Over time the foundation brick house can be destroyed under the influence of various factors. The most common type of supports for a massive structure is strip. Repairing the foundation of a private house is most often carried out in two steps: not only the load-bearing supports are affected, but also the soil under the foundation. Requirements for strengthening foundations during reconstruction are given in the joint venture “Design and installation of foundations and foundations of buildings and structures”, clause 13.9.
It is important to replace the malfunction of the load-bearing element of the building in a timely manner. The earlier a problem is identified, the less labor and financial costs will be required to solve it. Buildings are at risk in the following cases:
- the presence of several floors (the greater the mass of the overlying structures, the greater the likelihood of damage to the supporting part);
- design errors (incorrect geological data, incorrect selection of structures based on load-bearing capacity);
- implementation of redevelopment or superstructure;
- violation of operating conditions, improper use;
- soil erosion;
- rising groundwater levels;
- location next to a site containing highways, active construction or other sources of vibration.
It is impossible to eliminate all these factors, therefore, if a weakening of the supporting part is suspected, it is necessary to inspect it and properly repair the foundation in accordance with the cause and nature of the damage. The design study is carried out in the following order:
- Inspection from the basement (if there is one). This may require removing part of the room's finishing.
- Inspection of the outside. To do this, excavation pits are performed. A pit is a hole, most often rectangular shape. Excavation of soil in this way allows one to obtain information about the condition of the underground structure and soil characteristics. The bearing capacity of the soil does not change much over a short period of operation, Special attention It is worth paying attention to the location of groundwater. Places for excerpts are chosen where the base is most damaged. For a small private house, two or three points are enough to get a general idea of the condition of the foundation.
When examining the outside and inside, pay attention to the presence of cracks, chips, depressions, and cavities. For cracks, it is necessary to note the direction and magnitude of the opening.
You can determine the cause of cracks by their nature and direction using the table:
| Type of wall deformation | Causes of deformation |
| Settlement of the middle part of the house
|
Soil subsidence under the central part of the building ( weak soils, karst voids). |
| Drawdown of one side of the house
|
Weak soils under one of the sides of the building; karst voids; development of a pit near the foundation, shift retaining wall next to the foundation; constant soaking of the soil under the foundation. |
| The same reasons as in the previous case, but acting immediately under both parts of the house. | |
| Raspor rafter system(if it is not performed correctly); movements as a result of seismic activity; eccentric load from floors. |
Repair of the foundation of a brick house is carried out in two stages:
- soil strengthening;
- strengthening the structure.
Strengthening the foundation soil
The higher the bearing capacity of the soil, the higher the bearing capacity of the supporting part of the house. A solid foundation prevents shrinkage and destruction of the foundation. You can strengthen the soil in the immediate vicinity of the building in the following ways, depending on the type of soil:
- For medium or coarse sands, cementation, silicatization or bitumenization are used. Liquid solution is injected into the soil and binds the loose layer into a single whole. In addition, you can use a chemical strengthening method. Strengthening is done in the same way as in the previous case, but chemical solutions are used.
- Loess soils can be strengthened by chemical or thermal methods. With the latter, the soil is fixed under the influence of hot gases.
- For clays prone to heaving and characterized by high humidity, electroosmosis is suitable.
- Peat, silt and marshy soils strengthened by injection. This option is also suitable for other types of bases.
Scheme of strengthening the soil under the foundation.
In addition to the above options, amplification can be performed using electromechanical and mechanical methods. The first involves injecting chemical solutions while simultaneously passing them through the ground. electric current. The second includes a variety of activities such as:
- compaction;
- tamping;
- laying sand cushions;
- installation of soil piles.
Important! Proper strengthening of the foundation will prevent or delay the destruction of the foundation after repairs.
Strengthening the strip foundation
Previously, it was said about the need to identify the opening width and direction of cracks on the surface of the structure. This is because vertical, horizontal and inclined cracks occur for different reasons:
- horizontal and hairy due to mechanical damage or violations of concrete care technology during hardening, due to shrinkage;
- inclined and vertical ones arise due to uneven shrinkage of the base (they pose the greatest danger and require more serious measures).
