Specific gravity when disassembling a cement screed. Floor screed options. Cement-sand screed: material consumption
The density of the cement screed. Mass of mortars and inerts in m³ for the materials used by us in the installation of floors, values in a dry state. Standard screed mortar, lightened with perlite, polystyrene granules and heavy granite screening filler.
Standard solution. The density of a semi-dry cement screed in the standard preparation of the mortar varies in the range of 1900-2000 kg / m³. This type of mortar is the standard one that we prepare and use in the device of the screed using semi-dry technology. Such a solution consists of inert materials: Sand with a specific gravity of 1550-1650 kg / m³, depending on the sand fraction and aggregate size. Cement - binder, density (average value) 1500 kg / m³ with a consumption of 375-400 kg. ¼ to sand. Fiberglass - reinforcing additive - 900 gr. per m³ of solution. The weight of a screed 1 cm thick with such a density of the solution is 20-21 kg. per m²
The result of the test, in this example, the density of the solution is 2066 kg / m³
(will open in a new window)
Density of cement screed - 1900 kg per cubic meter
Density of cement screed with heavy filler, granite screening
heavy solution. The density of the heavy solution with fine gravel filler is up to 16 mm. This type of heavy cement mortar, which is used in semi-dry technology, is identical in the composition of the inert mortar to the main composition of the mortar, with the exception of a heavy gravel filler, most often we use granite screenings of a fraction of 5-10 mm. Density of granite screenings varies from 2100 to 2400 kg/m³. From this solution we make a semi-dry screed for rooms with high loads during floor operation and high strength, for example, a parking garage. The solution with the introduction of filler granite chips has a density of 2300-2400 kg / m³. The weight fraction of granite screenings in 1m³ of the solution is from 300-400 kg. The weight of a concrete screed with a heavy filler 1 cm thick is 23-24 kg. per m²
Light mortar types, perlite, polystyrene granules.
Lightweight solution. Mortar for screed with a light polyterm filler, polystyrene granules - a light type of polystyrene concrete mortar. We use this type of filler in 2 versions, as a separate filler in the cement mortar to lighten the specific gravity of the solution, in the second version as the main filler with a cement binder.
1 Structural option. Lightweight screed mortar with filler is prepared with a density of at least 600-700 kg / m³ This type of lightweight mortar is in most cases used on roofs on concrete floors without loss of bearing capacity under welded rolled waterproofing.
2 Option heat-insulating. We use lightweight polystyrene concrete mortar as an alternative to expanded clay, as a light base before installing a semi-dry standard screed in cases where the floor needs to be raised to a height of more than 100 mm, including on problematic bases with low bearing capacity. Also, this type of mortar has good thermal insulation characteristics at a mortar density of the D150-D400 brand and is used by us as a heater. More about polystyrene, wider destinations on the following pages "lightweight floor constructions" "material characteristics"
As an alternative for a lightweight filler, perlite can be used, we use this material as an underlay under the floors when installing a screed, as well as a filler in a cement mortar. An example of the use of perlite, see the publication on our work on the installation of floors at the construction site of the house of culture in DK Marfino floor screed with perlite
Weight indicator of cement-sand screed per 1m2, features of cement mixtures. Cement sand screed weight 1 m3
- 1 bag (50 kg) of cement;
- 27 liters of water.
Work order
dekormyhome.ru
The weight of the cement-sand screed per 1m2 - how to calculate and features of the mixture
When preparing the base for any type of flooring, screed is a durable and reliable way to provide a smooth, strong surface. Not all coatings require a level floor, but there are a number of reasons why you will need it:
- the need to drain;
- the unsuitability of the old foundation;
- when installing underfloor heating.
Despite the difficult pouring process, screed is still a reliable leveling method. About the features of the cement-sand mixture and about pouring - later in the article.
This screed is a mixture of cement and sand, into which special substances are mixed. Such a mixture is prepared independently - purchase the necessary components, or purchase ready-made mixtures in the store. Ready mixes are produced in two types: dry, which are kneaded, and wet, ready to use.
Homemade blend If we are talking about the first floor, then the use of home-made mixtures is acceptable, but starting from the second floor, store-bought ones have a clear advantage. This is due to the fact that the finished mixtures have a fixed weight and improving additives, which cannot be guaranteed when preparing the mixture by eye.
Working with ready mix The cement-sand screed itself, or DSP, in its pure form consists of sand and cement in a 4: 1 ratio. Water is added based on the fact that for every kilogram of cement there is ½ liter of water.
Features of the DSP
Cement-sand screed is a durable way to level floors. In addition to strength, it has a number of positive characteristics:
- does not pass harmful substances;
- conducts heat;
- good sound insulation performance;
The only drawback is the weight of the screed. Depending on the thickness of the layer, it ranges from 22 to 140 kg/m2. For this reason, it is imperative to take into account the strength of the floor - the exception is the first floors of buildings that are located on the foundation, and basements.
There are a number of other features:
- the mixture dries for a long time;
- installation is difficult;
- requires a lot of material.
The dismantling of such a primary coating is difficult, which makes it difficult to repair underfloor heating if necessary.
However, due to the structure of the mixture, it is used to fill individual sections. This avoids the dismantling of the entire coating and limits the area with surface damage.
DSP weight and material calculation: detailed analysis
Whatever flooring the surface is prepared for, the volumes of the floor screed are taken into account. On average, one centimeter of the DSP weighs 22 kilograms. To calculate the weight, multiply the height of the screed by 22 kg, and then multiply the resulting amount by the footage of the room.
After the result, compare with the capabilities of the bearing floor. If the mass exceeds or comes close to the reserve, it is worth reducing the height of the layer or abandoning the screed - after adding flooring and arranging furniture, there is a risk of exceeding the maximum indicator. This can provoke an emergency.
Finished screed on the ground floor of a private house When calculating material needs, it is necessary to build on the fact that the dry weight of the cement screed is 1800 kg per cubic meter. This is the standard and is taken as the basis for all calculations.
