DIY strip foundation repair step-by-step instructions

In detail: do-it-yourself strip foundation repair step-by-step instructions from a real wizard for the site my.housecope.com.

Restoring the foundation is not difficult, but time consuming.

You can strengthen the crumbling concrete tape in the following way - pour an additional layer of concrete with good reinforcement around it around the entire perimeter, that is, make a kind of sarcophagus.

At the same time, the new fill must take on the main load and prevent further destruction of the old foundation. To do this, it is necessary to ensure a strong adhesion of the new and old structures. The excavated foundation must be thoroughly washed, otherwise the new fill will not grab with dirty concrete. It is also important to provide reliable reinforcement. For this purpose, I decided to pull 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 with a pitch of 50-70 cm using a perforator with a long drill.

The harvested reinforcement rods were first bent at right angles at one end. Then he inserted the rod into the hole and bent the other end. The folded ends on both sides of the tape were tied to the reinforcement cage.

Thus, the frames on both sides of the tape were connected by S- or U-shaped bridges. Each bend of the lintel should be 40-50 mm from the foundation surface. In my case, the reinforcement cage is made of a metal mesh (4 mm thick) with a cell size of 100 * 100 mm, connected in the upper part with reinforcement bars of Ø 8 mm and tightened with jumpers.

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 lay concrete in such a narrow and high form with high quality. Therefore, I decided to pour concrete in two steps with the vertical rearrangement of the formwork.

Video (click to play).

For the manufacture of the formwork, I used flat slate lindens. This material is the best suited for this purpose: it is resilient and durable, and the surface of the finished filling is flat 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 the classic formwork made of boards or plywood.

The volume of concrete is small, so you can work without using mixers and concrete pumps. The concrete mixer stands next to the formwork, the mixture can be easily thrown with a shovel.

For a quick assembly of a flat slate formwork, I used a little trick. The two panels were temporarily but reliably connected to each other with an ordinary clamp. The main thing is not to forget, after pouring, until the concrete has hardened, to remove it in time.

On the second land, I removed the lower formwork and raised it higher. Since you have to make three tapes in turn, there is no need to wait for the concrete to harden: while the first pouring takes hold, I proceed to the second, and so on. Three tapes on two floors: six days and you're done.

Work is done. The result is a powerful (even too much) new strip foundation, which will stand, uh ... enough for our century!

The result obtained has a small drawback. In the classic version of a stone fence, the width of the foundation should not be greater than the thickness of the brickwork. If these proportions are not observed, the entire fence looks inharmonious. But in my case, there was no alternative.

I will proceed as follows. First, I will fill the foundation up to its upper edge, and finish the horizontal shelves with wild stone.

I tried to analyze why the foundation began to deteriorate so quickly and what my builders did wrong.Carefully examining the structure, I came to the conclusion that, in addition to the banal non-observance of the proportions of the concrete mixture and its poor mixing, there are two more reasons.

Firstly, the workers used unsifted sand with a large amount of clay impurities, which significantly reduces the grade of concrete. In addition, poorly mixed concrete quickly collapses during freeze-thaw cycles in early spring. Secondly, the 'builders - used too liquid concrete, believing that in this way it is possible to fill all the voids 8 of the formwork, and not suspecting that the strength of the structure is sharply reduced.

Well, as they say, if you want to do well - do it yourself!

Having dug up all three strips of the foundation around the perimeter, they found 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 pressure washer. We not only clean the surface of dirt, but also knock out all the gravel, which is weakly adhered to the old concrete, which means it will not give good adhesion.

2.To tie the frames with reinforcement rods, I made through holes for them with a pitch of 50-70 cm in the tape. For this, I used a hammer drill with a long drill.

3. S- and U-shaped crosspieces were connected to the reinforcing bar with annealed wire. My wire is thicker than usual, and the standard tool for twisting it did not fit. I had to work with pliers.

4-5. Finished reinforcement cage.

6-7. Armopoyas 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 from metal corners driven deep into the ground.

