The ground floor in a private house, made with your own hands according to the recommendations of experts, is strong and durable. A smooth, non-slip surface and low thermal conductivity are also indicators of quality. Each layer in the floor structure has its own purpose and it is very important to follow the technology of its construction.
In a private house, most often the floor is laid on a soil base. The main requirements for the construction of a residential floor are:
- Strength.
- Low thermal conductivity.
- Wear resistance.
- Fire safety.
- Durability.
- Environmental friendliness.
- Cost-effectiveness of building materials.
- Low labor intensity.
- Safety in operation.
The floor installation requires a positive room temperature, which should be at least 5 °C, depending on the characteristics of the floor composition.
Important! You cannot lay the floor on a frozen base!
Basic composition of the floor
The composition of the floor depends on:
- purpose of the premises;
- operating temperature and humidity;
- type of soil base;
- flooring technology;
- design solution coverings.
Floor pie on the ground: 1 - compacted soil; 2 - sand-gravel mixture; 3 - concrete lining; 4 - vapor barrier; 5 - thermal insulation; 6 - polyethylene film; 7 - reinforced screed
Base
The base for the floor is the soil that lies directly under the floor. Its purpose is to withstand the load on the floor, including its weight, without deforming the soil structure.
It is very important that there is no groundwater directly under the floor. Its level decreases when drainage is installed around the house. You can protect the floor from water by increasing the underlying layer of coarse materials (sand, crushed stone or gravel), or using waterproofing from synthetic materials under concrete preparation.
If backfilling is necessary, it is done with non-heaving soil. Bulk soil in mandatory compacted. The soil layer must be removed to its full depth. Weak soils are either replaced with low-compressible soils or compacted to prevent subsidence of the floor.
Heaving soil under the floor can be partially replaced with non-heaving soil, or the level can be lowered groundwater. You cannot lay the floor on soils of organic origin (peat, black soil, etc.). They are also replaced, for example, with sand or a sand-gravel mixture.
The surface of the base under the floor is leveled and compacted. The soil can be compacted by pushing a layer of crushed stone or gravel 5-8 cm thick into the base at least 4 cm deep.
Substrate
The purpose of the underlying layer is to distribute the load from the floor along the soil base. Its minimum value is accepted:
- sandy - 60 mm;
- crushed stone, gravel, slag - 80 mm;
- concrete - 80 mm.
Gravel (crushed stone), sand-gravel or sand preparation must be leveled and compacted. For a private house, its thickness is 10-15 cm.
Concrete preparation (concrete grade more than B7.5) must be laid in strips 3-4 m wide using lighthouse boards. Concreting of strips is carried out one strip at a time interval of 24 hours. Freshly laid concrete must be compacted.
For concrete preparation, a backfill of coarse sand and gravel (crushed stone) 12-15 cm thick is made, which is compacted to the full depth. Asphalt concrete preparation laid in layers of 40 mm. The bottom layer is coarse-grained (binder), and the top layer is cast asphalt concrete.
Screed
A screed is the foundation for a finished floor. Its purpose is to:
- load distribution on the underlying layer;
- leveling the base for the coating;
- arranging slopes in the floor if necessary;
- creating a heat-insulating layer (lightweight concrete);
- opportunities to hide communications.
Concrete for screed over a heat insulating layer is accepted as class not less than B15, the cement-sand mortar must have a compressive strength of more than 20 MPa. In addition to leveling the surface of the previous layer, lightweight concrete screeds also serve as thermal insulation. Concrete class is allowed no lower than B5. Insulating screeds made of porous cement-sand mortar must have a compressive strength of at least 5 MPa.
Concrete screed
The thickness of the screed in the case of covering pipelines in it is taken to be 4.5 cm greater than the diameter of the pipe. Minimum thickness screeds made from self-compacting mortars using dry floor mixtures on a cement binder, must exceed maximum size filler 1.5 times.
The semi-dry method of laying screed on a cement binder significantly reduces the hardening time of the solution and increases the strength of the layer. The low water-cement ratio of the mixture requires compulsory compaction of the freshly laid mortar and grinding of the surface. Fiber fiber in the mixture as a “mini-reinforcement” increases the strength of the floor, including working together its entire surface.
Semi-dry screed
With a high water-cement ratio cement-sand mixture it self-levels. The disadvantage of this layer is that it increases the hardening time of the screed. It is recommended to install highly plastic screeds over a layer of dry thermal insulation material.
