Sealing cracks in brick walls: step by step instructions

Everyone who builds for himself probably has a dream to build for centuries. So that the foundation and walls, ceiling and roof serve for a long time and do not require repair. In practice, this is almost impossible: even well-built structures are subject to destruction over time, especially if they have a significant load. But such literacy can be shown if a person builds a house himself, or attracts those specialists in whom he is confident. But there are situations when the owner of a building does not even know who built it.

And then involuntarily you have to do something with those miscalculations and possible bad faith of the builders. According to statistics, it rarely comes to direct collapse and decay of a structure. But cracks in walls, foundations, ceilings - in any material - can darken life even with a fresh renovation and a good interior. However, not everything is so bad. Repairing cracks in the walls is a task for which it is not necessary to involve specialists.

Having understood the issue, you can correct the situation on your own.

Why do cracks appear in the walls and what are they?

You have probably wondered more than once: why some houses stand for decades without any signs of cracking, while others begin to cover a network of cracks without even waiting for the finish? There are, of course, reasons for this, and they can be of completely different nature:

Sealing cracks in brick walls: step by step instructions
The reasons for the appearance of cracks can be different
  1. Excessive load on the supporting structures of the walls. Building design involves careful calculation of the loads that fall on the walls, especially if the building has several floors and a heavy roof. In case of overload, cracks begin to appear. So, in brickwork, as a result of increased pressure, the coloring of the mortar begins, after which the bricks break along the lines of greatest load.

    Some materials, for example, aerated concrete, are generally not designed for multi-storey construction and heavy floors.

  2. Inhomogeneity of the structure of the walls. When multiple window openings are placed in a wall, the distribution of weight against the wall is affected. Too wide windows without a support element can lead to cracks on the sides of the window opening. In the old days, one of the ways to distribute the load was arched window openings.

    And the windows were made much narrower than now. When designing a large glazing plane, provide load-bearing supports that will support the weight above.

  3. Shrinkage of materials. If, when building a house, you do not allow the foundation to stand properly, but immediately begin to erect walls, this can lead to cracks. The foundation will shrink, and it will be uneven.

    A skew will appear in the geometry of the house, the walls will begin to crack.

  4. Ground features. In regions with a large difference in daily and seasonal temperature fluctuations, changes have a detrimental effect on buildings. First, the walls themselves suffer from this.Compressing and expanding from cold and heat, building elements are subject to accelerated wear.

    Secondly, the very soil on which the house stands swells when the soil is rapidly cooled and the groundwater is close. The foundation falls through somewhere, but protrudes somewhere, and in turn transfers the deformation to the walls.

  5. Extensive construction work and terrain at the construction site. Deep mining - deep pits, trenches, and even more so the construction of a subway or mine workings - lead to the displacement of earth layers. With an inclined relief, the soil masses are prone to slow creeping - that is why terracing and foundations of special structures are used in mountainous regions.

    If these rules are neglected, the formation of cracks is inevitable.

  6. Redevelopment and completion of the structure. If we are talking about an apartment building, then the culprit may be irresponsible neighbors who, in the name of designer repair, destroy not just partitions inside the apartment, but fragments of load-bearing walls. If such a "repair" was carried out on the 1st floor of a 16-storey building, the appearance of cracks is only a matter of time. In private housing construction, over the years, houses have been overgrown with outbuildings, balconies, terraces and technical rooms.

    All this puts pressure on the ground, foundation, walls, as a result of which the owners are surprised to find cracks at the junctions of later structures. Cracks may appear at the joints with different extensions

Sealing cracks in brick walls: step by step instructions
The foundation has shrunk

Cracks caused by for different reasons, have a different nature. Some simply spoil the view, while others pose a danger to the entire home, and can lead to sad consequences if they are not repaired in time. For example, diagonal, horizontal, or vertical cracks indicate directions in which increased loads are applied to break walls.

Surface cracks do not cause any other inconvenience except visual.

If they have spread over the plaster, then only this layer is damaged by them. The deep ones are much more dangerous, and here is why: for the time being, a person does not see cracks at all, especially if it is a wall that is trimmed inside or outside with panels or wallpaper. They notice it when it comes to the surface and splits the wall along. It already needs to be fought with special methods.

Tears of wall materials are also classified into types such as stable and unstable.

A stable crack is a deformation of an integral mass of building material, which was formed as a result of some event (push, sinking of the ground, or other), and after that it no longer spreads. While these cracks can be large and dangerous, they can be dealt with. But the situation is even more complicated with unstable cracks. These troubles grow over time: starting from a small cavity in the masonry, the crack grows, covers the entire wall and can threaten the collapse of the structure.If you repaired a crack with mortar, and a month later there is trouble again at this place, you should know that you are faced with an unstable crack.