It must be remembered that the volumetric weight also includes various impurities, which:
- improve adhesion;
- increase resistance to moisture;
- reinforce the structure.
Based on their number, the specific gravity also changes.
It should be noted that the purchase costs 15-20% more than the planned volumes. This is necessary because when mixed, the cement shrinks in volume.
- Link element. Necessary for fastening the rough base and walls. Up to 4 cm
- Separate element. It is the base for flooring. Up to 5 cm.
- floating plate. If the mixture area is separated from the walls and floor by another layer. From 5 cm to 7 cm.
Screed for underfloor heating Height affects the weight of the cover. Therefore, it is important to soberly assess the possibilities and necessary characteristics of the base. If you can't match them, look for alternative alignment methods.
For a cement-sand type screed, there is a list of situations in which the use is justified:
- the use of water or electric underfloor heating;
- the presence of only a subfloor;
- the need to create systems for draining and draining water;
- strong relief coating.
Screed reinforcement can be used to strengthen the coating. This is optional, but recommended for durability.
DSP installation rules
Whatever the weight of the resulting cement-sand screed per 1m2, the work process does not change. The list of preliminary works is voluminous:
- setting landmarks - will help not to exceed the desired height;
- surface moistening - the subfloor must be thoroughly moistened for better interaction with the mixture;
- reinforcement is optional.
Filling the floor on the lighthouses Before carrying out any work, tap the subfloor. Pour the broken pieces of concrete and open voids with mortar and allow to dry. It is recommended to use a special primer, which will increase adhesion with DSP.
For convenience, when marking, use laser levels. They are guaranteed to give accurate results.
When preparing a dry mixture, mix the components until the consistency resembles a cream.
Ready mix Pour the finished solution to 1 cm above the mark. This is due to the fact that tamping will follow after - to eliminate excess air. After that, the mass will settle and be flush with the mark.
For reliability, make adjustments using a level.
The last stage is the elimination of landmarks, traces of them.
The drying speed directly depends on the characteristics of the mixture, however, specialized products can also be used. They speed up drying, but can have a negative effect on other additives. Make sure the selected additives are compatible before mixing. Look for the necessary information on the official websites of manufacturers or professional building resources.
In contact with
Needed goods
More than 200 products in the cataloglaminatepol.ru
To create a high-quality and durable foundation for any finishing floor covering, it is necessary to find out the bearing capacity of the entire structure.
The weight of the screed is large enough, and therefore it exerts a lot of pressure on the foundation of the structure.
In cases where, for the performance of work, not a ready-made mixture purchased in hardware stores is used, but a composition prepared independently, accurate calculations should be made taking into account the characteristics of the materials used.
The choice of materials and the preparation of the mixture
DSP or cement-sand screed is a necessary and fairly simple way to level surfaces. To create it, you need sand, cement and water. The amount of each of the components depends on their characteristics. 
So, for example, if cement grade M150 is taken, then three times more sand will be needed. If cement grade M500 is used to prepare the mixture, then sand is taken in accordance with a ratio of 1: 5.
For a 50 kg bag, take 150 kg of sand The use of cement grade M 150 is recognized as optimal, therefore, for this material weighing 50 kg, 150 kg of sand will be needed. As for the amount of water, it depends on the moisture content of the sand.
You can prepare a quality solution by taking:
- 1 bag (50 kg) of cement;
- 15 ten-liter buckets (150 kg) of dry sand;
- 27 liters of water.
The introduction of wet sand into the composition will reduce the volume of water to 25 liters.
The pressure that it will exert on the base of the structure depends on the weight of the cement-sand screed. Accordingly, before proceeding with the work, it is necessary to clarify the thickness of the poured layer.
The screed must be at least 30 mm thick The minimum thickness of the screed is 0.3 cm. Otherwise, after the mortar has hardened, the surface will become covered with cracks. Exceeding the maximum thickness of 0.5-1 cm leads to an excess of the permissible load on the base.
If this value reaches 8-10 cm, then the weight of the cement screed per square meter will be about 150 kg. This is unacceptable and therefore experts recommend not to exceed the established parameters.
The density of the mixture depends on the quality of the material When creating a cement-sand screed 1 cm thick, its consumption will be at least 20 kg per square meter. At the same time, for 1 cm² its weight will be from 15 to 20 kg.
It is necessary to take into account during the creation of a cement-sand screed the density of the composition, which depends on what materials will be chosen by the craftsmen.
According to this parameter, the compositions are divided into:
- Lightweight, the density of which does not exceed 1400 kg / m³.
- Heavy screeds, the specified indicator of which is significantly higher than 1400 kg / m³.
With strict observance of the technology, the specific gravity of the sand-cement screed, depending on the given characteristics of the sand, will not exceed the permissible limits.
In accordance with GOST 8736-77, one cubic meter of sand should contain no more than 1600 kg, and its specific gravity should be 1550 to 1700 kg / m³. For more information on how to make a solution, see this video:
You can calculate the consumption of materials using the existing formula and reference data. When working with cement grade M 400 for the construction of a 3 cm thick screed in a room with an area of 50 m², you will need such an amount of cement and sand, which a simple calculation will help you find out:
The volume of water is determined at the rate of 0.5 liters per 1 kg of cement. Accordingly, 4875 × 0.5 = 2437.5 liters will be required.
Compliance with all these standards will allow you to perform work efficiently and create a solid and reliable foundation for the finish coating.
Work order
It is necessary to start actions with the preparation of the foundation.
To do this, the floors are cleaned of the previous floor covering, the room is freed from construction debris and construction beacons are set up, having determined the horizon with the help of a level.
Arrangement of a sand-cement screed is possible in any premises, the temperature of the base in which does not fall below +5 ͦCelsius.
