Let's draw an analogy with a ship in which there is a line called the waterline and denotes a single level. Likewise in an apartment, in order to level the height of floors and ceilings at the same level, you need to find its zero level.
To make the level zero in the entire apartment, you need to proceed from two mandatory actions:
1. Determine the highest point of the floor along the perimeter of the entire apartment.
2. Using special tools to determine the level, find out the line that will be zero in the entire apartment.
Thus, based on this mini-plan, it is necessary to find the most protruding point of the floor relief, add 3-5 cm to it. And based on this point, draw a zero level, which will then need to be oriented towards when screeding the floor. Zero level the perimeter of the entire apartment must be measured using special construction tools.
Exist different types building levels. Let's consider the features of their application, availability, advantages, and also highlight their main disadvantages.
If there are no such tools, then you can use a simple, but not the most effective method calculating the zero level in the apartment. That is, first determine the highest point in the floor topography, and then measure an equal distance from the ceiling throughout the entire apartment, thereby determining the zero level. However this labor-intensive process, giving not entirely accurate measurements.
Answer from OLGA KHALIMOVA[guru]
As you know, any ship has a waterline, which is clearly visible to everyone and its meaning is clear to everyone. There is something similar in every apartment - this is the zero level. Although the meaning of the zero level follows from the name, it is not visible and it is not clear how and where it comes from.
When preparing the base of the floor using concrete or dry screed, the main goal is to reach a zero level over the entire area of the apartment. Make the floor surface in the entire apartment at such an identical level so that the finishing floor coverings are one flat surface, parallel to the horizon line.
How to carry out a zero level
The zero level is carried out based on two conditions:
the highest point in the relief over the entire area of the apartment is determined
are used special tools- building levels
3-5 cm is added to the highest point of the floor relief and the zero level is drawn. The run-up of the additional segment of 3-5 cm depends on the type of screed used. For wet screeds, a run-up from 1 to 10 cm is possible - it all depends on the specific conditions. Screeds based on self-leveling mixtures provide a thin layer of a few to tens of millimeters, while traditional concrete screeds start from 5 cm and thicker. For dry screed there is a limitation:
minimum thickness- 3 cm
maximum thickness is 5 cm when using one layer of dry backfill and one prefabricated base, and 7 cm when using several layers of precast base.
Variations of floor screed technologies are also possible. There are technologies where a concrete screed is used on top of a layer of large expanded clay, and there are known method laying plywood on concrete base- each method is good in individual execution.
How to coordinate rooms by level
It’s great if everything in the apartment is simple - linoleum or laminate everywhere. This means the screed is made to one level. What if, say, there are tiles in the hallway and bathroom, and parquet in the rooms? It will be necessary to coordinate the premises according to level before laying the finishing flooring.
The idea is simple: count all the layers of the future floor covering, subtract them from the finishing level and determine the height of the screed in each room. The truth is completely transparent, but it’s worth talking about it, since it is necessary to coordinate premises by level precisely at the very preliminary stages of renovating an apartment with your own hands. If you don’t do this, you will have to use the well-known Russian ingenuity or put up with the resulting mini podium and the inscription “beware the step” :)
Methods for marking the zero level
Measuring with a water level
The most logical and familiar way is to measure the premises with a water level - a spirit level. Two communicating vessels filled with water and connected by a long hose allow you to measure not only levels in one room, but throughout the entire apartment.
Advantages
Ease of measurement
Inexpensive measuring tool
Flaws
Two people are required to measure
The measurement accuracy depends on the condition of the liquid; if air gets into the liquid or the hoses are kinked, significant measurement errors appear
Method using an auxiliary level.
IN convenient place, a horizontal line is drawn at an arbitrary distance from the floor and the heights to the floor are measured after a certain distance. The number of marks increases the measurement accuracy. This method we have already described.
Advantages
The versatility of the method: suitable for working with horizontal and vertical lines, and even for measuring inclined surfaces
No assistant required
Flaws
Large number of measurements
Limited measurement accuracy, improved accuracy is achieved a large number measurements. In the case of erroneous measurements, the measurement error accumulates.
Using a laser level
Strictly speaking, the measurements do not involve laser level, and a laser level. Let's talk about this method in more detail here. The essence of the method follows from the principle of operation of a laser level: the line outlined in space is the desired level.
Do you remember how many ATP molecules are synthesized in our cells with the complete oxygen breakdown of one glucose molecule? (If you are a biologist, don't answer, it won't be interesting.) If you don't remember, then it's probably not that scary, although this information relates to basic level school curriculum in biology, and if, for example, you have children who are in the tenth grade and have positive grades in biology, they should learn this information one way or another. And in general, they know so much: what year was the Battle of Poltava, and what was it equal to? molar mass nitrogen, and what is the most high mountain Africans - even C students, after all, at the very least, they learn all this. Especially if it is scheduled for tomorrow. If this happened last year, then the chances, of course, decrease...
