How to make a concrete ceiling. Do-it-yourself concrete floor screed: a detailed process on how to fill floors with concrete screed Beacon system and reinforcement

A high-quality screed followed by painting gives the ceiling an excellent matte or glossy texture. But sometimes there are situations when the ceiling finished in this way begins to peel off and swell in places: this can happen both during the work and during operation. In fact, this problem is the most common for ceilings of this type, and it can be caused by a number of factors, both internal and external. And therefore, before starting to cosmetically eliminate a flaw, it is imperative to find out the cause of this phenomenon.

Let's look at the most basic causes of ceiling peeling and methods for solving them:

1. Old layer of putty or whitewash.

When preparing the base, many novice craftsmen do not take the careful removal of old finishes - whitewash, old putty, wallpaper - seriously.
But every small area that is missed subsequently becomes an area of increased risk: the layers of new mortar applied on top begin to pull the old material onto themselves, and after some time the screed will blow and peel off in this place. Very often this happens at the last stage of arranging the screed - during painting: the paint saturates the surface, and in places that are not strong enough it can pull the solution onto itself. 2. Unstable foundation.
You need to be very careful with fragile ceiling bases - shingles, old panels, old plaster. This refers to a situation where the foundation itself is not sufficiently solid and durable. In such cases, it is necessary to use the method of several primings, or even better, to reinforce such a base with a continuous painting or plaster mesh. If this is not done, then due to poor adhesion, new materials may simply come off along with particles of the old base.

3. Violation of finishing technology

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Peeling on the ceiling screed can occur in cases of violation of the recommendations for the implementation of the screed, namely, when the next layer is applied to the previous one that has not yet completely dried. This happens especially often in cases where, after the initial leveling layer, wet areas remain in places, but the beginner is led into the illusion that the surface in such areas is already hard. If you apply the next layer on top of them, the possibility of complete evaporation of residual moisture will be blocked: it will concentrate inside the screed, which can lead to crumbling, followed by peeling. Therefore, it is very important not to rush, allowing each layer of putty to dry thoroughly. 4. External exposure to moisture.
This could be either a leak in the ceiling from above or high humidity in the room itself where the work is taking place. Therefore, it is very important to provide all the required conditions for high-quality drying of the screed: an optimal temperature above +10 degrees and good ventilation.

Before decorating the ceiling, its surface must be made perfectly flat. Only in this case the quality of work will be high. First of all, this condition must be observed for ceilings made of prefabricated reinforced concrete slabs, which are not always perfectly installed. Therefore, first we screed the ceiling, and only then move on to the decorative design.

Design features

The answer to the question of why a ceiling screed is needed is quite simple. Reinforced concrete slabs are massive floor elements that, even with the help of technology, are difficult to install on one level, therefore, as a rule, there are some differences between them. Their size depends on the quality of installation of the floor: the better the specialists and their work, the smaller the difference in the levels of the bottom of the slabs will be.

Of course, you don’t have to save money on your own home and call a team of specialists who can quickly and efficiently screed the ceiling. But if you study all the nuances of this process, you can try to do it yourself.

Screed composition

The manufacturing technology and installation of cement-sand screed is extremely simple. The solution consists of cement grade 300 and higher, sand and water. The ratio of components is 1:3:2. In order to increase the density of the screed, the solution is supplemented with a plasticizer or similar special adhesive. For screeding, you can also use ready-made self-leveling mixtures.

Plasticizing additive for concrete

Cement-sand mortar is used on concrete, stone and brick foundations. On average, a load of up to 90 kg will be distributed per square meter of subfloor after screed installation.

Cement-sand mortar for screed

The thickness of the screed varies from 3 to 10 cm. If the coating in some areas is less than the minimum, be sure to add a plasticizer to the mixture so that the layer does not crack. If the thickness of the screed is more than 10 cm, reinforcement of the layer is required. Screeds over 10 cm high are unforgivably expensive.

Increasing the strength of the screed using reinforcement

Cement with grade 400 is an ideal option for screeding in a high-rise apartment. But cement M-500 does not mean at all that it is a more reliable ingredient. The meaning of this marking is the presence of specific additives in the cement that do not affect its durability.

Cement grade 400

Alignment methods

Before you begin screeding the ceiling surface, you need to decide on the method you will use. There are two types of ceiling surface screed: “wet” and “dry”. The first method involves the use of solutions or mixtures. This could be a concrete ceiling screed made from cement mortar.

The second method requires the use of sheet materials such as plasterboard, plywood, fiberboard or chipboard. How to determine the right method for making a screed with your own hands? Of several criteria, it is worth paying attention to one main one. To do this, measure the difference at the junction of the plates. If it exceeds 5 cm, then wet screed will not work, since the thickness of the applied plaster will exceed the normalized value. This is fraught with the fact that, under the weight of its own weight, the plaster layer simply cannot withstand it and falls, and this can lead to human injuries.

