We are often asked: How realistic is the opening in a load-bearing wall? And this is not without reason - in Lately one of the most common options for remodeling an apartment in standard houses is the arrangement of such openings. Most often, the need for an additional opening arises as a result of a bathroom or toilet due to which the entrance to the kitchen is laid, and a new one is made from the adjacent room. But there are many other redevelopment options that involve load-bearing walls.
But, no matter which one you choose, you should keep in mind that a permanent wall is always key element the design of the house, ensuring its strength and stability, and therefore the safety of all residents.
Moreover, they can be forced to return “everything as it was” before redevelopment, because the housing inspection is vested with very broad powers, starting with fines and ending with transferring the case to court, the verdict of which may be eviction from the apartment. Therefore, before you unauthorizedly make an opening in a load-bearing wall, you should obtain permission from the Moscow Housing Institute.
Many will have a question: “why is it possible for some, but not for others, it seems to be the same?” The fact of the matter is that “sort of.” In order to understand the difference, you need to know a lot of device features storey building, and specifically at your home.
In most standard panel and block houses, external and many interior walls apartments - load-bearing, that is, serving as a support for horizontal slabs (floors), thus ensuring the stability of a multi-ton structure. And the closer the wall is to the foundation, the greater the total weight it “holds.”
That is why it is more likely to obtain permission for an opening in a load-bearing wall if the apartment is located on one of the upper floors, although here everything depends on the current situation; in our practice, openings on the 2nd floor of a 17-story building were approved, and refusals were received for the openings on the 22nd floor of a 22-story building.
Also, the ability to obtain permission is affected by the condition of the walls in apartments located on the floor above and below. That is, if a similar opening has already been made in at least one of these apartments, your chances are greatly reduced. Although all the same, the opportunity to coordinate still remains, but the only condition is the exact coincidence of the openings vertically. The factors on which the ability to cut an opening in a load-bearing wall depends do not end there - one of the main ones is the indentation of the opening from outer wall at least 1 meter.
The author of the house project is also obliged to take into account the degree of wear and tear of the supporting structures, because houses, like people, tend to “age.” And also check whether the planned opening coincides with the junction of the ceilings and the wall.
All these components will determine (if the decision is positive) the dimensions of the opening in the load-bearing wall (the width of the standard opening in the houses of the State Unitary Enterprise MNIITEP is 90 cm), its possible location, as well as the method of using metal profiles.
All of the above and other information must be reflected in the design about the state of the structures and the possibility of opening the opening. And all work must be carried out in accordance with the redevelopment project approved by the Housing Inspectorate.
If the opening has already been completed, a technical specification on the admissibility and safety of its design will be required. It will show whether it will be permissible to leave it, or whether partial (or complete) filling of this opening is necessary, as well as other actions, for example, additional reinforcement. Prices for designing openings may fluctuate based on the type of house, year of construction and other factors.
We also note that work on organizing openings must be carried out in strict accordance with the project. If it specifies the use of unequal angles as reinforcement (relevant for MNIITEP houses), then channels should not be used instead. We will talk more about types of amplification below.
It is usually recommended to dismantle the section of wall under the opening using a non-impact tool, that is, a diamond wheel. Cutting and strengthening of a new opening must be inspected by hidden work. Therefore, it is better to immediately choose a contractor who has the appropriate one. If your repairmen do not have access, then when you contact us, we can, on the basis of a contract, carry out technical supervision of the work of your builders.
It should be noted that since 2007, in all apartment buildings, which were designed by the State Unitary Enterprise MNIITEP, and this is most of the panel housing stock in Moscow, openings in load-bearing walls it is prohibited to do. In addition to certain series (for example P44T), where in 3-room apartments a place has been prepared in advance for an opening between the kitchen and the room - the so-called transforming wall.
Now let's talk about the technical nuances and differences when constructing an opening in the load-bearing walls of houses of various types.
Let's start with opening in brick wall . From point of view construction work- this is the simplest type of reinforcement, since there are no loads that are distributed over the entire wall. Usually the load on the lintel is calculated, and based on the calculation results, the opening is reinforced with a lintel. The main difficulty when calculating an opening in a brick wall is the presence of many channels in them. Let us remind you that it is impossible to interfere with the design of ventilation ducts.