Having installed the beacons, proceed to pour the screed from the farthest corner Lighthouses are installed on a pre-laid waterproofing layer, which can be used as a polyethylene film. The edges of the canvas lead to the wall so that they protrude at the level of the screed.
They start pouring the screed from the most inaccessible places in the room, but if a door is provided in it, then it is important to make sure that the doorway is not blocked.
After the solution on which the beacons are installed has hardened, the prepared mixture is poured onto the base, filling one strip with it. Using the rule, the solution is leveled, and only after the first strip is ready, they begin to pour the solution into the second. After 12 hours, the beacons are removed, the resulting space is filled with a solution, which will take about 15 hours to completely solidify.
Now prepare the grout mixture and perform manipulations related to grouting the surface. You will need a dry or wet mixture, consisting of equal parts of sand and cement. Rub the surface with the help of special equipment or manually, using a polisher or grater. For all the details of the process of pouring concrete on lighthouses, see this video:
After completion of all work, a smooth, slightly rough surface will be obtained, which must be rolled with a wet roller and covered with plastic wrap. Moisten the screed for at least seven days, after which the film is removed.
Similar articles:
gurupola.ru
floor and screed weight per 1 m², DSP and device, do-it-yourself mixture, density 5 cm
Cement-sand screed has a long service life and good strength The installation of more floor coverings requires a level, smooth surface. And the most popular method is to fill the floors with a concrete screed. This process is labor-intensive and requires: skills and experience; the use of quality materials; exposure for a certain period of time. Despite the long drying time, DSP is popular in our country. Let's talk in more detail about the types and arrangement of floor screed.
Varieties: cement screed
According to the type of mounting, experts distinguish several types of screeds:
- Svyaznaya. Usually used in high-rise buildings - the DSP here serves to align the floor slabs. To make a reliable foundation, you need good adhesion - connection - of the poured layer with the old one. Therefore, the type of screed is called - connected. Its minimum layer is 3 cm.
- Incoherent. With this type of base, the new layer is not bonded to the old floor. For example, mounting on a pre-sanded concrete base or on a layer of insulating material. The minimum thickness of the screed is 5 cm.
- floating. If the floor needs to be made warm, it is unrealistic to achieve a rigid adhesion of the screed to the base. When the insulating material changes its dimensions, the concrete layer arranged above also lowers / rises. Therefore, such a screed is called - floating. To create rigidity, which requires a minimum thickness of the cement-sand mass in this variant of the screed, not less than 6.5 cm.
All these types of DSPs have their own characteristics during installation, but they are united by the use of sand-cement mortars. Sometimes, to increase reliability, fibers are added to the composition for reinforced. Usually it is fiberglass, there are additives from small pieces of steel wire, but they are not often used. Mortar reinforcement is required when the concrete layer is large.
Chaotically arranged fibers significantly increase the strength of the base and practically no cracks appear in it.
According to building regulations, the minimum thickness of the screed is 3 cm. With the thinnest layer during the period when the mortar dries, the canvas will crack, the base will be unreliable. At the same time, concrete is heavy: a 10 mm layer weighs approximately 20 kg per 1 m2. And since the minimum thickness is 3 cm, then the minimum weight of 1 m2 of screed will be 60 kilos. Not every foundation is able to hold such a load without consequences. Because of this, the foundation can sit down and crack. To reduce the weight of the screed, light binders, for example, expanded clay, are included in the solution. The mass of 1 cm of expanded clay concrete is 16 kilos. With volumetric poured footage, the difference is significant.
Handmade cement floor screed in the bath
To perform the alignment of the floor slabs, a connected screed is used. In apartment buildings, floors between floors are usually made of reinforced concrete slabs. Such a sand-cement screed is also suitable for a bathhouse structure on a slab foundation. But only when waterproofing and insulation are not needed.
This type of screed is also suitable for:
- Porch;
- Tambour;
- Verandas, etc.
The main task of preparation in this case is to create the best possible adhesion of the concrete layer to the base. To do this, it is necessary to clean the surface very well from debris and dust. It is better to do this using a vacuum cleaner - you cannot remove all the dust with a brush. It is not necessary to level out irregularities; on the contrary, if there are flat areas, grooves / pits must be made in them. Repair only very deep cracks correctly, and then do not level the surface. After all the dirt is removed, the surface is generously primed.
The primer can be poured onto the floor, and then treated with a brush.
The primer must be allowed to dry for at least 8 hours, the drying time depends on the humidity and temperature conditions in the room. After drying, you can install beacons and pour the mixture (cement, sand) with your own hands. In order to prevent the destruction of the screed or vertical surfaces due to the different magnitude of expansion when changing temperature conditions (different density), a damper tape must be arranged around the perimeter of the room. This plays a role especially when the vertical surfaces are wooden, which is almost the rule in baths.
The tape must be rolled out and grabbed to the walls. In height, it is usually larger than the screed, but when the cement sets, it must be cut to the floor level. If waterproofing of the DSP is required, then it will already be incoherent. Here the preparation is different. A waterproofing material is arranged on a clean and even surface. If the base is uneven, for example, the surface of the foundation-slabs in the bath, then it must be leveled. For this purpose, the leveling connection DSP described above is used.
After it dries, it is necessary to decompose the waterproofing and pour another layer of concrete (a special tape is also required). Due to the fact that the base does not absorb moisture during this installation, shells and pores may appear. Therefore, the solution must be treated with a vibrator. With an increase in the thickness of the floor surface screed up to 100 mm, the problem is resolved by itself, but the costs and weight are greater. It is important that the filling technology is observed.
The device of a cement-sand screed floating
This type of screed can usually be found when making floors in country houses and baths. Floating DSP is also used in the construction of a water-heated floor and some types of electric floors. It is she who makes it possible to make a floor surface in the bath on the ground. The thickness of the layers of the cake and building materials are selected individually, based on the climate in the region, but the principle is the same.