Minor damage
For surface defects, it is sufficient to use the gunite method. The work is carried out in accordance with the “Guidelines for the use of shotcrete in construction, repair and restoration building structures buildings and structures." The foundation is strengthened by restoring the outer layer of concrete. The work is performed in the following order:
- digging out the foundation around the perimeter of the house, cleaning the basement and underground wall from contamination;
- on the surface of the foundation, using a sharp, durable tool, I make notches that will allow the solution to firmly adhere to the wall;
- for reinforcement, a reinforcing mesh is provided (most often made of fiberglass);
- Concrete is distributed from a special gun over the surface of the structure.
After completion of the work, waterproofing is restored, insulation is provided if necessary, and backfilling is performed.
Damage due to shrinkage
Uneven ground movements affect not only the foundations, but also brick walls, which are especially sensitive to deformation (unlike wood). You can strengthen the tape in several ways:
Sole widening. In this case, you will need to dig out the supporting part on both sides, and then fill the base with concrete. Waterproof castings are most often used as a form for concrete mortar. In order for the new sole to work together with the existing structure, the ebbs and the old foundation are connected to each other with reinforcement.
Increasing depth. This option is suitable for non-recessed or shallow structures. It is performed in approximately the same way as the previous method, but the resizing occurs not in width, but in depth.
Taking in the clip. You can use concrete or brick to make the frame. This method is labor-intensive, but provides high reliability. It is best to use concrete because it can provide adhesion to the surface of the existing foundation, which ensures that the old and new structure work together. The step-by-step implementation of the activities is described below.
Scheme of strengthening the foundation with reinforced concrete frame.
Installation of piles. The load from the building (1) is transferred to the piles (6) using beams (4), which are laid perpendicular to the tape (2) with equal reach on both sides. Beams can be placed between the wall of the house and the foundation or in the body of the tape. To carry out the work, you will need to punch holes in the foundation above the installation site for the beams for the piles along the entire perimeter on both sides, into which an I-beam or channel (3) is then placed. When performing work, rolled metal plays the role of jumpers, and then allows you to increase rigidity strip foundation and evenly distribute the load on the piles (through perpendicularly installed beams).
Scheme of strengthening the foundation with piles.
Advice! When strengthening the tape, the foundation should be removed in sections no longer than 2-3 meters long. After completing work in one area, backfill is performed and move on to another. This will allow the structure to remain stable.
The order of work in the manufacture of reinforced concrete frames (“shirts”):
- foundation fragment;
- removing contaminants from the surface;
- making notches on concrete;
- driving anchors into the foundation horizontally;
- installation of formwork;
- strengthening the structure with reinforcement;
- welding of reinforcement to anchors;
- pouring concrete;
- Strengthening and care;
- backfilling.
Advice! The backfill needs to be compacted. The maximum thickness of the compaction layer at one time is 30 cm, so the backfill material is laid in layers.
Strengthening a columnar or piled concrete foundation
For small defects, shotcrete is used in the same way as in the previous case. The operating principle is no different.
In case of serious damage, you can use the following methods:
- combining separate foundation structures into a single strip (a labor-intensive and expensive option, but it gives a good result even with severe damage);
- widening the sole or increasing the depth of the foundation;
- reinforced concrete or brick frames.
Work for free-standing foundations is carried out by analogy with strip foundations. The only difference is the appearance of an additional option (combining pillars).
If you correctly repair the foundation of a brick house and strengthen the foundation, you don’t have to worry about the reliability and stability of underground supports and above-ground walls for a long time.
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The owner of a private house once always wonders how to strengthen the foundation. Entrust it to someone or try to do everything yourself? Let's look at the main stages and weigh the forces.
Correct Negative consequences the foundation under the house will be affected by external factors, but what to do if in your life you have never had to do foundation repairs with your own hands? To understand which strengthening of the base of the building is preferable, you should understand the reason for its collapse. There are two explanations why pieces of the foundation suddenly begin to fall off and the foundation itself to crumble: technology violations during construction or external negative factors (soil displacement, changes in its composition, movement groundwater, vibration).