Reinforcing an opening in a load-bearing brick wall is done as follows: two grooves are cut along the contour of the lintel, channels are inserted on both sides of the wall and pulled together. In this case, the voids between the brick and metal are filled cement mortar. After it dries, an opening is cut and vertical channels are installed.
Important: when constructing an opening in brick house There may be a masonry defect in the load-bearing wall; simply put, bricks may fall off. In this case, packers are used - special tubes that are driven into the brick through holes in the channel, after which the voids are filled with cement.
At construction of openings in load-bearing walls panel houses it is necessary to calculate the voltage vector in the wall. This can be done either with the help of special programs or with the help of pre-compiled tables (which are available in design institutes). The opening in the load-bearing wall is strengthened using an unequal corner with dimensions 100x63x8. The same as in the case with brick wall, use a self-expanding polymer solution.
Some “talents” reinforce openings in panel houses with the help of a channel, which is absolutely forbidden to do.
It is also worth noting that installation defects occur in panel houses load-bearing elements, in which the interpanel joint is displaced, and sometimes the panel has a thickness less than planned, and therefore the engineer of the design institute may refuse to construct the opening.
Is it possible to expand the load-bearing opening in a monolithic house? Device opening or its extension in the wall , somewhat safer than in panel houses, and there are fewer load-bearing walls in such buildings. The only difficulty is the thickness of the walls, which can reach half a meter on the lower floors.
You need to understand that widening the opening is quite a complex undertaking from the point of view of the engineer who will calculate it for you permissible width, and indeed the admissibility of its device, since in the case emergency situation it is he who bears criminal responsibility for it. As a rule, openings in load-bearing walls of panel houses are not allowed to be widened. By the way, in panel houses built after 2007 according to the designs of OJSC MNIITEP, it is also extremely rare that permission to construct an opening is given. Theoretically, it is possible to expand the opening in a load-bearing wall in any building, but in practice, many design institutes prefer not to link their fate with such a risk.
And now we'll talk about real architectural sophistication. Let us explain: it is much easier to create an ordinary rectangular opening with a headroom, and then install a plasterboard arch in it, than to reinforce an arched opening. The fact is that during this event, a certain number cuts, after which it is pushed into the opening using a jack. The work is technically complex, time consuming and more expensive. Thus, this is disadvantageous neither to the customer nor construction team. By the way, OJSC MNIITEP, as a rule, when an arched opening is discovered, does not complicate it and simply restores the wall.
Yes, yes, it happens, this usually applies to monolithic houses, because load bearing capacity monolith walls are much higher than their panel and brick counterparts, since they are often low-rise. Often, this happens on the upper floors of buildings.
As you can judge by reading the material in the article, making an opening in a load-bearing wall is quite difficult in compliance with all building codes, and therefore it is likely that you will turn to specialists. Our company not only develops redevelopment projects (including those with an opening in a load-bearing wall), but also successfully coordinates them with the Moscow Housing Inspectorate for more than one year. Call us or write to email, which can be found in the upper right corner of the screen.
Examples of openings in load-bearing walls
Regulatory acts governing the rules for constructing openings in load-bearing walls:
SP 20.13330.2011. Loads and impacts
SP 52-101-2003 Concrete and reinforced concrete structures
SP 15.13330.2010 Stone and reinforced stone structures
SP 70.13330.2011 Load-bearing and enclosing structures.
SP 54.13330.2011 Residential multi-apartment buildings
The main document regulating the impact of load-bearing structures and, in particular, the organization of openings in load-bearing walls is SNiP 3.03.01-87, which was introduced to replace several different SNiPs and SN.
During repair work in a country house or in an apartment, as well as when redevelopment is being done, owners are often faced with the need to expand the existing doorway. In general, these works do not belong to the category of complex ones, and therefore both the owner and invited specialists can perform them. It is only important to follow certain rules and know some nuances.
We will describe below how to expand a doorway. The procedure itself does not require much time - a maximum of one or two days. In the presence of necessary tools and knowledge, the only problem that you will have to come to terms with is the laboriousness of the process.
