The 1m line of the building is the ink line that pops up 1m above ± 0.000m of the finished surface of the first floor, or 1m above the point where other floors are the first floor, plus N times the height of the upper floor or the number of standard floors.
4 Functions in equipment installation After the completion of plastering works and door and window works, the supporting works will enter the site for construction.
It has been lost or covered up for many times in different stages.
1 Before the construction of the functional structure in the main structure, it is necessary to carefully check the slab elevation in the drawing and calculate the difference between the structural elevation and the elevation of the finished surface of the building.
If it is unclear, it should be put forward during the joint review of the drawing, and construction should not be based on experience.
The role of water and electricity embedment.
There are also the installation height of lamps and light strips, the height of switch sockets, the height of air conditioning equipment and pipe laying, etc.
The 1m line of each layer needs to be checked from the lower reference point to reduce the measurement error.
Taking a project as an example, the common structural elevation and building elevation of each room are: the structural plane of the toilet is Ht=H-0.145, and the building surface elevation is H-0.02 (at the threshold); The structural surface elevation of the kitchen Ht=H-0.085, and the building surface elevation is H-0.02; The structural surface elevation of the living room and bedroom walkway is Ht=H – 0.065, and the building surface elevation is H; The structural surface elevation of the living room balcony is Ht=H-0.125, and the building surface elevation is H-0.040 (the highest threshold); The elevation of kitchen living balcony is Ht=H-0.145, and the elevation of building surface is H-0.060 (the highest threshold); The external corridor of shared front chamber is Ht=H-0.08, and the building surface elevation is H-0.010; In order to avoid the wrong use of 1m line during structural construction, the surveyor must track and disclose the whole process, recheck the elevation values of each part of each floor, and the 1m line of the building shall be marked with red paint.
It is forbidden to measure from the structural plane at will.
5.
The 1 m line is easy to use in construction, and workers do not need to bend sharply, so it replaces the 50 lines.
Figure 1 Schematic Diagram of Main Structure 2.
During construction, the on-site water and electricity engineer must communicate with the surveyor to find out the elevation of the installation benchmark, and make sure whether the elevation marker of the civil engineering is the building 1m line or the absolute elevation line.
Inadequate floor net height will cause the owner’s complaint rate to rise.
For example, the toilet slab is 100 mm thick.
Therefore, it is conceivable that the main structure controls the elevation (Figure 1).
At present, there is infrared horizontal survey equipment, which is convenient and fast.
3 Role in door and window installation The door and window openings reserved during masonry construction shall be reserved according to the 1m line of the building.
The general contractor needs to snap the accurate 1m line of the building to each main room and important part.
Excerpted from Construction Workers in August 2021, Shen Dongsheng ◎ All original articles published by this WeChat, the content copyright is owned by the Construction Technology Magazine, any media.
The 1 m line is similar to the 50 lines in the past.
Therefore, each floor needs to be fixed.
The point shall be restored after plastering and coating.
In the construction, how to use the 1m line well is the focus of discussion, and it is also the place that many constructors often use incorrectly or neglect.
The water and electricity embedment height usually starts from the finished surface of the building.
6 Correct survey and maintenance 1 m line Building 1 m line has a long construction life, which requires frequent review and permanent protection.
The wrong elevation will bring a lot of inconvenience to the later decoration and pipe burying.
The 1m line of the building shall be rechecked for wall plastering to ensure that the height of the door and window openings is consistent after plastering; Ensure consistent ceiling height; Ensure that the opening height of the junction box distribution box is consistent; Ensure that the installation of ground pipelines does not exceed the height and meets the requirements of tile thickness.
The role of fine decoration construction is the 1m line of fine decoration project, which is mainly used for the installation control of suspended ceiling, indoor door, entrance door, handle installation, cabinet height, washstand height, etc.
Before the project acceptance, 1 m line should be kept for a long time to ensure accurate use, facilitate survey, and facilitate timely check and inspection.
The symbol of building elevation is “H”, and the symbol of structural elevation is “Ht”.
The ultra-high part needs to be cut, and the investment cost is large, resulting in economic loss no less than a quality accident.
According to different room functions and construction requirements, the height of slab to be lowered is different.
For the formal installation of the elevator, the 1m line shall be snapped to the middle partition wall of the elevator shaft; The 1m line required for fire protection installation shall be snapped onto the wall or column of the public walkway; The unified 1m line can ensure that the installation equipment will not have deviation and error.
The line needs to be snapped at the designated position, and the written elevation handover and on-site identification procedures will be handled.
A project caused millions of rectification costs and heavy economic losses due to the wrong embedded elevation of water and electricity.
After the completion of the formwork, the elevation of the bottom of the slab is 1.245 m measured from 1 m line, and the elevation of the reinforcement surface is 1.160 m measured from 1 m line.
In combination with the deepening drawing of door and window installation, determine the lintel position, review the width and height of the opening, and put the data on the wall to achieve 100% actual measurement.
Whether the embedded junction box is the bottom elevation or the center elevation, it is necessary to see the design description of the drawing clearly.
Do not wait for the window installation to handle the deviation problem, which will delay a lot of time.
