Cracks in a wall made of foam blocks: reasons for their appearance, how and with what they can be repaired?

Have the walls made of foam blocks started to show signs of cracking? Maintaining the integrity and aesthetics of your home can be aided by being aware of the causes of these cracks and knowing how to fix them. Despite being lightweight and effectively constructed, foam blocks are susceptible to cracking for a number of reasons.

Settling is a frequent reason for cracks in walls made of foam block. Hairline cracks may result from pressure applied to the walls over time by shifting ground beneath the walls, or the foundation. Changes in humidity and temperature can also cause the foam blocks to expand or contract, which can lead to the formation of cracks.

Using the proper tools and materials is crucial to fixing these cracks successfully. To begin with, clear the crack of any debris or loose material. A flexible sealant made specifically for foam blocks can be used to fill and seal small cracks. These sealants are made to withstand the small movements that foam block walls experience without jeopardizing the repair.

A more robust method might be required for cracks that are bigger or more significant. In order to preserve structural integrity, the crack may need to be filled with expanding foam filler before the surface is painted or sealed with a specific foam block sealer. These techniques not only fix the damage but also stop moisture from getting inside, which over time could erode the foam blocks even more.

Frequent upkeep and inspection of foam block walls can aid in the early detection of cracks, enabling timely repairs that stop more serious harm. Your home can be kept safe, structurally sound, and aesthetically pleasing for many years to come if you know why foam block walls crack and use the right repair methods.

Crack Cause Repair Method
Possible settling of the foundation or structural movement. Address underlying structural issues before repairing cracks with flexible sealants or injectable resins.
Inadequate reinforcement or poor construction techniques. Reinforce affected areas with mesh and apply a layer of suitable filler or adhesive.
Environmental factors such as temperature changes or moisture. Seal cracks with elastomeric caulking or waterproof coatings to prevent further damage.

What are they??

Cracks: Stress in the design causes this flaw in foam concrete blocks.

External factors or internal material alterations are the main causes of the cracks that appear on the walls.

Due to the high fragility of the foam block, flaws can arise easily and can be attributed to a variety of factors, including inaccurate calculations, a poorly constructed material, or one of the elements.

Different kinds of foam block cracks:

  1. Mechanical. Caused by physical reasons, improper distribution of pressure on the walls, uneven load on building elements.
  2. Shrinkage. Appear after exposure to external forces, including atmospheric phenomena, humidity, frost.

The depth and width of the opening that appears, as well as the surrounding area, are the primary parameters that people consider when studying faults.

When cracks are found in the wall of a foam block, repairs must be made as well as efforts to determine what caused them and stop them from happening again.

Why do they appear??

What may lead to a masonry flaw in a foam block wall:

  • Technological errors were made during the manufacturing process of building materials. In order to save money, the manufacturer can replace a component or reduce the required amount of ingredients. Creating foam blocks is an inexpensive enterprise; in the desire to look more affordable compared to competitors, factories use low-quality raw materials.
  • Errors in the production process itself. The material may begin to harden before the required time or the composition may not contain ingredients to increase the drying speed of the foam block. Due to improper gas formation inside the elements, the structure and uniformity of the cells is disrupted.

The performance qualities of foam blocks are diminished as a result of noncompliance with the technological process during production.

As early as two weeks after the wall is constructed, the first flaws might show up.

It is advised to fully disassemble the masonry and build a new wall out of a higher-quality material if cracks start to show up right away, are numerous, and keep getting bigger.

Construction mistakes that result in the appearance of flaws:

  • The foundation was not built according to the rules. The base structure is not reliable, lightweight, the weight of the walls, ceilings and roof is incorrectly calculated. The foundation must be of sufficient thickness and go down to a depth exceeding the freezing level of the soil. Preparation for the construction of the base must be carried out carefully, the substrate and waterproofing are carried out correctly. Failure to comply with the technology leads to deformation of the foundation, which brings with it the inevitable destruction of the walls.
  • Instead of special construction glue for foam blocks, another material was used, for example, cement mortar. As a result, the connecting mixture could not withstand weight and poor interaction with foam block. Either the glue was incorrectly divorced, did not follow the proportions. In this regard, the cold bridges were formed, the temperature difference inside the material led to the appearance of cracks.
  • Insufficient level of structure stiffness. Foam blocks do not withstand their own weight due to the height of the walls, are not able to take on the severity of the floors. This happens if the masonry was not carried out every 3-4 rows.
  • The construction of walls from foam blocks is possible only in dry, warm weather. The faults appear when the wet material dries and deforms, or freezes under the influence of low air temperatures. From frost, moisture inside the blocks freezes and expands, actually tears the element from the inside.
  • If the structure has 2 or more floors, after the construction of the first, the metal belt is installed. Its purpose is to hold and evenly distribute the weight of the future superstructure. When the belt is not installed or created incorrectly, cracks appear around the entire perimeter. This happens due to incorrect pressure on different parts of the wall.
  • The density of the elements must match. Cellular foam block does not always have the same structure, which will negatively affect the quality of the masonry. To avoid this, you need to purchase material from one seller, in one batch.
  • The foundation is unevenly built. This can happen when a separate foundation is formed for internal partitions and laid higher than the foundation under the load-bearing walls.

If it became evident during the explanation process that the foundation is "at fault" for the emergence of cracks, the first step in mitigating the effects should be to reinforce the foundation.

Additional explanations

  • Ground movement. Happens due to the passage of groundwater, frost heaving.
  • High dampness, lack of waterproofing. After drying, the foam block becomes deformed and becomes covered with cracks.
  • The components of the adhesive are mixed incorrectly. Even if the mixture itself is of high quality, failure to comply with the technology will lead to the destruction of the walls.
  • Most of the reasons are caused by the human factor and there is a chance to prevent the occurrence of cracks in advance.

Assessment of the scale of the problem

When immediate action is required:

  • if deep cracks appear;
  • if the crack crosses a large area of ​​the wall (by ¼ or more);
  • when the appearance of new defects does not stop.

There is a notion of an emergency situation with the building; the emergence of cracks signifies a progressive breakdown of the building’s compliance with technical requirements. In this instance, it’s time to start repairs right away.

There’s no need to worry about the repercussions when, in a short amount of time, a new building’s walls start to show tiny cracks; this is a sign of shrinkage. These cracks are thin, akin to a fractured shell, and frequently horizontal. Hair is the working name for them.

What to do next?

The foam block starts to collapse after the first winter and after a house is built. Typically, the cause is a failure to adhere to masonry technology and the use of subpar materials combined with fluctuations in humidity and temperature. The structure’s components are collapsing; floor to ceiling cracks adorn the walls. Being in a house like this is not safe. Here, emergency action is done, such as fortifying the walls.

In cases where multiple cracks are present, have uniform depths, and are not propagating, minor repairs can be made without requiring extensive interventions.

Crucial! A poorly done seam will result in horizontal cracks wider than 5 mm. The walls must be tightened in order to fix this flaw.

How to use plaster to check the dynamics of fault expansion:

  1. Along the edges of the crack at a distance of 3-5 cm, make 2 strokes of plaster.
  2. Cut a narrow strip of glass and attach it to the plaster. To do this, press the plate tightly and hold it for several seconds. The transparent part should match the crack in the wall.
  3. If the glass remains intact for a month, the crack will not get any bigger and you can start repairing it. If the glass is cracked, the defects will continue to appear, you need to look for the root cause and overhaul the building.

You should inspect the foundation if the crack widens. You will need to excavate it in order to accomplish this, after which the origin of the crack will become apparent. You should begin overhauling from this point on.

Sealing process

You can repair the crack using a variety of techniques if it poses no threat. Here, preventing cracks in the plaster and finishing materials is the primary goal.

Materials

Various materials are used, depending on how complicated the cracks are that have appeared.

  • special glue for laying foam blocks;
  • cement mortar with silicate chips;
  • mounting foam;
  • epoxy adhesive.

Advice: A mixture of cement or regular putty and crumbs from foam concrete works well for patching small, hair-like cracks.

Consumers and tools

To fix, apply:

  • vacuum cleaner;
  • water;
  • metal spatula;
  • primer;
  • reinforced mesh;
  • fiberglass mesh;
  • Grout.

