The screed is an intermediate layer between the base and the floor covering, which is necessary for leveling and stiffening the surface, covering utility lines, and also for installing a floating floor. Competent calculation of the floor screed will allow you not to overpay for unused material, and the savings can be spent on the purchase of Shumanet, insulating film and other devices for sound insulation.
Cement consumption per 1 m2 of screed
Fast-setting cement screed is one of the types of self-leveling floor. In order to calculate the cement for the floor screed, the surface area must be multiplied by the estimated layer thickness.
Let's look at an example. The area of \u200b\u200bthe room is 35 m2, and the height of the screed is 5 cm, therefore the volume of the sand-cement mortar will be: 35 m2 x 0.05 m \u003d 1.75 m3. The ratio of the components of cement and sand is 1: 4, therefore we need 1.4 m3 of sand and 0.35 m3 of cement.
Almost no repair or construction is complete without screed filling. This is an extremely important stage in the renovation. When performing this work, you must not only carefully adhere to proven technologies, but also correctly select and calculate the amount of material required. A preliminary calculation of materials for floor screed will save you both unnecessary costs and an unpleasant lack of material at the most crucial moment.
Experts note that the main mistakes when creating a screed are associated with calculating the proportions of components for preparing a solution. Namely, the quality of the future coating depends on this moment. Let's consider how to correctly calculate the required amount of ingredients and how to make a floor screed.
Before the home craftsman, who decided to fill the screed with his own hands, first of all, the question of choosing a solution for the screed arises. Mortars and mixtures for filling the floor differ in their composition, but each of them necessarily contains gypsum or cement, which are the binding ingredients. The filler for the screed is sand. To improve the quality of the mixture and give it certain properties, various mineral and polymer additives are added. The mixture is diluted with pure water and a solution of the desired consistency is obtained, which, as a rule, has the thickness of sour cream.
Depending on the composition, the mixture will have certain properties:
- The most versatile are cement compositions... They can be used in any room. Floors made on the basis of such mixtures are not afraid of moisture. However, it must be borne in mind that when dry, cement mortars give a large shrinkage, therefore, when working with such mixtures, you need to thoroughly mix the solution and tamp it well. If these requirements are not met, cracks may occur. To reduce the possibility of screed cracking, surface reinforcement with a reinforcing mesh will help.
- Gypsum solutions (anhydrite)Are quick-drying, easy to prepare and install solutions. These mortars do not shrink and can therefore be applied in a thin layer.
Consider! Do not use gypsum solutions in rooms with high humidity.
Cement and gypsum solutions can be prepared independently or you can buy ready-made dry mixes. Despite the higher price, it is profitable to buy such mixtures, since, firstly, they have a balanced composition, and secondly, manufacturers add modified additives to simplify mixing and improve the properties of the solution. Mortars prepared from ready-made mixtures harden faster and give less shrinkage.
In ready-made mixtures, the manufacturer has already worried about the correct ratio of components and useful additives
Preparation of cement-based mortar
Screed mortar composition
A cement floor screed is prepared from the following components:
The calculation of cement for the floor screed is made based on the grade of cement used and the grade of mortar that they want to receive.
| Cement grade | Cement / sand ratio | Solution grade |
| 600 | 1:3 | M300 |
| 600 | 1:4 | M200 |
| 500 | 1:2 | M300 |
| 500 | 1:3 | M200 |
| 400 | 1:1 | M300 |
| 400 | 1:3 | M150 |
| 300 | 1:1 | M200 |
| 300 | 1:3 | M100 |
Consider! For floor screed, the grade of mortar should not be lower than M150. The most popular for these purposes is the M200 solution grade.
It is very simple to determine the grade of the solution; for this, the grade of cement is divided by the amount of sand added to the mixture. For example, to prepare M150 grade mortar, you will need 1 bucket of 400 grade cement and 3 buckets of sand.
Rules for the preparation of cement mortar
If you use a ready-made dry mixture, then you should follow the instructions written by the manufacturer on the package. When composing a screed mixture from individual ingredients, you must first mix dry and liquid elements separately, in different containers. The procedure will be as follows:
- Mix thoroughly sand, cement and fiber in one container.
