During the construction of any house, special attention should be paid to the overlapping of beams. The ceiling structure may consist of slabs and beams, which are wooden, concrete or metal. Most importantly, consider how to support such supports on a brick wall, since the construction of brick houses is considered the most common. Bearing the beams on the beams and the wall in the designed building will be the most important element, since it will determine the reliability of the structure and the safety of its operation.
What are beams for?
They are not only a support for flooring and interfloor transitions, but also help to fasten together all the details of the structure, giving them the necessary strength and reliability. In the manufacture of beams, a large number of different floors are used. But the main and most common types of load-bearing elements should include metal, wood and reinforced concrete.
Wooden beam and its distinctive features
Beams for bearing on beams and walls made of wood must comply with the basic building standards, namely, be strong, rigid, and also comply with fire safety rules. The calculation of such an element is carried out depending on the material used in the construction.
A beam is an important part of any ceiling. Its main function is the separation of the floors of the house, as well as the uniform distribution of the load exerted on the upper walls, the roof of the house, communications, as well as furniture in the room.
The main advantages of supporting wooden beams:
- minimum laboriousness when mounting the installation (if compared with metal and reinforced concrete structures);
- affordable cost of wood;
- the possibility of self-assembly without the use of expensive equipment and other construction equipment;
- attractive appearance;
- light weight;
- the possibility of replacing or restoring them.
Disadvantages of wood structures
The main disadvantages of such bars are:
- high degree of ignition (in order to prevent sudden ignition, it is necessary to process the material with special protective impregnation);
- in comparison with metal and reinforced concrete analogues, this design is fragile;
- on a wooden material, the active spread of fungus, living organisms can begin, moisture can easily penetrate into it;
- the tree is subject to deformation under the condition of a regular temperature drop in the room.
What types of wood floors exist?
Wooden floor beams can be divided by their type of cross-section, size and material used for their manufacture. Its length will directly depend on the distance between adjacent walls. An additional 200β250 mm on each side is added to this value.
By section type, all structures can be divided into the following types:
- rectangular;
- I-beams;
- square;
- oval or round.
The square section of the beam is considered optimal, since it helps to achieve the most uniform load distribution over the structure. Builders also recommend choosing wooden floors with a rectangular cross section. When mounting them, the short side is placed horizontally, and the long side is vertically (for good strength it is important to increase the height of the structure).
Material and features of the overlap
Overlap is the connection of a beam with a supporting building wall, which can be an attic, attic or interfloor. Structurally, they are divided into two types: prefabricated (transverse flooring and a longitudinal beam), as well as monolithic (supported on a slab).
When designing private structures, greater preference is given to ceilings with wooden beams. This design is considered quite durable and is well suited for the residential sector. The optimal size of the support, depending on the purpose of its use and the applied loads, will vary:
- height - from 150 to 300 millimeters;
- width - from 100 to 250 millimeters.
In order to increase the service life of the support, they are impregnated with a specialized antiseptic, and also oiled.
In more complex structures, resorting to relying on metal beams. For this, construction companies create special strong steel supports. According to safety standards, when using beams of this type, their ends must rest on brickwork through specialized distribution pads.
Monolithic ceilings are created from reinforced concrete slabs. For this, it is customary to use factory slabs made of reinforcement and concrete mass. In order to reduce the load on the finished structure they are created hollow.
How does the beam embed?
Reliability and quality of the overlap will be largely determined by the method of embedding the beam in the wall. The embedment will determine the type of support on the brick wall - this is the stage of mounting the structure is the main.
A wooden beam is mounted in the free space created in masonry, up to 15 centimeters deep. The end ends are pre-processed: they perform chipping of one end at an angle of 60 degrees, they are treated with a special antiseptic and resin, they are wrapped with roofing paper or roofing material. The processed ends of the beams are carefully installed in a brick wall with a gap of 3-5 centimeters from the back wall of the niche. The formed gap is filled with felt or mineral wool. The transverse faces are carefully sealed with concrete mix, bitumen or roofed.