9. And here the short support pegs are simply pinned down with bricks used as struts.

10. Until the concrete reaches a normal strength, it must be kept wet. I watered it 4-5 times a day ido, 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 the mixture is not vibrated, the concrete will not fill all the voids - and there will be many pores. For high-quality concrete placement, I used a deep vibrator.

Image - Do-it-yourself strip foundation repair step-by-step instructions

Cracked foundation
The builders poured the strip foundation, and after a while cracks began to appear in it. It's good that they haven't started building the house yet. What should we do? Is it possible to fix everything? If so, how many floors will such a foundation withstand (we planned three)?

It's good that you saved your family budget from wasted expenses. If the foundation cracked without load, then imagine what will happen after the application of 20-30 tons, which weighs a decent dacha. Of course, these cracks will widen and the structures will sag. But in all this there is one positive moment: you must understand why this happened, and fundamentally exclude the very possibility of repeating these mistakes. There may be several of them.
First of all, it can be low-quality cement or cement of the wrong brand. Then, the sand could not be clean, but with an abundant inclusion of clay. The wrong dosage of the components could very well lead to your unfortunate results. Incorrect mixing of components in the wrong sequence is also a possible cause of cracked foundations. And of course, this concrete mixture had to be thoroughly compacted with a deep vibrator.
Did you have it at the construction site? In what weather was your foundation poured? Perhaps it was extremely cold or, on the contrary, the sun was shining mercilessly and you did not hide the foundation from the influence of these factors? Only after analyzing all these reasons can we take on a new foundation. And this one will smash well a tractor with a mounted hydraulic hammer.

Do-it-yourself repair and cracks in the foundation of an old wooden country or private house: step-by-step instructions + Video

It is not uncommon for the owners of private houses and cottages to encounter the problem of cracks in the 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.

They can be conditionally divided into two: deterioration in the bearing capacity of the soil and deterioration in the bearing capacity of the foundation itself.

In the first case, this can happen due to flooding. When saturated with water, some soils lose their bearing capacity. Also, during flooding, soil erosion can occur. This happens in areas where the soil consists of sandy and sandy loam layers.

Also, subsidence of soil consisting of limestones and marls is possible, if for some reason the groundwater has acquired acidic properties, which destroys calcites.

Soil subsidence as a result of mine workings, pumping out of artesian waters, oil and gas production have become very frequent occurrences.

The second reason is the deterioration of the bearing capacity of the foundation itself as a result of factors affecting it, leading to its destruction.

Ground water is one of the factors; ordinary water can cause corrosion of the metal and destruction of the base. Nowadays, acidic and alkaline groundwater is not uncommon, which can destroy the foundation of a house in a few years.

A common violation is not observing the depth of the foundation. The foundation laid to a shallower depth than the freezing of the soil is affected by frost heaving of the soil - this is a force that can break the foundation monolith and lead it to cracking.

Also, the reason for the destruction of the foundation is often the use of poor quality materials and savings on them.

To determine the causes of the destruction of the foundation, specialized firms can be attracted, but the cost of such work will be very high.

Do not despair, there are many ways that will allow you to determine the causes of the destruction of the foundation inexpensively and with acceptable accuracy.

This study is carried out in order to determine whether the crack continues to grow, the rate of increase, the nature of the process.

For this, the so-called beacon markers are used. They are made of gypsum or cement mortar with the addition of gypsum. It is very important that after drying it does not stretch and be brittle enough. It is also important that the mortar is firmly attached to the surface of the foundation, without peeling from it. For this, the base is pre-cleaned.

Having prepared a little composition, it is applied to the crack, the layer thickness is made 3-5 millimeters, ten fifteen centimeters long and three five centimeters high.

Place at least two markers per crack. One marker is installed near the beginning of the disclosure, the second near the end.

After applying a marker, a thin longitudinal line is made on it, it can be made either with a metal ruler or with a spatula. Markers are numbered. The number and date are recorded in the measurement log.

If the process of opening cracks continues, then the beacon also gets a crack. Making measurements of the crack width at certain intervals and making entries in the measurement log, they make a conclusion about the deformation rate of the foundation, about the part of the house that shrinks. They also make a forecast about further destruction of the foundation.

