The device of a floor screed: materials, technology and the basic stages of works
The device of a floor coupler for todayis, perhaps, one of the most common technologies for leveling the surface. Home masters and professional builders know a lot of different techniques, among them one should especially highlight the laying of the concrete floor, the installation of a semi-dry screed, as well as the method that involves the arrangement of the floor on the ground.
Why choose a concrete screed
As for leveling with concrete,it allows you to achieve a high-strength surface, which will undergo all sorts of load, without losing its quality characteristics. Inviting specialists to carry out such work is not necessary, because the process can be carried out independently.
Preparation of the surface before pouring concrete screed
The device of a floor coupler necessarily assumescarrying out of preparatory works. If the floor will be laid on the ground, which is relevant for the basement and private houses, then first you need to take out the soil, going down by 500 mm. At the bottom poured 100-mm cushion of sand, which should be well tampered, and over pour gravel layer.
Then it is possible to fill concrete withaddition of expanded clay. As soon as the base solidifies, it should be waterproofed with a dense polyethylene film or roofing material, which excludes penetration of ground moisture from below. The waterproofing layer should go to the wall. If necessary, one more layer of insulation is topped up, then you can proceed to pouring the reinforced finish layer of the screed.
Preparing the floor surface in the apartment
The device of a floor screed in an apartment assumesremoving the old rough surface layer. These works are necessary for the reason that old materials can be damaged, have cracks and delaminations. In addition, do not forget about the maximum loads on the slabs. For example, in high-rise buildings of old construction, this load is approximately 400 kg per square meter. As for the dynamic load, it is 150 kg. The weight of a square meter of concrete screed is 100 kg, this is true if the thickness is 50 mm.
If you do not remove the old screed, then the ceiling heightthe apartment will be even smaller than before. Dismantling of the old layer can be a perforator, but it is important to exclude the destruction of the slab. The base should then be inspected. You may need repair. If you plan to lay a bound screed, the existing grooves should be cleaned, cracked to a width of 5 mm, so that the concrete solution can penetrate there.
Advice from a specialist
If the floor screed device is plannedTo carry out on floating technology, flaws must be repaired. Under the layer of waterproofing, it is not necessary to leave any voids, since condensation can accumulate there. Fixing of defects can be carried out with repair composition, concrete mortar or epoxy putty. In the presence of quite impressive defects, a mounting foam is used.
Especially carefully it is necessary to repairangles between the floor and the walls, because the water from the concrete solution can easily penetrate deep into the ceiling and leak to the neighbors from below. The surface is treated with a penetrating primer, this will dust the base and increase the adhesion characteristics. Among other things, in this case, the overlap will not absorb moisture from the solution. The primer should be poured on the surface by strips and distributed by the roller. In hard-to-reach places, you can use a brush.
Additional recommendations for training
Before you fill the floor screed in the house, byperimeter walls it is necessary to glue a damper elastic tape that will compensate for the expansion of the concrete screed. This will prevent cracking and deformation of the material. Among other things, the screed will not contact vertical structures, columns and partitions.
If the screed is laid on the separating layer, thenthe whole overlapping surface should be covered with a polyethylene film, the thickness of which is 0.2 mm. Cloths should be laid with an overlap of 100 mm, and joints are glued with waterproof construction tape.
Beaconing and reinforcement
The technology of floor screeding on the followingstage involves the deployment of lighthouses. According to them, the master will carry out leveling of the surface of the future floor. It is important to make the markup by determining the zero level. To do this, you need to draw a horizontal line, determining the highest angle of the room. The mark on the wall is a mark, and then, with the help of a water level, it is transferred to all other walls. The distance between the risks should allow to connect the marks with one line. From the value at the highest point it is necessary to take away the thickness of the screed. This parameter can be at least 30 mm. The resulting value will become the zero level.
Marking for lighthouses is carried out after applicationzero level. The distance between the parallel guide and the nearest wall should be 300 mm. Between adjacent guides the distance is not regulated, but it should be somewhat less than the length of the rule for equalizing the solution. For reinforcement, a metal mesh made of galvanized wire is usually used. Arrange the frame at some distance from the floor. For this, polymeric supports are used.