- Mix the plasticizer with water. About 190 grams of plasticizer are taken for a 50 kg bag of cement.
- Add the dry mixture to the container with the liquid gradually, with continuous stirring. It is impossible to pour liquid into the mixture, since in this case difficult-to-grind lumps are formed.
To mix the solution, it is better to use a drill with a nozzle or a construction mixer. Using tools will not only speed up the work, but will also allow you to get a better quality solution.
For high-quality mixing of the solution, use a construction mixer or drill with a nozzle
The solution is ready for use. It should be noted that the more viscous it is, the more difficult it is to work with it, but such a solution, as a rule, gives a surface with a minimum number of cracks.
Our advice! To exclude the appearance of cracks on the surface of the screed, it is necessary to cover it with a film after the end of the work and moisten it with water every day, until it is completely cured.
Consumption of the mixture for the floor screed
- it is determined how much the finished coating will have. To calculate this value, the floor area must be multiplied by the planned screed thickness. For example, the floor area is 40 m 2 and it is supposed to make a screed 5 cm thick. We get that for this case you will need: 40 * 0.05 \u003d 2 m 3;
- having calculated the required volume of the screed, consider how much cement and sand will need to be taken. We will make a solution of the M150 brand. It is made of cement grade 400 in a ratio of 1: 3. That is, we need 5 m 3 of cement and 1.5 m 3 of sand. One cube of cement weighs about 1300 kg, that is, we need approximately 650 kg of cement or 13 bags of 50 kg each.
Having performed the calculations in this way, you will receive the quantity necessary materials.
Dry screed consumption
The dry screed technology proposed by Knauf is relatively recent. Such a screed can be completed in a shorter time frame and with less labor costs. It is dust-free, gives the floor additional thermal insulation and is easy to install. The disadvantage of such a screed is the high cost supplies... In addition, the thickness of such a screed is much greater than that of a cement one, and therefore it cannot be used in rooms with low ceilings.
The procedure for performing such a screed is as follows:
- A layer of waterproofing is laid on the base of the floor. For the concrete floor, use a plastic wrap, and on wood floors roofing material.
- Expanded clay concrete is poured onto the waterproofing layer.
- Next, special gypsum fiber sheets Knauf Superpol are placed on the floor, which are attached in the grooves and fixed with self-tapping screws.
- A thin leveling layer is applied on top.
Dry screed "cake"
Sometimes it is allowed to replace gypsum fiber sheets with chipboard, asbestos-cement slabs or thick plywood. Expanded clay can be replaced with slag or sand.
Let's calculate the consumption of materials for a floor screed in a standard room with an area of \u200b\u200b17 m 2 (3x5.65 m).
Waterproofing
For waterproofing, they take both sheet materials: polyethylene film, a special membrane material, a hydro-barrier, roofing material, and special mastics based on liquid glass or bitumen are used. Let's make a calculation for waterproofing from a conventional polyethylene film. This material is sold folded in sleeves, in rolls of 1.5 m. The film must be taken with a margin of about 15%, since it will be necessary to make allowances.
We will take as a basis waterproofing with sheet material - plastic wrap. The film is calculated for the area of \u200b\u200bthe room with a margin for allowances, that is, more by 15%. If you put the film along, then its width will not be enough for the allowances, so we will lay the film across the room. As a result, you need films of 3.20 * 2 \u003d 6.4 m. It is better to round up and take 6.5 polyethylene film.
Gypsum fiber sheets
When calculating, it is also necessary to take into account a small stock for cutting. Taking into account the stock of about 5%, we get the floor area - 18.2 m. The area of \u200b\u200bone GVL: 1.2 * 0.6 \u003d 0.72 m 2. We divide the floor area by the area of \u200b\u200bone element and we get the required number of sheets: 18.2 / 0.72 \u003d 25.3 pcs. We round up to a whole sheet and we get that we need to purchase 26 sheets.
