Why determine the zero level in construction? Reference mark The level of which gender is taken as zero.

To build a building or structure, first develop working drawings. As in mechanical engineering, typical connections and standard parts are widely used in construction. Drawings on them, as a rule, do not make up. They can be found in special albums and catalogs.

The rules for the execution and design of construction and engineering drawings are largely the same. However, construction drawings have a number of features.

38.1. Images on construction drawings. The main images on construction drawings are called facade, plan. incision (Fig. 261).

Rice. 261 Sample project building

Facade - images of the outer sides of the building. The facades show the location of windows and doors, as well as the architectural details of the building. These images are usually not marked with dimensions, with the exception of elevations.

A mark is a number indicating the height of a horizontal platform above the zero plane. The level of the floor of the first floor is taken as the zero mark.

The mark sign is in Figure 262. Marks are made in meters, the numbers are written on the shelf. This number shows how much higher or lower (with a minus sign) the marked level is from the zero mark. For example, height marks 0.789 and 3.010 may indicate that the window is located at a height of 0.78 m above the floor, and the floor of the attic is 3 m above the floor of the first floor. The zero mark is recorded as the number 0.00. A mark of -0.500 means that the floor surface in the basement is 0.5 m lower than the floor of the first floor.

Rice. 262. Elevation marks

A building plan is a section of a building with a horizontal plane at a level slightly above the window sills.

Plans are made for each floor. For example, on the left, half of the first floor plan is performed, and on the right, half of the second floor plan.

The plans show mutual arrangement premises, including staircases, the location of windows and doors, the thickness of walls and partitions, the position and size of columns. An image of sanitary equipment is also applied there. The width and length of the building, the distance between the axes of walls and columns, the dimensions of openings and piers are also applied on the plan.

In addition, indicate the area (in sq. m) of the premises with a figure underlined by a line. Sections of walls made of the material that is the main for the building can not be hatched. Separate sections from another material are highlighted by hatching.

The top view of the building is the roof plan.

The section serves to reveal the structure of the building and the height of the floors. It is obtained using vertical cutting planes, passing, as a rule, along window and doorways. The cuts are marked.

Above facades and plans, sometimes inscriptions are made according to the type: “Facade”, “Plan of the 1st floor”, etc.

38.2 Construction drawing scales. On construction drawings, reduction scales are used: 1:100, 1:200. 1:400. For small buildings and for facades, a scale of 1:50 is used. This makes it possible to reveal architectural details on the facade. Since the scale of different images can be different, it is usually indicated next to each of them.

38.3. Dimensions on construction drawings. Dimension lines on construction drawings are limited by short strokes at an angle of 45 ° to the dimension line (see Fig. 261).

Dimensions on construction drawings, except for marks, are indicated in millimeters, sometimes on drawings of buildings in centimeters.

On the plans, dimensions are applied with outside. Between each pair of adjacent axes, dimensions are usually applied in a closed chain, and the total dimension is between the extreme axes. In addition, indicate the area interior spaces in square meters, underlining the numbers with a thin line. For example, the area of a room is 12.85 in figure 261.

What information can be obtained by considering the facade in the drawing?
What information can be obtained by considering the building plan?
What information can be obtained by considering the sections of the building?
What scale is used in construction drawing? Can different images be made at different scales?
What is considered zero?

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 is dry or concrete screed, exit to zero level throughout the apartment. The floor, in the end, should be one parallel to the horizon, a perfectly flat surface.

What is zero level in construction

Put a mark in the high point relief in the apartment.
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.
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.

And there are different technologies leveling the subfloor in the 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 concrete base. different ways differently good.

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 floor covering and subtract them from the final level. Although everything is simple, but if preliminary stages apartment renovation is not done, 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.

Ease of use.
Small tool price.

One person is not enough to measure.
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 carry out horizontal line and measure the distance to the floor after a certain distance. The more marks, the higher the measurement accuracy.

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

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

More precisely, the measurements do not use laser level and a laser level. The method is based on the principles of operation laser level, that is, the line outlined by the laser beam in space is the desired level.

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

The high price of the tool.
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 on 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

All vertical dimensions and levels for new walls and buildings are measured from a single fixed point on the construction site. This point is called the "reference mark" (zero mark) and is usually determined on the site before the start of any construction works. The reference mark may also be referred to as a "temporary benchmark".

Most often, at a construction site, the level of a horizontally located waterproofing gasket (waterproofing layer) of the designed building or wall is taken as the zero level mark. For a completely isolated structure, the zero mark can simply be set at a suitable point near the proposed structure by driving a wooden peg in such a way that it top part was at a height of 150 mm above the completed zero level; 150 mm is the minimum height of the waterproofing layer above the completed ground level for new buildings, as required by building codes.

While there are no legal requirements for boundary walls and garden fences, there are specific reasons to change this minimum height no.

For walls being erected and buildings located next to an existing structure, it is customary to use the level of the waterproofing layer of the existing building as the zero mark. The peg is simply set next to this building at its waterproofing layer level, and then the zero level mark is transferred to Right place either with the help of a building level and a rule, or by means of a Cowley level.