Leaning on a brick wall
When leaning a beam on a brick wall, it is important to pay particular attention to the thickness of the structure. If the thickness of the brick wall is more than 600 millimeters, then the sealing method will be slightly different. This space in the masonry is created so that between the end of the beam and the rear wall of the niche there is a free space of at least 10 centimeters. The resulting gap helps to lay material in it for thermal insulation and allows you to create a special air gap.
The lower part of the gap is sealed with concrete, roofing material or roofing paper in several layers. Using this technology, it is possible to create a pillow for laying, which, in addition to everything else, evens the surface of the masonry. The sides of the resulting recess are treated with roofing material.
Bearing on a Wall of Lesser Thickness: Builder's Tips
When creating a ceiling with a support on a wall with a thickness of up to 500 millimeters (two bricks), the sealing method should be slightly different from the previous one. In a free space (its depth is not more than 250 millimeters), a wooden box with several walls is placed. Between the back wall of the niche and the box lay a tarred layer of felt. The walls are carefully treated with an anti-combustible compound and resin.
At the bottom of the recess should be sealed with two layers of roofing material or roofing felt. The side walls of the nest must be insulated with felt. The box is built into the free space so that it is pressed tightly to the felt. The floor beam is installed on the bottom of the box for a length of 15 centimeters.
If the wall thickness is less than the indicated mark, then it is important to pay special attention to the total wall thickness that remains after creating a free compartment. If it is less than 50 millimeters, there is a risk of free passage of cold air into the room. If there is such a problem, it is important to consider additional insulation of the area on which the beams are supported on the beams and the wall.
Beam Mounting
The installation of the support during the creation of the overlap will directly depend on the further goals of the use of the structure, the area and its load. Most often, a wooden beam is installed along load-bearing walls at a distance of 600 to 1,500 mm.
The embedment starts from the edges with the subsequent transition to the entire length of the wall. Between the extreme beams and the wall itself, builders recommend leaving a free space of at least 5 centimeters.
Another rather important condition when leaning the beams on the beam and the wall is to take into account the horizontal fastening of the support. In addition, you should evenly arrange all the bars in relation to the floor. Deviation from horizontalness and level unevenness will lead to additional loads on the abutment area of ββthe brick wall, especially after the installation of additional transverse beams.
Column support
It can be of articulated or rigid type. Builders advise to support the beam from above and transfer the main load to the center of the column profile. With lateral fastening of the structure, in addition to the compressive load, the moment from the action of this force additionally appears in the column. This provokes a significant increase in the load from the column.
When a metal beam is supported on a column from above, it is best to transfer the load to the rib. The edge size will be determined using the following formula: F / Ap is greater than or equal to RpYc.
- F in the presented formula is the support reaction of the beam;
- Ap is the area of ββcrushing of the support rib;
- Rp is the design resistance of steel to crushing of the end surface.
In order for the entire load to pass to the column through the rib, the rib protrusion should be observed, as a rule, by 1.5β2 centimeters. It is important to carefully plan the rib before installation, which will help to distribute the entire load exerted evenly over its area.
Since the node supporting the floor beams of the hinge type, only a few bolts on one side are enough to carry out the fastening. The diameter of the bolts is from 16 to 20 millimeters. Do not tighten them too much. The thickness of the support, as a rule, reaches 0β25 mm, the thickness of the rib is 8β12 mm.
If the roof angle is present in the structure, the rib should be planed at the required angle and take the washers with a bevel to mount the bolt.
Beam Supporting Standards
The regulatory documents set the minimum length of support of the beam on the beam and the brick wall - it reaches 9 centimeters. This value was determined by design engineers as a result of lengthy calculations and checks. The following factors act on the minimum beam support:
- span size and support length;
- the amount of load per applied beam;
- type of load - dynamic or static;
- the thickness of the brick wall, which accounts for support;
- type of construction - private residential, industrial, etc.
All the factors described are important to take into account when making calculations. The end of the beam should be superimposed on the wall so that the resulting overlap size does not exceed 12 centimeters.