In addition, a large thickness of plaster can exceed the normalized load for which the ceiling was designed, which will also lead to negative consequences. To prevent all this from happening, you should use a dry screed. Of course, she also has her shortcomings. For example, this method “steals” quite a lot of height from the room, so already low rooms will become even lower.

Plastering the ceiling

Plaster is a hardened concrete mixture, the application process of which is quite labor-intensive, especially on the ceiling surface. But this method of screeding the ceiling does not lose its relevance, because sometimes it is the only way to create a flat surface. In addition, you can plaster any coating: wood, concrete or metal. But in any case, it is necessary to carry out preparatory work. They include several stages:

Cleaning the surface of contaminants, for example, mold or other fungal stains that need to be disinfected;
Removing old coating in the form of paint, whitewash, etc.;
Priming the concrete surface using strengthening mixtures;
For wooden and metal structures, the installation of reinforcing mesh is required.

Then they move on to the installation of beacons, which are then used to plaster the ceiling. Using a paint cord, you need to mark the zero level, which determines the lowest level of the ceiling surface. It will be the first lighthouse. The rest are installed every 30-50 cm on plaster marks. The height of the beacons should not be greater than the thickness of the plaster, that is, 5 cm.

Applying plaster on beacons

After installing the beacons, you can begin plastering. To do this, you need to make a working solution based on gypsum, cement or lime. Then follow these simple instructions shown in the video:

Apply the first layer of spray without leveling;
Distribute several primer layers, gradually leveling the plaster;
After applying the last layer, remove the marks with beacons and fill the recesses remaining from them with the solution;
Using a rule applied along, across and diagonally to the ceiling, check the evenness of the surface (excess plaster is cut off, and, on the contrary, more mortar is added to the missing places);
Use a trowel to seal the internal corners and joints between the ceiling and the walls;
Apply a final, carefully leveled coat to create a smooth surface.

When applying plaster, be sure to ensure that no defects in the form of shells or pits are formed. After the rough screed, you can apply the finishing coat in the form of putty.

Dry screed

Do-it-yourself dry ceiling screed can be made from plasterboard, which serves as a high-quality alternative to the long and labor-intensive method using plaster.

As you can see in the photo, with the help of plasterboard sheets, designers implement various ideas and plans in interior design, which is a definite advantage.

In addition, simplicity and speed of installation can also be attributed to the advantages of dry screed. The sequence of work includes only three stages:

Marking the ceiling surface, when the zero level is placed on the walls, the corners and frame are marked, and options for laying out plasterboard sheets are determined so that their shift is equal to the pitch of the sheathing;
Installation of the frame structure is a stage that involves fastening guides, which can be made of wood (attached with screws or direct hangers) or metal (fastened only with direct hangers);
Cutting and installation of plasterboard sheets according to the drawing.

Purpose of impregnation

When a concrete screed is performed indoors, it is not influenced by external negative aspects. It's a different matter when it is performed on the street. In this version, on concrete

things like this work:

very high humidity;
high mechanical loads;
large and severe temperature changes.

The worst thing for concrete is sudden temperature changes - due to this, the screed begins to become covered with cracks. And then water gets into the cracks that form, which leads to irreversible damage.

This is all aggravated if poor quality cement was used during the work, or the pouring technique was violated. In this option, the destruction process will go much faster.

Due to this, the use of strengthening impregnations is simply necessary for screeds poured outdoors. Thanks to its own characteristics, it is absorbed into the outer layer of concrete and strengthens it. Moreover, similar products form a protective film on the surface, which prevents moisture from entering the screed.

Impregnation for concrete

Polymer impregnations

One of the most effective types of impregnations for concrete are those made on a polymer basis. They are intended for use both indoors and outdoors.

Good qualities:

the composition can penetrate deep into the screed by 3-5 mm;
at the same time, resistance to very high humidity and other atmospheric influences increases;
the screed
becomes stronger and more resistant to wear, it will not crumble.

Moreover, the working life of the coverage increases. In general, if the screed was made using concrete, grade 300-350, then after processing, the product strengthens it to grade 600.

Cement M500

Main! When working with a reinforcing compound, it is necessary to take into account the concrete grade from which the screed

– the quantity and method of its application may depend on this.

In most cases, when a solution with grade 150 was used to fill the floors, after applying the impregnation, they must be covered with polymer ethylene. This will allow it to penetrate as deeply as possible and perfectly secure the front layer.

Likewise, the use of such compositions is quite justified and is necessary when strengthening the solution. But in order to achieve the best results, you must follow the manufacturer’s instructions and not violate the technology.