Collapse of the base of the building
The first reason may include improper preparation of the binder, poor-quality building materials, incorrect measurements that led to the warping of the masonry. The second “critical moment” may be that the composition of the soil, its moisture content were not taken into account during construction, or drainage was not done correctly.
To determine whether the destruction of the base under the house continues and whether it needs to be strengthened urgently, paper tapes should be glued to the cracks found.. If within a week they are not broken, then the expansion of the splits does not occur. You can use plaster tape. In addition to visual inspection, soil samples are taken, including to determine its chemical composition. Thanks to this analysis, it is possible to select building materials that are not affected by external factors or their harmful effects are minimal.
Prevention of foundation construction
Like any structure, the foundation needs mandatory preventive procedures. Thanks to them, it is possible to significantly extend the life of a private house and delay the strengthening and bringing it into proper order. It is recommended to pay attention to the following "pain points":
- Before building a foundation, be sure to use geodetic and geological services that will determine whether it is possible to build a residential building on a certain piece of land.
- In no case do not deviate from the requirements of technology: do not use a binder solution that does not correspond to the project, brick with other hygroscopic properties, do not save on the components of the concrete mixture.
- Do not make changes to the plan of a private house (reconstruction of load-bearing partitions and walls, construction of additional floors and extensions), which can change the application of support points to the foundation and redistribute the weight load of the main building.
- The construction of a shock-absorbing cushion under the foundation, drainage ditches and moisture insulation should not be neglected. For long-term operation of the building, you should not save on these works.
- All communications should be laid before the foundation is erected. The deployment of these measures after construction can lead to improper shrinkage of the entire building, and as a result, to the appearance of cracks and the destruction of its foundation.
Let's start with the most popular, one might say, classic way to strengthen the foundation. The algorithm of actions has already been worked out for centuries, and therefore it is most preferable because of its efficiency and economy, and it is quite feasible with our own hands. The point is to build a new foundation, which is laid out around the house along its perimeter and serves as an additional support for laying the old foundation. All work is divided into a number of successive stages.
First, square holes must be dug at each corner of the building in order to expose the masonry of the old foundation. The parameters of the pit are 1x1 m. The depth must be made 0.5 m below the old base. Then it will be necessary to make frames from reinforcement according to the number of corners of the building or along the length of the walls, if it is decided to make reinforcement around the entire perimeter. Then there is the installation of structures made of metal rods in the resulting recesses and the filling of square pits with reinforcement with concrete, the brand of which guarantees the special strength of the material.
Strengthening the foundation with a metal rod structure
The work is rather scrupulous - too long exposure of the old foundation can lead to a negative impact of the external environment and subsequent distortion. That is why it is recommended to divide the pouring perimeter into sections not exceeding a length of 2 m. The next sector will be strengthened after the concrete “grabs” completely on the previous one. For the same reason, it is recommended to expose the corner parts of the foundation as they are poured, so that the exposure time is minimal.
Strengthening the foundation of a wooden house
If the first method is quite possible to do with your own hands even alone, then for wooden house organizing strengthening of the foundation is a little more difficult. The fact is that the most common misfortune of such buildings is the rotting of the crown, that is, the dilapidation of the lower logs of the log house. For everything to be successful, it is necessary to replace this part of the hut, at the same time you can use the case for laying waterproofing material.
How to strengthen the foundation of a wooden private house with your own hands - step by step diagram
Step 1: Dismantling the Base
It should be noted that the operation to replace the crown should precede the strengthening of the base. First, a small dismantling of the foundation is done under the lower log in order to freely remove the rotten wood. At the junctions with other logs, cuts must be made.
Step 2: Update the entire perimeter
After that, part of the dismantled foundation is restored. When the whole procedure is done, the same thing is done on the opposite side of the house. Having finished with one row around the perimeter, you can begin to replace the next. It should be noted that the crown of a wooden house is made up of two rows of logs, and each of them must be impregnated with special compounds and covered with a waterproofing agent when replacing.
Step 3: Unloading at home
But what to do if not only the logs let us down, but the old foundation collapsed in several places, and serious work is needed to restore it? Here you can not do without hydraulic devices. Remove the load on the foundation, i.e. remove pieces of furniture and heavy equipment from the room. It is also advisable to dismantle the doors and the floor.