The second method of work on the study of the foundation is the method of digging pits.

Next to the foundation, a hole is dug one meter long and deep to the base of the foundation (pit), the width is determined by the convenience of digging, taking into account the conditions for the production of slopes to prevent soil collapse, or strengthen the walls with boards.

At least two pits are dug in the most problematic places. The method of digging pits is the most informative. Using this method, it is possible to 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 a presence of groundwater, then it is possible to determine what properties they have.To do this, use ordinary litmus tests, which can be purchased at garden stores.

After determining the research and determining the causes of the destruction of the foundation, they begin to repair the foundation with their own hands.

The cause of the deformation can be eliminated, and 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 not be possible to repair it with your own hands. Or it will be necessary to repair the foundation, the price of which will be comparable to new construction.

There are two types of flooding: the first is caused by the influx of rain or melt water. The second is the rise in the level of groundwater.

In the first case, it is enough to create a bump barrier that directs water past the house, and the construction of a blind area at least 80 centimeters wide.

In the event of a rise in groundwater, it is necessary to carry out dewatering. For this, drainage is done. Drainage is a drainage system made in the form of a circuit with pipes laid in a trench and covered with gravel around the house. Drainage of excess water leads to the storm sewer.

Deformation caused by frost heaving.

This type of deformation occurs when the foundation is laid above the level of soil freezing. The amount of deformation depends on the degree of heaving of the soil. Both significant and small deformations are possible.

To eliminate freezing, it is necessary to insulate the foundation. Insulation is carried out to the bottom of the foundation sole. To do this, a trench is dug around the perimeter of the house, then the foundation is waterproofed, the side wall of the foundation is insulated and covered with screenings or small rubble. A layer of insulation is laid on top of the backfill and the blind area is poured.

In case of significant destruction of the foundation, while eliminating the destructive factors, the foundation is also repaired. Image - Do-it-yourself strip foundation repair step-by-step instructions

One of the most popular methods is considered to be the foundation liner. The essence of the method is to deepen and increase the area of the sole support. It can be implemented in two ways: with partial replacement of masonry and complete replacement.

The liner is carried out with the help of grips in separate sections with a length of one and a half to two meters, which depends on the depth of the foundation strength. When deeply laid, the grips are reinforced with uprights and beams.

Further, concreting is carried out, less often rubble laying is performed. The opening and concreting of the grips is carried out on the condition that the expanded grip is protected by the adjacent one.

The formwork is removed at the end of concreting. Metal fasteners are left in the concrete.

This method is advised to be used with a large volume of structures to be strengthened, a shallow depth of foundation, a deep finding of groundwater.

It is important to comply with the production technology of work to prevent the resumption of the destruction of the foundation.

The clips are side attachments 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 about the rationality of their use.

The most preferred are two-leg, torque-free ferrules.

This method allows not only to strengthen the foundation, but also part of the wall.

For strengthening by the broadening method, the foundation is marked out for grabs. The length of the marks is 2-3 meters.

The base of the foundation is cleaned of debris. I dig a trench around the perimeter of the house, and cover the bottom of the trench with rubble.

Holes are punched in the plinth for transverse reinforcement. A longitudinal beam is placed between the plinth and the wall. Further, formwork is installed in the trench and poured with concrete.

In conclusion, I would like to say that foundation repair works are especially dangerous.This type of work must be performed with extreme caution, applying all safety measures and not endangering either your life or your assistants.

The opening of cracks in the structures of a private house or other individual building object is most often evidence that the foundation of the building needs repair.Reconstruction of this highly critical part of the building is not an easy task, but in many cases it can be easily solved by the homeowner without the involvement of highly paid specialists with some kind of special equipment.But before you start repairing the strip foundation with your own hands, it is necessary to accurately find out the nature of the deformations or destruction, as well as their cause. Otherwise, you can not only waste your energy, time and money, but also aggravate an already unpleasant situation.Most often, problems with the foundation are due to the following reasons: Image - Do-it-yourself strip foundation repair step-by-step instructions

This event can occur due to the fact that:

A) Foundation materials were exposed to a chemically aggressive environment.

