Concrete floor screed with own hands

Concrete floor screed with their own hands

Different types of screeds

Screed with EPS polystyrene chips

The claydite concrete has good thermal insulation properties. The claydite concrete has sufficient strength, but some fillings and the face layer from the usual mortar will be required for the laying of some coatings. But ceramic tiles can be laid directly on such a foundation.

-Good performance features show screeds with micro-reinforcement with fiber. This technology allows you to dramatically increase the strength of the coating to mechanical stress, to stretching, bending.

Such couplers usually do not give t t cracks, less shrinkage when hardening, they have less dust formation. They are great for underfloor heating systems.

• Concrete floor screed can be made using classic, "wet" technology, or according to dry. Semi-dry screed is a relatively new thing, and not all are ready to test it in practice. In addition, it requires special professionalism in the preparation of the mortar mixture, in the compaction, compaction and leveling of the solution. Most home builders prefer to use proven "wet" technology, about which will go in the article in the future.

Mortar for pouring concrete screed

It is quite natural that, if necessary, pour concrete screed first of all it will be necessary to determine the type of solution. In this issue, some options are possible.

Under the existing canons SNiP , the minimum strength of a conventional concrete screed, regardless of the type of the further of its lining, must be at least M-150( the coating withstands a force of 150 kg / cm²).If the self-leveling is used, then the requirements are still higher - from the M-200.In accordance with these requirements, a solution must be selected.

1. " Classic" concrete mortar used for pouring a conventional floor screed is considered a cement-sand mixture in the proportion of 1: 3."Recipe" this - time-tested and fully justifies itself. However, there are a few nuances, without which can easily damage the future screed :

• For the preparation of concrete, you can not use ordinary "washed" river sand that has not undergone special treatment. Frozen surface will not be strong, will start with time to crumble, crumble and crack. The fact is that the grains of sand smoothed out from the prolonged impact of water outlines, not providing the proper clutch. In this regard, much better career sand, e its faceted grains of irregular shape. However, when selecting, you should carefully consider that in the he did not come across a large number of clay inclusions - this will also reduce the strength of the screed.

The presence of a small amount of gravel component of the fine fraction on the strength properties of the screed will not affect. However, if a smooth surface is required, it will be necessary to sift the sand through a sieve.

• Very important condition for the strength and durability of the screed to be filled becomes the optimum amount of water. It's no secret that some novice home builders, striving for to make easier for themselves to work on pouring and leveling concrete, use excess water, receiving a semi-liquid , easily spreading solution .In this way they lay the "delayed action time" - on the output of the coupler will not have the required qualities.

. Firstly, an excessively liquid solution will definitely give a strong shrinkage upon solidification. A flat surface, in accordance with the level set, in this case is not expected. And secondly, a violation of the cement-water balance will necessarily reduce the strength properties of solidified concrete. The surface turns out to be loose, unbound, with increased formation of dust.

There are certainly specially calculated standards for the amount of water in a concrete solution, but they are usually adhered to by the technology of enterprises producing reinforced concrete structures and large solution knots. In home construction conditions, they often rely on their own experience, intuition and common sense. In addition, accurately calculate the amount of water is very difficult and the from the , that it largely depends on the moisture content of the filler. Sand can be wet, heavy - and this is also water, which will participate in the process of making a solution.

Ideally, the concrete mix should be dense, but sufficiently plastic, so that when it is poured and leveled, there is no air void left in the floor. Approximately you can orientate to the following ratio - a liter of water per five kilograms of cement-sand dry mixture.

It is very difficult to mix the mortar manually with a shovel by means of a shovel. Better for this, use a concrete mixer or a construction mixer of high enough power. First, mix the dry components in a suitable ratio( possible - with a slight moistening), and then very carefully, portionwise, add water.

An important condition for the quality of the future concrete screed is the purity of water. It is forbidden to use industrial water with the content of fats, oils, oil residues and .Dirty fouled tanks should not be used to carry water to the mixing point of concrete.