Under no circumstances should you forget about the legal side of the issue. In certain situations, such work is regarded as redevelopment, which means that changes will need to be made to the existing technical passport of the residential premises. This will not be possible if you carry out all the work without informing the relevant utility services.
It should be understood that the expansion of a doorway located in a load-bearing wall requires mandatory approval from authorized authorities. Changes being considered in this case are called "partial breakdown". All work must be carried out competently, with preliminary calculations, ensuring that the strength characteristics of the structure are preserved. If you are not sure about own strength– It’s better to entrust the task to professionals.
Don't forget, it is an offense to overdo it and you may have to pay a fine and have to restore the wall to its original appearance.
By and large, all work is performed in the same way on walls made of the most different materials. The procedure here is as follows:
In the process you are allowed to use a variety of tools:
The most accurate opening is obtained if you use the last device. If the work is being done on a wall made of foam concrete or gypsum blocks, then the most ordinary hacksaw for wood will suffice.
WITH concrete structures special professional helps to cope a circular saw, equipped with large diameter diamond discs. Its use allows:
Depending on the type of material used in the construction of the wall, the list of works differs. There are also a number of nuances and features.
In particular, expand the passage to concrete wall The following tools will help:
The work itself is carried out in the following order:
As is easy to see, the technology itself is very simple. However, the work takes a lot of effort, and the process is accompanied by strong vibration and big amount dust.
Any wall consisting of masonry materials causes a lot of trouble:
First of all you will need:
If we're talking about about the supporting structure, you should prepare a mortgage - a steel beam or two wide corners. In other cases, a wooden lintel - a block of hardwood - will suffice. These elements will protect the opening from collapse. Their dimensions must exceed the width of the door by at least 20 centimeters.
The work is done like this:
The next stage is carried out no earlier than the cement hardens. When the mortgage is finally fixed, the unnecessary fragment is cut out. If the wall is too thick, then the pre-cut bricks are knocked out with a hammer and chisel. Then proceed to the next row.
When making an opening in brick or concrete, it is necessary to use personal protective equipment:
It is also recommended to periodically moisten the wall surface with water - you cannot do without dust completely, but its amount in the air will noticeably decrease. Keep in mind that the latter easily spreads throughout the house, so it is important to properly isolate the room in which the work is being carried out.
When work to expand the opening is carried out independently, the risk of cracking the walls and their subsequent destruction due to loss of strength characteristics increases significantly. If possible, try to avoid generating dangerous vibrations.
When using power tools, extreme care must be taken. In particular, do not, under any circumstances, remove the protection from the angle grinder. Of course, this will allow you to establish a larger circle, but with the slightest careless movement it is not difficult to get a serious injury.
It will certainly need to be increased. IN interior wall made of lightweight material, you can cut an opening of any shape, while an opening in a load-bearing wall requires some attention.
Not all factory doors are suitable for installation in an interior opening, which is especially true for those apartments that were built in Soviet time. Only widening the existing opening will save the situation. New door blocks have standard sizes, which makes them very different from older products that have been standing in place for several decades.
Great options could be height or width. The problem can be solved through the functional and decorative arrangement of the interior passage. The hole in the wall can be made larger or smaller. Expanding an opening in a load-bearing wall is not always safe. If you plan to restore a partition that is not the functional basis of the building, nothing bad will happen. In this case we are talking about walls made of cellular concrete, plasterboard or any other building material. But the work can be troublesome when it comes to the need to transfer a metal profile.
If you want to increase the passage in a load-bearing wall, then such a reconstruction will be a redevelopment. Work in this case must be carried out in accordance with a separate project, which contains an engineering calculation of the redistribution of loads on the floor after volume changes made. When expanding an opening in a load-bearing wall, you should collect some documents that are prescribed by regional requirements. This should include:
In the end, the decision to increase the passage can be a real red tape. This list of documents is not necessary for show, but for the safety of people who live in and around the apartment. If load-bearing partition will be damaged without permission, this may lead to the collapse of the wall and the collapse of part of the house. It is worth avoiding irreparable consequences by strengthening the opening.
