Expansion of the opening in the load-bearing wall: maximum dimensions, GOST requirements and work technique

Repair 2022
Expansion of the opening in the load-bearing wall: maximum dimensions, GOST requirements and work technique
Expansion of the opening in the load-bearing wall: maximum dimensions, GOST requirements and work technique

If you want to install a door in a load-bearing wall or make an arched opening there, then you will certainly need to increase it. In an 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.

What are the risks. Documentation

openings in load-bearing walls

Not all factory doors are suitable for installation in an interior opening, which is especially true for those apartments that were built in Soviet times. Only the expansion of the existing opening will save the situation. The new door blocks are of standard sizes, which makes them very different from older products that have been sitting in place for several decades.

Excellent parameters can be height or width. You can solve the problem due to the functional and decorative arrangement of the interior transition. The hole in the wall can be enlarged or reduced. Expanding an opening in a load-bearing wall is not always safe.If you are planning 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, drywall 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 the load-bearing wall, then such a reconstruction will be a redevelopment. Work in this case should be carried out in accordance with a separate project, which contains an engineering calculation of the redistribution of loads on the floor after the amount of changes made. When expanding the opening in the bearing wall, some documents should be collected that are prescribed by regional requirements. These should include:

  • documentation for housing ownership;
  • certificate from the local BTI;
  • extract from the house book;
  • reconstruction plan from architectural organization;
  • floor plan of the building;
  • plan of all stages of work.

In the end, the decision to increase the passage can be a real red tape. This list of documents is necessary not for show, but for the safety of people who live in and around the apartment. If the load-bearing partition is unauthorized damaged, this can 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.

Expansion parameter calculations

arrangement of a doorway in a load-bearing wall

If you have a doordesign, under which you can adjust the hole in the wall, you can calculate the exact parameters. You should not cut an opening by eye, it is necessary to carry out an accurate marking. You must measure the width and height of the existing door, and the width and thickness of the door frame that comes with the kit.

The next step is 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 start expanding the opening in the load-bearing wall, you need to determine the width of the passage, which will be made up of the thickness of the frame rack, the width of the door leaf and technological gaps on each side of 2 cm. You can determine the height of the doorway by adding the height of the sill to the thickness of the box. The technological gap should be added to the obtained value.

Usually the thickness of the wall is 75mm. If other indicators are available, add extensions when the walls are wider. An alternative solution would be to purchase a box with a narrow beam. Before proceeding with the expansion of the opening in the bearing wall, measurements and markings should be carried out, carrying out work with high accuracy. If the gaps are taken with a margin, they may not cover the wide architraves during decorative finishing.

Calculation of the arch according to state standards

expansion of the opening in a brick load-bearing wall

If you want to remove the arched vault when passing to the next room, it will not be possible to avoid widening the passage. Before you make an arched opening, you shouldcarry out its calculation. The opening can be of any type of configuration. The shape of the arched vault can be any, while the curved bend can be attributed to the creative eye.

When making an opening in a load-bearing wall, it will be more difficult to make a classic-shaped arch with a correct bend of 45 cm, so you need to stock up on certain equipment for making calculations on a scale of 1 to 50. Paper and compasses should be distinguished among improvised tools and materials.

When calculating, you will have to use the Pythagorean theorem from the school curriculum: R²=L² + (R²-H²). The well-known Pythagorean formula made it possible to derive, and for the masters of the construction area, to use the formula for calculating the radius of the circle of the arch in the opening. You will need to use the 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 extended dimensions is depicted on paper. Previously, a piece of wallpaper was used for this. After that, a compass should be installed on the axis of symmetry and, by changing the radius, draw several arcs. So you can choose the best option, the rest of the radii are erased after that.

Where to start

increase in the height of the opening in the load-bearing wall

Before opening the opening in the bearing wall, the old door structure should be dismantled and the opening strengthened. If work is carried out in an old panel house, then reinforcement can be done after the concrete is cut. As for brick openings, they require special attention.When manipulating a brick wall, certain tools and materials should be prepared, such as:

  • tie bolts;
  • coupling channel;
  • hairpins;
  • metal corners;
  • steel plates;
  • cement mortar;
  • petrol cutter;
  • electric drill;
  • grinder.

Tie bolts should be 20mm in diameter. The diameter of the studs is 16 mm. Steel plates should be made from sheet steel. Instead of a grinder, you can use an electric cutter or a power cutter. Diamond wheels should be prepared for the angle grinder. Concrete can be cut with a variety of tools, but diamond cutting is the most suitable option.

You will need jacks or props for the period of work. When you need to cut a brick wall, you should also prepare a perforator. The class of material used for reinforcement and the section of the beam should be determined during preliminary load calculations.

