Why determine the zero level in construction? Zero mark

Most developers, and even contractor teams of builders, when erecting foundations and drawing up acts, floor plans and other documents, are often confused in terms that determine the location of premises below the zero level. Let's explain the most frequently used terms.

Zero cycle- a term that exists in construction and specialized literature, not provided for by the Building Regulations and Rules and other regulatory documents. Indicates the underground part of buildings and structures or preparatory work at a construction site.

What are the differences between a basement floor (basement) and a basement floor?

Ground floor- a floor with a floor mark below the level of the sidewalk, blind area or planning mark of the earth, but not more than 1/2 of the height of the room (Fig. 29, a).

Basement (basement)- a floor with a floor mark below the level of the sidewalk, blind area or planning mark of the earth by more than 1/2 of the height of the premises located in it (Fig. 29, b).

Rice. 29. Scheme of the basement and basement floors:
a - ground floor; b - basement floor:
1 - floor of the room; 2 - underground overlap; 3 - foundation wall; 4 - base; 5 - floor of the 1st floor (zero mark);
h - room height (2.4 m); h1 - height from the floor to the level of the blind area (1.1 m), not more than 1/2 of the height of the room; h2 - height from the floor to the level of the blind area 1.5 m, more than 1/2 of the height of the room

plinth in construction - the lower part of the outer wall of a building or structure, lying directly on the foundation (). The outer (above-ground) surfaces of the base are made of durable materials.

It is often believed that the basement is the upper part of the foundation, and they are mistaken. The name plinth comes from the Italian zoccole, literally - a shoe with a wooden sole.

Zero mark. In construction, the zero mark (± 0.000) is considered to be the mark of the clean floor of the first floor. From this mark, all levels of underlying elements and structures are indicated with a (-) minus sign. Some authors of popular literature mistakenly take the level of land planning, which in construction is called a rough mark, as a zero mark.

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Types of foundations || The concept of the zero cycle and the underground part of buildings ||

For a relative mark of 0.000 (zero mark), the level of the finished floor of the 1st floor is taken. The floor mark in the vestibule is taken 2 cm below the zero mark, and the mark of the entrance platform (porch) cover is 2 cm below the vestibule mark (or 4 cm below the zero mark). If there is no vestibule in the building, the entrance platform (porch) coverage mark is taken 2 cm below the zero mark.

In public buildings, the mark of the floor of the premises at the entrance to the building should be at least 0.15 m higher than the mark of the sidewalk in front of the entrance. from precipitation. This is a requirement of paragraph 5.7 of the TCP 45-3.02-290-2013 “Public buildings and structures. Building design standards.

The floor mark of living rooms located on the first floor of a residential building must be at least 0.6 m higher than the planned ground level. This is a requirement of clause 4.29 of the National Security Council 3.02.04-03 "Residential buildings".

In buildings of industrial enterprises, the floor level of the first floor must be at least 0.15 m higher than the planning level of the ground. floors below the specified groundwater level, waterproofing of the premises or lowering the groundwater level should be provided. In this case, it is necessary to take into account the possibility of raising the level of groundwater during the operation of the enterprise. The requirements for the design of general plans for industrial enterprises can be found in TKP 45-3.01-155-2009 “General plans for industrial enterprises. Building design standards.

If there are ground tanks in the project, then remember that the level of the bottom of the bottom is taken at least 0.5 m above the level of the planning level of the ground near the tanks.

Water drainage from the building

The blind area along the perimeter of the building must have a width of at least 1 m and a slope of 10 - 25 0 / 00 (ppm) from the building to ensure water drainage.

The zero level can be compared with the waterline of a ship, only it is in full view of everyone and everyone understands why it is needed. From the name it seems to be clear why, but where and how it appears is not clear.

The main task in preparing for leveling the floor with a dry or concrete screed is to reach the zero level over the entire area of ​​​​the apartment. The floor, in the end, should be one parallel to the horizon, a perfectly flat surface.

What is zero level in construction

1. Put a mark at the highest point of the relief in the apartment.
2. We duplicate this mark strictly horizontally on all other walls in all rooms in the apartment. To do this, it is best to use special tools - building levels.
3. Then you need to connect all the points, and then you get a zero level, and you need to level on it when performing a floor screed.