The zero level peg should be located on the construction site in a place where it can be seen and easily approached, but where it cannot be touched or otherwise affected by construction workers passing by, falling materials and equipment. Maintaining an accurate zero point is critical as all vertical dimensions and elevations for a wall under construction are referenced from it, and if the zero point changes in the course of work, this can be disastrous.

The peg that sets the zero level mark must be driven into the ground, and then, if possible, concreted. The larger the building site, the longer the zero mark peg will be required, so additional protection in the form of a triangular wooden structure, as it shown on the picture.

When the zero mark is set, it must be transferred to both ends of the wall being erected or to all corners of the new building, again using either building level and a rule, or a Cowley level.

Concrete foundations cannot be expected to be flat or even, so the zero mark must be transferred to each corner of the building or to extreme points walls, so that the bricklayer, when erecting corners, can check the height of the row brickwork from the top of the concrete foundation. Thus, any height adjustments (thickening or thinning) should be made below ground level, thereby ensuring that when the waterproofing layer is reached, all brickwork will be leveled horizontally.

To avoid having to level the row height below ground level, the ground peg can be used as a reference to determine how deep the foundation trench should be dug so that when the concrete is placed, the vertical distance between the top of the foundation and the mark zero level exactly matched the height of the row of brickwork and there was no need to adjust the thickness of the bed joints (in other words, it would be a multiple of 75 mm).

As an example, assume that the minimum thickness of a simple strip footing is 150mm, and let the distance between the top of the concrete footing and the completed ground level be 1000mm.

Assuming that the zero mark is set at the level of the waterproofing layer at a height of 150 mm above the finished ground level, the total distance from the zero mark to the base of the foundation will be 1300 mm (calculated as follows: 150 mm + 1000 mm + 150 mm), while the top of the finished the foundation is 150 mm higher - at a depth of 1150 mm below the zero mark. Dividing 1150 mm by the height of a row of brickwork of 75 mm, we will end up with 15.33 rows of masonry from the top of the foundation to the zero level mark. It is clear that this value is not a multiple of the row height: 15 rows of masonry will not be enough, and 16 rows of masonry will be too high. Considering that you need to get only 0.33 of the row height (approximately 25 mm), the bricklayer usually chooses to adjust the height by increasing the thickness of the bed joints at the masonry stage from the ground level.

There is an alternative to increasing the thickness of the bed seams: rounding to the integer value of the series. This means laying 16 rows from the foundation level to the ground level, but the foundation trench is dug a little deeper to maintain the row height that would not require adjustment. You can round up to 15 rows, but this means raising the level of the foundation from possible risk violation of the requirements for the minimum depth of the foundation. When rounded up to 16 rows, the foundation trench will need to be dug to a depth of 1350 mm, i.e. 16 rows x 75 mm + 150 mm (concrete thickness).

Obviously, the bricklayer will have to make a decision based on the following conditions: bed seams can be thickened to add 25 mm, or maintain a row height of 75 mm, taking on the labor of marking and deepening the entire trench under the foundation by another 50 mm and laying another row of bricks. Undoubtedly, in the second case, more time will be required, more soil will need to be removed, more bricks will be used and mortar and it will cost more. In most cases, the convenience associated with the absence of the need to adjust the thickness of the bed seams is very expensive, which is not always advisable. Rounding up to 15 rows avoids all additional work excavation, use of additional bricks and mortar, but still takes time to accurately mark the corrected depth.

Most bricklayers will probably prefer thicker bed joints to achieve the required 25mm.

Construction sites with a high slope

For obvious reasons, the zero mark on construction sites with a large slope should be located on the top of the site so that the elevation marks are transferred down, down the slope, and not up. When marking and transferring elevations on such sites, it is recommended that the marking start with short pegs at the top of the site, and as you go down the slope, longer pegs are used. If the elevation is transferred up the slope from the lower starting point, then there is a chance that you will be below ground level before you set the last peg. That is why markup should always be done from top to bottom! It should be borne in mind that when viewed with the naked eye, the true value of the slope may not seem the same as it really is, and the site often has a much greater slope than it appears at first glance.

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 internal walls technical underground of 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)


	4,8; 5,4; 6,0; 6,6
	2,4; 3,0; 3,6; 4,8; 5,4; 6,0; 6,6
	1,2; 2,4; 3,0; 3,6
	1,2; 2,4; 3,0; 3,6

Table 2.2

Floor slabs with round voids (series 1.141-1)

		Dimensions in mm

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 strand tow tightly and evenly, followed by chasing in bold 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 a box-shaped 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 - door with a blind leaf, brand DO - door with glazed sheet. 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).

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 must be at least 0.15 m higher than the mark of the sidewalk in front of the entrance. side events to protect the premises 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.

Floor mark of living rooms located on the ground floor residential building, must be at least 0.6 m above the planning mark of the earth. This is a requirement of clause 4.29 of the National Security Council 3.02.04-03 "Residential buildings".

In buildings industrial enterprises the floor level of the first floor must be at least 0.15 m higher than the planning level of the ground. ground water not less than 0.5 m. If it is necessary to arrange such premises with a floor mark 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 master plans for industrial enterprises can be found in TKP 45-3.01-155-2009 " master plans 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.