Sealing cracks in brick walls: step by step instructions
Cracks can appear at the joints with various extensions

It is quite easy to detect it on purpose: write on the strip paper the current date and glue tightly across the divergence line. If the cracks grow and widen, the paper will tear. It is also convenient to use alabaster lumps for this, sticking them across the crack, or even just a thickly mixed portion of the finishing putty. If you are afraid that the inscription will be erased, the date can be squeezed out while the material is still soft. By making observations, it is possible to establish the rate of crack growth in this way.

Longitudinal cracking is detected by simply marking the edge of the crack with a date pencil. If the line has gone further, take action.

How to patch up cracks in different types of walls

Having dealt with the causes and types of cracks, you finally come to the main question: what to do now with these zigzag lines on the wall of your home ? There are many ways to seal cracks. And a lot depends on the materials in which the destruction occurred. No less important is the purpose of the wall - whether it is external or internal, load-bearing or just a partition.

Below are the most common cases when a quality finish is required.

Sealing cracks in brick walls

Brick is one of the most common building materials. And despite the widespread use of reinforced concrete structures in the construction of apartment buildings, and in private construction - frame structures and aerated concrete, brick is still well known to any resident of Russia. Non-bearing walls in high-rise buildings of the "monolith-brick" type continue to be built from it. They are also used to building on their site.

Sealing cracks in brick walls: step by step instructions
A crack in a brick wall often follows the line of least resistance

Having found a crack in brickwork, you need don't panic, but do a little research. The type of crack can be determined using the table:

Crack width Classification Possible repair
Up to 5 mm Small Sealing with putty is allowed
5 - 10 mm Medium Embedding of the DSP with preliminary joining
More than 10 mm Large Embedding of the DSP with crushed stone, reinforcement is required

After that, using plaster beacons on the street side or with paper strips on the inner wall, record the current state of the crack with the date and month. If you see that the crack is not growing, good, you can start sealing. The paper is torn, and the beacon is cracked or moved away from the wall - look for the cause of the cracking.Be guided by direction - usually vertical cracks are characteristic of a weak foundation, they expand upward when part of the house seems to fall off another.

If the crack has gone obliquely along the wall - the foundation is strong, the laying of the mortar has broken.

Important! Sealing of any crack should be started only when measures are taken to stop its further growth and spread. Otherwise, the crack bridging job may go down the drain.

Small surface cracks are filled with cement-sand mortar. The solution is prepared quite liquid, thinner than masonry and plaster.

This is done so that the mortar can be fed directly into the crack, since no hand-held tool will fit into a 5 mm wide slot.

Sealing cracks in brick walls: step by step instructions
For small fractures, a regular mortar is sufficient

It is best to use a construction syringe to pump the mortar into the fracture. It is often found in sealant tubes. The tube is inserted into the plunger pistol, the stem presses on the bottom, and the sealant comes out of the neck with a sausage. Such syringe pistols are equipped.

Here is an example of such works with your own hands:

Sealing a crack in the garage wall on our own

Shallow gaps between bricks or along the very body of the bricks is simply thrown with mortar. To do this, add a little less water to the mixture to get a thicker composition. Having collected a little mortar on a trowel or trowel, it is thrown over with a characteristic movement with a guy. Thanks to the speed with which it flies off the trowel, the mortar not only sticks to the wall, but also penetrates the crack. After that, the surface is leveled with a trowel or trowel.

Sometimes a crack is mistaken for spalling of mortar between bricks in the masonry. This can be easily removed by plugging the solution into the gap formed. If the house is lined with facade bricks, then the question of aesthetics arises. Then a special narrow spatula comes to the rescue. It can be made from a piece of metal of the desired width.

Drawing along the gap with this tool, the builder compresses the solution and removes excess.

Sealing cracks in brick walls: step by step instructions
It is possible to restore the layer of the fallen out plaster with such a spatula

But if the gap penetrates the wall to a considerable depth, the solution may not hold ... A whole range of measures is carried out:

  1. The crack is cleaned of dust, stuck debris, fragments of old dried mortar.

  2. Drill holes for dowels for self-tapping screws on both sides of it.
  3. Moisten the gap with water to increase the adhesion of the cement to the brick and prevent cracking of the applied layer during drying.
  4. Fill the crack with mortar. For deep penetration, you can find flat chips along the width of the slot.
  5. A reinforcing mesh is attached on top.

    Screw the screws into the pre-inserted dowels.