If you have a door structure that can fit a hole in the wall, you can calculate the exact parameters. You should not cut the opening by eye; it is necessary to make precise markings. You must take measurements of the width and height of the existing door, width and thickness door frame, which comes included.
At the next stage, you will need to find out what is the width of the platbands that you plan to install. It is important to choose the right threshold and measure its height. It may not exist. Before you begin to expand the opening in the load-bearing wall, you need to determine the width of the passage, which will be the sum of the thickness of the frame post, the width of the door leaf and 2 cm technological gaps on each side. You can determine the height of the doorway by adding the height of the threshold to the thickness of the frame . The technological gap should be added to the obtained value.
Typically the wall thickness is 75 mm. If other indicators are available, extensions should be added when the walls are wider. An alternative solution would be to purchase a box with a narrow beam. Before you begin to expand the opening in the load-bearing wall, you should take measurements and markings, carrying out work with high accuracy. If the gaps are taken with a margin, they may not cover the wide platbands when decorative finishing.
If you want to remove the arched vault when transitioning to an adjacent room, there is no way to avoid widening the transition. Before making an arched opening, you should calculate it. The opening can have any type of configuration. The shape of an arched vault can be any, while a curved bend can be attributed to a creative eye.
When constructing an opening in a load-bearing wall, make an arch classic shape with the correct bend of 45 cm it will be more difficult, so you need to stock up on certain equipment to carry out calculations on a scale of 1 to 50. Among the available tools and materials, you should highlight paper and a compass.
When calculating, you will need to use the Pythagorean theorem from school curriculum: R² = L² + (R²-H²). Famous formula Pythagoras allowed to be deduced, and the masters construction field- use the formula for calculating the radius of the circle of the arch in the opening. You will need to use a calculation based on the following formula: R = L² + H²/2H.
To determine the radius of the arch, you can use simpler, but not entirely accurate, calculations. To do this, a doorway of expanded dimensions is depicted on paper. Previously, a piece of wallpaper was used for this. After this, you should install a compass on the axis of symmetry and, changing the radius, draw several arcs. So you can choose best option, the remaining radii are then erased.
Before constructing an opening in a load-bearing wall, the old one should be dismantled door design and strengthen the opening. If work is carried out in the old panel house, then reinforcement can be done after the concrete cutting is completed. Concerning brick openings, then they require special attention. When manipulating a brick wall, you should prepare certain tools and materials, such as:
The coupling bolts must have a diameter of 20 mm. The diameter of the pins is 16 mm. Steel plates should be made from sheet steel. Instead of a grinder, you can use an electric cutter or a gas cutter. Diamond wheels should be prepared for the angle grinder. You can cut concrete using the most different instruments, but diamond cutting is the most suitable option.
You will need jacks or supports for the duration of the work. When you need to cut a brick wall, you should also prepare a hammer drill. The class of material used for reinforcement and the cross-section of the beam should be determined during preliminary load calculations.
The obtained figures should be included in the design documentation for the redevelopment of the premises. The steel channel profile should fit into the thickness of the brick wall by approximately 25 cm. Its length is selected taking this into account. To install the tightening bolts, holes are made in the channel; there must be at least 3 of them. This will be enough for the opening middle length. The channel ties are located at a distance of 50 cm.
Before constructing a doorway in a load-bearing wall, you first need to create markings on the plane. The process will be somewhat easier if you use diamond cutting. Great option There will be circles that will reach a cut depth of up to 10 cm. During operation, the walls are wetted with water, which will reduce dust formation. It is important to remember about safety measures, namely:
The construction of a doorway in a load-bearing wall provides for double-sided operation. It will be necessary to cut out with different sides due to the massiveness of the septum. Before dismantling work, the opening is strengthened. The best option To increase the reliability of the load-bearing partition, the use of welded frames, which are tightened with studs through the walls, will be used.
When expanding a doorway in a load-bearing concrete wall, you should work small areas in the form of squares or rectangles. IN brick partitions usually a through cut is made, while the blocks themselves must be knocked down with a hammer drill, after which you can use a sledgehammer if necessary. If we are talking about concrete, you should not use a hammer drill for it. Vibration effects can be destructive to the panel, which will lead to the formation of microcracks and weaken the entire structure. Brick walls require a different approach.