The most common damage to screeds

Even if good cement was used when pouring, this does not guarantee that the screed

will not deteriorate over time. In most cases, the following destruction occurs with concrete:

crumbling;
cracks appear;
the front layer peels off.

Main! Preventive measures must be taken immediately after deficiencies are found. If they are put aside, the screed may deteriorate greatly.

Naturally, to eliminate damage, it is best to use special means at the pouring step.

Cracks in the screed

Results

Screeding the ceiling with your own hands is possible, despite its labor intensity. The main thing is to follow the installation steps and recommendations of specialists. Then the ceiling with its evenness and beauty will only emphasize the interior design.

This article is about how to build a concrete ceiling. Pouring a concrete ceiling is a common technique in Europe. However, although it is more expensive and time consuming compared to a wood ceiling, it has several advantages that may make you think twice about building your home. Therefore, by constructing a concrete ceiling, the rigidity of your home will be much better and it can support more weight compared to lightweight structures. On the other hand, a concrete ceiling has good sound insulation and is more durable.

But this technology also has a few disadvantages, such as the high cost of the project or the fact that pouring a concrete ceiling can take up to several months before you can actually build the walls and roof. Additionally, you must build formwork to be able to construct a concrete ceiling.

Pouring a concrete ceiling is difficult without the help of a qualified engineer. In addition, you must comply with the rules in order to obtain a building permit. The thickness of concrete ceilings varies depending on the weight it must support, but it is generally in the 5-6″ range for residential buildings. It is necessary to take into account the weight of the reinforcement, as well as the weight of the concrete; this is very important for reliable construction.

In order to build a concrete ceiling, you need the following:

Materials

1 × 4 wooden planks for formwork construction / plywood 4 × 4 wooden beams for ceiling support / metal reinforcement, nails / screws for formwork fastening

Tools

protective gloves, glasses, tape measure, carpenter's pencils, square, circular saw, for creating formwork, hammer.

Adviсe

use protective clothing, clean your tools thoroughly after completing the project, wear safety glasses and gloves to avoid possible injury, ensure that the ceiling formwork is at the perfect level

Time

Several hours are possible per day, depending on the surface of your foundation and the number of workers

Proportions of cement and sand for floor screed

After you have decided what brand of composition you need, you can talk about the ratio of sand and cement. The most popular brands are shown in the table below. As you can see, with increasing grade of the solution, the amount of sand decreases. Its exact quantity depends on the brand of concrete. For example, the popular M150 sand concrete can be made from Portland cement PC400 and PC500. In the second case, the amount of sand is greater: for one part of PC 400 cement, take 3 parts of sand (medium + large fraction 2/3 and 1/3); when using PC 500 sand, one part of cement is 2.8-2.7 parts.

Proportions of cement and sand for floor screed depending on the brand of mortar

Once again we draw your attention: preferably washed river sand, of different fractions - coarse and medium. The table does not indicate the amount of water. This is because it depends on the use of additives and the moisture content of the sand. For a normal consistency, take 1 part water to 1 part cement. For semi-dry - two times less, but again, it depends on the factors listed above.

How to check the quality of cement (and mortar at the same time)

It is better to take proven cement. You can't always trust what's written on the packaging. How to check the quality of cement? If you have several manufacturers, buy a bag of cement. Knead the composition in the required proportion in a small amount - 300-500 grams, form a cake of the required thickness, leave at +20°C. We assume that we used Portland cement of at least grade M400. The solution should begin to set after 4 hours; after 12 hours there should be no trace left from the heel of the shoe when pressing with all the weight.

The screed will gain full strength only after 28 days.

If the curing process is very slow, look at the packaging. Maybe you took a binder with a long setting period. No? This means the cement is bad. Evaluate the result in a couple of days. If the cake is strong and does not split, perhaps this is a feature of this composition.

Another test is with a nail. This will help you decide whether to take this cement or not. If you run a nail through the solution:

After 24 hours, no scratches remain on a mortar made from good cement.
No traces are visible after two days - normal quality.
After three days the scratches are still visible and cannot be used.

All these tests are valid under normal conditions for cement based mortar. This is a temperature around +20°C and sufficient humidity. We provide humidity by covering the prototype with a piece of polyethylene.

How to make formwork for a concrete ceiling

In order to build a concrete ceiling, you need to make the right formwork. Building formwork is a complex process, but if you have experience working with wood, you will succeed.

Complete information about formwork, as well as reinforcement, must be provided in the plans of your house. Remember that constructing a concrete ceiling is essential to the longevity of your home, so you should consult a qualified professional before starting such a project. In addition, you must follow all the rules and obtain all necessary construction permits so as not to expose yourself to unnecessary threats.