The solution, seeping into the spaces between the insulation particles, binds them and creates a layer of lightweight concrete on top. This process strengthens and evens out the insulation layer. The minimum thickness of such a screed is 5 cm.
For dry screed installation the following are used:
- plywood;
- Fiberboard (fibreboard);
- GVL (gypsum fiber sheets);
- DSP ( cement bonded particle boards);
- Chipboard (chipboard);
- GSP (gypsum particle boards), etc.
Dry floor screed
Such a floor can only be installed in rooms with dry conditions, and it is necessary to reliably protect the screed from getting wet.
Thermal insulation
The following are used as thermal insulation for floors on a ground base:
- Lightweight concrete (expanded clay concrete, foam concrete, slag concrete, etc.).
- Bulk insulation (expanded clay, expanded vermiculite or perlite, granulated slag, etc.).
- Slabs and rolls (mineral wool, polystyrene foam, foam glass, etc.).
The choice of insulation depends on the choice of floor structure, in particular its covering.
Waterproofing
Waterproofing for floors on a soil base is necessary:
- to protect it from groundwater;
- to protect the heat insulator from moisture from the coating surface.
It should be continuous across the entire floor. The number of layers depends on the type of waterproofing:
- for bitumen and bitumen-polymer mastics, cement mortars, bitumen roll materials glued to bitumen mastics- at least 2 layers;
- for built-up bitumen, self-adhesive, polymer roll materials - at least 1 layer.
Surface bitumen waterproofing is prepared before applying layers, screeds, coatings with cement binder, and sprinkling with sand with a particle size of 1.5-5 mm. You can also use ready-made roll waterproofing with surface coating.
Except roll waterproofing materials Self-leveling insulation is used, which impregnates the preparatory layer of bulk crushed stone (gravel) with bitumen. Asphalt concrete is used as waterproofing, as well as rolled profiled polyethylene membranes. It is important that the waterproofing of the floor on the ground is combined with the waterproofing of foundations and walls.
Coating
The surface of the finished floor must be non-slippery, safe in composition, wear-resistant, fireproof and smooth. The last condition is checked by the amount of clearance between the control two-meter strip and the floor surface:
- from boards, parquet, linoleum, polymer mastic floors - 2 mm;
- concrete, xylolite, ceramic, porcelain stoneware floors - 4 mm.
Gaps for piece coating are allowed:
- between plank floor boards - 1 mm;
- between parquet floor boards - 0.5 mm;
- between strips of piece parquet flooring - 0.3 mm.
For carpeting Gaps between the panels being connected are not allowed. For tiled and block floor coverings, the width of the joints is taken to be no more than 6 mm if the tiles are laid on the interlayer manually.
Adhesive compositions for attaching the coating to the base must meet the requirements for the adhesion strength of the coating material to the previous layer for peeling. The thickness of the layer is also standardized.
Underground floor. Its composition and structure
An example of a floor on the ground is a floor with an underground. Columns made of concrete or clay solid bricks are installed on the compacted soil base. Their size in plan is 25x25 cm. The grade of brick is taken to be no less than 75, the grade of mortar is no less than 10.
For concrete columns under logs, concrete grades of at least 75 are used. The distance between the axes of the columns with a load not exceeding 400 kg/m2 is 1.1-1.4 m.
The height from the ground to the subfloor in the underground should not exceed 250 mm. 2 layers of rolled waterproofing are laid on the brick columns.
To determine the size of the log it is necessary to consider:
- span (distance between supports along the axis);
- insulation thickness;
- height of cranial bars;
- thickness of the subfloor;
- gap between the finished floor and the top edge of the insulation - min. 3 cm.
1 - beam; 2 - cranial block; 3 - subfloor; 4, 6 - vapor barrier; 5 - thermal insulation; 7 - floor board
The size of the cranial bars is 40x40 mm. A mineral wool board can be used as insulation. Used for waterproofing roll materials(bitumen, polymer or polymer-bitumen). All wooden elements floors must be antiseptic.
You can understand people who want to reduce the cost of construction and actually install floors on the ground. Here is one example. There is a foundation. To save money, backfill is not always used. Instead, you can simply place a panel on top. Most often these are round hollow panels. But there are several nuances when using them.