Description of technology

Work phases, if there are only minor cracks:

  1. The cracks are filled with putty and aligned with its help the wall.
  2. In the process of working in a place where cracks are localized, a mesh of fiberglass is glued. It additionally strengthens a weak place and will not let the defects switch to finishing materials.
  3. After the first layer dries, draw the finish coating with decorative plaster, which includes basalt and granite crumbs.
  4. After that, the faults will be blocked and will not go to the outer layer of finishes.

Work phases, if there are large cracks:

  1. The break must be cleaned. To do this, use a metal spatula and remove all the resulting foam block crumbs. Use a vacuum cleaner to remove dust and rinse the crack with water. Wait for it to dry.
  2. Apply primer.
  3. Depending on the volume of the void, fill it with a solution of cement or foam. Level the surface.
  4. A reinforced mesh is placed over the fault. It is attached to self-tapping screws, which are placed at a distance of more than 10 cm from the edges of the crack.
  5. The mesh is filled with the solution, after which you need to wait until it dries completely and cover the wall with putty. Next, facing material.

Crucial! Greasy crack filling materials are required. Sanding the wall is necessary prior to application in order to create corrugation and improve the mixture’s adhesion to the surface.

How to strengthen?

Fully reinforced walls in the event of a crisis or numerous tiny fissures following shrinkage. The procedure is executed cautiously; it is advised to first seek expert advice regarding the best course of action.

What you need?

There are multiple ways to perform the procedure; the technology and strengthening material vary:

  • Mesh reinforcement for finishing. In this case, a reinforced mesh (25*25) is attached to the cleaned, primed wall, after which it is covered with putty and facing material. This method is the simplest and cheapest. To be sure that the house will withstand several more decades, this procedure is carried out on both sides of the walls. From the outside they are covered with plastic panels, tiles, siding or other materials.
  • Covering with plasterboard, siding or plastic panels. Not the most reliable option. Suitable if the cracks are very small, there is no threat of destruction of the building.
  • Additional brick facing wall. This material is denser and is able to hold up walls and buildings. It turns out to be a kind of brick box, inside which is a house made of foam block. The option is more expensive than reinforcement, but the result is more durable. Experienced builders recommend installing a wall inside the house too, so that the beams and ceilings rest on the brick.
  • Brick or concrete pillars. They are installed in important places where the pressure is strongest (in places where beams are installed, in corners). Construction requires a lot of time and costs.

Whether a wall is strengthened with brick or reinforcement, its entire structure needs to be supported by a strong foundation. Should it be insufficient, you must add a few more centimeters of concrete; otherwise, the walls won’t be able to support their own weight.

What tools are needed?

What you’ll need for a reinforced belt is:

  • metal mesh 25*25;
  • cement-concrete mixture;
  • staples and anchors;
  • putty knife;
  • shovel;
  • container for solution.

Regarding brick finishing:

  • connecting solution;
  • trowel;
  • double-sided hammer;
  • putty knife;
  • brick;
  • flexible connections;
  • perforator;
  • anchor;
  • solution container or concrete mixer.

For siding, drywall and similar

  • the material itself for strengthening;
  • metal profiles;
  • straight hangers;
  • single-level connectors;
  • anchor;
  • self-tapping screws;
  • knife.

Regarding pillars made of concrete:

  • formwork;
  • reinforced mesh;
  • cement-concrete mortar;
  • container for solution.

Suggestions. Dowels can be used in place of anchors, but they need to be able to pass through the cellular foam block. Only specific plastic fasteners are appropriate in this situation.

Strengthening stages

It is necessary to prepare the wall before beginning work. In order to accomplish this, the cracks are cleaned, washed, and secured with a connecting solution using the same general procedure as in less urgent cases. Next, after the wall has had time to dry, the wall’s strengthening process starts.

Belt reinforcement:

  1. Drill holes every 60 cm vertically and horizontally from each other.
  2. Lay the reinforced mesh, secure it with anchors tightly over the entire surface.
  3. Cover with a thick cement layer, level the wall, wait until completely dry. Afterwards you can begin facing work.