Before you start enlarging the opening in the load-bearing wall, you must understand in which building the work is being carried out. If the building is block or panel, and was not designed by MNIITEP or Mosproekttoul, then the doorway can be made. But certain requirements will be imposed on him.
For example, the opening should be removed from the outer wall or from the existing opening in the load-bearing wall at a distance of 1 m. When constructing an opening in the load-bearing wall, craftsmen often wonder what the width of the box should be. Typically this value is 900 mm. Rarely, and in some series, the opening width ranges from 1000 to 1200 mm. However, this value should not be exceeded.
If you started to expand a doorway in a load-bearing wall, and the building was designed by MNIITEP, then such work may be prohibited if the apartment is located on the first or second floor. This is due to the fact that in these cases the remaining sections of the wall will not correspond to the strength calculations under the load from the floors located above. MNIITEP can permit and expand the doorway in a load-bearing wall only in one partition. From this it should be concluded that the possibilities of constructing the opening and its location, as well as its dimensions, will be determined by the organization that is the author of the project.
The property owner will have to receive technical conclusion about the safety and admissibility of redevelopment. Based on the conclusion and project documentation the appropriate approval authority will issue permission for repairs. When expanding an opening in a brick load-bearing wall, you should use SNiP 3.03.01-87, which specifies the requirements for enclosing and load-bearing structures.
To expand the opening, you can use one of several methods. The method can be crude, in this case the following are used:
At the first stage, you need to outline the contours on the wall, and then use tools to knock off the excess material. This process is quite labor-intensive, and microcracks formed due to impact loads can cause a decrease in the strength of the wall. The opening in the load-bearing wall can be enlarged using the dry cutting method. Here you will need a grinder, with which it is quite easy to enlarge the opening along the intended contour. The disadvantage of this process is that the wall must be cut from both sides.
Dry cutting leads to formation large quantity dust, and you will also experience rapid wear of the diamond blade. Cutting can also be wet. This method is accompanied by the use of a spray bottle, with which you can irrigate the surface while working with an angle grinder. It would be more rational to use a construction cutter with diamond blade. He must have large diameter. You should also use a water container.
Before enlarging a doorway in a load-bearing wall, you must make sure that there is no partition inside hidden wiring, pipes or fittings. There may be a chimney inside. In order to receive details, you should use a metal detector. When any obstacles are found, they can be eliminated by moving the electrical wiring to another location or moving 300 mm away from the chimney. If there are pipes inside, they are dismantled and moved, but this will require the help of a specialist.
Redevelopment of an opening in a load-bearing wall at the first stage involves removing the additions and platbands using a nail puller. It is necessary to remove the canvas from the hinges by lifting it from below with a crowbar. Vertical racks it is necessary to cut it with a grinder and tear it off with a nail puller. If the height of the opening in the load-bearing wall is increased, the top lintel must be torn off. Otherwise, it is left in place.
The magnification contour should be marked around the perimeter. Holes are made along the marking line with an impact drill to simplify dismantling work. The panel needs to be cut on each side. After cutting the reinforcement with blows with a sledgehammer, it is necessary to remove the remains of the wall. The opening should be reinforced with metal corners, pieces of rod or strips.
Now you know the parameters of the maximum opening in a load-bearing wall. But this is not enough for successful work. For example, if you want to work with a brick wall, then you need to prevent it from collapsing. A floor beam should be installed above the doorway. It can be used as reinforced concrete beam or metal channel. On top of the opening you need to cut a niche, going onto the walls. A beam is laid there. All voids above and below it are filled with concrete mortar.
Once the concrete has hardened, the opening can be widened. To do this, use a cutter to cut through the brickwork along the contour. The cut opening must be smaller than the beam installed on top. The cutter should be directed perpendicular to the wall. If you want to move an opening in a load-bearing wall, then cutting will have to be done on both sides, because the partition has a thickness of more than 10 cm.