We live in a difficult ecological situation and it is not surprising that soil moisture can suddenly change its neutral reaction to acidic or alkaline. Such a solvent will eventually leave only one reinforcement from the foundation.

B) Technological errors were made or unsuitable / low-quality materials were used.

The waterproofing or reinforcement may have been improperly done. In addition, private traders often build a base not from the "correct" materials, but from what they have or managed to buy at a cheap price.

For example, from sand-lime brick or cinder concrete. Most often, such mistakes are made when building small objects that are not used as permanent housing: garages, outbuildings, various buildings on a garden plot.

In order not to spend money in the future on repairing the strip foundation of a country house, use only appropriate materials of proper quality during construction.

In the overwhelming majority of cases, soil moisture becomes the culprit for this undesirable phenomenon. Flooding provoked by the rise of groundwater or heavy rainfall softens the soil, because of which it begins to sink.

If the base has a heterogeneous structure, some of its components can be washed out. Here, too, the insidiousness of the chemically enriched water can manifest itself. For example, acidic solutions very actively destroy the inclusions of marls and limestones, turning the soil into a fragile porous mass.

Unexpected ground movements may be the result of an unjustified laying of the base of the foundation above the freezing depth.

Moisture-saturated soil also becomes unstable after several cycles of freezing and thawing.

Here, too, water was not without, since its heaving depends on its amount in the soil. The main danger is not so much the heaving forces themselves, but the uneven nature of their distribution.

One corner of the house can be raised with swollen soil by 50 mm, and the other by 150 mm. The result of such a skew will be the appearance of cracks in the basement or on the wall.

So, if the soil swelled strongly, the following could happen:

the groundwater level has risen or the area has been flooded by precipitation, melt water or leaks from the water pipe;
in an abnormally cold winter, the soil was frozen deeper than usual, while the depth of the foundation was chosen "end-to-end" without taking into account the margin for such a case;
the depth of the foundation was calculated taking into account the presence of a heating system, but for some reason the building was not heated in winter or was heated poorly.

Although the opening of cracks is an alarming signal, when they are found, you should not drop everything and urgently start opening the foundation.Perhaps, having given a small subsidence, the soil has settled down and deformations will not progress in the future.

To determine exactly what is happening with the construction, special beacons will help:

beacon (marker) - a strip of plaster or cement mortar with the addition of plaster, laid across the crack. Its length should be about 100 - 120 mm, width - 30 - 50 mm, layer thickness - from 3 to 5 mm. The use of polymer mixtures to create a beacon is not allowed, since they are plastic, and such a beacon will simply stretch in the event of further crack opening. It is important to carefully clean the surface of the wall with which the marker will contact so that the latter has good adhesion to the substrate. Lighthouses are placed in the extreme zones of cracks, at least two for each of them;
on a freshly applied lighthouse, a long, thin furrow is squeezed out with the edge of a trowel. If cracks develop, the lighthouse will crack, and by the displacement of the furrows on its halves relative to each other, it will be possible to accurately determine how the individual parts of the building move;

If the size of the cracks increases over time, a recess is dug in the problem area along the foundation - a pit, with which the hidden building structures can be directly inspected.

The pit should be about a meter long and reach the bottom of the foundation. The slopes are reinforced with wooden shields.

The depth of the foundation, is this what you want to know? Go to this article of ours.

If you do not know what a junction box for electrical wiring is, but you are very interested in this, then look here.

After identifying the cause of the deformations, the technology for repairing and strengthening the strip foundation is selected. The most commonly used methods are:

If the base of the foundation is located above the level of freezing of the soil and the effect of frost heaving forces turned out to be too significant, the soil along the base is selected and replaced with sand or fine gravel.

The depth of the backfill should be equal to the depth of the foundation.

Before filling the trench with sand, you should restore the waterproofing of the foundation, if necessary, and also insulate its surface.