Step 4: Opening the Foundation
Along the entire perimeter of the building, every 2 m, it is necessary to prepare holes into which channels or I-beams should be inserted, they will act as a platform. With the help of hydraulic jacks, these iron structures evenly raise the house to a height that allows strengthening the foundation itself. Temporary supports are installed under the house (welded structures or wooden blocks). When full access to the foundation is obtained, it is possible to fully strengthen it. When the work is done, you just need to put the house in place and bring in all the things.
But what about the views of the foundation itself, because most often it is columnar and tape? Will their strengthening take place in some specific way? Many people know that a columnar is a system of piles (pillars) that are installed in places of maximum load. In order to properly distribute the load on these supports, various devices such as grillages and strapping beams are used. The design of the tape is also intuitive from the name. This reinforced concrete structure in the form of a closed loop. Often, columnar is combined with tape.
Reinforced strip foundation
If you want to deploy the reinforcement of any of these structures, then both methods described above are suitable for this. In addition, it can be improved by drilling holes in the posts and providing them with reinforced rods. How to strengthen, you can even choose from several options: by replacing parts with new ones (block), or by erecting formwork and pouring a layer of concrete (monolithic).
Foundation. Cracks can appear for several reasons. Let's take a closer look at them and how to repair the foundation of a private house.
Conventionally, they can be divided into two: deterioration of the bearing capacity and deterioration of the bearing capacity of the foundation itself.
In the first case, this may occur due to flooding. When saturated with water, some soils lose their bearing capacity. Also, during flooding, soil erosion may occur. This happens in areas where the soil consists of sandy and sandy loam layers.
At least two holes are dug in the most problematic areas. The method of digging holes is the most informative. Using this method, you can determine the depth of the foundation, the presence and condition of waterproofing, the material from which the foundation is made, as well as the presence of groundwater.
If there is the presence of groundwater, then it is possible to determine what properties they have. To do this, use ordinary litmus papers, which can be purchased at garden stores.
After determining the research and determining the reasons for the destruction of the foundation, they begin to repair the foundation with their own hands.
The cause of the deformation can be eliminated, but the destruction is not significant and only cosmetic repairs may be required.
Also, sometimes the deformation of the foundation is so serious that it will be impossible to repair it yourself. Or the foundation will need to be repaired, the price of which will be comparable to new construction.
How to eliminate the causes of foundation deformation?
- Deformations caused by flooding.
To eliminate freezing, it is necessary to insulate the foundation. Insulation is carried out to the bottom of the foundation. To do this, dig a trench around the perimeter of the house, then insulate the side wall of the foundation and fill it with screenings or small crushed stone. A layer of insulation is laid on top of the backfill and poured.
In case of significant damage to the foundation, repair of the foundation is also carried out while eliminating the destructive factors.
Foundation repair
One of the most popular methods is foundation installation. The essence of the method is to deepen and increase the area of support of the sole. It can be implemented in two ways: with partial replacement masonry and complete replacement.
The liner is carried out using grips in separate sections one and a half to two meters long, which depends on the depth of the foundation strength. When laid deeply, the grips are reinforced with posts and beams.
Removed upon completion of concreting. Metal fasteners are left in concrete.
This method is recommended for use when there is a large volume of structures to be strengthened, a shallow foundation depth, or deep groundwater.
It is important to follow the work technology to prevent the resumption of foundation destruction.
Foundation repair using clips
The frames are side supports made of concrete blocks connected to the old masonry.
Wide clips are not reliable and durable; difficulties also arise during anchoring; the impossibility of transverse through reinforcement leads to the conclusion that their use is rational.
The most preferable are two-leg cages that do not experience torque.
Application of the method of widening the base of the “reinforced concrete jacket”
This method allows you not only to strengthen the foundation, but also part of the wall.
To strengthen it using the widening method, the foundation is marked with claws. The length of the marks is 2-3 meters.
Reinforcement installation
Restoring the foundation is not a difficult task, but it is labor-intensive.
You can strengthen a collapsing concrete strip in the following way - pour an additional layer of concrete with good reinforcement around its entire perimeter, that is, make a kind of sarcophagus.