There can be many and varied layers here, but the main distinguishing feature is that there is no connection with vertical surfaces or the base. Such a floor does not react to shrinkage of the foundation or a wooden frame. Therefore, it is right to arrange such floors in a newly installed bath. Although, it is still better to wait until the shrinkage is carried out.
Experts give some advice:
- The recommended minimum thickness is 65 mm.
- First of all, it is necessary to lay a layer of 2 cm and leave it for 24 hours.
- Aligning the rest of the part will already be easy, since the first layer will compact under its own weight.
To increase the strength of a high screed, it should be reinforced before cementing. Fiber is often used. For baths, a mesh consumption with a cell of 200 mm is quite suitable. After the screed has set, you can lay tiles on the floor or make a wooden floor - pouring (leaky) or airtight. During installation, it is important to follow the rules of SNIP and the proportions according to the scheme. If tile is laid, then grout is needed.
Semi-dry cement-sand mixture for floor screed
If additives / reinforcing additives are included in the standard DSP of the screed, less water is needed in order for the concrete to gain strength. Additives or additives make this process faster.
They are different, give different qualities:
- Frost protection additives. They accelerate the maturation of the screed, at the same time, reducing the temperature regime of water freezing. They are used if the temperature has become less than +5 ° C.
- Fiberglass or pieces of steel wire significantly increase strength, and even under heavy loads, the DSP will not crack.
- For water repellent qualities. They are suitable for pouring DSP in the washing room and steam room of the sauna room, bathroom, toilet room or kitchen.
- How much to add additives is indicated by the instructions on the packages. They vary within 0.3-10% of the cement mass. That is, for a kilo of cement, you need to add from 3 to 100 grams of additives.
When creating a semi-dry screed, much less water is needed. First, dry ingredients are mixed well, then water is poured. But the solution should be like wet sand. If you take it in your hand and squeeze it, moisture should appear, but the water should not flow, it should remain a lump in your hand. This is the correct consistency of the solution. Due to the fact that such a solution is not so plastic, its alignment is difficult: more labor will be required. When laying the mixture between the guides, it must be compacted. You can do this using special surface vibrators for concrete, or you can simply crush it with your feet. There are special additives, thanks to which the mass is self-compacting.
Weight of cement-sand screed per 1m2
On average, 1 cm of the CPS has a specific gravity of 22 kilos. To calculate the consumption, multiply the height of the screed by 22 kg, after which the resulting amount is multiplied by the total meters of the room. The result that will be obtained must be compared with the capabilities of the main overlap. If the mass is larger or comes close to the reserve, it is necessary to reduce the height of the layer or not use the DSP. This can cause an accident. The weight of the DSP in dry form is 1800 kg per m3. This is the standard.
It must be remembered that the volumetric weight includes various kinds of additives, which:
- Increase adhesion;
- Improve moisture resistance;
- Makes structure stronger.
Based on their number, the specific gravity also changes. Coated thread is suitable for marking while working. The m150 screed brand is well suited for pouring. Also an excellent solution for the bath is the leveling mixture of CPR.
Care of DSP for floor screed
It is important to carry out care after pouring the DSP.
It consists of the following activities:
- The next day after pouring, the floor must be moistened;
- Cover with PE film and leave for 4 days;
- The next 8-12 days should be moistened, but not much;
- A week later, the floor will already ripen.
You can walk on it after 30 days.
Cement floor screed (video)
It is possible to do a floor screed in an apartment building, house or bathhouse on your own. It's not very easy, but it's not that difficult either. The main thing is to understand the technology and get the first experience.
Attention, only TODAY!
oteplicah.ru
Consumption of cement-sand mixture per 1m2: screeds and m300
Each construction of a structure must begin with the calculation of the amount of materials required for this action. Accordingly, various questions arise regarding the quantity, quality and standard proportions for the mixture.
Knowing the volume of materials, it is possible to significantly save on the purchase of only the necessary components. Also, you do not have to go for an additional amount of the mixture, only if unplanned work has arisen.
Characteristic
As a result of mixing cement and sand, a mixture is obtained that, when water is added, becomes usable. In large-scale construction, self-preparation of the mixture is often used, although there is also a specially prepared DSP at the enterprise.
If you purchase a factory mixture, then in its composition, in addition to the basic components, there are plasticizers and other additives. They are used to make the solution uniform, plastic, some add frost-resistant additives to work in the cold season.
The preparation of cement mortar is highly dependent on the brand of cement and the required mortar. From this, the required ratio of ingredients is calculated.
The number of components strongly depends on the purpose of the mixture, so some types of work involve a smaller amount of sand (concreting) or vice versa more (masonry).
For more flexible preparation of the mortar, sand and cement should be manually mixed, a ratio of 1 to 3 is used as standard, but it can also be 1 to 2-4. Mixtures are also different, a huge range covers most ordinary needs.
To avoid unnecessary costs for materials that are not useful in construction, a calculation should be made. It will help you more accurately find out the required amount of the mixture.
But it is not always possible to achieve an exact value due to the lack of information about the density of the material, because it may differ.
The purpose of cement plays an important role when choosing a brand:
- m100 is used only for plastering walls, the approximate consumption is 550-570 kg / m3;
- m150 is usually used for laying bricks, cinder blocks or installation, in rare cases for concreting, the consumption is 570-590 kg / m3;
- m200 masonry and assembly mixture must be prepared 590-620 kg / m3;
- m300 is used for concreting and pouring areas on which an increased load falls, consumption 620-660 kg / m3;
- m400 for highly durable concrete structures, consumption ranges from 660-710 kg/m3.
When calculating the necessary materials per 1 m3, it is possible to accurately determine the grade and quantity of the DSP. They are also interchangeable, if the use of M150 is recommended, it is possible to replace the cement with M200 and M100 without much damage to the calculations and structural strength.