Plates of extruded polystyrene foam are placed on top of the sand or crushed stone as thermal insulation, and then a blind area is arranged.

If, as a result of diagnostics, the destruction of the old foundation was revealed, a new one is brought under it. For this, a recess no more than 80 cm long is made under the existing base, which is then concreted.

If there are cracks in the foundation, the length of the excavation is reduced to one third of the minimum crack spacing. If possible, sampling of soil under the foundation is best done from both sides.

Repairing the strip foundations of a wooden house will require less effort. It is enough to strengthen the base under the extreme points of the log and then work on building up the support structure in the middle part can be performed more freely - the length of the recesses in this case can be increased to 2 m.

If the soil under the foundation "gave slack", it can be saturated with concrete or cement mortar. For this, a shaft with a diameter of 150-200 mm is dug or drilled, the shaft of which has an inclination of 35 degrees. The excavation must reach the ground below the foundation.

A steel or asbestos-cement pipe is put into the mine, into which the mortar is then poured. As the mixture decreases, it should be added until absorption stops. The procedure must be repeated two or three times with a time interval of a day or two.

If further observation shows that the foundation continues to sink, the grouting can be done again.

If you respond in a timely manner to the flooding of the site or an increase in the level of groundwater, the repair of the strip foundation of the house may not be necessary.

With an increase in soil moisture due to heavy rainfall or melting snow, several shallow trenches are made around the house, through which water will drain, bypassing the building. You should also carefully examine the blind area and, if necessary, restore it.

To drain the groundwater, a drainage system is arranged around the house.

It consists of perforated pipes laid in trenches and covered with gravel. Drainage should be designed so that water is directed to a storm drain or other suitable location.

Foundation repair video

A strip (continuous) foundation is a foundation that runs under the entire perimeter of the walls and consists of precast concrete blocks, monolithic reinforced concrete, concrete, brick or rubble concrete. By itself, the strip foundation has a fairly long operational life, sometimes reaching 50 years or more. First of all, it depends on the high strength and solidity of the structure. However, the adverse effect of external factors can lead to a significant decrease in strength parameters or to its partial destruction. In such a case, it is worth repairing the tape base.First of all, it is required to determine the causal relationships of the violation of integrity in general and its grounds in particular.Possible causes of deformation and crack initiation are:

excessive moisture caused by excessive precipitation and, as a consequence, overvoltage of the soil;

insufficient depth of the bookmark;

heterogeneity of the structure of the supporting or underlying soil layer of the base;

insufficient frictional resistance caused by clayey soils highly moistened with water, as a result of which the axis shifts along with the structure;

destruction of masonry solution due to the impact of aggressive or underground waters of sanitary-technical communications;

penetration into the base of surface waters due to the absence or violation of the integrity of the blind area;

excessive load and insufficient penetration into the ground;

freezing of the base caused by poor deepening during construction work and improper cutting of the soil near the house;

clogging or disruption of the drainage system, which causes an excessive rise in the level of groundwater and softening of the soil layer;

change in the permissible loads for superstructures of additional parts of the building.

The malfunction of the base is determined by the presence of cracks on the main walls of the house.As a rule, they are in places of partitions and their abutment to walls.Strip foundation diagram.Before starting any repair work, you should find out the moment when the uneven shrinkage is completely finished.To do this, control beacons (gypsum linings) are installed across the detected crack. They are firmly fixed on both sides of the crack on the load-bearing parts of the wall (with the calculation of 1 beacon per 2-3 mm crack). Lighthouses are made of plaster mortar (width - up to 8 cm, length - up to 5 cm, length - up to 30 cm) and stacked on well-cleaned places.After 3 weeks, in the absence of changes in the lighthouses, the crack formation process can be considered complete. When lighthouses are destroyed, it is necessary to find out the level of intensity of uneven precipitation. In this case, simultaneously with the beacons, a special lever device is installed on the cracks, showing the size of the sediment in millimeters.After determining the nature of the destruction and the causes of the appearance of cracks, it is necessary to choose the main method of its strengthening, on the basis of which further repairs will be carried out.The repair of the strip base is divided into several stages, and subsequently, after all the work has been carried out, it should not harm the general structure of the building:

Thorough cleaning of all surfaces of the strip foundation around the entire perimeter from dirt and old plaster. First of all, the basement is cleared from the ground at a sufficient distance for repair work.

