It is not uncommon for the owners of private houses and cottages to encounter the problem of foundation cracks. 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 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 acting on it, leading to its destruction.
Ground water is one of the factors; ordinary water can cause corrosion of metal and destruction of the base. In our time, acidic and alkaline groundwater is not uncommon, which can destroy the foundation of a house in a few years.
However, the most important reason for the destruction of foundations is the violation of building codes, neglect of technology.
Failure to comply with the depth of the foundation is a frequent violation.
Frost heaving of the soil acts on the foundation laid at a shallower depth than the freezing 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 reasons for the destruction of the foundation can be attracted by specialized firms, 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 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.
Set at least two markers per crack. One marker is placed near the beginning of the opening, the second near the end.
After applying the 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 crack opening process continues, then the beacon also receives 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 predict further destruction of the foundation.
The second method of work on researching 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 reinforce 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 the usual litmus tests, 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 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 rainfall 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 directing water past the house, and the construction of a blind area at least 80 centimeters wide.
In case of groundwater rise, 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.
In both cases, the foundation is additionally waterproofed.
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.
One of the most popular methods is considered to be foundations. 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 the masonry and complete replacement.
Laying 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. With a deep setting, the grabs are reinforced with racks and beams.
Next, concreting is carried out, less often rubble laying is performed. The opening and concreting of the grips is carried out provided 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 reinforced structures, a shallow depth of foundation, deep finding of groundwater.
It is important to observe the technology of production of works to prevent the renewal of the destruction of the foundation.
It is not recommended to use the liner in cases of deep foundation, if the groundwater level is high, in emergency situations.
The clips are side attachments made of concrete blocks connected to 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 rationality their application.
Torque-free double-leg clips are preferred.
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 for transverse reinforcement are punched in the base. 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 work is one of the most dangerous. This type of work must be performed with extreme caution, applying all safety measures and not endangering either your life or your assistants.
( 4 marks, average 3 of 5 )
Posted By: Work Style |13, Nov 2020
Posted By: Work Style |05, Nov 2020
Posted By: Work Style |10, Nov 2020
Posted By: Work Style |08, Nov 2020
Posted By: Work Style |05, Nov 2020