Brick masonry is one of the most ancient ways of laying artificial stones. The first samples were discovered during excavations in the territory of modern Balochistan: in the village of Mergharh, the buildings were laid out from stones similar to a modern brick. After analyzing, it turned out that our distant ancestors used the simplest technology for laying walls of brick even during the Neolithic because it was not for nothing that this era was called the “new stone”.
Advantages and Disadvantages of Brick Walls
The main advantage of brick walls is that they have high strength. In addition, red brick is not susceptible to rot and microorganisms. Brick walls allow the use of reinforced concrete floor slabs. This is necessary if you want to cover a large span between the walls. The small size of the bricks allows you to build walls of complex configurations from them, lay out the decorative elements of the facade. With brickwork, the walls of the house have large thermal inertia – in the summer it is cool behind them in any heat, in the winter it is warm.
There are also disadvantages to brick walls: if the house has not been heated for a long time in winter, it will have to be heated for several days. With the seasonal operation of the building, after 25 years, the walls will require serious repairs. Brick walls are very heavy and do not tolerate deformations, so they need a strip foundation to the depth of freezing. To ensure proper thermal insulation, brick walls must have a greater thickness (51 cm in the suburbs). Therefore, in a house with a useful area of 50 m2, they will occupy 17 m2 – 1/3 of the area, for a house of 200 m2 this ratio will be 1/6.
Technology and Masonry Thickness of Lightweight Brick Walls
Homogeneous walls are made of ordinary hollow or light building bricks.
In heterogeneous, lightweight walls, part of the brickwork replaces the thickness of the wall with heat-insulating tiles and an air gap.
The walls are erected with a thickness of 1/2, 1.1 1/2, 2.2 1/2, 3 bricks or more, given the thickness of the vertical joints, equal to 10 mm. Accordingly, the wall thickness for masonry is 120, 250, 380, 510, 640, 770 mm or more. The thickness of the horizontal joints is 12 mm, then the height of 13 rows of masonry should be 1 m.
Brick walls are of two types: two-row (chain) and six-row (spoon).
In the two-row masonry system, the stalk rows alternate with the spoon rows. Cross seams in this system overlap 1/4 brick and longitudinal seams overlap 1/2 brick.
As can be seen in the photo, six-row brickwork of the walls involves the alternation of five spoon rows with one poke.
In each spoon row, the transverse vertical seams are tied into a half-brick, while the longitudinal vertical seams formed by the spoons are tied in rows of rows through five spoon rows. Masonry using a six-row system is simpler than double-row. To reduce the breathability of the walls, the front joints of the masonry are sealed with a special tool, giving the seams the shape of a roller, fillet or triangle. This method is called stitching.
In the middle climate region, the brickwork of the outer walls is 2 1/2 bricks thick. Hollow brick masonry reduces thickness by 1/2 brick.
The disadvantage of ordinary solid brick, clay or silicate, is its large volumetric weight and, therefore, high thermal conductivity.
Walls with a thickness of 2 bricks, laid out of hollow bricks with 32 or 78 holes with bulk weight of 1800 kg / m3, have a total heat transfer resistance that meets the requirements of the average climatic region.
The lateral and upper planes of the apertures – galleys, have quarters, i.e. protrusions that close the gap between the masonry and the window frame.
Currently, the most common prefabricated slab or squared reinforced concrete lintels. Jumpers according to bearing capacity are divided into 2 groups. The first group includes load-bearing lintels that absorb the load from its own weight, masonry above them, floors and other elements of the building.
Prefabricated reinforced concrete non-bearing lintels are marked: on the block – with the letter B, slab letters Bp.
Bar jumpers are released 120 mm wide, 65 mm high with a length of 1.2; 1.6; 2.0 m, and a height of 140 mm with a length of 2.4; 2.6; 2.8; 3m.
Non-bearing plate lintels are produced with a height of 220, 300 mm and a width of 120 and 250 mm with a length of 1.4 to 3.2 m.
Non-bearing jumpers are laid in the walls on supports not less than 125 mm, and bearing – 250 mm. When laying the bar jumpers, one bar at the outer surface of the wall is laid 75 mm below the rest to form a quarter. The box of the window block adjoins the last.
Smoke and ventilation ducts are arranged, as a rule, with the brickwork of internal walls, since in the ducts located in the outer walls, the draft is disturbed in winter due to the cooling of their walls. If it is impossible to do without the installation of channels in the outer walls, the wall is thickened so that the distance from the inner surface of the channel to the outer surface of the wall is not less than the minimum wall thickness corresponding to climatic conditions.
The cross-section of the smoke channels of heating stoves and kitchen centers is taken to be 1/2 x 1 brick. Smoke ducts of small furnaces, for example, bathtub columns, and ventilation ducts allow a section of 1/2 x 1/2 brick.
The crowning cornice of a brick masonry wall with a small extension – up to 300 mm and not more than x / 2 of the wall thickness can be laid out of brick by gradually releasing rows of masonry 60–80 mm in each row. With the removal of more than 300 mm, the eaves are arranged from prefabricated reinforced concrete slabs embedded in the walls.
The inner ends of reinforced concrete slabs are covered with prefabricated longitudinal reinforced concrete beams, which are attached to the masonry using steel anchors embedded in it, thereby ensuring the stability of the cornice.
Lightweight brick walls, in which the brick is partially freed from unusual heat-insulating functions by replacing part of the masonry with less heat-conducting materials, can significantly reduce brick consumption, thereby increasing material savings.
Lightweight brick walls are divided into 2 groups. The first group includes structures consisting of two thin longitudinal brick walls between which thermal insulation material is laid, to the second group – structures consisting of one brick wall insulated with heat-insulating plates.
The backfill walls consist of two walls with a thickness of 1/2 brick each, the space between which is blocked every 4 rows by two horizontal rows of continuous masonry. These two rows divide the masonry in height into shallow cavities, filled with slag as the wall is erected. Filling at the same time almost does not precipitate.
When laying lightweight brick walls, solid horizontal rows give strength to them, but they worsen its thermal performance, creating areas with high thermal conductivity. The walls with backfill are arranged at a height of the house no more than two floors.
Walls filled with lightweight concrete differ from walls with slag backfill in that the space between the enclosing walls of 1/2 brick is filled with lightweight concrete. For walls with filling every 3-5 spoon rows, layout one row of rows of bricks included in concrete.
In this case, the rows of rows are arranged in one row, in walls 510 mm thick and thicker, or staggered, in walls 380 mm thick. The minimum thickness of such walls is 380 mm, the maximum is 650 mm.
In the inner walls, the diaphragm is formed by overlapping poked rows in the solution. The voids of the inner walls are filled with light or ordinary concrete, and also fall asleep with a brick fight with a grout, i.e. make a spin.
The advantage of brick-concrete walls in comparison with filled walls is that the adhesion of concrete to the masonry provides a more reliable connection between the brick walls and, in addition, the concrete accepts part of the load transmitted to the wall. Brick-concrete walls are erected during the construction of a house with a height of up to 6 floors.
When performing work in the winter, the complexity of the work increases, since the drying of the masonry slows down the introduction of a large amount of moisture into the concrete wall.