The choice of mark: from 10 to 100 mm is added to the highest point, how much is added depends on the type of screed used. From 30 to 50 mm is added with a dry screed, and there are restrictions, the minimum thickness is 30 mm, the maximum is 50 mm, if several layers of a prefabricated base are used, then 70 mm. For a wet screed, the additional length can vary from 10 to 100 mm - it all depends on the specific conditions.

Moreover, there are different technologies for leveling the subfloor in an apartment: it is possible, on top of a layer of large expanded clay, to apply a dry floor screed with expanded clay, you can lay plywood on a concrete base. Different ways are good in different ways.

How to coordinate rooms by level

When the apartment has the same floor covering, then the floor screed is made under one level. But often, for example, laminate flooring is laid in the room, tiles in the corridor and bathroom, because of this, it is necessary to coordinate the rooms in terms of level before laying the final floor covering.

It's simple: to determine the height of the screed in each room, you need to count all the layers of the future flooring and subtract them from the final level. Although everything is simple, but if this is not done at the preliminary stages of apartment renovation, then the floor with steps is provided to you.

Zero level markup methods

water level

The most affordable and easiest way is to beat off the zero point of the room with a water level - a spirit level. Two glass tubes with water connected by a long hose allow you to measure not only the levels in one room, but throughout the entire dwelling.

1. Ease of use.
2. Small tool price.

1. One person is not enough to measure.
2. Accuracy depends on the condition of the tool: the hose must not be kinked, air must not enter, etc.

Auxiliary level method

At an arbitrary height, we draw a horizontal line and measure the distance to the floor after a certain distance. The more marks, the higher the measurement accuracy.

1. Versatility: can be applied to any horizontal and vertical surfaces.
2. One person is enough.

1. Lots of measurement samples to achieve an accurate result.
2. If there are erroneous measurements, then measurement errors accumulate.

To be more precise, the measurements do not use a laser level, but a laser level. The method is based on the principles of the laser level, that is, the line outlined by the laser beam in space is the desired level.

1. The most accurate measurements.
2. One person is enough to measure.

1. The high price of the tool.
2. The possibility of measurements depends on the conditions in the apartment, problems may arise with strong illumination or with a lot of dust in the room.

Bottom line: all methods are good if you apply them when necessary. The result will be at a high level, especially if you arm yourself with a high-quality and serviceable tool. We do home repairs for ourselves, so the result, as a rule, is at a good level.

P.S. And for dessert, I suggest watching a video clip: Comparison of laser levels

FOUNDATIONS (GOST 13580-85): foundation pillows for transverse walls are taken 1200, 1400 mm wide, 2380, 1180 long and 300 mm high (FL12.24; FL12.12; FL14.24; FL14.12). Under the longitudinal walls, foundation pillows with a width of 1000 mm (FL10.24; FL10.12) are taken;

FOUNDATION BLOCKS FOR BASEMENT WALLS (GOST 13579-78*): foundation blocks of the FBS brand are accepted with the option of internal walls of the technical underground from these elements. Blocks of basement walls are laid on mortar M100 with dressing of vertical joints in the corners and at their intersections, the dressing depth should be at least 0.5 of the height of the block.

EXTERIOR PITCH WALL PANELS: accept 50mm thinner than exterior wall panels.

INTERNAL GROUND WALL PANELS: accept 140 mm thick. The internal plinth panels have openings for the passage and passage of communications.

2.2. Structural elements above 0.000

EXTERIOR WALL PANELS: manufactured at the factory with a thickness of 200, 250, 300, 350 and 400 mm. The thickness of the wall panel is taken after performing the heat engineering calculation. Panels can be single-layer or three-layer. Single-row wall panels, one or two rooms in size for residential large-panel buildings with a floor height of 2.8 m.

INTERIOR WALL PANELS: prefabricated reinforced concrete 120 thick; 140; 160 mm for residential large-panel buildings with a floor height of 2.8 m. Prefabricated reinforced concrete partitions 60 mm thick.

OUTDOOR ATTIC PANELS: are made for residential large-panel buildings with warm or cold attics.

FLOOR PLATES: (GOST 12767-94) flat reinforced concrete solid 160 mm thick. They are made of concrete of class B20 and concrete of class B30 with holes for the passage of engineering systems. Room-sized slabs rest on three or four sides. The dimensions of the floor slabs are given in Table. 2.1 and 2.2.

BALCONIES, LOGGIES: balcony slabs 1240 mm wide, 2990, 3290.3590 mm long, 120 mm thick.