At this stage, the repair will require a certain set of tools, namely a jack, a pole with a diameter of 11-18 cm, plank gaskets 50-60 mm wide and 50-80 cm long (they can be replaced with bars of the same length, but 80-120 mm thick ) and temporary chocks for installation under the lower foundations (crowns) of the house.

Then, having retreated from the main building by 1-1.2 m, you should start disassembling the destroyed area and install a jack on a special gasket under the lower crown of the house.

After determining the level of the position of the lower rim next to the jack for its subsequent release, a chock or a piece of timber is installed. A similar operation is performed at the corners, at the intersection and destruction.

Repair with the belt folding principle at the replacement stage will require the preparation of the following tool: pick, wedges, sledgehammer (or ax), steel scrap and bolt.

Disassembling bricks can be done manually with a crowbar or pickaxe, striking the horizontal joints from top to bottom.

When executed from cement mortar, wedges are used, hammered with a sledgehammer or an ax into horizontal or vertical masonry seams;

Work is carried out in a similar way when disassembling rubble.

Pile foundation diagram.Having completed the repair and partial reconstruction of the cracked base of the strip foundation, they proceed to the formation of horizontal waterproofing, which can be performed by partially cutting the wall. The base is carefully dug out in short sections to its sole, after which it is trimmed, and a waterproofing material is laid in the gap formed. Horizontal waterproofing is also installed at the joints with the walls. In addition, various water drainage systems (drainage) are being constructed.There are two main methods of horizontal waterproofing:Scheme of pile and slab foundations.

The first method is based on the use of roofing material (rolls of polymer-bitumen waterproofing), which is placed in the bottom and poured with concrete mortar. To create greater strength and reliability, sheets of roofing material are coated with hot resin.

The second method is more effective than the first, and consists in the use of specialized waterproofing materials, for example, such as penetron. It is a special mixture that penetrates deep into concrete, making it waterproof.

For easy and quick waterproofing work, you can use specially made sprayers, with which the waterproofing layer is applied directly to the foundation.Due to its structure, sprayed waterproofing repeats all the unevenness of the foundation surface. Subsequently, a reinforcing layer of geotextile material is applied, which helps the waterproofing to perform its protective functions.After the completion of the waterproofing work, the damp walls are dried and vertical waterproofing is performed.Slab foundation diagram.The repair of vertical waterproofing involves a similar laying of waterproofing materials, for which a properly prepared base and preliminary drying of the areas remain important conditions to obtain the maximum effect of the work carried out.Modern methods of draining basement walls, which do not require preliminary excavation, include the method of penetrating waterproofing using special substances that can penetrate into the wall and crystallize in microcracks. This will make it possible to prevent unnecessary filtration of the water.Finally, you can start pouring concrete into the new structure. The best option would be to use factory-made concrete, as this mix will be of better quality.Repair of the strip basement can also be done by strengthening the old one.Typically, this method is used when the base of the building is skewed as a result of the difference in pressure applied to different areas.What tools should you use? Mainly:

level;

roulette;

trowel;

concrete mixer;

puncher;

capacity;

putty knife;

brush and others, the need for which arises in the process of work.

It is carried out by increasing the area of its base according to a certain scheme:

digging a trench near the house along the base;

preparation of the old one for joining with a new way of drilling holes for grooves and fittings;

the formwork of a new base is being carried out;

the prepared reinforcement cage is connected to the reinforcement inserted into the house;

everything is poured with concrete mortar;

after the solution dries, the foundation is buried.

In case of violation of the rules for laying a part during the construction of a house, which led to its subsequent deformation, it may be necessary to further expand and deepen the basement base.