In progress overhaul A situation may arise when the dimensions of the old opening for the installation of new, stylish, wide doors, clearly too small. If manipulations occur with interior partition, no special problems will arise - there will be no harmful consequences from such local reconstruction and the work can be carried out independently.
However, if property owners planned to implement a project widening openings in load-bearing walls, it is advisable to enlist the help of qualified performers. main feature load-bearing wall - ensure the safety and integrity of the overall structure of the building, so any destructive effects can lead to an undesirable outcome.
When, without expanding the existing opening standard sizes not enough:
A team of responsible, professional specialists takes a comprehensive approach to solving these issues.
When bringing large furniture or bulky equipment into the room.
Today, diamond cutting is The best decision for sawing concrete and brick walls. Impact-free impact on the surface allows you to maintain the nominal strength of the wall, achieve ideal opening geometry and practically get rid of dust spreading throughout the room.
Thanks to compliance with building codes and safety rules at the site, competent craftsmen are able to expand almost any opening with further reinforcement using a metal frame.
Takes into account individual parameters:
To make an accurate calculation of the final cost, it is better to contact the manager-consultant of the repair and construction organization and settle all your questions over the phone. If the thickness of a brick or concrete wall does not exceed 25 cm, experienced craftsmen use a hand cutter, and to eliminate thick-walled areas a powerful hydraulic wall saw may be required.
It is important to understand that guarantees of safety and efficiency in performing the entire range of work can only be given by real professionals. First-class experts, using a clearly thought-out algorithm, will dismantle wall structures in the shortest possible time.
To strengthen the opening in a brick wall, a strong reinforced concrete beam or metal channel is installed in a special niche above the opening. To fill the resulting voids it is used concrete mortar. To ensure that the protective frame made of steel corners is reliable and durable and forms a solid structure, it is connected to the brickwork using anchor bolts.
An identical scheme is used to strengthen the opening in the load-bearing concrete wall. The only difference is technological process is the absence of preliminary reinforcement with corners - it is enough to install rolled metal around the perimeter. If the room does not have a clean finish - construction site, the reconstructed object, then – this perfect option. In a residential building, it is advisable to use more gentle methods, using a construction vacuum cleaner to eliminate dust and providing waterproofing that will prevent possible leakage of coolant to the lower floors.
December 16, 2017When working on the reconstruction of buildings and their redevelopment, it often becomes necessary to expand the doorway in a brick wall. Today, many are moving away from standard apartment layouts, which were previously built as standard ones.
If earlier we adjusted our furniture to the geometry of existing walls, now modern conditions On the contrary, many can afford to tie the layout to our desires and convenience of living.
Many people combine living rooms with kitchens, personal hygiene rooms with toilets, and install more functional doors in order to save money. usable space – sliding doors, doors are accordions, which is associated with changes in the size of the openings.
In addition, when replacing old doors with new ones, we often want to modern doors design looked like uniform style, were of a different width. I would also like to add here that existing openings often do not suit us with their location, so it makes sense to lay them and construct them in more convenient places.
Based on all this, let's consider the question of how to correctly widen a doorway in a brick wall, comply with all regulatory documents, and obtain permits to carry out this work.
The expansion of a doorway, like the expansion of a window opening in a brick wall, is carried out based on the design of the walls.
According to the nature of the work, walls can be divided into:
Before starting work, you should decide on this issue. According to the architectural planning solution, the load-bearing wall can be located inside the apartment.
Therefore, any redevelopment, like reconstruction, requires an agreed project design organization, which makes all the necessary calculations and gives you a project to work on.
This is not discussed as it is provided regulatory documents, but you can’t do it at random, because you could end up with a collapse of the structure of the upper floors, injuries and prosecution.
Now let's move directly to our walls. There can be two options for expanding and further strengthening the opening in the wall:
The first is the expansion of the doorway in a brick load-bearing and self-supporting wall(the principle is the same).
The second is a non-load-bearing wall or partition made of brick.
Let us dwell in more detail and consider the technology for performing the work of both options.
Let's consider the most common option - expanding the doorway in a brick wall. Before starting work, reinforcing must be installed metal jumper above the opening.