Laying gypsum fiber sheets
If we take into account the coefficient of engineering error, then we get that we need 1 more spare sheet, that is, we need 27 sheets of GVL. If the gypsum fiber sheets are replaced by another material, then the calculations are carried out in the same way.
Edging tape and glue
The length of the required edge band is equal to the perimeter of the room minus the width of the doorways. Thus, taking into account the stock, we need to buy 17 meters of edging tape. It is better to take a tape with a thickness of 8-12 mm for these purposes.
When calculating the amount of glue, take into account that it needs 50 grams for each square meter GVL. Thus, one kilogram package will be enough for our room. If the glue is purchased in tubes, then their quantity is calculated depending on the weight of 1 package.
Self-tapping screws for fastening
A small sheet will need at least 6 pieces of self-tapping screws. Taking into account the docking, we will increase this number to 10 pcs. on one sheet. As a result, we get that we need about 270-300 screws.
According to the dry screed technology, the length of the screws should be 19 mm. In some cases, self-tapping screws with a length of 25 or 30 mm can be used.
Expanded clay
According to the project, 0.01 cubic meters of expanded clay is consumed for each square meter of floor area 1 cm thick. Considering that the room has an area of \u200b\u200b17 m 2, and the height of the backfill will be at least 3-4 cm in height, we get that 0.51-0.68 m 2 will be required. This is about 500-700 liters. Taking into account the run-up, we take a large figure and we get that you need to purchase 0.7 m 2 or 14 bags of 50 kg each.
If the room has a slope, then the consumption of expanded clay will increase, since there will be a passing task of leveling the surface of the room. In addition, you will need more profiles for beacons and various tools for performing dry screed.
With specific examples, we have shown you how to calculate the amount of materials required for both classic cement and dry screeds. Having correctly calculated the materials and having performed all the operations taking into account the recommendations of specialists, you will get an even monolithic coating that will last for many years.
Video: installation of a dry floor screed
Cement screed, or as it is also called "traditional screed", is considered to be the most reliable and economical in terms of money costs. It is very often used in premises for various purposes, for example: in apartments, country houses, cafes, offices, shops, garages, and so on. A dry mixture (sand concrete) M-150 or M-300 is used as the basis for such a cement-sand screed. And how much of this mixture is needed for the screed? Calculation of sand concrete for floor screed presented below.
Calculation of the mixture for the floor screed
First of all, it is necessary to measure the room. With the help of a laser level and a tape measure, we measure and measure the entire room and see where the differences are. We calculate how many m 2 we need to make, then we consider all the building materials needed for work. It is especially important to correctly calculate the amount of required dry mix.
Example:
We need to make a screed in a room with an area 25 m 2 thick 5 cm
.
On 1 m 2 at thickness 1 cm leaves about 22 kg mixtures.
Multiply 5 cm screeds on 22 kg mixtures (5 x 22 \u003d 110). Means 110 kg will weigh 1 m 2 our 5 cm screed.
Now 25 m 2 multiply by 110 kg mixtures (25 x 110 \u003d 2750). Means 2 750
kg will weigh a screed of 5 cm on an area of \u200b\u200b25 m 2.
Further 2 750
kg divided by the weight of a bag of dry mix (2 750 kg: 50 kg \u003d 55). Means 55
bags of mix weighing 50 Kg we will need.
The rest of the material is easily calculated by the floor area.
For the screed device we need:
- Profile for lighthouses;
- Dry mix M-150 or M-300;
- Primer or concrete contact;
- Reinforcing mesh (used on a loose basis);
- Edge tape;
- Vapor barrier film (on the second or third day you need to spill the screed with water and cover with a film for 7 days). The process can be repeated one more time.
Note that a higher grade of a mixture indicates that the mixture contains more cement. Pure cement is marked with M-500. Therefore, the higher the brand of dry mix, the stronger the screed will be.
The cement-sand screed hardens (gains strength) within 30 days, during this time only tiles can be laid on it, the rest floor coverings can be mounted after 30 days. The fact is that the moisture in the screed will be absorbed and spoil the coating. If the thickness of the screed is more than 5 cm, then we recommend using expanded clay on the bottom layer. It is lightweight and will allow you to remove the total weight of the screed, therefore, the load on the floor slab will decrease.
