The occurrence of cracks in the base and the distortion of the openings may indicate a deformation of the foundation of the building. This presents some degree of risk and may threaten the collapse of the walls of the building. To independently determine whether the foundation is deformed, you can install gypsum beacons. They must be applied across the cracks. If within a few days after the installation of the marks their surface has not collapsed, then it can be judged that the deformation process has completed. In this case, the resulting small cracks can simply be repaired with cement mortar. When deep gaps appear, a thorough restoration of the foundation may be required.
Destruction of the foundation: causes and types
Before choosing various methods of strengthening the foundations, it is necessary to identify the causes that led to the destruction of the brick or reinforced concrete foundation under the structure.
The main factors include:
- Increase the load on the base of the house. This situation may appear due to the construction of additional add-ons.
- The occurrence of shifts in the soil during freezing.
- Violation of the waterproofing system.
- Emergencies when using communications.
- High groundwater table.
A common reason for the gradual destruction of the foundation is a seasonal increase in groundwater levels. It can manifest itself in the form of ruptures of the cap in height or vertical cracks. To eliminate this problem, a perimeter drainage device is most likely required.
As a reason, backfilling of the foundation with frozen soil may be. In the case of alternating freezing and thawing, swelling may occur, exerting significant pressure on the foundation. To eliminate this problem, it is necessary to replace the soil, filling the gap with a concrete mortar. In this case, a more effective way to eliminate the defect is to redistribute the load on the foundation by installing external beams and increase the area of the foundation.
Exposure to aggressive environments
Permanent accidents in communications passing near the house can lead to leaching of concrete due to exposure to salt or alkaline water. If the restoration of the foundation is still possible, then reducing the influence of an aggressive environment will be problematic.
To restore around the foundation, it is necessary to remove the soil. After that, the concrete surface is cleaned. Affected areas are filled with solution. Together with the foundation, brickwork is being erected in parallel, which is isolated by roofing material from the old base of the structure. The brick is impregnated with mastic and coated with clay. At the final stage, a drainage device around the foundation is provided to reduce the level of aggressive environment.
Restoration of the strip foundation: the classical method
Restoring the foundation can be done on their own. During operation, do not forget to adhere to safety precautions. The rise of the house consists in the parallel construction of another reinforced concrete tape, which is rigidly attached to the collapsing foundation.
The process of combining them into one whole system consists of several stages:
- A pit breaks out in the corners of the old house in order to expose the walls underground. The recess should have a width sufficient to carry out work in it. The depth of the pit should be at least 0.5 m below the foundation.
- At an angle of the house is a three-dimensional frame made of reinforcement.
- A foundation pit with a concrete structure placed in it is poured with concrete. Before the final solidification of the solution, it is impossible to proceed to the next step.
- When the concrete gains strength, you can begin to strengthen the base around the perimeter of the structure. For this, the system is divided into conditional sections, the length of which can reach 2 m.
- In the future, the recovery process is carried out in parts at each interval. Such caution is needed in order to stop a possible collapse and keep the base of the house.
- A trench must be made along the foundation at a predetermined site.
- Holes are made in the foundation body, which are intended in order to then install steel reinforcement in them. In size, these holes should be equal to 2-3 diameters of the metal rod placed in them. This will ensure full cementation.
- The old pins installed in the previous foundation must be rigidly connected to the surround frame immersed in the trench. For this, welding works are carried out.
- After preparing and installing the formwork, a concrete solution is placed in the prepared part.
Thus, perimeter recovery occurs. When lifting a house, it is necessary to take into account that the strengthening of structures underground is carried out only after the concrete has gained the necessary strength.
How to restore the sole of the foundation?
Often, owners of private homes are interested in the question of what to do if the foundation sank. In some cases, to stop the shrinkage of the foundation of the old building, it may be necessary to expand the area of the sole lying under the base. The restoration work in this case will be rather laborious and provide that a reinforced concrete slab is brought under the sagging area, and a concrete cushion is also arranged.
Foundation unloading
Before restoring the foundation, it is often necessary to unload it. For this purpose, several holes are made every few meters above the upper section of the base of the old building. Metal beams are placed in them. On both sides, under the installed cross members, supports are made that will take on the entire load. For this purpose, it will be necessary to partially disassemble the floor of the first floor of the building, as well as the inner side of the walls.
Installation of reinforced concrete slabs during restoration
If the restoration of the foundation of the house requires the supply of reinforced concrete slabs, then large-scale repair work is necessary. The dimensions of the pit should guarantee unhindered installation of the plate on the prepared base. It must be aligned and tamped. Between the sole of the base and the surface of the slab it is necessary to leave a gap, which will subsequently be filled with a layer of cement. To determine whether the individual elements of the old foundation masonry are suitable, a strength assessment must be performed. Many today are interested in how to calculate the foundation. A calculator for carrying out these calculations today can be found on most construction sites.
When creating a pillow made of concrete at the bottom of the pit, it is necessary to lay a grid of reinforcement and build a formwork. The mortar, which has not yet hardened, is compacted after pouring concrete to get rid of voids. To create a single monolith, it is necessary to perform concreting to a level of 100-150 mm.
Cementation and Silicate Method
You can lift the house by silicatization or cementation. To use this technology, special compressor equipment is required. The soil around the perimeter of the foundation is opened if necessary. Pipes made of steel with perforation are immersed into the holes made in a checkerboard pattern. They are connected to the injection unit. With the help of it, a sand-cement mortar is pumped into the wall. The consumption of the mixture will depend on the wear of the structure and the density of the composition. Silicatization is carried out in a similar manner.
How to choose the recovery method?
How to repair the foundation of the house? In itself, restoration of the foundation is a rather laborious and costly type of repair work. There are many ways to restore the foundation. Their implementation requires the availability of special equipment, as well as significant cash costs. Before starting the implementation of measures to restore the foundation, it is necessary to carefully evaluate all the advantages and disadvantages. The cost of restoration work may ultimately be significantly higher than the price of a new building. In this case, a calculator for calculating the foundation will be an excellent option.
Non-standard foundation strengthening methods
Various methods can be used to restore the base. For example, an unconventional option is to use an overloaded clip. Thanks to this, partial unloading of the foundation can be easily performed. The space around the old foundation in the framework of this method can be divided into several sections.
This technology involves digging the foundation. After that, the soil is taken out from under the suspended part. Next , a reinforced concrete bridge is mounted , and the empty space is filled with mortar. After the composition has hardened, consoles are mounted. In turn, the nuts must be screwed onto the rods. Thus, overvoltage occurs. When the beams are removed, the overloaded cage will put a strain on the tides.
Restoring the foundation is a simple process that you can do with your own hands. The most important thing is to adhere to certain instructions during operation and observe safety precautions.