Consumption of materials per 1 m2, 1 m3
The calculation of the amount of cement-sand mixture is made on the basis of the cubic capacity of the room or site. The footage is easy to calculate using an ordinary tape measure, and then multiplying the length by the width, you get the area of \u200b\u200bthe place that needs to be filled with cement.
The key parameter is the layer depth. Depth is a necessary indicator, as it directly affects consumption. On average, if the layer thickness is 10 mm, then 22 kg per m2 is needed. For a 10 cm screed, 50 kg of M400 mixture is required.
If the area of the room is 100 m2, and the layer depth is 10 cm (to be converted to m), then it will turn out: 100 * 0.1 = 10 m3.
It is very rough, but on average 555 - 713 kg of the mixture falls on 1 m3, more accurate data should be contained on the packaging. If mixed by hand, then it is necessary to approximately calculate the required weight. The rule is that the higher the grade of the solution, the greater its weight.
M400 cement is characterized by a maximum weight in the range of 700 kg per m3. As the brand decreases, the weight also decreases. M100 weighs approximately 550-600 kg per 1 m3.
This pattern is true for both manual and winding mixtures. The amount of dry mixture does not reflect its volume as a solution, 1 liter contains about 1.4 kg of dry mixture. Thus, if it is necessary to fill in 10 m3, then the further calculation will be (using the example of M300):
(10 m3 * 650 kg)*1.4 = 9100 kg
Thus, to fill 10 m3, you will need a mixture in the amount of 6500 liters or 9100 kg of dry mixture.
Calculation of materials for plaster
It is rather difficult to determine the quantity and cubic capacity of consumables for plastering a wall. The reason is that the walls are rarely even, they usually have ledges, recesses and the layer in each section is somewhat different.
It is necessary to determine the average depth of the layer in order to calculate the volume of the cement-sand mixture. For example, 5 mm layer accounts for 7 kg of the mixture per 1 m2.
The thickness of the plaster varies between 5 - 30 mm. When plastering, it is worth considering the number of additional components, as slaked lime is often added.
For large volumes of work, a batch is produced consisting of:
- 4 bags of cement;
- 40 kg of slaked lime;
- 550 kg of sand;
- 100 liters of water.
So many ingredients comply with regulatory rules per 1 m3.
When plastering, the standard proportion of cement with sand is 1 to 3. If the layer thickness does not exceed 12 mm, then 1 m2 of plaster will draw approximately 1.6 kg of the M400 brand mixture, if you use M500, then the amount will drop to 1.4 kg.
Plasticizers, liquid soap and the like should not be taken into account, since their proportion is insignificant. It is not recommended to make large batches at a time, since the solution may harden if it is not possible to smear it within 1-1.5 hours.
The laying of a brick wall should be carried out using a mixture with a brand corresponding to the brick. Such a structure is obtained as durable and uniform as possible. In general, M100-M200 is used for masonry.
So it is necessary to take into account the quality and strength of the material (both mixture and brick). Using the basic standards for 1 m3 of wall, approximately 250 kg of the M100 mixture should go.
Cement is the main and main component for most buildings and structures. Here is how to properly dilute the cement.
The use of sand is a necessary measure when carrying out any construction or repair work. It's all about quartz sand.
Renovation of the kitchen is a very important and serious matter and it must be approached with all responsibility. By clicking on the link, get acquainted with the wall panels for the kitchen made of plastic with photo printing.
If you prepare the solution yourself, then you should observe a ratio of 1 to 4. Liquid should be added to the DSP, which is usually half the total weight of the mixture.
Of course, the laying of the wall is highly dependent on the thickness of the seams, as the space between the bricks expands, the amount of mortar per 1 m3 also increases. The thickness of the walls also plays an important role, so for a facing brick laid in 1 layer, cement is required significantly less than for load-bearing walls in 2-4 bricks.
Regulatory documents contain detailed recommendations and the dependence of wall thickness and the amount of mortar used.
Examples are presented based on ordinary bricks and the required amount per 1 m3:
- wall 12 cm - 420 bricks and 0.19 m3 of mortar;
- wall 25 cm - 400 bricks and 0.22 m3 of mortar;
- wall 38cm - 395 bricks and 0.234 m3 of mortar;
- wall 51cm - 394 bricks and 0.24 m3 of mortar;
- wall 64cm - 392 bricks and 0.245 m3 of mortar.
The screed is characterized by the presence of increased pressure on the finished site. This characterizes the increased need for screed strength. Therefore, a mixture of M300 or M400 should be used. In some cases, M200 is also used, but only where high strength is not required.
The main nuance with the screed is its depth, the larger it is, the more solution will go per 1 m2. In general, the screed rarely exceeds 30 cm; an additional layer of crushed stone or gravel is laid out from below to create a platform.
It is necessary to calculate the number of DSPs after the formation of a platform from bulk materials, if such is planned.
The calculation of the required amount of materials can be made based on the parameter 1 m3. First, the area and depth should be converted to this value. A room with an area of 50 m2 and a screed depth of 20 cm will require 50 m2 * 0.2 m = 10 m3.
Further, by selecting the brand of mixture required for the task, usually M200 or M300, you can determine the amount of purchased material. In addition to the brand, the weight per 1 m3 also depends on the manufacturer and the components that it was used.
For M200 per 10 m3, it is necessary to use a flow rate of about 600 kg / m3 * 10 m3 = 6000 kg, while taking into account a draft of 1 to 1.4. That is, you should acquire 8400 kg of mixture for 10 m3 of screed.
For M300, the volume is slightly different 650 kg/m3 * 10 m3 = 6500 kg. When taking into account some settling during the preparation of the mixture, the volume becomes approximately equal to 9100 m3.
Regardless of the method of preparation (manually or ready-made DSP), such a calculation will help you roughly navigate the amount of materials. But when producing the mixture manually, it is necessary to accurately determine the grade of the solution.
For more information about the calculation of materials for screed, see the video:
It should be borne in mind that each individual mixture may contain a different number of components and their ratio or quality. Thus, it is quite difficult to accurately determine the weight, only approximately take the average statistical data based on the brand of the mixture as a basis.
