaged area, but not less than 1 meter.

Creating a concrete clip

The concrete casing forms an additional layer of material on both sides of the belt. The technology resembles the method of installing a reinforced concrete jacket, but an additional layer is poured on both sides of the problem area of ​​the tape.

All actions are performed both from the inside and outside of the tape . As a result, a significant thickening of the foundation is formed. capable of withstanding high loads.

Many experts express distrust of the installation of clips. They argue that there is no quality connection between the old concrete and the new casting. The processes occurring in the fresh material do not allow the layers to connect qualitatively, so the technique is suitable only if there are relatively small damages.

Through the use of piles

The method of reinforcing piles is quite complex and diverse. Piles are being installed to provide additional support for the tape. They rest on dense layers of soil, stopping subsidence or increasing the bearing capacity of the foundation. to accept the increased load from the outbuildings or new structural elements of the house.

Various types of piles are used:

• Micropiles.
• Depressed.
• Bored.
• Screw.
• Remote.

Each type of pile performs its own function and is used in certain situations., where their use is the best solution to the problem. So, screw piles can be installed manually, using the most gentle methods.

Pressed piles require the use of special equipment, so their use for reinforcement is limited..

External piles are installed at some distance from the perimeter of the old tape, then metal beams are passed through it, which are connected to the piles. As a result, the house is, as it were, "suspended" on the beams, receiving additional support..

The weight of the building is distributed between the old and new bases, which allows you to carry increased loads.

With the help of tides

The technique is used when reinforcing a tape made of piece elements - brick or rubble stone. Ebbs are designed to perform the functions of an armored belt.

They are installed on the surface of the tape on both sides, squeezed out so that the upper part does not come into contact with the wall surface, and the lower part is pressed as tightly as possible to it.

After that, the structure is firmly fixed with the help of jacks. A trench is dug to form a concrete mold. As a result, an additional reinforced concrete layer is formed around the tape, which enhances the bearing capacity and strength of the base.

Shotcrete reinforcement

Shotcrete is the process of applying concrete with a special spraying method.. For this, special equipment is used. The essence of the method is to supply a dry mixture of cement and sand, called a shotcrete mixture, under compressed air pressure.

Simultaneously with the supply of the mixture from another tank, water is supplied, the mixing mixture. As a result, a layer of dense and durable concrete appears on the reinforced surface., which has enhanced characteristics compared to conventional types of material.

NOTE!

The technology is complex, it requires the involvement of specialists, the use of sophisticated equipment.

Useful video

In this section, you can see how the process we discussed in the article takes place:

Conclusion

Strengthening the strip foundation allows you to get a more load-resistant and durable support structure, capable of accepting additional loads or resuming the functions performed.

All work from beginning to end must be performed by experienced professionals, there should not be any independent work here. The result of the work performed can be both positive and negative, so all actions must be carried out by competently trained people.

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Due to the absence of planned repairs for a long time or under the influence of increased loads, the foundation begins to collapse. If the walls are quite strong, then the owners of the building decide to repair the foundation themselves. This allows you to extend its operational life and save some money. Strengthening the foundation of a private house is carried out in several ways, most of which do not require technical capabilities and specialized knowledge. The involvement of professional builders is necessary only in some severe cases.

Reasons for the destruction of the base

Strengthening the foundation is necessarily carried out, having found signs of deformation or planning to make changes to the existing structure. For example, if a decision is made to complete the second floor. Before starting work, it is important to determine the causes of destruction, since the choice of a set of restoration measures will depend on this.

Changes in the structure of the support can provoke:

• Earthworks carried out on the site in the immediate vicinity of the building. By creating an additional load on a separate segment, they lead to the formation of subsidence and cracks.
• Vibration. It is often observed if the house is located near the railway, as well as after earthquakes.
• Strong soil moisture due to an increase in the level of groundwater, past floods.
• Incorrect operation. One example is that the building is not heated in winter.
• Violation of technology caused by insufficient volume of binder (cement), the amount of installed reinforcement.
• Errors in calculating the maximum load.
• The location of the base is above the freezing level of the soil, which causes it to move.
• Remodeling of the building with the displacement of load-bearing walls.