The first thing you should pay attention to is that the round-hollow panel is not designed to work in such conditions. Today, all such panels are prestressed. It is assumed that the panel is attached to the base of the foundation with anchors. And this is her weak point. The protective layer of these fasteners is thin. And first of all, it is the steel anchors on the edges of the slab that are affected. Then the reinforcement begins to collapse. And then concrete.
This process occurs because there is free space between the soil and the slab. Moisture coming from the ground evaporates and condenses on the concrete, since its temperature is quite low.
At the moment, people rarely pay enough attention to frost protection. As a result, at the junction between the slab and the foundation, a a large number of frozen condensate. Namely there protective layer There are fewer reinforcement anchors.
This can be avoided quite simply. To do this, you need to punch through ventilation holes in the supports on which the slab is placed. They work by blowing excess moisture out from under the slab. In essence, this is an eternal draft created by yourself.
But here everything is not so simple. The height of the plinth should be taken into account. IN winter period Over time, snowdrifts can block the vents. Therefore, the distance from the ground to the holes should be at least 50 cm. Depending on climatic conditions, this value may vary.
Unfortunately, not all houses meet these conditions. The panel is located much closer to the ground and as a result, organizing such vents becomes very problematic. In this situation, in the absence of a well-built basement, it is necessary to build floors on the ground.
But not every builder can do them. And the issue is not the exceptional complexity of the work. Rather, the problem lies in a lack of understanding of the importance of fulfilling certain conditions. For example, elements such as crushed stone backfill and concrete preparation are mandatory, but not every professional can name the reasons for this. Therefore, it is so important to understand the reasons why this or that layer is made.
So, the first thing that is done is the foundation. Then it is waterproofed and sprinkled. The next important step is backfilling. Of course, this will require additional financial costs. But without this it is impossible to make floors on the ground. Naturally, this implies that there is simply not enough space for vents.
When performing backfilling, it is necessary to take into account that this must be done in stages, in several layers. In this case, the layers should not exceed 20-30 cm in thickness. The reason is very simple. A typical compactor weighs about 150 kg. Therefore, it can compact no more than 30 cm of soil.
To make compaction more efficient, crushed stone backfill is used. But leveling it with a shovel is not enough. The crushed stone must also be compacted. The crushed stone fraction should be about 40-60 mm. When compacting it, the force will be redirected into the ground. Since it will be concentrated in small pebbles, the impact will penetrate deeper. This is the difference between crushed stone backfill and soil compaction with crushed stone.
The next stage is concrete preparation. IN in this case it is used as a basis for sticking water vapor barrier. Not to be confused with waterproofing. It only protects against water. And in this case it is necessary to protect yourself, including from steam. Since the soil has natural moisture, and the temperature inside the building is positive, the moisture will accordingly begin to evaporate. Without a vapor barrier, moisture will enter the floor structure and condense there.
Vapor barriers based on bitumen or mastic can only be laid on a rigid base. Since the workers have not yet learned to fly, they will have to walk on this foundation. If it is soft, there may be a void under the vapor barrier caused by the weight of a person. Or a pebble will just roll there. As a result, the vapor barrier has a high chance of simply breaking. Accordingly, it will no longer be able to perform its functions. Therefore, concrete preparation or screed is carried out on the compacted soil. Preparation is done using low-strength mortars; there is simply no need for high-strength mortars; concrete grade B7.5 is sufficient.
Next is laying the insulation. To do this, you can use various materials, but the best is extruded polystyrene. It has a low water saturation coefficient and is quite durable. At the same time, it has high crush strength.
After laying it on the hydro-vapor barrier, both horizontally and vertically, a screed is made to protect against the cold coming from the walls. It is also called floating because it does not have a rigid connection to the base. It must be reinforced with welded mesh. If the floor is located in a living room, then 100x100 cells with a diameter of 3 mm and a screed thickness of 5-6 cm are sufficient. If it is a garage, then a mesh with a cell of 50x50 mm and 4 mm wire is used. The height of the screed is at least 10 cm. In this case, it will have to be made of concrete using crushed stone with a fraction of 10-20 mm.
Next, a finishing coating is applied to this screed. And absolutely anything. This could be wood, as there is a vapor barrier, or a ceramic coating. This entire set of works is expensive, but reliable. Of course, it can be made cheaper. But if expensive finishing materials or floor heating, water or electric, will be used, then it is better not to use economy options.
How to save on ground floors?
