The appearance of a gap in the plaster or concrete immediately signals a violation of the integrity of the construct or local stress in the finishing layer. Diagnostics It is necessary to start by determining the nature of the damage: whether it is a superficial cosmetic defect or a symptom of shrinkage of the foundation. Ignoring even a thin thread on the surface can lead to massive destruction. load-bearing in a few years. The right technology is selected crack It depends on the material of the walls and the dynamics of the defect expansion.
The first priority is to clean the damaged area of dust and crumbling particles to assess the depth of penetration. If a deaf sound is heard when tapping, then the plaster has moved away from the base and its complete removal to a hard layer is required. In some cases, installation is required. locator from plaster or paper to help track whether the deformation is ongoing. Only after stopping the deformation process, it makes sense to start cosmetic repairs.
⚠️ Warning: If the crack is more than 10 mm wide or continues to expand after the installation of control beacons, this may indicate an emergency condition of the foundation. In this case, a simple filling of seams will not solve the problem, consultation of a civil engineer is necessary.
Classification of defects and causes of their occurrence
Before you choose repair-mortarIt is necessary to determine the type of damage, since the methods of recovery for different types of destruction are radically different. Static cracks usually occur after the completion of the basic shrinkage processes of the building and stabilize over time. Dynamic gaps continue to grow under the influence of vibration, ground movements or violation of construction technology, requiring preliminary strengthening of the base.
- 🏗️ Constructive - arise due to errors in the calculation of loads or damage to the bearing elements of the frame.
- 💧 Deformational - caused by uneven precipitation of the foundation, soil tufting or thermal expansions of materials.
- 🎨 Technological - appear in violation of the rules of applying plaster, drying the solution or using low-quality mixtures.
Particular attention should be paid to temperature seams, which are often masked as damage. In panel houses or buildings made of aerated concrete, such lines can be laid by the project to compensate for the expansion of materials. If it is a question of hair-crack in the layer of putty, the reason is most often hidden in drafts when drying or lack of primer before applying the finish layer.
⚠️ Attention: Horizontal cracks on the facade or basement often indicate problems with the foundation, while vertical cracks can be a consequence of the load of the floors. Diagonal faults in the corners of window openings are a classic sign of uneven precipitation.
Required tools and materials for repair
The quality of the work performed depends on the correctness of the selected toolkit Compatibility of materials with the base of the wall. To prepare the surface, a set of spatulas of various widths, a rigid brush to remove dust and a construction knife to decorate the edges will be required. When working with deep defects can not do without puncher with a blade nozzle or chisel to give the defect the correct geometric shape.
The table below shows the main materials and their purpose in the process of restoring the integrity of the wall:
| Materials | Appointment | Type of base |
|---|---|---|
| Deep penetration ground | Dust binding and adhesion | Concrete, brick, drywall |
| Plastering | Finishing alignment | Indoor dry spaces |
| Cement-sand mortar | Recovery of deep defects | Wet spaces, facade |
| Reinforcing net (selpian) | Preventing re-rupture | Material joints, angles |
The use of the structure is often required reinforcement. A fiberglass mesh or selp tape distributes the voltage and does not allow the crack to manifest again after the solution is dry. When working with large volumes of damage, it is recommended to use special repair compositions with fibre, which have increased elasticity and tensile strength.
To seal the cracks in drywall, use only specialized putty marked "for the seams of GCL", as ordinary plaster may not withstand the movements of the sheet.
Technology of fixing small cracks in plaster
Work with small defects, the width of which does not exceed 1-2 mm, requires accuracy and the use of liquid consistency solutions. The first step is always the scaling Artificial expansion of the crack with a spatula or knife at an angle of 45 degrees. This is necessary in order that the repair composition penetrated deep into the damage, and did not remain on the surface, forming a film.
After mechanical cleaning and dust removal, a layer is applied with a brush. primer. Waiting for the soil to dry completely is not always necessary if the material instructions allow the application of the next layer "wet wet", but for a guaranteed result it is better to give the surface to grasp. Then the putty is rubbed with a spatula, the movements must be transverse relative to the direction of the fault to fill the void as much as possible.
☑️ Checklist for surface preparation
The final stage is grinding the dried area with small sandpaper. It is important to achieve a perfectly flat surface that will not stand out from the rest of the wall after painting. If the wall is prepared for pasting with thick wallpaper, the ideal smoothness may not be so critical, but careful painting is required. polishing.