When the sand concrete for the floor screed and other material are calculated and delivered to the object, the master starts working. First of all, the floor slab is prepared for pouring the screed, that is, it is cleaned of all kinds of debris and primed. When the primer is dry, we attach the edge tape to the wall, it is needed to relieve the tension of the screed. We install beacons with a pre-measured height. If it is necessary to use a reinforcing mesh, it must be lifted and secured just below the center of the floor screed itself.
Preparing the mixture: 10 kg of dry mixture should be poured into 0.8 - 1.3 liters of clean water and stirred until a homogeneous mass without lumps with a construction mixer. You need to use the resulting mixture within 1 hour.
Pour out the finished mixture and pull it together with an even rail along the beacons, until the room is completely filled. 2-3 days after pouring the screed, it must be spilled with water and covered with a film. We withstand the screed for 30 days and the screed is ready for further use!
No construction or major renovation is complete without flooring. A screed calculator will help to avoid unnecessary expenses when purchasing materials. Initial installation of floors, base under decorative trim it is necessary to produce thoroughly so that the floors will serve for more than a dozen years.
What materials are better to use, how to correctly calculate the amount of materials for a high-quality mixture and how to calculate the floor screed, we will consider in this article.
Concrete pouring over interfloor overlap performs several functions:
- insulates;
- isolates;
- evens out the surface under the finishing floor covering.
With different layer thicknesses, you can level the floor between different rooms in the same room.
For example, let's say you decide to lay tiles in the kitchen and laminate flooring in the dining area.
The material is different in height and method of laying. You can avoid floor drops by arranging a screed of various layer widths and quality.
Various screed options
In a private house, expanded clay is first poured onto the floor, and only then concrete mortar is poured
Depending on what the goal is and in which building the work is being carried out, the screed can be done in different ways:
- For the option of performing work in a city high-rise building, it is enough to fill the floor with concrete over the floor slabs. Sometimes, to improve the quality of the screed, this is done in two layers.
- In the production of works in the private sector, usually for floor insulation, dry bulk material is additionally used for floor screed, for example, expanded clay, and then concrete is poured.
- In both cases, films with hydro and thermal insulation properties can be used to reduce heat loss and improve sound insulation.
It must be understood that the concrete floor should not be narrower than 8 mm at its thinnest point.
Usually the screed is made to a height of 30-40 mm. It is possible to fill in even higher, if these costs are justified.
Calculations based on materials
To calculate the amount of concrete, you need to know the area of \u200b\u200bthe room and the level of the floor drop
To find out the height, you need to understand the level of the floor drop. To do this, you will have to use any type of building level: water or laser. With the help of a level, it is necessary to establish a zero boundary throughout the room. This mark will come in handy in many works.
As a result, you will get several marks in different rooms at the same level. They need to be connected with lines. How to make a floor screed according to German standards, see this video:
Next, we measure the height of the floor drop, measuring the distance from the zero level to the floor. Write the received data directly on the wall within the measurement limit. Calculate the difference between the highest and the highest low level floor - this is called the level of the height difference. As a result, if the obtained value is less than 3 cm, then a layer height of 30 mm will be sufficient.
To calculate the floor screed, multiply the area of \u200b\u200bthe room by the height of the pouring and get the volume of the required solution.
Purchase of the required amount of materials
Dry mix for screed Having calculated the amount of raw materials required, calculate the materials for the floor screed.
A regular liquid mixture can be prepared in two ways:
- by mixing all the dry ingredients of the mixture with water in the right proportions;
- buying ready-made dry building mixture and dissolving it in water.
The second option is simpler, but much more expensive. For cooking concrete mortar from the prepared mixture, follow the instructions on the package. Additionally, the instructions will indicate the maximum possible thickness of 1 layer of screed, which can be poured from this material.
Having chosen the first method, it is necessary to make preliminary calculations of materials for the floor screed.