It’s still worth mentioning the opportunities to save on floors on the ground. Instead of vapor barrier, you can use ordinary plastic film, always in two layers. It is sold by the sleeve. It must be laid with an overlap of 15-20 cm on a compacted base. But you should not lay the film on crushed stone. This is a fairly delicate material. Therefore, it can tear under the weight of the builder. Accordingly, moisture will get into the floor covering. The result is fungus and unpleasant odors.
But if the thickness of the backfill does not exceed 20 cm, then the soil can be compacted with clay, even slightly moistened. And already on this clay base you can lay polyethylene, always with an overlap. It is also safe to say that polyethylene film does not provide a complete guarantee that moisture will not get into the body of the floor. But if the decision was nevertheless made, then the entire subsequent set of works remains the same. The heat insulator is installed in the same way. Then a screed reinforced with steel mesh is performed.
Of course, such a design will also perform its functions. But professionals advise using it in less critical areas. It can be guest houses, sheds, garage. That is, those premises in which expensive coatings will not be used. Just to play it safe.
These were the basic principles of building a floor on the ground.
What not to do?
Thanks to the Internet, a huge amount of incorrect information is now freely available, in particular advice and recommendations regarding flooring. One of these recommendations is the use of geotextiles. This is the advice of one of the regular visitors to construction forums. He suggested laying geotextiles on the ground. Then it is planned to backfill it with crushed stone or expanded clay. But this is extremely inappropriate. If you remember what was described above, then when you try to compact the soil, geotextiles simply will not allow you to do this. Whatever the tamping force, the geotextile will hold the crushed stone and prevent compaction of the soil. This material has a fairly high tensile strength, so tamping will be useless.
Therefore, the soil must be compacted before laying geotextiles. Logical? No. In this case, the need for geotextiles completely disappears. It is neither a vapor barrier nor a waterproofing material. To make it a little clearer, geotextiles are used in completely different conditions. For example, if you need to make drainage, filter out sand or gravel. Accordingly, such a design is completely ineffective, irrational and unacceptable.
In addition, the recommendation spoke about the use of expanded clay. This point also requires clarification. Expanded clay is a specific material. It picks up moisture very quickly. Accordingly, it is completely unsuitable as insulation for this design. The reason is extremely simple. In just a week, it will be completely saturated with moisture coming from the soil and will stop performing its functions. That is, it will be money thrown away.
After this, it was recommended to do a screed and a finishing coat. Without water vapor barrier and insulation. Again, this will be wasted money. That is why it is necessary to be extremely careful about information read on the Internet, be sure to double-check it and not follow the lead of such “experts.”
Also on forums, the question is often asked: “Why is it not recommended to use expanded clay concrete for floors on the ground? It’s light and durable.” This question deserves a more detailed answer. Yes it is light weight and is sufficient durable material. But at the same time it is a terrible heat insulator. Today there are many, much more suitable materials. This includes extruded polystyrene foam and foam glass. As for glass, it costs almost 2 times more than polystyrene, but is an ideal protection against rodents. Even moles won't be able to break through it. So this is an additional guarantee of peace of mind for the inhabitants of the house.
And if we return to expanded clay concrete as a material, we should take into account that it is very capricious. When an expanded clay concrete mixture is prepared, the expanded clay itself absorbs a lot of moisture. And he takes it out of the concrete. And just a day later, when the cement has just set, the following situation occurs. Porous expanded clay absorbed moisture from the concrete. A day has passed. As a result, the cement mortar, which is a kind of glue, envelops the expanded clay. Accordingly, all moisture is clogged inside. Thus, expanded clay concrete will not dry for a month, unlike ordinary heavy concrete with granite filler. This process will take 2-3 months. And if such concrete is used in a basement with poor ventilation, then no further finishing of the floor will be possible for a long time.
Otherwise, moisture, which will continue to evaporate from expanded clay in the absence of a vapor barrier, will ruin any finishing coating. It will simply undermine the wooden floor, it will simply swell and rise. If ceramic tiles were used, then fungus will appear on its seams, and a persistent unpleasant odor will appear in the room.
Thus, if the decision to use expanded clay concrete was nevertheless made, then a much longer technological break will be required to dry it. It is also necessary to measure the moisture content of the base before laying the final floor covering.
As mentioned earlier, there are two fundamental approaches to creating floors on the ground. This is an economical and budget option. In the first case, a polyethylene film is used, which is laid on the ground. The insulation, screed and finishing materials. This option is preferable in rooms where inexpensive finishing is planned: cheap ceramic tiles or inexpensive floors.
