In construction, a variety of materials are used. One of the most popular is brick. The walls of this material are durable, resistant to aggressive environments. However, the brick eventually deteriorates. In the presence of removable damage, the masonry or restoration of the brickwork of the external walls is performed . Let us consider in more detail what it represents.
General information
Restoration of old brickwork includes a complex of various activities. First of all, an assessment is made of the condition and quality of the wall. After that, cleaning, removal of crumbled elements is performed. The next step is the preparation of restoration solutions and filling them with voids.
In practice, quite often it happens that in a building one brick wall is damaged, and the rest remain intact. In such situations, demolishing the entire building is impractical. It is much more economical to restore the brickwork. Rates per m2 vary depending on the severity of the damage, the age of the building itself and other factors.
Causes of destruction
Violation of the constructive monolithicity of brick walls is caused by different circumstances. The main cause of the damage is the shrinkage of the structure. A year or two after the construction, the structure shrinks. Accordingly, restoration of the brickwork of the new building will be required in any case.
Walls put some pressure on the foundation. This causes its deformation over time, which, in turn, negatively affects the condition of the base: a crack appears. She goes higher, destroying the wall.
Equally important are the weather conditions. With constant exposure to precipitation, a shallow crack increases in size.
Another cause of destruction is the deflection of the wall. It occurs as a result of increased pressure of the floors and arches of the building. In such a situation, experts recommend first determining the exact cause of the damage, and then deciding on the need for restoration of the brickwork. The price per m2 of wall can reach a considerable size. Therefore, it is necessary to evaluate the economic feasibility of restoration work.
Counter-drilling
Among all methods of restoration of masonry, this method is considered the most reliable and cheapest.
The restoration of the wall is as follows. At a certain level, holes are made in a chain or staggered at a given distance. In thick walls, they are drilled on both sides opposite each other. The holes are filled with a hydrophobic solution (in liquid or creamy form). To restore the statics of the masonry, a mineral suspension is added.
Partial analysis
As the name implies, this brickwork restoration technology involves the dismantling of a damaged section of the wall. Waterproofing is laid in it and closed with new bricks.
The disadvantage of this method is the high cost and cost overrun of the material.
Microwave dehumidification
A microwave field is created in the wall using an autonomous electrical system. It provides the conversion of moisture into steam that escapes through the capillaries. Different-pole electrodes are introduced into the wall and ground, to which current is supplied.
This method allows you to remove excess moisture from the masonry and prevent further destruction.
Saw method
This method of restoration of masonry is considered the most expensive. Its essence is as follows.
The masonry is sawed horizontally. The resulting opening is filled with waterproofing material, and the gaps are filled with mineral suspensions, which contribute to the restoration of masonry statics.
The disadvantage of this method is the frequent incompatibility of the suspensions with the old masonry. This leads to delamination of the compositions.
Laboratory research
This stage is one of the obligatory in the process of restoration of masonry.
For analysis, samples are taken from different parts of the wall. They are examined for sulfates, nitrates, moisture and salts.
With a visual examination, it is far from always possible to find water in the masonry capillaries. For laboratory testing, samples from at least three sites are required. They are studied and set the percentage of water in each, then the results are compared. If the performance is high, a cut-off is done.
In a similar way, the salt content is investigated. If their high content is revealed, measures are taken to eliminate their negative impact on the wall.
In addition to surface cleaning, stopping is also performed. It involves the conversion of salts to an insoluble form. In this case, a special chemical treatment is carried out. It allows you to stop the hygroscopic swelling of salt, which prevents its exit to the surface of the masonry and the destruction of the wall.
If the salinity is very high, light porous solutions are used. The compositions are applied directly to the masonry. Their task is to draw out salts, after which the solutions are knocked off the wall and thrown away. Then do repeated laboratory tests. If the salt content has not decreased enough, the solution is applied again. If their number has decreased, go to the next stage of recovery.
Injection
It is carried out during restoration of joints in masonry. Injection is performed with mineral, epoxy or polyurethane compounds that do not allow moisture to pass. The masonry condition, load and humidity affect the choice of a specific composition.
Organosilicon mixtures are considered most suitable for reduction. As a solvent, kerosene or white spirit are used.
The crack is plugged, the composition is injected under pressure. The solutions are viscous and penetrate into small cracks.