COATING PLATES: for residential large-panel buildings with a warm attic, tray slabs and coating slabs of expanded clay concrete (250 mm) for roofing from rolled materials are made; three-layer tray slabs and roofing slabs (430 mm) for roofing with mastic waterproofing, without roll materials.

Table 2.1

Dimensions of flat solid floor slabs (GOST 12767-94)

Table 2.2

Floor slabs with round voids (series 1.141-1)

REINFORCED CONCRETE ROOF PRODUCTS: tray supports, buttresses, parapet slabs and other attic products. Internal attic panels have openings for the passage and passage of communications.

STAIRS AND LANDINGS: reinforced concrete flights of stairs for residential buildings with a floor height of 2.8 m, a width of 1050 and 1200 mm. Platforms are flat, 2200 and 2800 mm long, 1300, 1600 mm wide, depending on the size of the staircase.

ELEVATOR SHAFT (series 1.189.1-9 issue 3/89): elevator shaft structures are designed for residential buildings of all structural systems up to 10 floors high at a floor height of 2.8 m. The set of prefabricated reinforced concrete structures of the elevator shaft includes four elements. Volumetric blocks are medium ShLS 28-40 high per floor (the number of blocks is equal to the number of floors in the building). The volume block lower ShLN 14-40. The volume block top ShLV 9-40. Floor slab over the elevator shaft PL 20.18-40.

Elevator shaft blocks are made of heavy concrete of B12.5 compressive strength class. The floor slab above the shaft is made of heavy concrete of B15 compressive strength class. The design of the elevator shaft provides the regulatory requirement for a minimum fire resistance of 1 hour.

Passenger elevators with a carrying capacity of 400 kg are mounted in the shafts with a counterweight behind the cabin and with a speed of 1.0 m/s.

Horizontal joints between blocks are caulked with rigid fine-grained concrete of compressive strength class B 12.5 or with a hard mortar of brand 150. The thickness of the seam between the blocks is 20 mm.

GARBAGE CHAIN: garbage chute elements are developed on the basis of series 83р.10.8-1. The trunk of the garbage chute is mounted from asbestos-cement pipes BNT 400 (GOST 1839-80 *) with a length of 3950, 2400, 500 and 300 mm. Caulking in the section of couplings is produced with tarred stranded tow tightly and evenly, followed by chasing with greasy cement mortar. In places where asbestos-cement pipes pass through the floor slabs on the trunk of the garbage chute, it is necessary to provide rubber sleeves-gaskets.

The garbage chamber is assembled element by element (series 1.174.1-1). Bottom slab and floor slab made of heavy concrete class B20. Wall panels made of heavy concrete class B12.5. The height of the chamber in the panel version is 2320 mm, in terms of 1230 × 1230 mm.

Wall panels are reinforced with meshes and embedded parts, which serve to connect the products to each other and fasten the door block to them. The bottom plate is reinforced with box mesh and embedded parts for fastening wall panels. Plumbing fittings are laid in the slab. The floor is tiled with ceramic tiles. For houses up to 10 floors, the chamber is equipped with a container with a capacity of 600 liters.

SANITATION CABINS: type "cap" with the main dimensions of a separate cabin 2730 × 1600 mm, height 2360 mm (mark SK1-27.16.24-14 right, left); type "cap" with dimensions of the combined cabin 2080 × 1820 mm, height 2360 mm (mark SK2-21.18.24-18 right, left).

WINDOWS (GOST 11214-86):

With separate bindings for living rooms and kitchens, brands OR15-6, OR15-9, OR15-12, OR15-15 (the first digit is the height of the window block 1460 mm, the second is the width of the window block 570, 870, 1170, 1470 mm);

For stairwells brand OP6-12; balcony door brand BR22-7.5 (the first digit is a height of 2175 mm, the second is a width of 720 mm).

GOST 6629-88 - internal doors, brand DG - a door with a blind leaf, brand DO - a door with a glazed leaf. Intra-apartment doors of the brand DG-8, DG-9, DG-10 and DO21-13, DO21-15 (the first digit is the height of the door block 2071 mm, the second is the width 770, 870, 970, 1272, 1472 mm). Doors to the bathroom and toilet brand DG21-7 (height 2071 mm, width 670 mm);

GOST 24698-81 - external doors of the brand DN21-13, DN21-15 (door block height 2085 mm, width - 1274, 1474 mm).