  6. Plastering work is performed on top of the mesh. The mesh will prevent cracking if its strength is negligible.

For wide cracks, the tensile force of the mesh may not be sufficient. Even if a set of measures is taken to eliminate the cause causing cracking, the severity of the masonry and thermal compression-expansion of materials can still expand the crack and even cause the metal mesh to lag behind the walls.

For such situations, a more serious strengthening of the wall is provided. Two diverging sides can be caught by an iron strip, the so-called tire, or preferably several. Such tires are anchored either by direct driving into the wall, or screwed on with special fasteners. Conventional self-tapping screws will not be enough here, use an anchor. Bars welded onto embedments

Sealing cracks in brick walls: step by step instructions
Removing bricks around the crack

When the crack is through, it is not enough to simply fill it with mortar.

With the help of a scalpel and a hammer, adjacent bricks are removed along the crack line, including whole ones. By and large, in the crack area, the wall is partially disassembled. After the bricks are removed, the surface of the remaining ones is leveled with the same scarpel from the remnants of the old mortar.

Then part of the removed masonry is restored. New bricks are placed in fresh mortar.

for the Mortar it is better to apply with an overabundance, and then hammer the brick into the wall on the old seat using a rubber tamping hammer, which is used when laying paving slabs. As a result, part of the crack is filled with mortar more densely. Even if it is squeezed out through the joints between the bricks, it can always be assembled or smeared on the wall with a scraper.

The part of the masonry laid over in this way will be much stronger than simply filling the crack with a cement-sand mixture diluted with water. This happens because the adhesion between the edges of the gap is added to the adhesion of the top, bottom and sides of the bricks, which are also recommended to be sprayed with water before work.

Sealing cracks in brick walls: step by step instructions
If the tires are buried, they are covered with mortar

In order to completely get rid of further divergence of the edges of large cracks, use metal tires, most often iron. Such a tire is a strip with a width of 3-5 cm and a thickness of 2-3 mm . The length of the tire must be selected so that on each side of the crack it reaches the wall no less than 25 - 30 cm.

At the ends of the strip, holes are drilled with which it will be attached to the wall ..

. There are two ways to fix it:

  1. On the anchor. The threaded rods of the anchors are inserted into the drilled holes. Then a tire is put on them. After that, nuts are screwed onto the thread with a wrench.

    Due to the special petal mechanism, the anchor shank diverges in the hole with a cone and wedges. After that, you can pull it out of the brick wall only by destroying this area. The reliability of such an attachment is considered high and can withstand significant loads.

  2. On mortgages. Embedded are also metal rods.

    They are carved at one end, and plumage at the other, to better stick in the wall. It is hammered into a hole drilled or punched with a perforator with a hammer, and then it is also covered with mortar. After the mortar dries, the mortgage remains firmly fixed in the wall, then you can put on the tire and tighten it with nuts.

Sometimes a tire is made of two parts. This option is convenient if you don't want to mess around with drilling holes, but you have a welding machine.

The parts are driven into the wall on both sides of the crack, then bent at right angles towards each other. The ends of the strips are overlapped and the tire is ready.

Two pieces are also required in the case of a through crack. They should now be the same size and the holes are drilled through the wall. One strip is placed on the inside of the wall, the other on the outside.

Studs with two nuts are used to tighten them.

Good to know! For wide cracks, in which it is necessary to fill large volumes of voids, it is convenient and useful to include gravel fraction in the solution. Firstly, it will reduce the consumption of the mortar, which is made with a high cement content for cracks. Secondly, crushed stone will act as a reinforcement, turning the mortar into concrete and thereby increasing the strength of the aggregate after hardening and standing.

Prices for various types of cement


Sealing cracks in the plaster of internal walls

Cracks in the inner walls bring home owners as much anxiety and trouble as they do outside.

Plaster is a finishing layer that is applied over the main wall material. It seems that cracking it does not carry any catastrophic consequences, such as moving a wall or digging up a foundation. However, cracks in the plaster do an irreparable blow to the room's appearance. Cracks on the inner walls cause irreparable damage to the appearance

Previously, when the interior decoration of walls everywhere provided for gluing wallpaper, a crack could sometimes only be found during repairs, tearing off the old wallpaper and getting ready to paste the new one. Modern ideas about renovation as an alternative to wallpaper have put forward the coating of plastered walls with water-based paint.

The surface for this procedure must be perfectly flat.

Sealing cracks in brick walls: step by step instructions
Shrinkage cracks in a high-rise building can not be opposed by anything but sealing

A layer of plastic putty is applied over the plaster to remove the smallest irregularities. Mix for plastering, putty, paint - all these funds cost a lot, especially from well-known manufacturers. Imagine the chagrin of the owners when they see all this expensive beauty covered with a network of cracks. Therefore, filling cracks in the plaster of internal walls is a task where, first of all, the aesthetic aspect is solved.