2. The modern assortment of stainless steel products, available on the market, makes it much easier to fill the screed. For these purposes, ready-made dry mortars can be used.

ratio. Compared with the use of the usual cement-sand mixture, this technology has the a number of advantages:

• For strength and other performance indicators, screeds made from ready-mixed mortars are not inferior to ordinary concrete, and even can exceed it in a number of parameters.
• For the preparation of a solution, a powerful technique or heavy is not needed for manual work - there is enough mixer or even a powerful electric drill( perforator) with a suitable nozzle.
• There is basically no problem with the dosage of components - everything is already provided by the manufacturer, and the master remains only clearly follow the instructions for the preparation of the solution.
• Many solutions made from such mixtures are much lighter, which reduces the load on the overlap, reduces transportation costs and facilitates the lifting of materials to the floors.

• There is an opportunity to select the right composition for specific operating conditions. So, there are solutions for coarse or leveling screeds, for the system " warm floor" and for rooms with high humidity. Added to their composition special plasticizers or microfiber not only increase the strength characteristics of the coating, but also reduce the time for complete hardening of the screed, reducing the overall duration of construction work.
• What is very important for beginners - working with such compounds is simple and does not require particularly high skills. The main thing is to follow the recommendations on filling technology, which are necessarily attached to any batch of material.

All this will be true only if a quality dry mix is ​​purchased. Alas, but in the market of building materials in this segment there are a lot of fakes or base mixes. It is best to choose compositions from reputable manufacturers, necessarily checking the certificate so as not to run into counterfeit. It is also important to check the shelf-life of the material - it is limited, and the expired mixture can significantly lose its qualities.

The only drawback of this approach to pouring screeds is the on it can get a little higher than with self-made mortar. Well, for the convenience and quality you need to pay.

Surface preparation for pouring concrete tie

Surface for screed casting is prepared in different ways , based on of specific conditions:

• If the floor is laid on the ground, for example in a private house without a pile or basement, the work is carried out in the nextsequences :

- The soil is selected to a depth of up to 500 mm.

- A pillow of sand, 100 mm thick, is poured thoroughly. On top of the , a gravel layer is also poured in the same way.

- Coarse concrete casting is applied with the addition of expanded clay to a height of 150 - 200 mm - for the insulation of the floor surface.

- After hardening of the substrate, it is mandatory is waterproofed with - a roofing material or a dense polyethylene with film to prevent ingress of ground from below. Waterproofing material must necessarily go on the walls on the height , slightly larger than the height of the planned screed. If necessary, the can be covered with a single layer of insulation from above and then the reinforced screed is poured over.

• In apartments, first of all, it is necessary to remove the old screed. This is done for several reasons:

- First, the old screed does not guarantee integrity, as it can peel, crack, and these deformations will be transferred again to the poured layer.

- Secondly, do not forget about the maximum permissible loads on the slabs. So, in the standard high-rise buildings, the permissible load of about 400 kg per square meter is static and 150 kg is dynamic. A west of one square meter of concrete screed, 50 mm thick, is approaching 100 kg. Therefore, all work related to thickening of the screed will have to be coordinated by in design organizations. And it's far from the fact that such permission will be received.

- And thirdly, the height of the shelves in the apartments is usually not so significant that you could afford to raise the floor level.

The old screed is dismantled by a puncher, but very carefully to prevent damage or damage to the slab. Remains of chipped concrete are taken out, followed by thorough cleaning and dust removal of the surface.

Next, the base is inspected and, if necessary, repaired:

• If a tie is planned, carefully clean the existing grooves, split cracks or crevices for a width of less than 5 mm,so that they can freely penetrate the concrete solution when pouring.
• If the coupler is floating or on the separation layer, then all defects must be immediately repaired. Do not leave a void under the layer of waterproofing - condensation can accumulate there, and these areas of high humidity are likely to become a "problem place".

Fixing of defects is made by repair composition, epoxy putty or usual concrete solution. In the case of large defects, you can sometimes apply a mounting foam.

The angles between the walls and the floor are especially carefully checked and repaired - water from the concrete solution when pouring the screed can penetrate the into the depth of the overlap or even leak to the neighbors from the bottom.