Repair of deep and end-to-end damage
Deep cracks require a more serious approach, including the use of reinforcing elements and aggregates. After embroidery and cleaning the defect, it must be moistened with water so that dry concrete or brick does not draw moisture from the repair solution too quickly. The depth is used to fill the foaming (for through slits in the facade) or cement mortar, which is stuffed layer by layer with a stamp.
The key to repairing deep faults is reinforcement. A mesh with a cell of 2-5 mm or a fiberglass tape is laid on the fresh solution, which is then pressed with a spatula and covered with another layer of the mixture. This "seal" works on the break and compensates for possible movements of the walls. In the case of very wide slits (more than 1 cm), wooden or metal wedges are sometimes used, which are clogged into the crack to stabilize it before closing.
⚠️ Attention: When using mounting foam to seal through the cracks in brickwork, be sure to cut the excess dry foam level with the wall before applying the plaster, otherwise it will create irregularities.
After drying the main layer, a finishing spat is carried out. If the crack was through and was on the outer wall, after repair, a layer is necessarily applied. waterproofing or facade paint to prevent moisture from entering the structure. The interior walls require only decorative finishing in tone to the rest of the interior.
The Secret Method for Old Homes
In the old fund before filling the crack, it is recommended to lay a slab along its course and lay a metal plate (ancair) there, fixing its ends in intact masonry. This will create a mechanical lock.
Features of working with cracks in drywall
Gypsum cardboard structures (GCL) are subject to the formation of cracks mainly at the joints of sheets and in corners. The main reason is the absence of a gap between the sheets during installation or the wrong technology of sealing the seams. For repair, it is necessary to cut off the damaged section of cardboard and plaster, forming a V-shaped groove. This will create a space to fill. putty And laying the reinforcement tape.
There are two main methods of reinforcement: the use of paper tape or fiberglass mesh. Paper tape, especially perforated, is considered more reliable for joints, as it has the same degree of expansion as drywall. The grid is more often used to prevent cracks on large planes or in corners. It is important to use a specialized putty for the sutures of the GCL, which has increased elasticity.
If the crack went down the sheet itself, it could mean damage to the frame or a strong impact. In this case, the crack should be expanded, cutting out the damaged piece, and insert a patch from the new drywall, fixing it on profiles or wooden bars on the back side. After that, the seams are sealed using standard double reinforcement technology.
The main cause of cracks on the GCL is a draft when drying putty. Close the windows and doors in the room while the first layer is drying.
Prevention and control of the condition of walls
To avoid the recurrence of defects, it is important to comply with the technology of finishing works and the climatic regime in the room. Sharp changes in temperature and humidity are the main enemies of fresh plaster and putty. In new homes, it is not recommended to start major repairs immediately after the delivery of the object, it is better to wait out the first year of active construction. shrinkage buildings, limited to cosmetic work.
Regular inspection of the walls allows you to identify problems at an early stage. If you notice that old patched cracks are reappearing, it is worth installing professional beacons or contacting specialists to assess the condition of the foundation. The use of quality materials with the desired elasticity (for example, latex paints or elastic putty) also reduces the risk of a “web” on the surface.
Can I repair the cracks in the winter in an unheated house?
It's not recommended. Most construction mixtures require temperatures above +5°C and stable conditions for polymerization or drying. The water in the solution may freeze, destroying the structure of the material, or evaporate too slowly, leading to detachment.
How to distinguish a crack in a plaster from a crack in a load-bearing wall?
You need to carefully clean the defect in one place. If the crack goes deep, changes direction or expands behind the plaster layer, the problem is in the load-bearing structure. If only a layer of finish is visible and then a monolithic material goes on, only the finish is damaged.
Do I need to lay a crack before finishing?
I will. The grounder binds the dust that inevitably remains inside the fault, and provides adhesion (clutch) of the repair composition to the base. Without a primer, the putty may simply crumble after a while.
Which material is better for finishing: plaster or cement?
For internal dry rooms, plaster putty is better suited - it is easier to work and does not shrink. For wet rooms (bathroom, kitchen) and outdoor work, it is necessary to use cement mixtures, since gypsum is afraid of moisture and is destroyed.
What if the crack reappears after repair?
The reappearance of the crack indicates that the cause of the deformation has not been eliminated. It is necessary to expand the defect, install a reinforcement mesh of greater width or stiffness, and possibly change the type of material used to more elastic.