I teach biology to high school students. Well, as it usually happens, the subject for passing the Unified State Exam, it turns out that most of the necessary knowledge is either safely lost or was never acquired, which means that you need to do special work. Depending on their current performance at school, students (and their parents) usually somehow assess their level. Sometimes (not so rarely) you have to deal with the fact that the level is assessed as “zero”. This is a rather self-critical assessment - well, the child never paid attention to this subject, somehow he earned his C grades by “getting it off”, and as a result, he learned practically no knowledge from studying the subject. Happenes. And then, it turns out, you have to pass the exam. It means you need to work out well. How much material do we have there? A school biology course is actually four textbooks, each two hundred pages long. There is probably a lot of unnecessary information there - look, children, around you, wave right hand, wave your left hand... There are manuals for applicants - there, in a condensed form, everything is given clearly and without any unnecessary distractions necessary information. This is one book of, say, four hundred pages. You need to learn everything that is written there - and it’s done. And the tests, of course, will be decided. And just in case with the teacher, otherwise the child himself is lazy. (Of course, a good option, they often think that they can limit themselves only to tests - just learn the answers to all the questions, why else need some textbooks?)
So, we have a zero level, but there are still several months before the exam; the volume of material does not seem prohibitive; We don’t need a super high score on the exam, so it’s okay. I need to work out.
Well, let's go. And then it suddenly becomes clear: in order to understand how the functions of DNA are carried out, you must first of all understand at least what molecules are and what chemical bond. To solve problems in genetics, you need to have the skill of calculating percentages and some understanding of what probabilities are. Mastering the topic of the cycle of substances in the biosphere is impossible without basic ideas about the structure of our planet. To understand cellular energy, it is necessary to have at least a firmly understood law of conservation of energy in your head and a confident readiness to use it at the right time. Excuse me, these are all other subjects, we are weak in this, but we are not going to take them, we actually wanted biology...
Then, as Alice said, everything becomes more wonderful. It turns out that, although a separate subject “biology” appears (depending on the program) in grades 6-7, students begin to acquire knowledge in biology earlier. For example, from the subject " the world”, in which generally important things are studied. And worse than that, a person normally begins to acquire knowledge of biology literally from birth. How many legs a dog has or what color the leaves are on the trees in summer - we don’t know all these things from textbooks. So “zero level” is such a flirtatious figure of speech, behind which there is actually nothing definite. A newborn baby has a zero level. And how far our eleventh grader has gone from him - this is his real level.
And here is the most wonderful thing. Have you seen demotivators on the Internet: some more or less abstruse formula and the postscript “I’m still waiting for when I need it”? Both students and parents very often not only do not understand, but are also completely unprepared for the idea that everything that a child was taught at school for eleven years, generally speaking, may be needed and will affect how ready he is to study , for example, biology. No one, of course, doubts that it is necessary to be able to read. Or perform simple arithmetic operations. But, let’s say, physics: why is this, it’s a completely different subject?
It is this, and not the lack of being stuffed with some specific facts from the textbook, that usually creates the main obstacles in learning. It is the opportunity to “pass and forget”, and then move on to cramming the next sections, that creates the opportunity for a student to demonstrate the illusion of moving forward, without having any sufficient basis for mastering new knowledge. The problem is that usually no one specifically tests basic knowledge, so if you don’t “dig”, you may not find a reason to be horrified. There is no formal reason to ask this. Many of my colleagues work in various more or less elite schools with gifted, motivated children, and it’s not that they don’t believe me at all, but they believe that I’m greatly exaggerating. But I'm not exaggerating. My sample consists of students from regular Moscow schools who, one way or another, decided to take biology as an elective subject. I testify that the situation is quite common when an eleventh grader calculates 10% of ten (sic!) on a calculator, or operates with probabilities greater than one, or does not understand that if a substance enters a system, then it must go somewhere, or asserts that we get energy from oxygen, or I’m sure that in the mountains high pressure, or answers that the spider feeds on cobwebs, that cones grow on oak trees... Honestly, I really heard all this. The list goes on, but I don’t have the task of compiling a detailed list of my students’ gems, especially since it would be too extensive.
Jokes aside, I heard about cones on oak trees only once, but, say, hypotheses that clearly violate the law of conservation of energy do not confuse almost anyone. And the ability to calculate in your head, without drawing up a proportion on a piece of paper, how much 20% of thirty is, is the exception rather than the rule.