Floor screed calculator
In order to understand how much materials may be required for pouring a floor per 1 m2, use a calculator. For information on how to calculate the amount of concrete, see this helpful video:
To screed the floor in the garage or utility rooms, you can use concrete grade M 150. The best option for pouring floors in residential premises would be a mortar grade M 200. Concrete of a higher number will be needed in rooms with increased load or in cases where an increased setting speed or high wear resistance.
Knowing the proportions for mixing the mortar, it is easy to calculate the consumption of sand concrete for the floor screed.
| Concrete grade | Cement grade 400 | Cement grade 500 |
|---|---|---|
| 150 | 1 / 3 / 5 | 1 / 4 / 6 |
| 200 | 1/ 2,5 / 4 | 1 / 3 / 5 |
| 250 | 1 / 1,8 / 3,3 | 1/ 2,5 / 4 |
| 300 | 1 / 1,5 / 3 | 1 / 2 / 4 |
The proportions of sand, cement and crushed stone for calculating the mixture for screed floors of the most popular brands.
The strength of the concrete will be given by plasticizers, which must be added to the mixture at the kneading stage. To improve the quality, crushed stone of fine fractions is taken into use. If crushed stone is removed from the solution, then the classic proportions for calculating the consumption of the mixture for the screed and preparing the cement-bonded particle board ( cement-sand mixture) 1/4 or 1/3.
To increase the strength, you can add plasticizers to the solution. Using the data in the table, you can calculate the consumption of materials per 1 m2 of the screed. About 1.7 liters of water are poured into 10 kg of dry solution. The mortar consumption per m2 is 19-20 kg of grade 250 concrete with a layer height of 10 cm.
Note that the higher the water content in the solution, the more likely it is to crack.
Observing simple rules when mixing the screed solution, you ensure the high quality of the resulting mixture:
- Dry screed materials are mixed with each other, carefully observing the proportions. If the proportionality of the ingredients is violated, the quality of the composition deteriorates.
- The plasticizers are thoroughly mixed in water. The proportions for the use of additives are indicated on the product packaging. Most often, 200 gr is added to 50 kg of cement. plasticizer.
- After preparation of dry and liquid components, they are mixed together. Dry materials are poured into water and stirred until there are no lumps. For more information on how to make high-quality concrete with your own hands, see this video:
To thoroughly mix the solution, use an electric mixer or a drill with a special attachment.
When planning work on pouring a concrete screed, it is necessary to take into account that the solution sets on average within a day. But for the complete drying of the concrete mixture, according to the norms, it takes 4 weeks.
You should not carry out further work on the flooring without waiting for complete drying.
A floor screed is one of many floor leveling options in modern construction. Despite new technologies, the concrete screed remains the most popular and reliable way of leveling the floor under the final coating. Although each new technology in this segment trying to compete with cement-sand pavement, but few have achieved results.
What is a floor screed? Is a self-leveling coating of different consistency (depending on the task at hand), consisting of cement, sand and various additives. The simplest type is a cement-sand mortar diluted with water.
The proportions depend on the brand of cement and the thickness of the poured layer. More complex mixtures are sold ready-made, usually self-leveling self-leveling floors, which are intended for finishing. Ready-made mixtures are simply diluted with water, and they are intended to level out minor flaws in the floor surface. Self-leveling screeds can serve as a topcoat in technical rooms, in workshops, in production, in warehouses. Unlike a simple rough sandy cement screed, bulk mixes have a smooth surface after drying. The problem of sand dust in the air, when using the finished floor, does not arise with such solutions.
Leveling the floor in the apartment: making a screed
Why do you need a cement screed? During laying, floor slabs have seams and level transitions, potholes and technological holes for hooks. Often floor slabs on a construction site lose protective layer, in places exposing the fittings. The main task of the cement screed is to protect the floor slab and level the levels throughout the facility according to the project. In private construction (houses, cottages), this type of floor covering is used over a water heated floor, thereby protecting pipes from external influences and leveling the surface to a horizontal level.