• Then, in any case, the surface of the overlap should be treated with a penetrating primer. Such a measure and will dust additionally the surface of the plate, and improve the its adhesion to the concrete poured .In addition, the overlap will not actively absorb moisture from the solution. This is extremely important. The lack of water in the layer of raw concrete adjacent to the base, will cause the to incomplete maturation of the cement stone, the screed will peel or decay even with the not the with the most significant loads.

The primer is poured over the surfaces with strips and evenly distributed by the roller. In hard-to-reach places, for example, in the corners, it is better to use a brush.

• An elastic damper belt is glued along the perimeter of the walls. It will become an expansion joint of the concrete screed, which will prevent the from its deformation or cracking. In addition, the coupler should never be in contact with vertical structures, be it walls, partitions or columns.

• is adhered around the perimeter. If the screed is on the separating layer, then the whole surface of the overlap is closed first with a dense polyethylene with film, at least 0.2 mm thick. The stripes overlap, not less than 100 mm. Joints must be pasted with waterproof construction tape. It is necessary to try very carefully to lay the film at the corners so that the does not form the of strong jams and folds - there may remain air "pockets". Aside films on the walls must be above the of the planned screed by 5 ÷ 10 mm -it will not be difficult to trim.

separation layer After the polyethylene is laid, a damper tape is adhered - also as mentioned above.

Beacon system and reinforcement

To achieve the leveling of the screed and the of its of the required height, it is necessary to create a beacon system, through which the concrete mortar will be leveled.

Definition of a zero level

It is very successful if the farm has a laser level or it is possible to take it from a friend. The work in this case is much simpler - to repel horizontal strips on the walls and to control the level of the guide rails will be much easier.

. If this is not possible, you can set up the beacons with the help of a water and usual building level.

The water level consists of two cylindrical transparent vessels with bearing the same scale, connected by with a long elastic thin hose. According to the physical law of the communicating vessels, the level of fluid in them is always at the same height from the horizon. Thus, by making one mark on the defined by the level, it is possible to transfer the of its with high accuracy to other surfaces within the length of the flexible hose.

Start marking with the definition of the zero level of the future screed. For this, first of all, you need to draw a base horizontal line. This is done as follows:

• The highest expected corner of the room is visually determined. On the wall in this corner a mark is made at an arbitrary height. Better, of course, to make its so that it would be most convenient to work, for example, one and a half meter from the floor.

• With the help of the water level, this mark is transferred to all walls of the room. The distance between the risks should allow them to be joined by a line using the existing ruler( you can use a long construction level or a clean rule).
• The line must pass along the entire perimeter of the room and close at one point - it will speak about the correctness of the measurements.
• Measurements are made from on the baseline plotted to the floor surface. The measurement points are usually - every 0, 5 m . must be sure that the measurement is strictly vertical. The obtained values ​​should be recorded( on a piece of paper or even on a wall with a pencil).

The measurement point that will give the minimum height of this distance will correspond to the highest part of the base.

• The received value at the highest point takes away the thickness of the future screed( minimum - 30 mm).For example, the minimum height is 1420 mm. We take away the thickness of the screed( 30 mm) and get 1390 mm. This is the distance from the of the bearing reference line to the zero level.
• Now it will be easy to draw the entire zero-level line around the perimeter of the room - for this you need to measure from the base down the received value, mark the points and connect them straight. To simplify the work, you can make a rake - a template and quickly move the marks from the baseline. After their connection, the main zero-level line will be obtained.
• In construction practice it is rare, but still it happens when the floor level in the center of the room is slightly higher than that of the walls. This must be checked by pulling the cord at zero level between the opposite walls and measuring the height from it to the floor. This check should be carried out in several places. In case the finds that there is an elevation in the center, it will be necessary to shift the zero level upwards to ensure the minimum allowable thickness of the screed over the entire area of ​​the room.

Marking for the system of beacons

It is advisable to make a marking for the beacons and guides immediately after beating the zero level, guided by the following principles:

• Orientation of the guides must be in accordance with the intended direction of the most convenient filling of the screed. Usually this is done along the room, from the far wall to the exit.
• It happens that due to the complexity of the configuration of the room, it will be necessary to change the direction of the fill on the defined by the section. This should also be taken into account immediately when marking out the beacon lines.
• The distance between the wall and the parallel parallel rail is usually not more than 250 - 300 mm. If you leave it large, a badly aligned area or even a gap may form along the wall, which will require additional intervention afterwards.