Smart advice
: When constructing formwork, you should use pressure treated wood, make sure it can support the weight of the reinforcement as well as the concrete.

As you can see in the image, you must build the first row of formwork using 4×4 boards. On this structure you need to install 2 × 4 wooden planks or plywood. The first option is better for a project with a limited budget, but we recommend that you use sheets of plywood, then everything will be completely straight at the bottom of the ceiling and you will not have to put in extra effort to make it level.

If you are using wooden boards, you must ensure that they are straight and in good condition. Also, make sure that you do not leave any gaps between the boards, as this may cause the concrete to leak.

Smart Tip:
When building formwork, you must use a level to make sure it is level, otherwise you will waste money and time correcting these imperfections.

You can look at the ceiling from inside the house to get a better idea of the procedure. This may look unusual to you, but this is the correct way to pour a concrete ceiling. You will notice that there are many 4×4 timbers installed every 15″ to support the weight of the structure and concrete.

Smart Tip:
use adjustable metal reinforcement when constructing a concrete ceiling. It can support more weight and can be easily adjusted to the height of your room.

We have prepared this sketch to show you in detail what the ceiling formwork structure should look like. As we said, these details will be provided by the architect, but we want you to get used to these construction techniques.

Smart Tip:
Use a 4' spirit level to ensure the shape and level of the supports are plumb correctly. Construction of a concrete ceiling requires, in most cases, to build a strong reinforcement, otherwise it will not be stable and the walls will not support their weight.

If you are using 4×4 joists, you must carefully attach them to the base of your ceiling. Hence, you should use 2×4 lumber and some nails to fix it firmly. Use a level to check that the supports are plumb correctly.

Strengthening the screed with repair mixture

In most cases, it will be reasonable to use repair mixtures. How to do the job correctly:

using a hammer drill, holes with a diameter of 20 mm are made in the concrete base. The distance between the holes is 20-25 cm;
the hole is drilled to the full depth of the screed, the drill must reach the base;
further, the top of the holes that were created are expanded using a drill with a diameter of 30 mm, the depth is within 3-4 cm;
Now, it is necessary to clean the pits from dust; for this, it is best to use a construction vacuum cleaner;
an expansion anchor bolt is placed in the hole and clamped;
then, the expansion is allowed to be filled with repair mixture.

Main! In case of severe damage, it is much more rational to dismantle the outdated concrete and pour new one than to try to resurrect the old surface.

In the same way, it turns out to significantly strengthen the screed. Additionally, you can open the surface with an epoxy-based resin mixture.

Epoxy based adhesive

Strengthening the building structure for a concrete ceiling

After you have built the formwork for pouring concrete, you must create and fix the reinforcement in the desired position. The concrete ceiling is almost floating, it is supported only by a few walls and pillars, so you must use a lot of reinforcement (the architect will calculate the required amount)

Smart Tip:
If your formwork is made of wooden planks, it would be a good idea to stretch plastic film over the entire surface to prevent concrete leakage.

In this photo you can see a close-up of the reinforcement used to strengthen the concrete ceiling. You may have noticed the thick iron pins, are you wondering what they are for? The reinforcement pins are located at the top of the wall and are connected to the rest of the reinforced concrete ceiling. This way, the concrete ceiling will support the walls and will be more rigid and durable.

Smart Tip:
You must always follow the construction plan, otherwise you may jeopardize your safety.

In this photo you can see the reinforcement of the structure around the stairs. You may have noticed that we used a lot of rebar around the stairs and along the walls.

Smart Tip:
These kinds of projects need to be carried out by qualified and experienced professionals, so you should learn the basic principles for yourself. We recommend that you hire an experienced architect and a team of qualified workers.

Surface preparation

Before working with the cement-sand mixture, you need to prepare the surface and install beacons.

First stage. The floor in the room where you plan to screed must be level and free of dirt. If work is carried out on the ground, it should first be compacted and filled with bitumen so that the cement screed lies smoothly. Secondly, if the cement screed contains dry mixtures, then the surface must first be dust-free and coated with a primer so that the screed adheres better to the floor surface.

The second stage is the installation of beacons. It is necessary to measure the space using a level and install beacons corresponding to the level of the future floor throughout the entire area of the room. This is done so that the surface of the screed is as horizontal and level as possible.

Installed beacons

How to pour concrete on a ceiling

After installing the formwork and strengthening the structure, you must fill everything with concrete. Therefore, you must rent a machine equipped with a pump and several hoses to pour concrete into the ceiling form.

Additionally, you must order the required amount of concrete from your local company (they will deliver it by car). You should be aware that there are several types of concrete, so make sure you order the one specified in your building plan (generally for ceilings, you should use B250). Ideally, you should hire an engineer to supervise the workers who are pouring the concrete ceiling.