The figures obtained should be included in the design documentation for the redevelopment of the premises. The profile of the steel channel should be about 25 cm thick in the brick wall. Taking this into account, its length is selected. To install the tie bolts, holes are made in the channel, there must be at least 3 of them. This will be enough for an opening of medium length. Ties along the channel are located at a distance of 50 cm.


expansion of the doorway in the load-bearing wall

In front of the doorway in the load-bearing wall to startit is necessary to create markup on the plane. The process will be somewhat easier if you use diamond cutting. An excellent option would be circles that 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 equipment, namely:

  • protective suit;
  • respirator;
  • gloves;
  • special glasses.

The device of the doorway in the load-bearing wall provides for double-sided operation. It will be necessary to cut out from different sides due to the massiveness of the partition. Before dismantling, the opening is strengthened. The best option to increase the reliability of a load-bearing partition would be to use welded frames that are pulled together with studs through the walls.

When widening a doorway in a load-bearing concrete wall, work in small areas in the form of squares or rectangles. In brick partitions, a through cut is usually made, while the blocks themselves must be knocked down with a puncher, 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 can be destructive to the panel, leading to microcracks and weakening the entire structure. Brick walls require a different approach.

Additional opening requirements and standards

enlargement of the doorway in the load-bearing wall

Before you start increasing the opening in the load-bearing wall, you need to figure out which building is beingwork. If the building is block or panel, but was not designed by MNIITEP or Mosproektul, then the doorway can be made. But there will be certain requirements for it.

For example, the opening should be 1 m away from the outer wall or from the existing opening in the load-bearing wall. Usually this value is 900 mm. Rarely, and in some series, the opening width ranges from 1000 to 1200 mm. However, this value must not be exceeded.

If you started expanding the doorway in the 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 comply with the load strength calculations from the higher floors. MNIITEP can allow and execute the expansion of a doorway in a load-bearing wall in only one partition. From this it should be concluded that the possibilities of the opening device and its location, as well as the dimensions will be determined by the organization that is the author of the project.

The property owner will need to obtain a technical opinion on the safety and admissibility of redevelopment. Based on the conclusion and project documentation, the relevant approval authority will issue a permit for repairs. When expanding the opening in a brick bearing wall, you should use SNiP 3.03.01-87, which spells out the requirements for enclosing andsupporting structures.

Methods of expansion and features of work

enlargement of the opening in the load-bearing wall

To expand the opening, you can use one of several methods. The method can be rough, in which case:

  • sledgehammer;
  • perforator;
  • jackhammer.

At the first stage, it is necessary to outline the contours on the wall, and then use the tools to knock off excess material. Such a process is quite laborious, and microcracks formed due to shock loading can cause a decrease in the strength of the wall. Enlargement of the opening in the load-bearing wall can be carried out using the dry cutting method. Here you need a grinder, with which it is quite simple to enlarge the opening along the intended contour. The disadvantage of this process is that the wall should be cut from both sides.

Dry cutting generates a lot of dust, in addition, you will experience rapid wear of the diamond blade. Cutting may also be wet. This method is accompanied by the use of a spray gun, with which you can irrigate the surface while working with an angle grinder. It would be more rational to use a construction cutter with a diamond blade. It must have a large diameter. An additional water tank should be used.

Things to consider before starting work

Before enlarging a doorway in a load-bearing wall, you must make sure that there are no hidden wiring, pipes or fittings inside the partition. Perhaps there is a chimney inside.In order to obtain detailed information, you should use a metal detector. When any obstacles are found, they can be eliminated by moving the electrical wiring to another location or stepping back from the chimney 300 mm. If there are pipes inside, they are dismantled and transferred, but this will require the help of a specialist.

Main stages of opening enlargement

Re-planning of the opening in the load-bearing wall at the first stage involves the removal of extensions and platbands with the help of a nail puller. It is necessary to remove the canvas from the hinges by lifting it from below with a crowbar. Vertical racks must be cut with a grinder and torn off with a nail puller. If the height of the opening in the bearing wall is increased, the upper lintel must be torn off. Otherwise, it is left in place.

The contour of the increase should be marked around the perimeter. Holes are made along the marking line with an impact drill to simplify dismantling. On each side, you need to cut the panel. After cutting the reinforcement with a sledgehammer, it is necessary to remove the remnants of the wall. The opening should be reinforced with metal corners, pieces of rod or planks.

In conclusion

Now you know the parameters of the maximum opening in the 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 exclude its collapse. A floor beam should be installed above the doorway. A reinforced concrete beam or a metal channel can be used as it. On top of the opening, you need to cut through niches by going to the walls. A beam is laid there. All voids aboveit and under it are poured with concrete mortar.

As soon as the concrete hardens, you can expand the opening. To do this, using a cutter, cut through the brickwork along the contour. The opening to be cut 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 you will need to cut on both sides, because the partition has a thickness of more than 10 cm.

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