In this case, the new fill should take on the main load and prevent further destruction of the old foundation. To do this, it is necessary to ensure strong adhesion between the new and old structures. The excavated foundation must be thoroughly washed, otherwise the new fill will not adhere to the dirty concrete. It is also important to ensure reliable reinforcement. For this purpose, I decided to tighten the reinforcement cage on both sides of the tape with jumpers - studs passing through the old foundation, for which I made through holes in the tape in increments of 50-70 cm, using a hammer drill with a long drill.
The prepared reinforcement bars were first bent at a right angle at one end. Then he inserted the rod into the hole and bent the other end. The bent ends on both sides of the tape were connected to the reinforcement cage.
Thus, the frames on both sides of the tape were connected by S- or U-shaped jumpers. Each bend of the lintel should be 40-50 mm from the surface of the foundation. In my case, the reinforcement frame is made of metal mesh (4 mm thick) with a cell size of 100 * 100 mm, connected at the top with 0 8 mm reinforcement bars and tightened with jumpers.
Installation of formwork
The height of the excavated part of the foundation is about 70 cm. If the formwork is installed entirely at once, then it is unrealistic to properly lay concrete in such a narrow and high form. Therefore, I decided to pour the concrete in two stages, with the formwork rearranged vertically.
I used flat slate linden to make the formwork. This material is ideally suited for this purpose: it is elastic and durable, and the surface of the finished pour is even and smooth. But the most important thing is that the slate easily moves away from the hardened concrete, and the formwork is easy to disassemble. There is no need to lay polyethylene or glassine, as is done in classic formwork made of boards or plywood.
Pouring concrete
The volume of concrete is small, so you can work without the use of mixers and concrete pumps. The concrete mixer stands next to the formwork; it is easy to transfer the mixture with a shovel.
To quickly assemble smooth slate formwork, I used a little trick. The two panels were temporarily but securely connected to each other by an ordinary clamp. The main thing is not to forget to remove it in time after pouring, before the concrete hardens.
For the second sushi, I removed the lower formwork and raised it higher. Since you have to make three strips in turn, you don’t have to wait for the concrete to harden: while the first pour is setting, I start the second, and so on. Three tapes on two floors: six days - and everything is ready.
Work is done. The result is a powerful (even too powerful) new strip foundation that will last uh... enough for our lifetime!
The result obtained has a small minus. IN classic version stone fence, the width of the foundation should not be greater than the thickness brickwork. If these proportions are not observed, the entire fence will look inharmonious. But in my case there was no alternative.
I will proceed as follows. Firstly, I will fill the foundation up to its upper edge, and trim the horizontal shelves with wild stone.
I tried to analyze why the foundation began to deteriorate so quickly and what my builders did wrong. Having carefully examined the structure, I came to the conclusion that, in addition to the banal non-compliance with the proportions of the concrete mixture and its poor mixing, there are two more reasons.
Firstly, workers used unsifted sand with a large amount of clay admixtures, which significantly reduces the grade of concrete. In addition, in early spring, during freeze-thaw cycles, poorly mixed concrete quickly breaks down. Secondly, ‘the builders used too much liquid concrete, believing that in this way it is possible to fill all the voids in the formwork, and not suspecting that the strength of the structure is sharply reduced.
Well, as they say, if you want it done well, do it yourself!
Do-it-yourself strip foundation repair - progress of work
Having dug up all three foundation strips along the perimeter, we discovered an unsightly picture. Almost two-thirds of the tape's volume simply disappeared, turning into a pile of small pieces.
1. To clean the old foundation, it is better to use a high-pressure washer. We not only clean the surface of dirt, but also knock out all the crushed stone, which weakly adheres to the old concrete, which means it will not provide good adhesion.
2. To tie the frames with reinforcement rods, I made through holes for them in the tape in increments of 50-70 cm. To do this, I used a hammer drill with a long drill.
3. S- and U-shaped jumpers were connected to the reinforcing bar with annealed wire. My wire is thicker than usual, and the standard tool for twisting it was not suitable. I had to work with pliers.
4-5. Ready reinforcement frame.
6-7. The armored belt and mesh hug the entire foundation around the perimeter, forming a closed loop.