The end result should be made as invisible as possible against the background of the overall picture.

In the case of cracks in the plaster, it is not necessary to reveal the stability of the cracks, unless the finishing layer is deformed due to displacement in the walls themselves. Fortunately, this does not happen very often, although it does happen. For example, in an apartment building, where cracks in the plaster can be caused by the shrinkage of the house due to miscalculations at the stage of laying the foundation, nothing can be done at all. All that remains is to patch up the cracks.

But what you really need to do is walk the entire length of the crack with a spatula and hammer. With a spatula, remove plaster dust and debris, tap with a hammer along the entire gap on both sides. If you feel emptiness under the hammer and the blow is muffled by an air cushion, feel free to whip this piece of plaster. If you do not do this now, it will still fall off, and all efforts will be wasted.

Sealing cracks in brick walls: step by step instructions

After thorough cleaning, the cracks are moistened with water and filled with mortar or a special plaster mixture.

If you want to play it safe, prime the surface before applying the mixture - this will improve adhesion and reduce the possibility of new cracks. The applied composition is leveled with a half-trowel, and if the plaster has moved away from the wall to a large width - the rule. After plastering, the sealed area is putty.

If the plaster layer was thick enough, and in the process of cleaning the crack fell off to the wall itself, then you cannot do without a reinforcing mesh. It can be metal and polymer, with cells of different sizes.

Typically, the thicker the layer is applied, the larger the cells are selected. Attach the mesh to nails or screws. Plaster adheres better to the mesh.

Sealing cracks in brick walls: step by step instructions
Even old shingles will hold up new plaster well

For narrow vertical cracks, which, after being knocked down hammer, they did not give the pieces that fell out, the use of a reinforcing tape is permissible. It is made of fine mesh, and the material - fiberglass - is chemically inert and physically strong.

For small cracks with a shallow depth, it is permissible not to use a plaster mixture at all, but to do only with a finishing putty.

Sealing cracks in brick walls: step by step instructions
Rapid sealing of a crack in the wall

The appearance of cracks on the walls of old houses - private and multi-apartment - is generally a natural thing. Previously, there were no special high-tech building mixtures, housing had to be cheap, and the materials used were appropriate. If you lived in an old house, then you probably saw from the fallen layers of plaster that there was too much sand in the mixture, and part of the cement was replaced with lime. Under the layer of plaster, you can see the shingles - these are special wooden planks nailed in a cross, on which a layer of plaster was thrown.

This replaced the reinforcing mesh, and I must say, quite well. Therefore, do not rush to dismantle the shingles, unless you plan to beat off the plaster throughout the room. It will hold well both cement-sand mortar and modern gypsum mixtures.The latter, by the way, often do not require reinforcement.

Video - How to repair a crack in the wall?

Tip: it is recommended to use the smallest fractions for the solution to seal cracks in the inner walls river sand.

Then the solution turns out to be homogeneous, it is easy to apply it in a thin layer and level it.

Prices for various types of plaster


Sealing cracks in concrete walls

Concrete has long been trying to supplant older building materials like brick and wood. Perhaps, only in private low-rise construction, monolithic concrete and reinforced concrete are used only in foundations and floor slabs. In the construction of high-rise buildings, commercial and industrial premises, concrete has long become number one.

Cracks in concrete are an unpleasant thing, given that this material itself is strong enough and has a monolithic structure.

However, even despite the reinforcement with corrugated steel rods and embeds, concrete can still crack. Then the tenant of a panel or large-block house will be faced with the question of the features of sealing cracks in concrete.

Small cracks can often be found in the concrete walls of apartments. They do not pose any danger, but they greatly spoil the view and sometimes interfere with finishing or wallpapering. They can form even at the stage of production of concrete panels as a result of improper drying or disruption of other technological processes.

If you bought an apartment without finishing, found cracks and sinks there, and hurry to a hardware store to buy the most expensive and sophisticated building mixture, do not rush. Perhaps one very simple and effective way will be enough for you.

The fact is that it is quite difficult for a beginner to apply the putty in an even thin layer. In addition, this material is not so cheap, and there can be many cracks. But to seal small cracks, you can use a conventional cement-sand mortar.

It can be argued that the solution as a heavier and less "sticky" material requires even more skill than a putty. And if she can still forgive the newcomer for the inability, then the solution will either fall to the floor or freeze on the wall with ugly humps. Leave skepticism and prepare the finest sand and Portland cement M-400 or M-500. You will also need a wonderful tool that looks like a half-rake, but has two strips at the top that are held down by wing nuts. Next, you need to find a piece of an old fur coat or sheepskin coat with short, dense fur.