Our school system allows a student to cheat at some point and “jump” to the next level without properly mastering the previous one. From this moment on, a vicious circle begins - further learning will mostly consist of memorizing meaningless texts and memorizing magic formulas. I remember how I myself, when I was still at school, was surprised that I could get a positive grade in a quarter simply by having some kind of certain number positive ratings in the magazine. And it doesn’t matter what they were assigned for. I can miss a topic, skip it, and nothing will ever force me to learn it. And if I am not obliged to somehow master it, then why is it needed at all? If it’s just “for show,” then all the knowledge gained in this way will, of course, add to the list of things that “I’m still waiting for to come in handy.”
By following this path, you can more or less safely account for the current homework, but when it comes to the exam, it turns out that you can’t remember everything and you need at least some systematic mastery of the subject. This is where a “zero level” in, say, biology is declared. But the depth of the gap that needs to be filled in order to honestly, with good reason, begin studying the subject is usually not realized. Yes, in general, it never occurs to anyone to look into it. The knowledge that is required at the “current” level is tested. Moreover, knowledge and its simulation usually do not differ. And if it occurs to someone... then most likely he will not do it, since, no matter how unpleasant it is to admit, it is not beneficial to anyone. Who would have the courage to conduct a mass test in eleventh grades on the ability to add simple fractions and publish the results? And the results, I am sure, would have been depressing. However, it is no secret to anyone that, according to surveys, about 30% of our citizens believe that the Sun revolves around the Earth (for those who did not know, I am telling you this bitter truth). But these are adults, they have been at school for a long time, and there are no teachers who, with their signature, would be responsible for the grades in their diaries. And the schoolchildren have these signatures. Teachers put them on.
Of course we have very good schools. We have very good teachers. And, of course, there are schoolchildren whose results we can be proud of. They win on international olympiads, participate in various educational projects, and generally achieve excellent success. And that's great. However, our country is traditionally strong in results suitable for a conditional “exhibition of achievements.” But assessing the average level is very difficult. Grades? I have seen excellent students who are unable to answer the most basic questions. Grades can sometimes be earned in a bunch of different ways; there may or may not be a real level behind them. And if they tell me “weak C,” it usually means that real, meaningful learning ended somewhere in the fourth or fifth grade. And began the fall into the abyss, which has no zero mark.
The zero level can be compared to the waterline of a ship, only it is in plain sight and everyone understands why it is needed. From the name it seems clear what it is for, but where and how it appears is not clear.
The main task when preparing to level the floor with dry or concrete screed is to reach a zero level over the entire area of the apartment. The floor, ultimately, should be one perfectly flat surface parallel to the horizon.
Place a mark at the highest point of the 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 dots, and then you get a zero level, and you need to align yourself with it when screeding the floor.
Selecting a mark: add from 10 to 100 mm 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 wet screed the additional length can vary from 10 to 100 mm - it all depends on the specific conditions.
And there are different technologies screeds: you can apply it on top of a layer of large expanded clay concrete screed, you can lay plywood on a concrete base. Different ways good in different ways.
How to coordinate rooms by level.
When the apartment has the same floor covering, the screed is made to the same level. But often, for example, laminate flooring is laid in a room, tiles in the hallway and bathroom, because of this, it is necessary to coordinate the rooms by 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, if this is not done at the preliminary stages of renovating the apartment, then you are guaranteed a floor with steps.
Methods for marking the zero level
1.1. Water level.
The most accessible and simple way is to hit the zero point of the room with a water level - a spirit level. Two glass tubes with water connected to each other by a long hose allow you to measure not only the levels in one room, but throughout the entire home.
Plus:
Ease of use.
Low price of the tool.
Minuses:
One person is not enough to measure.
Accuracy depends on the condition of the tool: do not allow the hose to bend, air to enter, etc.
1.2. Method using an auxiliary level.
At an arbitrary height, draw a horizontal line and measure the distance to the floor after a certain distance. The more marks, the higher the measurement accuracy.
Pros:
Versatility: can be used on any horizontal and vertical surfaces.
One person is enough.
Minuses:
Lots of measuring tests to achieve an accurate result.
If there are erroneous measurements, then measurement errors accumulate.
1.3. Laser level
More precisely, in measurements, it is not a laser level that is used, but a laser level. The method is based on the operating principles of a laser level, that is, the line outlined by a laser beam in space is the desired level.
Pros:
The most accurate measurements.
One person is enough to measure.
Minuses:
High price of the tool.
The possibility of measurements depends on the conditions in the apartment; problems may arise in strong lighting conditions or in very dusty rooms.
Bottom line: all methods are good if you use them when necessary. The result will be on high level, especially if you arm yourself with high-quality and serviceable tools. We do home renovations for ourselves, so the result, as a rule, is at a good level.
P.S. And for dessert, I suggest watching a video: Comparison of laser levels