• . The distances between adjacent guides are not specifically are regulated by .The main thing is that the existing rule for alignment, installed on them, protrudes from both sides by approximately 200 mm. Too much to disperse guides should not be - in the center between them after shrinkage of solidifying concrete can appear quite large gaps.
• I distribute the guide lines to the width of the room, usually at the same distance from each other.

How beacons and guides are set to zero level

Previously, for the beacon system, various materials were used as guide rails, for example, wooden blocks or unnecessary pipes. Today, mainly for these purposes use metal profiles.

• So, galvanized U-shaped profiles from plasterboard systems show themselves very well. They are resistant to deflections and create the a robust "rail" for rule work.
• Plaster profiles are very popular, although they are not without some drawbacks. They have an edge rigidity , however on long sections when working by rule they can still bend. Therefore, when using them, the number of support points needs to be increased.
• In some cases, can generally do without without the use of profiles.

There are a lot of ways to install it, and it's impossible to consider everything. Let us dwell only on some of them.

• One of the most accurate and uncomplicated ones - with the use of self-tapping screws.

- At the far end of the room, at a distance of 250 - 300 mm from the angle between the opposite walls, a strong cord( for example, a fishing line or thick kapron thread) is tightened strictly to zero level. It is important to pull it to the maximum, so that there is no sag in the center.

- At the intersection of the line of the extended cord with the line closest to the wall, of the guide in the , the hole is drilled into the floor, where the plastic plug is screwed and the screw is screwed in. Using screwdriver , it is screwed in such a way that the upper edge of its cap exactly coincides with the zero level.

- This operation is repeated in the opposite, near the exit, side of the room.

- Two self-tapping screws defining the guide line are connected with each other by a tightly stretched cord, so that it passes on the top of the of their hats.

- In this segment, mark out and drill the holes for dowels , distributing them evenly so that an interval of 350 ÷ 400 mm is maintained between them.

- Screws are screwed into the dowels before the matching of their cap with a tight cord. It is necessary to check with the help of the building level - if necessary, you can make the necessary adjustments.

- In the same way, the self-tapping line is executed on the opposite rail, and then on the intermediate guides. In this case, the test should be carried out in all directions - longitudinal, transverse and diagonal.

- Once all the lines have reached the same zero level, the tensioned cords are removed. Prepare a thick concrete solution. It is laid out by small slides on the line of screwed screws. Then, the U-shaped profile is put on top and pressed into the solution. The transverse profile shelf should rest against the head of the screw. It is important that the profile " sat " evenly on both sides, without any distortion.

- Once the solution is seized and the is secure, the locks the profiles in the set position, you can proceed to the screed pouring.

With plastering profiles it turns out somewhat more difficult - they are more difficult to fix on the heads of screws. For these purposes, special fastening elements can be used - " of the ", which are put on self-tapping screws, and their side flanges are crimped with petals.

Video: setting of beacons using screws and fasteners- " of "

Another has one fineness - the plaster profiles have still and its own height, and this must also be taken into account when setting self-tapping screws in the zero level.

In addition, a solution for fixing will require significantly more - flesh to the fact that I resort to laying even a solid shaft into which the profile is embedded with the emphasis in the screws of self-tapping screws.

• solution Some masters are used and do without metal profiles at all.

- The self-tapping screws are tied with a thin wire, thus creating an original reinforcement cage. Then a solution is placed along the entire line in a somewhat excessive amount, so that the resulting shaft is slightly above the zero level.

- When starts to set , form the guide plane. With the help of the rule, the upper edge of this shaft is compared and smoothed to the self-tapping screws.

- After hardening, you get excellent guides, which can be used to work as a rule, and then they will enter the structure of the screed.

• If the screed is applied to the waterproofing, the self-tapping method becomes inapplicable - it is impossible to break the film, and in addition to the , there should be no rigid clutch of a new screed with a base. In this case the will have to tinker more, laying out the slides of the solution and accurately inserting the guides at zero level along the tensioned cords.