Without eliminating the cause of the destruction of the supporting structure, repair work will be less effective.. Therefore, if the deformation is caused by a high level of groundwater, then it is first necessary to make a drainage system on the site and only then strengthen the base.

Repair of the foundation of a brick house

The most popular are several options for repairing damage. The simplest, when, with a slight subsidence, a crack went on the base. It is slightly expanded, cleaned of dirt and, well primed, sealed with sand-cement mortar.

In difficult cases, choose the method of installing a reinforced concrete pad, poured under the supports. Due to the large area, it reduces the load and, additionally insulating the soil, stops frost heaving. But the restoration of the base should be carried out in small sections up to two meters in length.

After waiting for one segment to be repaired to gain the necessary strength (within 25–28 days), they continue to restore the other. Therefore, this method is well suited to prevent subsidence of a separate part or one of the corners of the house. But strengthening the foundation in a circle in this way is a long process.

Filling the reinforcing belt is used if there are numerous cracks, while their number does not increase. The method allows you to prevent further changes, but the strength of the supporting structure increases slightly. The base is replaced when it can completely collapse. It is easier to perform such work with a wooden house, due to its low weight. Under the building of brick, stone, repairs are carried out in small pieces about a meter.

Before pouring the pillow, the problem area of ​​the house is dug inside and out, trying to create two ditches up to 3/4 of the depth of the foundation and up to 3 meters in length. The presence of trenches will allow you to assess the condition of the support and decide on further actions to replace or restore it. Further:

• A hole up to 2 meters long is dug under the pillow, deepening below the base by 40–50 cm.
• Having covered the bottom with geotextiles, they make a sand bed 3–5 cm thick, and another 10 cm of rubble on top.
• Additionally, a layer of sand is spilled and, having leveled it, a hard foam 50 mm in size is laid.
• Having assembled the reinforcing structure, formwork is installed.
• Bay concrete, the solution is compacted with a vibrator.
• Leave to stand for 25-28 days.

You can move on to the next sections after the solution has completely hardened. If the repair work was not completed before the onset of cold weather, then the already finished trenches are covered with earth and covered with foam.

It is recommended to replace the plinth in separate pieces, no more than a meter long, keeping 3 m between the repaired areas. Considering the complexity of the work, you will need: a concrete chain saw for cutting and removing damaged parts, a welding machine for connecting reinforcing elements, a perforator. The order of work is as follows:

• With the help of a saw, several vertical, then horizontal cuts are made in the wall, trying to divide the selected area into separate fragments.
• After removing the pieces, all surfaces are cleaned.
• Formwork is made, one part of which is installed from the side of the street, and the other inside the building. It should be 5–7 cm wider than its wall. If two indents fail, then one of the sides is erected flush.
• Having prepared the formwork, a reinforcing structure is installed. For which, having drilled holes in the wall, vertical pins 18–22 mm in diameter are driven into it.
• The blanks are placed in a horizontal plane, fixing them in the old base.
• The reinforcement is connected to each other with a knitting wire, by welding.
• At the end, they are concreted and allowed to stand for up to 25 days.
• The replacement of adjacent sections is started no earlier than the specified period.

The device of the reinforcing belt can be performed on one or all walls at once. With this method, part of the load is removed, due to which it is possible to effectively strengthen the foundation of a brick house. Another positive point is its protection from frost heaving, which is very important if the building is located in an area with a high location of groundwater.