We knock off a layer of plaster from the surface in the places where the expansion is designed and above the opening so that the lintel and the masonry above it are visible - 30 cm is enough.
We mark the future opening with chalk, stylus, or other material that leaves a noticeable mark. The width of the opening cannot exceed 2 meters because the redistribution of loads can become dangerous, or, if this occurs, then they install an additional support - a column.
If the lintel (purlin) turns out to be shorter than the width of the opening, it should be supported with racks while the work is being carried out to avoid accidental collapse.
It will absorb part of the load from the overlying structures, and you can work calmly. Its edges must extend beyond the boundaries of the future opening at a distance of at least 250 mm on each side.
Let us now consider the most popular option, when the frame is made of two paired channels No. 14-20, which are tightened together with through pins with washers and nuts.
Before installing a new lintel over the opening in the wall, seats- niches on both sides, immediately above the existing lintel.
The depth of the niche for installing the channel should be approximately equal to the size of the channel shelf, so that it does not protrude beyond the plane of the masonry and is subsequently hidden under a layer of plaster.
For reasons of strength, the number of studs should be at least three - with a diameter of 16 mm or more, the distance between the studs should not be more than 400 mm.
When tightening the channels for a uniform fit to the surface of the niche, an M-100 solution is placed under the walls of the channel, which fills the unevenness on inner surface niches.
Holes with a diameter slightly larger than the diameter of the studs are drilled in the walls of the channels. The holes on both channels must be coaxial. The channel is installed in a niche and through holes are marked in the wall, which are then drilled. After this, the jumpers are installed.
Now you can begin dismantling the masonry to widen the doorway along the markings to the foundation or floor slab.
The expansion of an opening in a brick wall is associated with obtaining smooth vertical edges of the opening being broken, which is achieved by sawing out fragments of masonry with a grinder saw with a diamond blade.
Oh, and this is a thankless task - dust is everywhere, wetting with water will not help either. You have to work in a respirator. The cutting is done, it is convenient to disassemble the masonry using a hammer drill.
If the length of the lintel is less than the width of the opening and it seems to “hang” over it, then it must be dismantled.
The next step is to install the side posts that frame the opening and rest their upper end against metal beam- jumper. They are made from a corner of 75-100mm. The connection with the beam is fixed by welding in the corners at the junction of the stiffeners.
The racks must be rigidly fixed in the opening, for which they are connected to each other along the thickness of the wall with strip steel, to which pointed pins made of reinforcement with a diameter of 12 mm are welded into the wall.
At the bottom of the opening, a spacer is made from a 45-50mm corner or reinforcement with a diameter of 20-25mm, which is then hidden in the thickness of the floor. All metal elements welded together to form a durable metal carcass- the so-called “clip”.
It is also possible to expand the doorway in a brick wall with reinforcement of the lintel from two corners No. 100-150. The corners are connected to each other by tightening strips and strips. Then everything is done in the same way as described above.
We strengthen the widened opening with a corner WITH curtain walls and partitions, everything is much simpler, since this is a structure made within one floor and does not bear the load from the overlying structures. Read more about brick partitions in the article at the link.
Based constructive solution, the thickness of the partitions is taken to be much thinner and is built at a quarter or half a brick. Labor costs when changing the size of the doorway are correspondingly lower.
I will describe the process in less detail, since the technology is the same and all stages are described in detail above.
Step by step and briefly it looks like this:
Marking on the surface of the contour of the future opening.
Disassembly brickwork over an existing doorway, removing the old lintel.
We install a longer lintel over the widened doorway. Lay brickwork on top.
If necessary (for example, when the height of the partition is 4 meters), the newly erected section of the partition is attached to the ceiling with special embedded parts.
Sometimes, in critical structures, the thickness of the masonry is increased to one brick - all according to calculations and the dimensions of the room.
After completing the entire procedure for widening the opening and strengthening it, a hidden work certificate is drawn up, which is signed by a representative of the customer’s technical supervision.
Only after this do they begin plastering. In order for the plaster to adhere firmly and efficiently to the metal, it is covered with metal mesh“chain-link” with a small mesh.