To prevent stratification of the composition, fine sand is added to it. Otherwise, only the liquid component will penetrate into the depth of the crack, and the base will remain at the top.
Important points
It happens that during restoration it is necessary to preserve old materials, for example, if work is carried out with historical masonry. In such cases, weaknesses need to be identified already by visual inspection. After this, the degree of strength of materials is determined by a laboratory method. At a low rate, the wall is strengthened with solutions containing silicon.
Brick is restored using restoration solutions, and the seams - with special suture. In terms of strength, grain and color, they must match the samples. The necessary parameters are determined in laboratory studies.
Solutions
Restoration and suture compositions are of three types:
- Based on lime.
- Cement-containing.
- Acrylic
The choice of a specific solution is influenced by the strength of the masonry, as well as the requirements that apply to the object.
Quite rarely, in practice, epoxy and polyurethane compounds are used. Lime mixed with sand is used to restore the walls of old buildings. If in such a masonry there are seams and bricks of different colors, color imitation is allowed. To do this, use azure with the addition of dyes.
Modern technology allows you to restore masonry for at least 10 years. As preservatives, creamy or liquid hydrophobizing agents are used, based on which silane-siloxane is present. Silicone compounds and silicates are less commonly used. The most effective are creamy water repellents.
Do-it-yourself brickwork restoration
The following tools will be required to restore the surface:
- Drill.
- Hammer drill.
- Chisel.
- Hammer.
- Master OK.
- Metal brush.
Before starting work, you must fix the wall.
DIY restoration technology for masonry is as follows.
Using a drill with a special nozzle, bricks to be removed and adjacent seams are cut.
Joints along the perimeter of the destroyed brick are knocked down with a hammer and a chisel. In this case, you must act carefully so as not to damage adjacent whole elements of the masonry. They must be carefully cleaned of the old solution. Pre-wetted bricks with water.
Next, prepare a solution. An additive is added for a better setting. If necessary, you can add dye.
The solution should be laid out on all sides of the hole formed from the removed bricks. The composition layer is not less than 2 cm. Entire bricks are soaked in water, smeared with a solution from all contact parts. They are inserted in place of the deleted damaged items.
To shrink them into the holes, tap them gently with the handle of the trowel.
Supports and other fasteners can be removed after the work is completed.
Masonry restoration: prices
Today, many companies offer their services in the field of repair. Their cost, of course, varies in each region.
As a rule, companies offer comprehensive services for structural bonding of cracks, reinforcement of masonry, and cut-off device. Their cost is formed from the price of work and materials. The first, in turn, depends on the volume and complexity of the restoration measures. The cost of the material is calculated based on its quantity and unit price, taking into account delivery to the object.
Currently, in most cases, an injectable (injected) composition is used for restoration. His choice is determined by the goals of recovery, the degree of complexity of the problem. The more pores and cracks in the masonry, the naturally more material and working time are needed.
In addition, factors such as:
- The need for reinforcing masonry.
- Working conditions.
- The height of the building.
- The need for heating the work area.
- The remoteness of the object.
- The need to deliver restoration material from another region (on order).
- Additional costs (transportation costs, etc.).
In St. Petersburg, for example, the average prices for restoration activities are as follows:
Types of jobs | Units measuring | Price, rub.) |
Injection Strengthening | m 2 | 6600 |
The device of anticapillary (cut-off) waterproofing | m. | 3600 |
Application of sanitizing plaster with a layer of up to 3 cm | m 2 | 850 |
Preparatory work: - masonry cutting (depth 20 mm);
- applying a repair compound (plastering)
| m 2 | 750 |
Injection | kg dry solution | thirty |
Filling cracks with restoration mortar | m 2 | 3500 |
High precision cementing |
Preparatory work (cleaning, dust removal, degreasing) | m 2 | 200 |
Cementing | kg dry solution | thirty |
As you can see, the cost of the whole complex of works can be quite high. At the same time, additional costs may be required to perform laboratory tests.
In case of significant damage to the masonry, it is more advisable to contact professionals. If the cracks are small, then it is quite possible to cope on their own. This, however, does not apply to structures with historical masonry. The fact is that for its restoration it is necessary to have a certain experience and knowledge. In addition, you can not do without laboratory tests.