They operate according to the following algorithm:

• Work begins with the creation of ditches around the foundation (on the inside and outside of the walls), deepening to a sandy, gravel cushion. The width is kept within 80–100 cm, smaller sizes will make it difficult to attach the belt to the base.
• Having completed the preparation of the trenches, the soil, and then the layer of crushed stone poured on top of 10-15 cm, is compacted with a manual rammer.
• To hide the irregularities, an additional layer of sand is laid, and foam sheets 50 mm thick are laid on it. To protect it from welding, it is covered with a tarpaulin.
• After 60–90 cm, holes Ø 18–25 mm are drilled in the foundation. Prepared cuts of rolled steel are driven into them. Grids are welded to the reinforcement, which must be additionally tied together with pieces of wire, placing them at a distance of 5–7 cm from the base.
• In the lower part, in order to evenly distribute the load on the ground, another grid is installed.
• After the reinforcing structure is created, the tarpaulin is removed and the formwork is fixed.
• Start pouring concrete.

All work is carried out in stages, first the pillow itself is prepared, and after 2-3 days the strengthening belt. It is believed that in order to enhance the characteristics of the base, it must be allowed to stand for a month, but this is not always possible. Therefore, after the final pouring of concrete, after waiting 3–5 days, the formwork is removed and the trench is covered with soil.

Strengthening the foundation of an old wooden house

Work is carried out taking into account the degree of destruction, or when the structure has gone into the ground. In the first case, the methods listed above are used, in the latter, the building is raised. This solution facilitates access to the foundation and reduces the load on it. All furniture is removed from the house, as far as possible and the stove. When the dimensions and weight of the building are small, they try to raise it with the help of a log. To do this, use a bar 80x80 mm. Substituting it under one of the corners and making an emphasis from the log, pressing on it like a lever, they squeeze the wall.

A heavier old house is lifted using several jacks. Having installed them in certain places, the building is moved to the desired height and the base is built up with the help of bricks, concrete mortar. In serious cases, when the strengthening of one of the parties is not enough, the entire perimeter is strengthened.

Sometimes in the repair of an old wooden house they are limited to concreting corner sections.

• Before starting work, problem areas are exposed by digging a hole about a meter in diameter from each of them, placing it below the depth of the base.
• To get to the reinforcement, the old foundation is cleaned in some places.
• The reinforcing mesh is attached by welding.
• Having installed it, layer-by-layer pouring with concrete is carried out, after which it is left to harden.

You can increase the degree of reliability by simultaneously strengthening the corners and the most problematic places along the perimeter of the home.

To do this, having prepared ditches up to 0.5 meters wide, reinforcement is carried out with a reinforcing lattice with cell sizes of 20 × 20 cm. The depth of the ditches is limited by the occurrence of the old support. Having connected the base and the reinforcement together, the formwork is prepared and concreted.

One of the effective ways to increase the strength of the foundation of an old wooden house is the pile method, which is divided into several types:

• Boronabivnaya. On the sides of the base, with an interval of every one and a half meters, wells of two meters deep are prepared. After waterproofing, reinforced structures are laid and concrete is poured.
• With screw piles. The method is less laborious, but it is necessary to simultaneously maintain the direction of the rods and engage in their deepening, therefore, several people are needed for its correct implementation.

It is difficult to list the available options for strengthening the foundation of a private house. All of them were developed taking into account existing defects and based on the possibilities of their solution. But in each case, a set of works to increase the bearing capacity of the foundation is easy to perform independently.

Strengthening the strip foundation is a very important and responsible decision in relation to the durability of your home. Each building has its own lifespan, as it is constantly influenced by the environment. On the foundation or building, various kinds of cracks and deformations may appear, which require immediate correction. Just in this case, strengthening the base is useful. In our article, we will consider the features of this process and the main ways to complete it for a strip foundation.

The need to strengthen the foundation

If your main goal is a solid and reliable home, then the first thing you must do is to monitor the condition of its base and foundation. Since the tape type is the most popular today, we will consider all questions using its example. It is worth noting that buildings of this type provide for additional fasteners that can be mounted both during the construction of the building and after construction is completed.