Not only the amount of sand matters, but also its fraction. Fine-grained sand is heavier than coarse sand. An increase in emptiness, with a large fraction, leads to lightening of the entire solution. A self-prepared solution cannot be counted at all, since each batch will be slightly different from the previous one.
In general, the grade of the composition may vary somewhat from the recommended parameters, but in this case, a larger amount of mortar will go per 1 m2, which somewhat compensates for the decrease in strength.
Similarly, with a larger brand, 1 m2 will have a smaller amount of the mixture. So when pouring the site, you can use other brands instead of M300, both M200 and M400, the results will differ slightly.
The freshness of cement plays an important role. If the cement was produced more than 1 month ago, then its characteristics are slightly reduced, by approximately 10-15%. Thus, a little more cement is added to the solution.
Drying of the solution from the moment of preparation takes about 1-1.5 hours. In the future, it ceases to be suitable and begins to form into a single whole. Even adding water will not restore the proper elasticity of the mixture.
Conclusion
Cement and DSP are needed for the construction of premises and their improvement inside, but it is very difficult to accurately determine the amount of materials. Spending a lot of time on the daily purchase of a new portion of the DSP, there is a lot of wasted time and there are additional costs for fuel.
Using the methods described in the article, you can correctly determine the total amount of the mixture and purchase it at a time.
strmaterials.com
Weight indicator of cement-sand screed per 1m2, features of cement mixtures
When preparing the base for any type of floor covering, screed is a reliable and durable method of providing a smooth, strong surface. Not all floorings require a level floor, but there are a number of reasons why this will be required:
- the need for a drain;
- the worthlessness of the old foundation;
- during installation of underfloor heating.
Regardless of the time-consuming pouring process, screed is still a good way to level. About the specifics of the cement-sand mixture and about pouring - further in the publication.
The result of the finished DSP in the form of a platform
What is a cement-sand screed?
This screed is a mixture of cement and sand, into which specialized substances are mixed. Such a mixture is prepared with one's own hand - buy the necessary elements, or buy mixtures in the store that are ready for use. Mixtures that are already ready for use are produced in two versions: dry, which are kneaded, and wet, ready for use.
Homemade mix
If we are talking about the first floor, then the use of self-prepared mixtures is allowed, but starting from the other, the store ones have a certain advantage. This can be explained by the fact that mixtures that are ready for use have a fixed weight and improvers, which cannot be provided during the preparation of the mixture by eye.
Working with ready mix
The cement-sand screed itself, or DSP, in its pure form consists of sand and cement in a ratio of 4: 1. Water is added taking into account the fact that for every kilogram of cement it is necessary? liters of water.
DSP specifics
Cement-sand screed is a reliable floor leveling method. In addition to strength, it has a number of positive parameters:
- does not pass substances that are harmful;
- passes heat;
- good indicators of sound insulation;
One downside is the weight of the screed. Depending on the thickness of the layer, it varies from 22 to 140 kg/m2. Because of this reason, it is imperative to provide for the reliability of the floor - as an exception, there may be lower floors of buildings that are placed on the foundation, and basement rooms.
There are a number of other options:
- the mixture dries for a long time;
- installation is difficult;
- requires excessive consumption of materials.
Demolition of such a primary coating is difficult, which makes it difficult to repair underfloor heating if necessary.
However, due to the structure of the mixture, it is used to fill some areas. This makes it possible to avoid the dismantling of the entire coating and bypass the area with surface damage.
DSP weight and material calculation: detailed analysis
Whatever flooring the surface is prepared for, take into account the volume of the floor screed. On average, one centimeter of the DSP weighs 22 kilograms. To calculate the weight, multiply the height of the screed by 22 kg, after which the amount that turned out to be multiplied by the footage of the room.
After the result, which turned out to be compared with the possibilities of the bearing floor. If the mass exceeds or comes close to the reserve, it is worth lowering the layer height or abandoning the screed - after adding flooring and furniture placement, there is a risk of increasing the largest indicator. This can lead to a dangerous situation.
Finished screed on the lower floor of a privatized house
When calculating the financial need, one should start from the fact that the dry weight of the cement-based screed is 1800 kg per cubic meter. This is considered the standard and is taken as the basis for all calculations.
It must be remembered that the volumetric weight also includes various impurities, which:
- improve bonding;
- increase resistance to moisture;
- reinforce the structure.
Based on their number, the specific gravity also changes.
I would like to highlight that the purchase costs 15-20% more than the planned volumes. This is necessary, because when mixed, the cement shrinks in volume.
When to apply the IPS: layer height
- Link component. Needed to secure the rough base and walls. Up to 4 cm
- Separate component. serves as a base for flooring. up to five centimeters.
- floating plate. If the mixture area is fenced off from the floor and walls with another layer. From 5 cm to 7 cm.
Heated floor screed
Height affects the weight of the cover. Due to this, the main thing is to sensibly evaluate the possibilities and the necessary characteristics of the base. If you can't connect them, look for alternative alignment methods.
For a cement-sand type screed, there is a list of circumstances in which use is reasonable:
- use of water or electric floor heating;
- the presence of only the base floor;
- the need to create drainage systems and drainage;
- strong relief coating.
To strengthen the coating, reinforcement of the screed can be used. This is not considered to be just a mandatory item, but it is advised to ensure strength.
DSP installation rules
Whatever the weight of the resulting cement-sand screed per 1m2, the work process does not change. The list of preparation works is voluminous:
- setting landmarks - will help not to exceed the required height;
- moistening the surface - the "dirty" floor must be thoroughly moistened for better mutual action with the mixture;
- reinforcement - is not considered simply mandatory.
Filling the floor on the lighthouses
Before carrying out any work, knock on the "dirty" floor. Pour the broken pieces of concrete and open voids with mortar and allow to dry. It is best to use a specialized primer, which will make it possible to increase bonding with DSP.