Smart Tip:
if the surface to be filled is large, then it is better to start from the farthest corner. In this case, you won't have to run through liquid concrete with a hose. Additionally, you should wear rubber boots to protect your feet from getting dirty from the concrete.

After finishing pouring the concrete into the formwork, you must level it from one end to the other. But first you must pound the concrete to make sure there are no air pockets left in the concrete.

Make sure you level the surfaces properly, make sure it is level. However, in most cases you will need to screed after the concrete ceiling has dried to make it completely level.

Next, you must wait a couple of months until the concrete ceiling is completely dry. Once the ceiling is dry, you can remove the formwork and continue building the walls and the rest of your home.

Smart Tip:
If the outside temperature is high, you should spray the concrete with water at least twice a day.

Spray the concrete with water, otherwise the ceiling may crack. In the worst case, you'll have to do it all over again if the cracks are too deep (cracks can affect the rigidity of the ceiling).

Smart Tip:
Do not remove the formwork too early, otherwise the ceiling will crack or become crooked. This is why it is important to consult a qualified structural engineer.

Once the ceiling has dried properly, you can begin to build the walls and roof of your home. Pouring a concrete ceiling is not very difficult if you follow the directions from your structural plans.

Smart Tip:
just make sure you install the fortifications properly. Make sure you use the right tools and materials to ensure your project is done to a high standard.

A perfectly flat ceiling surface is a prerequisite that must be met before decorative finishing of this surface, so that the quality of the work carried out is of a high level. This is especially true for ceilings made of reinforced concrete slabs. The evenness of the ceiling is achieved after the ceiling has been dry screeded.

A perfectly flat ceiling surface is a prerequisite that must be met before decorative finishing of this surface.

Definition of zero level

To achieve a level concrete floor screed, the installation of beacons is necessary, and in order to position them correctly, you need to find the zero level.

If you use a laser level, the procedure is very simple:

The laser is directed at a wall with a height of, for example, 160 cm and a line is drawn on the wall at this height. The remaining walls are knocked off in the same way, and the resulting lines are connected together.

If you use a water level, the procedure is more complicated:

Fill the level with water.
On the selected wall we select an arbitrary point, for example at a height of 160 cm.
We apply one end of the level to the mark, and bring the second to another point on the wall and move it vertically so that the basic indicators on the level coincide.
Using this algorithm, we measure all the walls and connect the resulting points with a line.

In these ways, a basic level is obtained. Then we measure the distance from it to the base, recording the obtained values on any medium.

Design Features

The difficulty in leveling the surface of reinforced concrete slabs (unlike others) lies in the fact that most often they do not lie in the same plane, but there are significant differences between them. In any newspaper you can find advertisements in which professional builders will do everything quickly and efficiently for a certain fee. But if you want to save money, then you can try to do everything yourself, based on the recommendations of experts. Moreover, the described nuances are suitable for almost any ceilings.

There are two known ways to level (screed) the ceiling:

"wet";
"dry".

“Wet” screed involves the use of special solutions and mixtures, and “dry” screed involves leveling the ceiling surface using sheet material. These include:

drywall;
plywood;
Fiberboard, chipboard and many others.

There are several criteria for choosing a ceiling screed method, but the main one is that if the differences at the joints are more than 50 mm, then you should choose the “dry” leveling method, since the thickness of the plaster layer will exceed the permissible standard and may fall off during operation, causing serious injury person.

It should also be noted that the ceiling screed significantly reduces the height of the room, which is not very beneficial for. In this case, it is more advisable to use putty for leveling (provided there are small differences).

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How to calculate cement consumption?

There are several basic, proven values:

For 1 m2 with a layer thickness of 5 cm, 20 kg of mixture is required.
For 1 m2 with a height of 10 cm - 50 kg.

One bag of the finished composition usually contains fifty kilograms; they are multiplied by the area of the room and the required amount of composition is obtained.

Ceiling screed: installation process

To work, you will need to prepare the following tools and devices:

In preparation for screeding, the layer of previous finishing material, whitewash, and putty is removed from the ceiling.

spatulas of different sizes;
aluminum rule;
metal smoother or grater;
plaster comb;
plaster falcon;
a plastic container with a volume of at least 18 liters;
drill with mixer attachment;
sponge grout.

Before you begin directly leveling the ceiling surface with your own hands, you need to prepare it, especially if this is not a newly built house. The layer of previous finishing material, whitewash, putty, etc. is removed from the ceiling.

To ensure that the work progresses quickly and not too tediously, you should use the recommendations of experts:

The plaster is removed with a sharp spatula, periodically sharpening it.

To make work easier, you can lengthen the handle of the spatula by screwing a wooden or plastic stick to it.