Attention! Strengthening the foundation after its construction will take much more effort than doing this process during construction. This is a very extreme scenario, since the project was prepared for one base format, but you have to revise it.

When to strengthen the foundation after the completion of construction, the process will require large cash costs. Therefore, experts in this industry advise thinking about this when designing a house, but, unfortunately, practice shows that people rarely listen to recommendations.

Let's still find out why there may be a need for these works for the home. So, the first is the completion of the house, the second is if cracks appeared on the building. You should also add here the negative impact of frost on the structure of the building and various kinds of mechanical damage.

Reasons for the formation of cracks

The need to repair the foundation sometimes arises earlier - this is due to the appearance of cracks. Where do they come from? This is what we will now find out in this section.

So, there can be many reasons for this, let's name the most common situations:

• If the foundation is erected on bulk moving soil, then subsidence of the soil may occur;
• With strip construction, if the bricks were not reinforced, then cracks in the structure are possible over time;
• If the concrete slab does not have a strong metal frame;
• If the foundation of bricks does not have a metal mesh in the structure, then the divergence of the structure and many cracks are quite realistic;
• If the ventilation passages were not closed during the winter period;
• Incorrect load calculations were made;
• The building does not have a drainage system to remove water.

Attention! There are several ways to solve these situations, the choice of which depends on the reasons for the formation of deformations. We will talk about the features and methods in the following sections.

Types of hardening technologies

Any renovation of a building should include strengthening the foundation. This is necessary in the following situations:

• When planning the completion of a building, for example, the second floor;
• With the negative impact of the natural environment and violation of the integrity of the structure;
• When building elements settle, which can cause destruction.

So, when performing work to strengthen the bases, the following types are used:

1. Typical way;
2. The original way.

Attention! These methods are developed in order to save historical monuments of architecture. But in our time they are applicable to all types of buildings.

For example, the first method was applied in the reconstruction of the Bolshoi Theater, which breathed a second wind into it. Specialized companies are engaged in improving the methods, because, as practice has shown, it is much cheaper to repair a building than to build a new one.

Ways to strengthen the tape building

Strengthening the base of the strip foundation can be done in several ways. It all depends on the level of damage. So, if the building has a scratch or a slight deviation, then one method is useful, but if you want to complete the building, then this is another way.

Attention! Only a specialist can determine the method you need. Only detailed calculations of the load, taking into account the subsidence of the base of the old room, can be allowed to the stage of choosing the reinforcement method.

Methods for strengthening the strip foundation:

1. The first method is based on a reinforced concrete widening structure. It works like this: transverse beams are mounted in the openings in the base - this allows you to create an increase in the width of the foundation.
2. Piling method. The peculiarity is that the piles have the ability to take on a certain size of the load of the transverse beams. There are such types of piles: bored, pressed and root-shaped.
3. Method of fixing the soil under the sole.
4. Clip reinforcement technique without additional expansion of the base space. This is the most popular scheme today. The principle of operation is to place pillars and slabs under the foundation, which are used to remove old parts and install new ones.

Important! When carrying out any work, do not forget about thermal insulation and drainage system.

Strengthening the base of the strip foundation

To perform this process, several techniques and methods are used, and sometimes several at the same time. If the soil is heavily eroded under the foundation, then the first thing they do is partially replace it with a layer of sand, which is tightly compacted. The top must be filled with concrete. You can perform additional reinforcement by expanding the boundaries of the base, which will reduce the level of pressure. A very popular method is the laying of beams attached to the foundation. They significantly reduce the load and expand the dimensions.

pile method

This method has several ways of development, which depend on the problem. The most popular is to place piles next to the base of the house and connect to it. There is an even more reliable way using through fastening. The principle of operation lies in the holes that are made with a drill and connect the walls, foundation and soil. Their placement is carried out through one in different directions. For example, the direction of one pile to the house, and the other - away from the house. The holes are mounted with a metal mesh, which is installed gradually. Further, all the cracks are filled with a solution of concrete.