To speed up the readiness of the lighthouse system, tile glue is often used instead of the usual solution - the term of its hardening is much less. But gypsum compounds are unacceptable. First, they practically do not shrink, unlike cement ones. Secondly, the gypsum compositions have completely different water absorption, adhesion, strength, ductility and , .It is possible with absolute certainty to state that in the locations of the lighthouses on the screed I will go t t of the river.

Nuances of the reinforcement of the screed

Of course, this measure is useful, especially for screeds of large thickness. Used for this, most often, a metal mesh of galvanized steel wire with cells from 50 to 100 mm - its can be purchased in finished form in stores. Only here with its placement very many admit serious error.

If you look at the numerous photos on the Internet, you can see on them a grid laid directly on the slab or on the layer of waterproofing. There are a lot of doubts about the utility of such reinforcement. Ideally, for the reinforcement belt to play its role, it should be placed in the thickness of the mortar to be poured, approximately in the middle of the screed height.

For this you can purchase special polymer stands. However, do not make t t ore to make supports from the wire or even raise the mesh on the pads of pieces of broken tiles or fragments of the old concrete screed. Wooden lining should not be used in any case.

Obviously, it is installing reinforcing grilles before the installation. Most often, the beacons and fittings are being installed in parallel, and the grid can also be fixed on the of those slides of cement, into which metal profiles are embedded.

Video: more some tips for installing the system of the

lighthouses

bayonet filling. Strangely enough, the process of pouring the screed looks like a series of all technological operations, probably the easiest. If all the preparatory work is done correctly, this stage of complexity will not be presented.

• For normal filling and hardening of the screed, the optimum temperature is from 15 to 25 degrees. It is allowed to work at lower temperatures( but not below +5), but the period of maturation of concrete will increase significantly. In too hot weather, too, it is better to refrain from pouring - = the top layer can quickly dry up and go cracked. He does not like screed and skvoznjakov, although it is impossible to block access to fresh air.
• Best of all, of course, work together - one is preparing the concrete solution, and the second - directly pouring and leveling the screed. The technology of kneading the solution has already been described above.
• Work lead from the far corner of the room, gradually moving to the exit. It is necessary to try to fill in within one working day - so the screed will be as homogeneous and durable as possible. If, for some reason, this is not possible, then the floor surface is preliminarily divided into sections( they are called fill cards) with the installation of jumpers between them.
• The ready solution in excess quantity is spread between the guides, so that its layer is on the 15 -, 20 mm above the zero level. The initial distribution is carried out using a trowel or shovel. It is necessary to make sure that there is no left for the seats - this often happens under the guides, under the rods fittings or in the corners. It is necessary to achieve the maximum consolidation of concrete solution, the release of air bubbles from it. For this, it is possible to carry out the " bayonet " - mortar is pierced with a shovel or trowel before leveling.
• Next, the on the on the control is set by the rule .Progressive and transverse zigzag movements, the solution is leveled to the level of the guides, so that a smooth smooth surface is obtained.

If the sand was not sifted and large fragments( pebbles or shells) remained in the there are certain problems - these inclusions may leave grooves and will have to suffer a lot by removing them and smoothing Unevenness to bring the surface to an ideal state.

should remain. Concrete solution is added as needed, so that the work continues continuously. Surplus solutions at the end of the filling of the room are carefully removed.

Video: a clear example of filling the screed on the lighthouses

Once the fill is completed, the must provide measures to prevent accidental entry into the premises of people or pets during the first 5 - for 7 days. In order for the process with to run efficiently, the surface must be wetted daily( starting from the second day) with water, supporting the its in wet condition. In severe heat, it makes sense after the initial setting to cover with its with film, to avoid drying out.

If a conventional sand-cement mortar was used, then the load can be talked about as soon as possible after 3 weeks before the is ready for use with the operational .When using dry construction mixtures, the dates can be different - they are always indicated in the attached instructions.

Once the screed is ready, the of its is checked for evenness and the quality of the surface. To do this, set the rule to the guides and measure the resulting gap in the center. From shrinkage of concrete can not escape, and if the gap does not exceed 1 - 2 mm, it will be within the norm.

Often, px st is filled with a thin layer of self-leveling compound to make the surface perfectly smooth. However, this is already a topic for a separate consideration.