8. On this side, the formwork is fastened in the form of supports made of metal corners driven deep into the ground.
9. And here the short support pegs are simply pressed against the bricks used as spacers.
10. Until the concrete gains normal strength, it must be kept wet. I watered it 4-5 times a day and after removing the formwork.
11-12. In some places, the distance between the old foundation and the formwork is no more than 7-8 cm. If you do not vibrate the mixture, the concrete will not fill all the voids - and there will be many pores. For high-quality concrete laying, I used an internal vibrator.
How to repair a strip foundation with your own hands - photo
Foundation repair is a costly and complex undertaking; to do it correctly, you need to know the principle of the structure, the causes and signs of foundation failure. Wood a private house It is very common in our area, which is not surprising, because wood is an affordable material, construction costs are relatively low, and the completed house will be environmentally friendly and warm. These are the absolute advantages of a wooden structure. There are also disadvantages, but they do not appear immediately, but after some time of use.
Most often the owners wooden houses They are faced with the fact that the house is “bursting at the seams.” Windows and doors warp, walls sag, and cracks appear. All these visual defects are caused by one reason - the destruction of the foundation. To extend the life of the house, it is necessary to eliminate this destruction in a timely manner. This will require strengthening or reconstruction of the foundation (restoration), complete ( major renovation) or partial (removal of cracks).
It is worth noting that repairing the foundation of an old wooden house is not an easy undertaking, so it is advisable to entrust it to professionals. But, you can do the work yourself. The main thing here is the time factor. The problem must be fixed as soon as it is discovered.
Causes of foundation destruction
Before you begin a detailed study of how to repair the foundation of a wooden house, you need to understand what caused its deformation. Two factors can contribute to this:
change in the bearing capacity of the soil. This occurs due to an increase in the load on the foundation, and therefore on the soil underneath it. The reason may be improper drainage of rain/melt water or an increase in groundwater levels, which leads to soil erosion. The construction of other buildings near the house also increases the load on the soil. As a result, the soil seems to be squeezed out from under the foundation of the house, which can ultimately lead to subsidence of the house or its warping.
loss of strength of the material from which the foundation is made. Among the main reasons are the following: incorrect choice of foundation type, exposure to water, incorrect brand of concrete used during construction, incorrect calculation of soil freezing depth, violation of construction technology.
Identifying the cause of foundation failure provides a starting point for investigation.
Types of foundation deformation
The second point to consider is identifying the extent of damage to the foundation. According to the criterion of maintainability, they can be divided into 4 types.
1. Minimal damage.
These include partially exfoliated finishing of the foundation of a wooden house. Such defects do not have a significant effect on the bearing capacity of the foundation. In addition, they are visible to the naked eye and can be removed without any problems.
2. Moderate damage.
These include the appearance of cracks in the foundation of a house due to subsidence or destruction of the foundation. In this case, you should be careful, because... crack crack discord. First of all, its direction is determined. As a rule, horizontal cracks in the foundation are the least dangerous, but vertical or zigzag cracks should alert you. It will also be determined whether the subsidence of the foundation is temporary or whether it is progressive.
The nature of the destruction can be determined using beacons installed on the crack (see photo).
You can use ordinary paper as beacons, but it is worth remembering that when moisture gets in, the paper gets wet and will no longer give a complete picture of the behavior of the crack. Plaster plasters are suitable for use. But the easiest way is to apply a little putty to the wall and use a spatula to draw a straight line and make a mark. Such a beacon is good because it breaks at the slightest movement of the surface. Installing a beacon will not only allow you to notice the enlargement of the crack, but also determine the rate of destruction.
Important. The beacon must be installed on a clean, dry wall to prevent it from moving. The thickness of the beacon should not exceed 5 mm.
If the foundation temporarily settles, the beacons will remain motionless. That is, there is a high probability that the soil under the foundation has moved a little, has taken its place and does not intend to move anymore. Therefore, you only need to perform routine repairs to foundation cracks.
Repairing cracks:
- widen the crack;
- clean it from falling parts and dust;
- treat with a primer;
- seal the seam with a special mixture or cement mortar.