The foundation perceives heavy loads, but sometimes it does not withstand them and collapses

Violation of the foundation construction technology in the future can turn into the most catastrophic consequences, up to the destruction of the building. Along with this, some problems that have arisen due to improper arrangement of the base can be corrected on their own, eliminating the risk of more serious damage. It is with information on repairing the foundation on your own that you are invited to familiarize yourself further.

DIY foundation repair

The list of reasons that can lead to deformation of the foundation is given in the table.

Table. Why is the foundation crumbling

Reducing the bearing capacity of the soil

The formation of voids in the soil

The presence of inclusions in the soil

Decrease in the bearing capacity of the support under the influence of groundwater

Violation of building technologies

Common foundation defects

The table provides a list of the most common defects in support foundations.

Table. Foundations defects

Destruction of the base of the log bath

Destruction of the foundation under atmospheric influences

Destruction of the foundation from FBS blocks

Cracks in a brick support

Pushing piles out of the ground

Deformations of the walls of the foundation

Layering of rubble masonry

Violation of the integrity of the side surfaces of the support base

Break of the supporting structure in height

Cracks in the slab part of the supporting structure

To determine the nature of damage, the causes of their occurrence, the possibility of self-elimination of defects and, in general, the need to perform any actions, it is necessary to perform a number of research activities.

Exploring the nature of destruction

The item on the need to take actions is included in the list for a reason. It is possible that the reasons that led to the occurrence of certain deformations of the supporting structure were of a single nature and will never appear again. For example, once every 100 years there was a very snowy and frosty winter, during which even the soil under the foundation was frozen. If such weather conditions are not typical for the area in which the building is located, all repairs can be reduced to one only elimination of cosmetic defects. But the diagnosis is carried out under any circumstances, because an outwardly insignificant problem can in fact be very serious and dangerous.

Determine if cracks are growing

The challenge boils down to the following: you need to understand whether the cracks continue to grow. If yes, the nature of the process and the rate of its development are additionally established.

The study is carried out using special markers (beacons).

The easiest way to make a lighthouse is plaster or cement mortar. It is most convenient to use a ready-made mixture for plaster. In general, you can use any material from this series that is not prone to plastic deformation after setting, i.e. the composition should be relatively fragile, but, at the same time, reliably adhere to the outside of the basement (aboveground part of the foundation).

We recommend using a plaster mixture. Prepare it according to the manufacturer's instructions and place it on the crack in a 0.3-0.5 cm layer. The length of the marker is about 100-120 mm. The composition is applied so that the crack is approximately in the middle of the strip.

We use plaster mix

Complete each crack with at least two markers. Make one near the beginning of the fault, the second - at its end. The principle is shown in the image.

Marking house cracks and possible reasons for their appearance

Apply the plaster mixture with a narrow trowel. First, it is necessary to clean the surface of the base from dirt in order to ensure the highest quality adhesion of the beacon to the base.

We clean the plinth from dirt

Without waiting for the marker to harden, print a thin horizontal line on it. To do this, it is enough to gently press the side edge of a spatula, metal ruler or other suitable device into the mixture.

Number the markers by embossing the numbers with a nail or toothpick. Record in a notebook the date of the study and the serial numbers of the beacons.

Then watch. If the marker cracks, the foundation crack continues to widen. Every few days (the main thing is that equal time intervals are maintained between observations), measure the width of the crack on a plaster marker and record the results in a notebook. Such observations will help you draw conclusions about the rate of development of the deformity and predict the possible outcome.

Monitor the status of the marker

Follow the strip left with a putty knife / ruler. If parts of this mark are displaced in relation to each other, there are not only cracks, but also settlement of the structure. Common sediment varieties and their relationship to fracture patterns are highlighted in the above image.

This event is characterized by more pronounced information content and increased labor intensity. The bottom line is to prepare several (at least two) pits near the foundation. The pit is a pit with a depth to the base of the support and a length of about 100 cm. Choose the width individually, so that in the future it will be convenient for you to work with the foundation. To prevent the earth from collapsing, you can support the walls of the pit with unedged boards.

The described pit looks like this.