How to make an opening in a load-bearing wall

Recommendation points

• Structural wall opening design
• Jumper installation
• A little about insulation
• The lintel is ready: we cut the opening

If it is necessary to re-plan an apartment or arrange additional doors and windows, the master often faces the problem of making openings in the load-bearing walls. Let’s figure out how to do such a difficult job with high quality and safety..

Structural wall opening design

Since load-bearing walls are subject to tremendous stress, changes in their design and intense mechanical impact on the structure of these elements can lead not only to the destruction of the floor, but also endanger the integrity of the entire house. In this regard, the arrangement of openings and cutouts in the supporting structures, as a rule, is not allowed..

Nevertheless, it is quite possible to perform this work efficiently and safely if you strictly adhere to a certain order of actions and follow the technology. So, how to accurately plan and make the desired cut in the load-bearing wall? Before performing the work, first of all, you should decide on the project that the master plans to implement, depending on the specific goal that he set for himself.

The following versions are possible:

1. Equip a simple new opening in the supporting structure.
2. Implement a more complex type of opening with sawing through an arch with different bending shapes. It is most problematic to do this work with a brick wall, since in this case you will have to take into account the seams of the masonry.
3. Partial transfer or expansion of an old opening with cutting out a fragment of the load-bearing wall adjacent to the existing passage. This option seems to be as simple and safe as possible..

If the master has little or no work experience, it is better to first consult with professionals. The fact is that when designing and arranging openings in load-bearing walls, many factors need to be calculated, including:

• the ratio of the size of the opening to the wall area;
• the endurance of the material from which the supporting structure is made;
• thickness, degree of preservation, general condition of the wall;
• number of storeys and placement of floor slabs;
• estimated load and its critical points.

Jumper installation

A jumper is an obligatory element of strengthening the opening in the bearing wall. Currently, as a rule, lintels made of steel are used, since structures made of other materials, for example, wood, may not withstand the load – this applies primarily to apartment buildings.

The lintel consists of two channels, but it can be mounted, including from I-beams or angles. Before installing the lintel, it is recommended to make stops for the floor slabs in order to relieve the wall as much as possible during operation. Stops will definitely be required if the dimensions of the future opening are large enough.

The procedure for the manufacture and installation of the jumper is as follows:

1. Calculation of the size and cutting of channels. The length of the channel must be calculated in such a way that, after cutting the opening, the lintel goes onto the wall to the right and left by a width of at least 150 millimeters..
2. Selection of bolts. In order to pull the profiles together, you need to pick up bolts with a diameter of at least 20 mm. The length of the bolts is selected so that, after screwing in, they protrude from the channel by about 50 millimeters.
3. Making holes in the channel. Drilling holes in the channel must be done with a frequency of at least one for every 500 millimeters. It should be borne in mind that the outermost bolts are additionally screwed in in the support area of ​​the lintel.
4. Site preparation. The outline of the lintel is marked on the wall on both sides, the plaster in the installation area must be knocked down.
5. Arrangement of niches for channels, drilling holes for the corresponding bolts.
6. Cleaning niches from particles of building materials, washing off dust with water.
7. Application of cement mortar followed by pressing the bridges into the cavity of the niches. Channel voids should be filled with brick fragments or cellular concrete..
8. At the final stage of the installation of the jumpers, bolts are passed through the channels, washers are placed on them and nuts are screwed on.

A little about insulation

If the master plans to make an opening in the external load-bearing wall, he should take care that the steel lintel does not become a cold bridge and does not lead to heat loss in the room. After installing the channel, if necessary, install insulation materials on the outside of the wall.

It should be remembered: direct contact of the jumper with a heater such as expanded polystyrene can lead to metal corrosion.

To prevent this, you will need to apply anti-corrosion paint to it before installing the jumper or use galvanized steel channels.

The lintel is ready: we cut the opening

After the cement mortar has finally hardened and the lintel becomes “tightly” in the wall, you can start directly for sawing the opening.

The arrangement of the opening is carried out using the following technologies:

1. Rope cutting. This is a relatively new method involving the use of wire saws, which are usually hydraulically driven. Special diamond-coated ropes are used as a working nozzle in such tools. Diamond cutting with wire saws is now considered a fairly effective method, it allows you to make cuts in walls of any thickness, regardless of the density of the material.

2. Diamond drilling. The use of hammer drills is not recommended for making openings in load-bearing walls..

Attention! Vibrations, inevitably created when using perforating technology, can lead to the destruction or decrease in the degree of strength of structural elements of the house..

Therefore, diamond drilling is used as a safe alternative to percussion tools. The use of diamond core bits with a diameter of up to 650 millimeters allows you to work extremely quickly – the penetration speed is within 40 millimeters per minute.

3. Diamond cutting of concrete. To work, you need a wall saw equipped with a diamond disc. Such tools are suitable for use even in the most difficult cases. At the same time, diamond cutting of concrete is carried out as quickly as possible, and the level of noise and vibration is low, of course, provided that the tool and nozzles are of sufficient quality and serviceable.

So, we are convinced that the arrangement of openings in load-bearing walls is not an easy task, technically difficult and time-consuming. In addition to the fact that the master will require certain knowledge and experience, it must be borne in mind that there is another serious factor – the threat of collapse of the supporting structures if the technology is violated or safety rules are not followed.

Nevertheless, if you have basic skills in working with construction tools and subject to careful planning of work, the task of sawing an opening in a load-bearing wall is quite within the power of a novice builder.