Do not be confused by the materials - sometimes the folk method works better than scientific developments.

Step-by-step instructions for sealing cracks in concrete

Step 1. Wrap a half-trench with a piece of fur and secure its edges with clamping strips. Fasten with the fur outward.

Sealing cracks in brick walls: step by step instructions
A polisher will help to cope with cracks

Step 2.

Prepare a liquid cement-sand mortar.Be sure to sift both sand and cement. The smaller the particles, the better the result will be. The consistency should be the same as that of the ready-made mixture for pouring floors on beacons.

Sealing cracks in brick walls: step by step instructions
Cement-sand mortar

Step 3.

Prepare a second bucket of water.

Step 4. Dip a half-grater wrapped in fur into water, then pick up a little mortar with a spatula and apply it on the grater plane.

Sealing cracks in brick walls: step by step instructions
Bucket of water

Step 5. Press the grater against the concrete surface and make movements, as if rubbing mortar into the wall.

The movements can be circular, reciprocating, sliding. It is best to move across the crack.

Sealing cracks in brick walls: step by step instructions
Heavy-bristled scrubber

Step 6. When the solution dries, wet the fur again and continue to apply solution.

Sealing cracks in brick walls: step by step instructions
This is how a concrete wall looks like after grinding

This method is called by builders "grinding", with its with the help, you can remove all irregularities in concrete, including depth and width up to 1.

5 cm, just for greater depth, the solution should be thicker. The fact is that during rubbing, the particles of cement and sand evenly, with a thin layer, fill everything that they cling to - pits, holes, cracks, holes, seams and even shallow grooves. Using a piece of unnecessary fur is just very convenient to get the necessary skill, even a beginner can handle it. The method is one hundred percent working and tested when decorating houses from monolithic reinforced concrete.

Sealing cracks in brick walls: step by step instructions
Epoxy resin is very convenient to apply

True, it is not always possible to do with such simple means.

If only because the crack can be deep and wide, then the solution will simply pour out of it. If the cracks are wide enough, they can also be repaired with reinforcing tape. But the special material for concrete repair is epoxy resin. It is available in different versions depending on the application. For construction work, it is packed in plastic buckets of 5-10-15 kg.

In addition, you will need to buy a bottle of hardener. The good thing about using epoxy is that it has high adhesion properties, it fills voids well, and after drying it acquires the hardness of a stone.

In medium cracks, epoxy can be applied with a trowel. In deep and narrow gaps in the middle of thick load-bearing walls, special epoxy compounds are injected with a special syringe through nozzles. The nozzle is a special plug with a pipe that is installed into the crack through the prepared holes.

The crack itself is closed with mastic from the same epoxy. The resin mixed with the hardener is pumped through the bottom nozzle, when the resin is squeezed out through the tube, it is plugged with a stopper, and transferred to the nozzle located above. So gradually the entire crack is filled with epoxy sealant, which dries for about a day. After that, the plugs are cut off and the sealed place is putty with the finishing mixture.

Materials for sealing cracks in walls

The simplest and most affordable material for "treating" walls from cracking is a cement-sand mortar.

It is done in a proportion of 3 parts of sand to 1 part of cement. For large through cracks, gravel fraction is introduced into the solution. To strengthen and improve adhesion and adhesion, liquid soap is added to the solution (at the rate of 30 g per bucket of solution), liquid glass (it is also silicate glue, up to 20% by volume), PVA glue (100 g per bucket of solution) or factory ready plasticizers.

Silicone sealant is often used to seal small cracks. Its trump card is very convenient application and quick drying.

The nozzle of the glue gun can be pushed into almost any crevice, and the adhesive power grasps the edges of the crack, grabs the edges of the crack and prevents them from diverging. Such glue is convenient for quick work: when dried with a building hairdryer, it completely solidifies in just a few hours.

Prices for silicone sealant

Silicone sealant

Sealing cracks in brick walls: step by step instructions
Complete sealant will fill the crack, and it is easy to apply

In cellular structures - gas and foam concrete - it is permissible to use polyurethane foam, if only the wall is strengthened against further creeping. The good thing about foam is that it fills all voids when it expands and has excellent thermal insulation properties.

Prices for polyurethane sealant

Polyurethane sealant


Sealing cracks in the walls are a responsible business.

It happens that unattended cracks lead to the collapse of the wall, and it is always easier to repair than to build anew. And that's not to mention the consequences. Seal cracks wisely, prevent cracks, and your home will serve you for a long time.