The plaster must first be moistened with a spray bottle or a foam sponge.

It will be much easier to remove a layer of water-based paint if you add a few drops of iodine to the water.

The most difficult situation is with water-dispersion paint. Here you will need to use either a drill with a wire brush, or a special remover, which can be purchased at any hardware store.

a layer of old material is removed not only from the surface itself, but also from the tile joints. To do this, take a pick, hammer and spatula. Only the lagging and cracked part of the material needs to be removed;
if there is fungus on the surface, then you definitely need to pay attention to this problem. Otherwise, the new surface will suffer the same fate. First, the surface is treated with an antiseptic, which is either bought in a store or made by hand, and then it is primed to increase adhesion to the material.

Screeding the ceiling with your own hands begins with eliminating the largest defects using coarse putty for rough work. You can use tow, which is soaked in a solution of such putty and you get a kind of sponge for sealing cracks. To prevent the joints between the plates from cracking, they are reinforced with a special mesh, which is pressed into the layer of putty.

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Equipment and tools for laying concrete screed

The choice of tools and equipment is based on the scope of work and the technology used.

In general, the implementation of laying a concrete screed may require the following:

concrete mixer – for mixing traditional working solutions for large volumes of work. When filling small areas, it is enough to use a construction drill with a mixing attachment and a clean container;
mortar pumps, pneumatic blowers - used in the implementation of semi-dry screed technology;
metal profile - for arranging guides;
level (laser or water) – for precise marking and measurements. For such work you will also need a tape measure, a ruler, and a tapping cord;
rule or vibrating screed - used for leveling and compacting screeds;
concrete finishing machines – for troweling the surface. To prepare the base, you will need milling or sandblasting machines, construction vacuum cleaners, and hard metal brushes;
shovels, spatulas, smoothers.

When preparing screed bases on the ground, tamping machines are used

Final moments: do-it-yourself flat ceiling

Before applying the second layer of putty, you need to “comb” the first one with a plaster comb, without waiting for it to harden.

After all of the above, they begin to putty the entire surface of the ceiling, for which the prepared mixture is applied to the base and carefully leveled with a spatula. The putty mixture is applied in a direction away from you, with a thickness of no more than 20 mm. Next, the layer is leveled with a rule of zigzag movements towards itself. Before applying the second layer, it is necessary to “comb” the first one with a plaster comb, without waiting for it to harden.

Only after two days can you begin to apply the next layer.

Combing the previous layer allows you to roughen the surface to increase the adhesion of materials.

The length of time the layers are kept is determined by the level of humidity in the room.

If the room is dry and warm, then the plaster hardens very quickly, and high humidity promotes uniform hardening of the material.

It is necessary to take into account the fact that during work the air humidity increases, therefore, the plaster will not dry quickly. You should not change the humidity level artificially, since the layers of plaster must harden under the same conditions in which they were applied.

To level each subsequent layer, the rule is set with a straight edge towards itself.

Thus, the new layer will be thinner and smoother than the previous one, since the rule will remove all unnecessary things. Before applying a layer of plaster, carefully check the levelness of the ceiling.

To do this, you need to move the rule from one side to the other, and if there are any irregularities, they are sanded with sandpaper.

If the ceiling is to be pasted or painted, after applying the plaster, work is stopped for 10 minutes, and then the surface is moistened and rubbed in a circular motion with a special sponge grater.

This will make it possible to mask the marks left from working with a wide spatula. As soon as the surface of the ceiling becomes matte, this will indicate that the plaster has dried and can be smoothed over with a metal trowel. The ceiling screed is completed by applying a finishing layer of putty.

From all of the above, we can conclude that screeding the ceiling with your own hands is possible if you follow all the recommendations of professionals.

If a man is independent, then this is good, but if he is also constantly learning something new, then this is a godsend for his wife. Not everyone can make a ceiling canopy with their own hands, but everyone can learn how to do it, but this requires desire

If you feel it, then you have come to the right place - here you will find several valuable lessons from an experienced master for the home owner.

How to reduce dry cracks

Let's start with the fact that cement floor screed can vary in the amount of water. There are two types:

Conventional, in which the volume of water is approximately equal to the volume of cement.
Semi-dry, in which water is only 20-30% of the volume of cement.

With the same proportions of cement and sand, a semi-dry screed has higher strength and gains strength faster. After drying, it has fewer irregularities and fewer cracks. For some coatings, you can only rub the surface without using leveling mixtures. Why does this happen? Because there is less water, therefore less volume evaporates, causing less shrinkage (change in size). Hence - fewer cracks, fewer irregularities.

Cracks are not always visible, but they are always there.