The destruction of beacons indicates that the fault in the foundation or wall is increasing. This means that sealing cracks will not help, it is time to take urgent measures - this type of deformation can be classified as catastrophic.
3. Catastrophic damage.
These are foundation defects that can lead to the destruction of the house. Of course, it is advisable to repair the foundation under a wooden house in a timely manner, but there are times when the moment is missed.
Then the technology for carrying out repair work will be determined by the type of foundation. The most popular of which are columnar and ribbon. In each individual case, each owner decides for himself whether he needs to strengthen the foundation or completely replace it.
4. Unremovable deformations.
In this case, the condition of the foundation is so deplorable that there is nothing to repair. It is usually easier and cheaper to destroy an old house and build a new cottage in its place that meets all the requirements of a modern person.
Repairing the strip foundation of a wooden house is somewhat more complicated, so we will dwell on it in more detail.
Strengthening the foundation of a private house - ways to strengthen it
The strengthening method is chosen when the deformations of the foundation are removable and the soil underneath is stable. Or if there is a need for an addition to the house, and the existing foundation cannot cope with the increasing load.
Technology for strengthening strip foundations - instructions
- dig a trench around the perimeter of the foundation. Its width should be sufficient for convenient work and take into account the fact that the thickness of the foundation will increase;
- clean the foundation surface from soil;
Advice. You can clean the surface well using a metal brush.
- drill holes. Its diameter should exceed the diameter of the reinforcement by 1 mm. This is necessary for a more dense installation of metal rods;
- hammer the reinforcement into the holes. Thus, new foundation will be securely connected to the existing one;
- make a reinforced belt. To do this, reinforcement is welded to the installed pieces;
Advice. It is advisable to weld the reinforcement only in a few places, and do the main part of the strapping using wire. This type of fastening does not require special skills or tools. But if it is present, the reinforcing belt does not deform when concrete is poured and hardened.
- formwork is installed;
- concrete is poured. After the concrete has hardened, the formwork is removed, and the reinforced foundation stands for several more days;
- the new foundation is being waterproofed;
- a blind area is made that will allow water to be drained away from the foundation.
Strengthening the foundation of a wooden house allows you to redistribute the load of the structure over a larger area. As a result, the foundation will stop subsiding or collapsing.
Complete replacement of the house foundation
Often the foundation sags so much that water can easily flow into the room. In this case, you need to figure out how to raise the foundation of a wooden house? Or the old foundation can no longer cope with the load on it and then the foundation is reconstructed.
Replacing the foundation under a wooden house - technology
- maximum reduction of constant and variable load on the foundation. To do this, everything that can be taken out of the house is removed, it is advisable to even dismantle the floor and disassemble the stoves. The exception is furnaces on a separately poured foundation. Naturally, residents are also evicted during the renovation;
- load calculation (weight of the house). Weight can be easily determined by having data regarding the density of the wood from which the house is built and the total cubic capacity of the wood used. The cubic capacity is calculated based on the dimensions of the house and the thickness of the walls;
Advice. A small and light wooden house is raised using a vault. To do this, an 80x80 beam is placed at the corner of the house. Next, the timber rests on the log. By pressing on the beam you can lift the house like a large lever.
- choosing a jack to raise a house. Depends on the weight of the structure, the lifting capacity of the jack and their number;
- digging pits (trenches). It breaks out along the entire perimeter of the house or only in those places where the house needs to be raised. Its presence simplifies access to the foundation. In addition, the appearance of water in the pit will make it possible to understand the level of groundwater;
- jack establishment. To raise the house smoothly, you need to install the jack correctly. It is installed only in safe places, without destruction or damage;
- lifting the house. You need to lift the house carefully, slowly, and most importantly evenly;
Advice. To protect yourself in case the jack cannot cope with the load or is installed unsuccessfully, you need to place wooden wedges between the house and the foundation pad. It is advisable to insert wedges every 15-20 mm.
Important: To lay the foundation for a wooden house, you need to raise the entire structure. Considering that the house is wooden, the maximum load will fall on the lower crowns. To prevent them from sagging, you need to tighten the lower crown with a steel hoop or fill it with boards.