Material calculation
The floor screed calculator includes several components. When starting the calculation, it is necessary to determine the coverage area. The total area of \u200b\u200ball rooms in which the pouring will be carried out should be taken into account. The main feature of the floor screed at the calculation stage is the thickness of the applied solution, this point should be taken into account when determining the area. In some cases, it is more relevant to divide the entire surface into rooms with approximately equal horizontal level marks.
The next step is level determination. This process boils down to determining the highest point in the horizontal floor surface. Such a point is located using a laser level, or with a lace. After completing this procedure, the thickness of the screed can be determined with an accuracy of 86%.
Determine the level - the upper point of the floor under the screed Having found two quantities, one of which is the thickness, and the other is the coverage area, we can find the volume of concrete that we need by simply multiplying these two numbers. But finding the volume is not all, the main thing is to understand how much material is needed to make concrete in such an amount. To do this, it is necessary to refer to building codes and regulations, which state that the preparation of one cubic meter of concrete requires 490 kilograms of cement. A classic floor screed is prepared in a ratio of 1/3, where one part is cement, and three is sand, so you can simply determine the amount of sand you need. So, summarizing the screed calculator:
- H * S * 1.02 \u003d amount of concrete. (Н- screed height, S- area, 1.02 - consumption coefficient)
- Concrete amount * 0.5 \u003d cement amount
- The amount of cement * 3 \u003d the amount of sand
Screed tools
For a fruitful leveling of the floor under a warm floor using a cement screed, you will need a number of tools necessary for high-quality and quick installation:
- The main tool for such a laborious process is a concrete mixer; it will not be possible to stir a large amount of cement with simple shovels, or it will be a very long process.
- Of course, one cannot do without good shovels and trowels, they will be needed to prepare the mortar, fill in the sand and pour the screed.
- Wheelbarrow and buckets, when working on a large volume, you cannot do without a small garden or construction wheelbarrow, buckets are also suitable in extreme cases, but with this type of work, the speed will leave much to be desired.
- The rule is a device for leveling the screed along the beacons. It is the rule that will be responsible for the evenness of the screed. With its help, the surface is leveled and when plastering vertical surfaces.
- Laser and normal level. The laser level is necessary for the correct search for the top point of the floor. Determining the upper value correctly will help save material costs. A good laser level may seem expensive, but it can be rented. The correct skipping of the horizon will save both time and effort. The usual level is indispensable when placing beacons along which the floor will be leveled.
We prepare tools for screed installation On the construction market, you can find various types of beacons for floor screed, usually a perforated metal "T" -shaped profile. But you can also use a simple ceiling profile for drywall, it has a large abutment surface and, when carrying out the rule, will not allow mistakes. When calculating the material, you need to take into account the step of the beacons, usually it is 60 centimeters, but some masters also make a larger step up to 80 centimeters.
Installing beacons for floor screed The order of work of the screed device
General rule of thumb for all concrete work. The substrate should be dry and clean, or better, primed with special deep-penetrating primers.
- Find the highest point on the floor. For this, horizontal skipping is made along the walls of all rooms, after which the highest points of the floor are visually determined. By setting the laser level, you can determine the highest point with a tape measure.
- Exposed at the highest point of the lighthouse. The lighthouse is placed on a level on a thick solution. The mortar can be tile adhesive or thick sand-cement mortar. From the first lighthouse, others are exhibited strictly at the same level and with a certain step.
- All beacons at the time of the screed must be securely installed, the solution on which they are held must dry completely!
- Solution preparation and pouring. Preparing and pouring the solution onto the floor is the most difficult physical labor in the floor installation. But if the first steps are performed correctly, then further work will go without problems.
- Particular attention should be paid to leveling the floor with the rule. Correct work with the rule is a guarantee of the correct floor plane, without pits and dips.
Level the floor with a concrete screed using the rule If the screed is mounted throughout the house, then ending it with rooms is a good idea for installation.
A prerequisite for a good result is drying the floor after completing the work. Good room ventilation will help the floor dry quickly and remove excess moisture from the air, which in any case appears when working with cement mortar.
For all the seeming simplicity of this event, and the simplicity of the materials used, one should not forget about the calculator , after all, the device of a cement screed is a rather expensive technology and very laborious.