Why is a regular liquid screed used more often? Because it's easier to make it. The liquid solution has a longer time to set. This allows even workers without experience to lay and level the composition. For a semi-dry solution, the time before setting begins is very short - about 20-30 minutes. And this is provided that the composition contains an additive to increase plasticity, prolonging the installation time.

To make a semi-dry screed with a longer period to start setting, look for cement with a long period to start crystallizing. This parameter is indicated on the bags. There are short periods - up to 20 minutes, there are 2 hours or more.

If a semi-dry mortar begins to “become”, but there is no time to lay it, it will not gain sufficient strength. That is why there are so many stories about fragile and crumbling semi-dry floor screed. It was just done incorrectly, with the installation time not correct. A properly made semi-dry cement floor screed is very strong and smooth.

A high-quality cement floor screed has very small differences, and to minimize cracking, expansion joints are laid

So what can you do to ensure that there are fewer cracks in the screed when filling the screed with ordinary mortar?

Add the minimum possible amount of water.
If necessary (on an elastic base), lay reinforcing mesh.
Use reinforcing additives.
Grind the surface after it begins to set.
Lay a damper membrane around the perimeter of the room.
For large rooms (more than 10*8 m), cut/lay expansion joints.

This is a whole set of measures that allows you to obtain a concrete floor with a minimum number of cracks. But first of all, we must follow the technology and recipe. This will be a guarantee of quality.

How to choose materials

The strength of a cement floor screed depends not only on the quality of the cement, but also on the quality of the sand. For a good result, you need washed river sand, from which all dust and foreign components have been removed. It is highly desirable that the sand contains grains of sand of different sizes. If the sand is of only one fraction, part of it (1/3 or 1/4) can be replaced with fine granots. With this composition - large, medium and fine fractions - sand fills the voids well, and the remaining empty space is filled with dusty cement. This cement floor screed is dense and durable. This is good for sound insulation, it cracks less and behaves better in use.

Brand of mortar for floor screed - from M100 to M200

What brand of cement should I use? The best choice is Portland cement. Marked PC. A cheaper ShPC is suitable. It is better not to take any mixes, since the result of their use is unknown. We do not add clay and lime to the CPS. These are dust-like particles; they replace cement, reducing its strength.

Features of the batch

Beginners often have the desire to add more cement to the screed solution. It seems that the more binder, the stronger the floor will be. Well, no. There will be more cracks. That's for sure. And the presence of a large number of cracks means poor quality of the foundation. Another point: in order for the cement floor screed to be strong, you cannot add a lot of water to it. To make it easier to lay the “steep” solution, plasticizers are added to it. The most affordable is dish detergent. A couple of spoons per batch, and the solution with a small amount of water is perfectly leveled. But if possible, it is better to add an industrial plasticizer. Detergents that increase elasticity reduce strength. So it is better not to use it for solutions of low grades.

Sand-cement mixture for floor screed - the basis for mixing

Even if you make a traditional solution, do not pour water right away. First, mix the dry ingredients - sand and cement, and then add a little water (half the norm). Add a little water, stir well, add a plasticizer (special additive or dishwashing detergent), stir. Too thick? Add a little water. After laying the solution, there should be no puddles on the surface. The presence of puddles indicates that there is a lot of water and its amount needs to be reduced.

The most popular ceilings in the house

This article will consider two types of ceiling repairs - a suspended ceiling made of plasterboard and leveling (plaster)

putty solutions. There is also a video clip at your service that will allow you to visually consolidate the acquired knowledge.

Due to the fact that it is simply impossible to post absolutely all the information about these issues, here are the basics of these two types of finishing, the use of which will allow you to grow as a master.

Plasterboard ceiling

To make a ceiling canopy with your own hands, you definitely need to learn how to use a water level
.
This is not difficult, but there is one caveat - given that we will have to place marks right under the ceiling, the plastic cones that are attached to the ends of the tube will interfere, resting against the ceiling. There are two options - put the marks 10-15 cm lower
, and then raise them using a tape measure, or simply
get rid of the cones
, which is much preferable.
So, let's put the first mark on the wall
.
Please note that the minimum distance from the main ceiling must be no less than the thickness of the CD profile for the suspended frame, which is 25mm
. So if you want to raise the suspended structure as much as possible, then these figures will be the limit for you, and besides, the calculation must be made from the lowest point on the main ceiling.

Using a water level
(you can also use
a laser level
), transfer the reference point to all internal and external corners of the room.
After this, stretch the chokeline (painting cord)
and beat off a control line, which will indicate the lower plane of the hanging frame.