Setting up a brick pillar:

  1. Waterproof the base under the first row of bricks with 2 layers of roofing material or membrane. Stretch the mooring thread, which will be used to check the geometry of the rows.
  2. Laying is carried out in ½ or ¼ brick, as desired. First row without solution, on dry. First raise 4-5 rows from the corners of the walls.
  3. Check the horizontal alignment and correct angles (if any).
  4. Connect the corners into a single composition in compliance with the order (offset the bricks by ½ or ¼ in adjacent rows).
  5. Place reinforcement bars into the seam.
  6. Drill holes in the foam block. Attach flexible connections, drive in anchors.
  7. Start the next row of masonry again from the corners and follow the same principle as in the previous ones. It is not recommended to raise walls more than 1.2 meters at a time. Otherwise, the unhardened solution may not withstand.

Crucial! Only in those areas where the foam block is intact and does not crumble can you drill into it. In certain places, such as the northern areas and central Russia, insulation is installed in between the walls. Vents will need to be left in the brickwork.

Plasterboard reinforcement:

  1. Metal profiles are installed, attached to anchors or screws.
  2. Drywall is mounted in them, fixed.
  3. Covered with finishing material.

This foam block wall strengthening option is appropriate for rooms where heavy furniture or equipment won’t be hung on the wall.

The space should be compact and adequately heated.

Setting up the concrete pillars:

  1. Place a mark in the places where you plan to install floor beams.
  2. Install formwork with a height of 30-40 cm, a width equal to the width of the beam multiplied by 3.
  3. Pour concrete, wait until completely dry. Lay reinforcement mesh 10*10.
  4. Enlarge the formwork, pour another layer of concrete, wait for it to dry, reinforce. Continue until the structure is completely built.

The most time-consuming and labor-intensive process is building pillars. Furthermore, in order to prevent the finish from deteriorating over time, the walls will still need to be fixed in order to remove cracks.

Of course! The following is the thesis statement for your paper: This article examines the typical reasons for foam block wall cracks and provides helpful advice on how homeowners can spot and fix these problems. We offer a thorough guide to help preserve the structural integrity and visual appeal of foam block walls in building and renovation projects, covering everything from comprehending the effects of settling and temperature changes to talking about efficient repair techniques using appropriate materials.

Possible difficulties and errors

Things to be mindful of:

  • Before starting repairs, the crack must be cleaned and degreased. Otherwise, the connecting solution will not work and all efforts will be in vain – the defect will transfer to the facing coating.
  • Reinforced mesh is attached to the foam block with brackets or anchors. Holes for fasteners should be in places where there are no cracks. Otherwise, the metal will jump out of the cell, the mesh will sag or crack the finish coating.
  • Do not work with wet foam blocks or in high humidity conditions. He is losing his strength. You need to wait for dry weather or install the canopy in advance.
  • Waterproofing under brick is a mandatory procedure, since the material is hygroscopic and can draw moisture from the foundation. The result will be a crack on the brick itself.
  • It is necessary to connect a brick wall with a foam block with flexible connections. Thin brickwork may not withstand the overall stress without additional support from load-bearing walls.

Although foam block wall cracks can be unsettling, knowing what causes them and how to fix them can help keep the structural integrity of your house intact. Sedimentation, which occurs when the foundation moves over time and stresses the walls, is a frequent cause of cracks. Cracking can also result from subpar building techniques, such as insufficient reinforcement or incorrect block curing.

Determining the extent of these cracks is the first step towards fixing them. It might be sufficient to fill in hairline cracks with a masonry-specific flexible sealant to stop moisture from entering and spreading. Larger cracks might require professional inspection and repair because they could be a sign of more serious structural problems.

A straightforward do-it-yourself fix for small cracks is to clean the crack, fill it with the appropriate material, and smooth it out to blend in with the surrounding surface. This method stops moisture from penetrating in, which could eventually exacerbate the damage, while also restoring aesthetic appeal.

For foam block walls to remain intact, timely repairs and routine upkeep are essential. Keep an eye out for any new cracks and fix them quickly to avoid further damage and expensive repairs later on. Homeowners can guarantee that their foam block walls stay strong and dependable for many years by being aware of the reasons behind cracks and using the proper repair techniques.

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Fedor Pavlov

Interior designer, author of books on residential design. I will help you make your home not only functional, but also beautiful.

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