For comfort when marking, use plane builders. They are guaranteed to give accurate results.
When preparing a dry mixture, it is necessary to mix the elements until the consistency resembles a cream.
Ready mix
It is necessary to fill in the prepared solution 1 cm above the mark. This can be explained by the fact that tamping will follow after - to eliminate excess air. After that, the mass will not settle and will be on a par with the mark.
For fidelity, carry out the correction by applying the level.
The final step is the removal of landmarks, traces of them.
The setting speed depends on the properties of the mixture, but special tools can also be used. They speed up drying, but will have a negative effect on other additives. Make sure the compatibility of the selected additional funds before starting the batch. Look for the necessary information on the official websites of manufacturers or professional building resources.
What weight and height should the child have? - Doctor Komarovsky
offthevylc.ru
Cement sand screed
Cement-sand floor screed is the most common type of flooring foundation. This is the embodiment of reliability and long-term service in the arrangement of residential and office premises in civil engineering. Despite the abundance of new technologies that the rapidly developing industry operates today, the cement-sand screed device remains the leader in capital construction.
Very often, the decisive factor in choosing the type of screed is its weight. This nuance can be quite significant if it is necessary to make the floor even in an apartment with large height differences along the base. Roughly speaking, if the floor slabs are very uneven: in one room you need to make a screed 4-5 cm high, and, for example, in the corridor the thickness will be from 8 to 10 cm. It turns out that in some rooms the weight of the screed will be very large . And such a load may exceed the permissible.
For example, let's compare two rooms with an area of 14 square meters with a screed thickness of 8 cm:
cement screed has a mass of about 2400 kg
If desired, the weight of the cement screed can be reduced by using coarse expanded clay, polystyrene or expanded polystyrene as a substrate. The layer of such a substrate can be 4 cm in this case. Thus, we will reduce the weight of a traditional cement-sand screed by almost half. If we neglect the mass of expanded clay or other bulk material, then it will all look like this:
cement screed has a mass of about 1200 kg
dry screed weighs about 650 kg
Making a cement screed less than 4 cm thick is not recommended, so we considered its minimum weight. Similarly, the Knauf dry screed is performed with a minimum layer of 4 cm. To make it more convenient for you to use these data by square meters, we will select them separately:
cement screed weight per 1 sq. meter with a layer of 4 cm will be about 85 kg
each additional 1 cm will add about 21-22 kg.
dry screed weight per 1 sq. meter with a layer of 4 cm will be about 30 kg.
each additional 1 cm will add about 4-5 kg*
*Since with a minimum layer of dry screed the floor element has the bulk of the mass, and the dry filling weighs very little, after 4 cm an increase in thickness will have a slight increase in mass.
Here we looked at examples of the simplest designs of dry and cement screeds. The weight of 1 square meter may differ when using a variety of floor structures (using additional lightweight materials, laying an additional layer of GVLV, etc.). But we hope that the principle itself will be clear to you.
If you need an individual calculation of the weight and thickness of a dry screed, then call us, we will answer all questions and perform high-quality installation of the Knauf bulk floor.
We work in Moscow and the nearest suburbs.
Cement-sand screed (DSP) is a simple and quick-to-implement method for leveling floor coverings. With the help of DSP, stone and concrete floors can be leveled, preparing them for the installation of a finishing floor. Among its advantages are durability, resistance to deformation under the influence of loads of any type and low cost.
In this article, the device of a cement-sand screed is considered. You will learn how to make a calculation of materials, prepare a solution, install beacons, fill and level the DSP.
Weight, curing time, types of DSP
The only factor that limits the possibility of using a cement-sand screed is its heavy weight. So, the weight of a square meter of a DSP 1 cm thick can reach up to 15 kg / m 2. At the same time, the minimum thickness of the cement screed is 3 cm, so in practice (taking into account the weight of the insulation and the front floor covering - laminate or parquet board) 1 m 2 of the screed weighs at least 50 kilograms. In most cases, the thickness of the poured DSP is 5 cm, if a tile is placed on such a screed, then its weight will be about 100 kg / m 2.
As a result, the use of a screed for leveling the floors of the first floor is not limited, however, in multi-storey buildings it can only be used in rooms where the load-bearing floors are designed for a load of at least 300 kg / m 2.
The period during which the cement-sand screed dries directly depends on its thickness. So, DSP 40 mm thick dries within 7 days, and with each increase in its thickness by 1 cm, 5 additional days are needed to set strength.
There are two ways to level the floor with a screed - using a ready-made mixture for the DSP or preparing a sand-cement mortar with your own hands. According to the provisions of GOST No. 28013, store mixes are classified into two varieties: dry - kneaded directly at the construction site, and wet - supplied ready-to-use. Among the proven mixtures with the optimal price / quality ratio, we highlight such compositions as Knauf OP-135, Ceresit CN-69 and Knauf UBO. These are dry mixes, which are sold in 25 kg bags.
The Knauf-UBO mixture deserves special attention, to which polystyrene foam granules are added. Due to such a filler, the screed receives additional thermal insulation capabilities, which is especially important when leveling a cold floor on the first floor of a house. The consumption of the solution prepared from the Knauf-UBO mixture per 1 m 2 of the floor is 17.6 kg with a screed thickness of 3 cm. The coating density is 600 kg / m 3, the strength after hardening is 1 MPa.
There are also compounds with an admixture of fiber, which increases the strength and resistance of the screed to cracking, which makes it possible not to use a steel mesh when pouring it. The use of fiber-optic DSP allows you to save money and time, compared with the arrangement of a classic analogue, while the cost of such a mixture does not differ much from mixtures for conventional screeds.
1.1 Composition, consumption of materials
The composition of the solution for pouring the screed includes water, sand and Portland cement. It is necessary to use cement for class M400 screed, the numerical nomenclature in this case means that after hardening, the concrete can withstand a load of up to 400 kg / cm 2.