Pour the screed
Rough floor screed in the next stageinvolves the pouring of the solution. The optimum working temperature is considered to be a limit of 15 to 25 ° C. If this value is reduced, the maturation period of the concrete will increase. Work on the fill should start from the far corner of the room, moving to the exit. It is recommended to finish the filling during the day, in this case it will be possible to get the most durable and homogeneous screed.
The finished solution is laid out between the guidesand distributed using a shovel or trowel. It is important to maximize the compaction of the solution and the release of air bubbles. To do this, you can use the method of bayonet. On the guides, the rule is established in the next step. Zigzag movements should be carried out in such a way that a smooth surface is obtained. The concrete solution can be added as needed. Its excess at the end of the filling is carefully removed.
Semi-dry screed technology
As an alternative, you canbe used semi-dry floor screed. For this, a solution is prepared using fiber-reinforced fibers. For 120 liters of sand, you need to prepare 50 kg of cement and 150 g of fiber. If you are going to work with a room, the area of which is 20 m2, then the fiber consumption will be 0.54 kg.
The ingredients are mixed for 3 minutes,after they are added with water, the solution is again mixed and placed on the surface. If the layer is additionally reinforced, then one part of Portland cement will need 3 pieces of sifted sand. The mixture can be prepared on site without the use of a concrete mixer. In the dry composition, water is gradually added. The solution should be semi-dry.
It is scattered over the surface, and the followinglayer will be reinforced mesh, which again cover with a semi-dry mixture. The composition is rammed, and leveling is done using the level and rule. When the irregularities are formed, they are sprinkled with a solution.
The last stage will be grouting and grinding. This allows for perfect smoothness. After hardening, screeds of irregularities can be knocked down with a metal spatula. If grooves are formed, they can be filled with a solution of sand and cement in a ratio of one to one. Grout the base with a polyurethane or wooden float. If the semi-dry floor screed is laid using lighthouses, then they should be removed, and their location should be wiped and sanded using a special machine.
Screed on the ground
After excavation of soil from the territory of pouring screedit is necessary to fill the bottom with sand. The thickness of this layer should be about 10 cm. The quality of the tamping will be improved if we additionally use special mechanisms such as vibration compactors or vibrating rammers. In this case, sand should form a horizontal surface.
The device of a floor screed on a ground at this stageinvolves wetting the base, which will increase the degree of shrinkage of the layer. You can feed water from buckets or hoses. Then a layer of crushed stone is poured, its thickness can vary from 5 to 10 cm. The layer is well trampled. This will increase the load-bearing characteristics of the base.
After the concrete mixture is prepared, whichcan do by yourself. The density should be moderate in density. This will allow the concrete to be spilled on its own. As one of the advantages of a liquid mixture, there is no need to use beacons for leveling. The masters will only have to adjust the level slightly in the places where the material is being fed.
Reinforced floor screed at this stageprovides for the laying of a grid. Fasten the frame to 3 cm from the floor, and then pour the solution. The grid can be formed from wire elements, which are twisted together. If the wire has a diameter greater than 6 mm, then it is better to use welding for the connection. However, the best solution is to purchase a ready-made net.
Calculation of materials for screed
Calculation of floor screed must be carried out,so as not to interrupt work. Forming a 10-cm layer, the cement must be purchased in an amount of 50 kg per square meter. For a more accurate calculation of cement and sand, a concrete example can be considered. If you want to work with an area of 60 m2, then this value must be multiplied by 0.06 m. This is the thickness of the screed. As a result, you will be able to get 3 m3 solution.
Calculation of floor screed may look as followsway: 1 liter of the mixture will need 1.4 kg of cement. This indicates that in one bag there will be only 36 liters, and the finished solution will be enough for 30% of the volume.
Conclusion
Before starting work, it is important to consider whether you will beuse the services of specialists. If you decide to do the work yourself, then you should evaluate your knowledge and skills. Most often, home masters use the technology of laying a concrete screed, you too can follow their example. But the floor screed in the new building is best laid on a semi-dry technique.