Attention! Such a compaction of the base after the concrete has hardened provides a reliable support.

Metal clip method

Strengthening the foundation with metal clips is necessary when shedding the base tape. The reasons for this situation may be as follows:

• The foundation was badly damaged during the winter and autumn period, when the level of precipitation exceeds the norm. Concrete undergoes great damage to the structure when it melts.
• The strength of the solution may lose strength if the rate of water during its manufacture was exceeded;
• Theft of workers at your construction site, who could take some of the quality materials and add a cheaper look or apply other tricks;
• The shedding process may be due to sand with a high clay content.

Attention! The presence of clay in the solution can be checked by simply looking at the foundation, if there are pits in the form of craters, then it is this sand that was used to create the solution. In autumn, clay has the ability to collect moisture, which freezes in winter, and then simply repels concrete, which is why traces form.

• When purchasing cement, pay attention to its technical characteristics.

You can strengthen this strip foundation and save it from possible destruction in the following ways:

• Try to constantly monitor its condition, because cosmetic repairs will not give any result;
• If large pits appear, then they need to be plastered, using a special composition of the mixture for this purpose;
• To prevent destruction, we recommend thermal insulation of external walls.

After a certain time, you still have to replace the foundation tape, since it is not durable and is constantly under the influence of various damages.

Advice. With high-quality waterproofing and insulation of the facade, the structure can last a very long time.

The method of dismantling the old foundation

There are situations when the deformation of the tape occurs in one place, for example, you can simply pinch off a piece of it, and it will be like plasticine in structure. This is a very rare case, the reason for which can be only one - there is too little cement in the solution or there is clay in it.

In such a situation, the only way out is the complete dismantling of the strip foundation. Because no strengthening will save here, only a new foundation.

Attention! These problems are noticeable when the tape dries, so check the quality immediately, while the house is not yet erected.

This process is quite complicated and costly, because the defective foundation will have to be completely removed, and then a new one will be built in compliance with all building codes and technologies.

One-sided tape reinforcement process

If the deformation of the strip foundation has occurred only on one side, then the house is skewed, and cracks will begin to appear. The impetus for this development could be a violation of the requirements for the construction of the foundation of the building. Usually, the manifestation of this deficiency appears immediately after the end of the winter season, since heaving will not be able to plant the tape.

What to do in order to strengthen the tape base? This is a rather complicated process, because it is necessary not only to fill the gap, but also to level the building.

Attention! Before starting work, you need to carefully inspect the strip foundation for cracks and deformations. If their level is very high, then it will be necessary to perform a very complex and expensive method.

In the event that the state of the foundation is not in the most terrible form, then you can simply level it. To do this, the resulting voids must be filled with a concrete mixture. With this process, you need to constantly monitor the condition of your building, so as not to increase the deformation. The interval of work is directly proportional to the state of damage. This criterion affects both the cost of work and the need for certain equipment.

If the structure is cracked, then the process of strengthening the base is simply irreplaceable. But, still, do not forget about preventive examinations in order to identify the existing problem in time.

The most popular way

A little higher, we wrote that the most popular way to strengthen the foundation is to use a reinforced concrete clip. This process can take place in two ways:

• With the increase in the sole of the building;
• No magnification.

Significant advantages include the possibility of working without deepening the foundation. Clips can be mounted on a certain area or at the full height of the strip foundation. Types of clips for this base:

• Reinforced concrete;
• Concrete.

To prepare for the start of work, it is necessary to apply notches with a perforator along the entire perimeter in order to increase the level of tenacity due to the roughness of the surface. When strengthening the foundation, the clips are fastened together with beams.

The level of plasticity of the reinforcement affects the density of the solution. In this situation, the density will have a value equal to 10 cm of sediment. The best cement for mortar is Portland cement, because it only gives the necessary strength.

Attention! To protect against precipitation when adding the width of the strip foundation, you need to make a compression with a jack.