The proportions of the components in the solution are 4 parts of sand to 1 part of cement. The amount of water is determined based on the weight of the added cement - 0.5 liters per kilogram. The prepared solution should have a sufficiently thick consistency so that after pouring it does not spread when trying to level the screed with a profil.
The average consumption of cement for a 5 cm thick screed is 15 kg/m2. You can accurately determine its amount by performing a calculation. Here is an algorithm for such a calculation using the example of a DSP with a thickness of 4 cm and an area of 25 m 2:
- We determine the volume of the screed by multiplying its area and thickness: 25 * 0.04 \u003d 1 m 3.
- Taking into account the proportions of the composition 4:1, we calculate the volume of each of the components: ¼ = 0.2 m3.
- We calculate the actual volume of 4 parts of sand: 4 * 0.2 \u003d 0.8 m 3 and one part of cement: 1 * 0.2 \u003d 0.2 m 3.
- Based on the reference data, we determine the specific gravity of 1 m 3 of sand, which is 1600 kg, and cement - 1300 kg.
- We calculate the consumption of materials for concreting the screed of given dimensions: cement: 0.2 * 1300 = 260 kg, sand - 0.8 * 1600 = 1280 kg.
Thus, the calculation showed how many materials are required to fill the screed. However, they need to be purchased with a margin of 15-20%, since in the process of preparing the mortar, the cement shrinks in volume.
1.2 What you need to know when pouring the screed? (video)
2 DSP potting technology
Preparation of the subfloor before concreting the screed begins with its cleaning. It is necessary to knock out the entire floor or floor slab and remove the exfoliated pieces of concrete, the resulting holes are filled with mortar. Next you need to cover the surface with a primer, which will increase the adhesion between the base and the DSP. It is necessary to prime in two layers, the second is applied after the time necessary for the complete drying of the first layer.
It is most convenient to mark the screed using a laser level. The device is installed at the highest point of the floor of the room, its pointers are placed along the walls of the room and appropriate marks are made on them.
The next step is to install beacons. These are metal profile guides, along which the screed will be aligned after pouring. There are two types of beacons - conventional steel and mortar, we recommend using the first option, as it is less labor intensive and provides better alignment accuracy. The width between the beacons to be installed should be 20 cm narrower than the width of the wire used.
Lighthouses sit on a mortar cake, you can also use pieces of brick and mounting foam. The upper edge of the beacon should be along the line of the upper contour of the screed. Keep in mind that the beacon should not sag in length; to avoid this, you need to use a sufficient number of stands.
Next, the solution is mixed. Proportions: 1 part cement, 4 parts sand and 0.5 liters of water per kilogram of cement. It is necessary to start concreting from the part of the room farthest from the door - the solution is poured onto the base from a bucket and leveled over the beacons with the help of a profil. In this way, sections of 1-2 m 2 are traversed.
After 12-15 hours after pouring, the surface of the screed must be rubbed with a mixture of cement and sand (1 to 1). This is done by means of a special trowel or a hand tool made of foam. In the process of grinding, all irregularities made at the pouring stage are removed from the surface. After grouting, the screed must be moistened with a wet roller and covered with oilcloth, wetting must be repeated daily for 7 days.
A few words about reinforcement. It is done if it is necessary to compensate for the bending and vibration loads acting on the screed, which may be present in industrial premises, or in the case of leveling an elastic, deformation-prone base - lag floor, heat-insulating panels. In this case, the reinforcement frame embedded in the screed or the steel mesh takes on the load, reducing the risk of concrete deformation.
If you are leveling the floor in a residential area with a screed, then most likely there is no real need for reinforcement. If it is decided to reinforce, then it is best to use a road mesh with a cell size of 100 * 100 mm. The mesh is laid on supports - pieces of brick or concrete cakes so that it is raised above the floor by half the thickness of the screed, and beacons are already placed on top of it. There should be a distance of 5 mm between the walls of the room and the edges of the grid. The concreting process itself is carried out according to standard technology.
The cement-sand floor screed device is the most proven and reliable way to level the surface. With its help, the floor is not only leveled, but also additionally gives the necessary rigidity, which will be required in the future. You can buy a ready-made mixture for arranging a screed in hardware stores, or you can cook it yourself.
The composition and proportions of the cement-sand screed.
The composition of the cement-sand screed includes, as the name implies, cement, sand and water. For plasticity, you can add a plasticizer. For a conventional screed, a solution of grade M 150 is used. Proportions to obtain the required grade of cement-sand mixture: for 1 bag of cement (50 kg.) You need to take 150 kg of sand (about 10 buckets with a volume of 10 liters) and about 25-27 liters of water. The amount of water largely depends on the moisture content of the sand. The more moisture the sand, the less water is required.
Consumption, weight and density of the cement-sand screed.
The density of the cement-sand screed directly depends on the choice of materials used. They are divided into light and heavy. Light screed - density up to 1400 kg / m3, heavy - more than 1400 kg / m3. The greater the density of the composition, the higher the strength and frost resistance. When used compositions of any kind. The consumption of a cement-sand screed is not difficult to calculate based on the manufacturer's data (see the back of the bag). The consumption of a cement-sand floor screed is approximately 20 kg per 1 m2, with a layer thickness of 10 mm. In this case, the weight of the cement-sand screed will be approximately 15-20 kg. for every centimeter of thickness.
The minimum and maximum thickness of the cement-sand screed.
The recommended minimum thickness of the cement-sand screed is 30 mm. If the minimum thickness of the screed is less, then small cracks will certainly appear in it. The maximum thickness of the cement-sand screed is limited only by the bearing capacity of the floor and the increased overspending of the material. With a thickness of 80-100 mm, the weight of the screed will reach 150-200 kg per square meter, which is not always acceptable. The optimal thickness recommended by experts is 30-50 mm.