When the control line
, you can proceed to the installation of the frame, and start with the wall profile
UD
.
You screw it along the reference line so that the bottom of the UD coincides with the reference line. Some UD profiles are available with mounting holes, but if there are none, then do it at a distance of 40-50cm.
To secure the profile, you can mark the places for drilling
on the wall through the profile holes, and then make them. But there is a faster way - to drill holes in the wall through the body of the profile. To do this, use a 6mm drill and dowels of the same diameter, and the screw head will still be larger.
Let's move on to marking the ceiling for hangers.
I would like to immediately make a reservation that we will not make a cellular frame, but only with transverse profiles - practice shows that in terms of strength it is not inferior to a cellular one, but, at the same time, it saves both time for its installation and the financial costs of the material. The plasterboard sheet is 250 cm in length, so we will make markings every 50 cm, across the intended direction of the gypsum board.

On the lines marked on the main ceiling, we install ribbon hangers
on which the
CD
.
The distance between the pawns should be no more than 50-60cm
, and they need to be installed on two of the same dowels as the
UD
.

Recommendation. Hangers are often installed on a ceiling made of concrete floors that have voids in the middle. An ordinary dowel falls through there during installation, so you can use two little tricks.

Firstly

, dowels can be purchased
with an extension at the inlet hole
so that it is wider than the seat.

Secondly

, if there are no such dowels, then insert it through the suspension so that the edge lingers on the tape, and then it will not fall through.
The optimal screw thickness for a 6 mm dowel is 4-5 mm.

We continue to install the ceilings in the room with our own hands and move on to installing the CD
.
The length of the profile will be equal to the distance between the opposite walls on which the UD is screwed minus 5mm
. This allowance is necessary to cover the thickness of the wall profile, as well as for ease of installation so that the CD does not deform. Insert all the profiles, but do not screw them in yet.

To make the ceiling even, you need to level each profile,

a nylon thread
, stretched under the frame and secured with screws to the lower UD shelves, will help with this But the thread will be pulled back by the CD profiles, so they need to be temporarily tightened with hangers. Bend the middle pawn under each CD to raise it above the plane and begin leveling one at a time.

The profiles are screwed to the hangers and to each other with special self-tapping screws
made of galvanized or oxidized steel for sheet material up to 0.9 mm.
in 1 screw
on each side of the profile , sometimes there will be some play left, so to prevent the frame from “rattling”, screw in an additional self-tapping screw.

A screw is put on the PH#2 nozzle and installed in a horizontal position, but with a slope towards the screw by 40⁰-45⁰. If the screw does not fly off in this position, then it will be easy to work with.

When the frame is ready, you can begin installing drywall
, but do not forget that there will be lighting in the room and the lamps will most likely be installed on the ceiling.
Therefore, you need to make a wiring harness
and hide it in a corrugated cable channel, which, in turn, needs to be attached to the main ceiling.
For recessed lamps, as a rule, loops are made on the wire
, and you can make them together with a protective hose. When you need to connect the lighting device, cut the corrugation along with the wire, and remove the excess pieces of the hose by simply pulling it to the required distance.

To attach one plasterboard sheet to the ceiling, about 60 metal screws, 25 mm long,
. They are screwed in at a distance of 30 cm from each other and the head of the screw should be recessed under the plane of the gypsum board, but without breaking through the paper. To ensure that the paper remains intact, use a special attachment for drywall with a lampshade that fixes the depth of the cap.

You need two people to lift a sheet of drywall (if there is no special mechanism) so that it does not break, and in this case it is much easier to fix it with screws. When the gypsum board is in place, fix its edges and center
, and then you can release it and tighten it with two screwdrivers.

Please note that the edge of the plasterboard covers only half of the CD profile
, because the next one will lie on the other half. It is especially important to adjust this when installing the first sheet as the walls may not be level, so you may have to trim the drywall around the edges of the wall to get it to fit correctly.
In technical rooms, sometimes instead of gypsum board (gypsum plasterboard sheet) they use GVL (gypsum fiber sheet)
. In appearance, the materials are almost the same, but GVL is made without a cardboard shell, and its structure is reinforced with reinforcement in the form of fluffed cellulose, waste paper, etc. Its density is much higher and has 1250 kg/m 3.
You can make ceilings from gypsum plasterboard with your own hands in the same way as from ordinary plasterboard, but the whole question is whether it is advisable to use
such a material. Typically, GVL is used for walls, and sometimes for floors.
When installing gypsum boards, do not forget to take out the wires for the lamps

a hook
or other type of console must first be installed for it

The joints between the sheets should be sealed with fugenfüller or ordinary putty
, but in this case an additional adhesive perforated tape is installed. The entire surface of the ceiling (not just the joints) should be primed. After the primer has dried, the ceiling is ready for further finishing.

Recommendation. If the ceiling area is large enough, then the gypsum boards should be installed in a staggered manner so that there is no continuous joint line. This is especially important in houses located near a railway or road where heavy vehicles pass, and in order to cause a seam failure, start installing every second sheet from half.