- dismantling the old foundation. If the budget is very limited, and the condition of some parts of the foundation is satisfactory, then partial disassembly can be performed, i.e. remove only the destroyed foundation. However, this will not reduce the cost of work significantly, but the quality of work may suffer;
Advice. The old foundation must be dismantled down to the ground.
- installation of a sand-cement cushion for the future foundation. Despite the fact that the foundation is laid for a finished house, the pillow is an important component of it;
- installation of concrete or brick supports in the corners of the house. Installation of piles is also possible. They will reduce the load on the foundation in the future. The height of the support is equal to the height of the new foundation;
- reinforcement. After the columns are installed, the reinforcement is installed. The reinforcement belt will give the foundation strength. We remind you that his installation of an armored belt for the foundation is carried out using wire, not welding;
- installation of formwork;
- pouring concrete. The foundation must stand for several days to gain strength. After this, the formwork is removed and the foundation is left open for another 1-2 days;
- waterproofing. To protect the wood of the house from rotting, you should lay a layer of waterproofing on the foundation. Roofing felt is excellent for these purposes;
- lowering the house. The house goes down as slowly as it went up;
- Finishing work. This includes complete waterproofing, cladding, drainage and blind areas.
From the description it is clear that replacing the foundation under a wooden house is a rather risky and time-consuming undertaking, for the implementation of which it is advisable to invite specialists.
How to lift a house and move it to a new foundation in practice can be seen in the video
Using the methods described above, you can repair the strip foundation of a wooden house. But what about those who have a columnar foundation?
Repair of a columnar foundation of a wooden house - technology
- the house rises to the calculated height. The height should be sufficient to carry out the work and at the same time not contribute to severe sagging of the lower crown.
- leaning pillars are dismantled. It is worth noting that a dilapidated support post must be removed, and a tilted one is simply leveled.
- soil is selected at the site where new pillars will be installed. We remind you that the pillars are installed at the corners of the building and at the junction/intersection of walls.
- a sand-cement cushion is placed under the pillar.
- The pillar is being reinforced.
- concrete is poured.
- steel or wooden beams are installed, which take on the entire load from the weight of the house and transfer it to the pillars.
- the building is going down.
If you need to replace one or two pillars, you can do it as follows. A dig is made in the place where the pillar to be replaced is installed. The tilt angle is 35°. A pipe is inserted into it and filled with solution. After hardening, the old pillar is removed and the new one is leveled. The process is presented more clearly in the photo.
It is worth noting that repairs or complete replacement A pile foundation is much simpler and faster than a strip foundation and takes only a few days, after which you can operate the house as usual.
Repair of brick and rubble foundations - replacement with a monolith
In times of total shortage, i.e. During the construction of the main part of the houses, the foundations were built of bricks (both strip and columnar). Due to fragility, repair brick foundation The construction of a wooden house usually involves replacing brickwork with a more durable material - concrete. This reinforcement technology is applicable for rubble stone foundations. The method was described on the “House and Dacha” forum and judging by the reviews, the technique showed itself well in practice.
To carry out repair work you will need
- Concrete solution.
- Fittings.
- Corner for making supports.
- Jacks for raising a house with a lifting capacity of 20 tons.
We dismantle the old rubble foundation (or brick) in small sections of half a meter.
The freed fragments at the base of the house are needed to install a jack and further transfer the weight of the house onto metal supports.
A base plate for the jack is made at the site of the destroyed base. The platform must be strong and stable, it is poured from concrete with mandatory reinforcement. 
If the soil is hard, you can use concrete paving slabs. 
Hanging a house using jacks. You need to lift alternately in all openings. 
When the house is hung, it is necessary to install supports, pre-welded from the corner, on which we lower the house. 
Scheme of a steel support for a house - dimensions and principle of construction. 
After transferring the weight of the house to the supports, formwork is installed from the inside. 
Reinforcement is laid and tied inside the supports. 
Upon completion of the reinforcement, the outer part of the formwork is installed and concrete is poured. In this way, the foundation under a wooden house is replaced.
Conclusion
After reading this article, you have gained an idea of how to repair a damaged foundation, how to strengthen the foundation of a wooden house, and in which cases it must be completely replaced. Using this information, you will gain sufficient knowledge to do the work yourself.