But if you plan to make heated floors or lay an expensive topcoat, then saving is no longer recommended. The reason is that the likelihood that the film will be broken through with a mesh or pressed with a stone during the work remains quite high. Therefore, when subsequently laying expensive floors, you should not skimp on the preparatory stages.
But on forums questions are regularly asked about the use of film. And they demand an answer.
Is it possible to use black polyethylene film in one layer not for vapor barrier, but to avoid pouring concrete on the ground? It's inexpensive and seems like it would be better.
But do not forget that the best is the enemy of the good. As has been said more than once, the film does not provide 100% tightness. Professional builders during dismantling similar designs A layer of water between the film and concrete is regularly observed. Moisture is always in the soil, and concrete or mortar always remain inert materials. Therefore, it is at the soil/concrete interface that the dew point will form. Accordingly, moist air will condense between the film and concrete. This is a natural physical process.
This results in the following situation. There is concrete. A film was laid underneath it. Just because it’s inexpensive. But there is always excess moisture in concrete, because only 5-10% of water by weight is enough for cement to set. Naturally, there is much more water in the solution and it needs to go somewhere. Question: where? It will not be able to go upstairs, since a vapor barrier will be laid there, and it will not be able to seep into the ground due to the polyethylene laid. Accordingly, the water chemically bound in the concrete structure will not go anywhere, and excess moisture condenses in the layers between the concrete and the plastic film.
A humid environment at a positive temperature is an ideal environment for the development of microorganisms. And the concrete will begin to become covered with a black coating. This doesn't always happen. But often, when dismantling such screeds, the concrete turns out to be completely painted in black and blue shades. Of course, there is no particular danger to the health of residents. On top there is a vapor barrier and insulation, for example the same extruded polystyrene, which does not allow any fungi to pass to the top. But concrete will one way or another work in difficult conditions and its service life will be much shorter.
If the film under the concrete is damaged somewhere or there are loose joints, then the moisture that will rise from the ground will only enhance the effect. And the film will retain moisture and prevent it from leaving. Accordingly, moisture gradually accumulates and leads to various unpleasant moments.
What if there is no such film? If the groundwater is deep enough, the moisture content of the soil itself will be about 15%. The reason is capillary moisture. It rises from the groundwater level and increases humidity. It all depends on the type of soil. If these are sandy soils, then the height of the rise of capillary moisture will be no more than 30 cm. If the soils are clayey, then the height will already be a meter or one and a half. Accordingly, the humidity in the area of the border between the soil and the screed may be much higher.
On the other hand, the humidity of the solution is 100% at the time of pouring. Even if it's 90%. And even with high humidity soil, excess moisture will still go into it. Based on the physical laws of diffusion, it turns out that after some time the moisture content of concrete and soil will eventually level out. Up to the same 15%. Naturally in different situations this value may vary. But in any case, the lower the humidity concrete screed all the better.
And if you lay the film, then this humidity of 90% will be maintained throughout the entire life of the screed. Of course, pay money so that the concrete purchased also with your own savings will work in worst conditions– an inalienable right of the consumer. But still, you shouldn’t do this. This is simply not necessary.
Application of vapor barrier in floors on the ground
Next questions:
- Is it necessary to round the concrete screed when moving to the wall so as not to tear the water vapor barrier?
- How long does it need to dry before laying a built-up hydro-vapor barrier on top?
The fact is that vapor barrier, unlike waterproofing, does not require gluing to the base. If there is a screed that is closely adjacent to the wall and it is necessary to make a vapor barrier, then the most important thing is to glue all the joints. But we must take into account that all joints of vapor barrier strips must be very reliable.
As a result, when the membrane heats up, it becomes very elastic, wraps itself on the wall and everything seems to go fine. But do not forget that after a short time it will cool down. And then the vapor barrier layer will certainly decrease in volume and a kind of tension will occur.
If, when laying the screed, all the corners between the wall and the floor were not rounded, then a void will form there. There's nothing wrong with that. But there is a serious danger that when subsequently laying the mesh, the vapor barrier can very easily and naturally be torn. To do this, it will be enough to hit the corner with the edge of the net, hit it with a boot, press in crushed stone - whatever. And it is impossible to protect yourself from such accidents. This is construction. That is why the arrangement of this rounding is necessary. It will serve to minimize the human factor and the likelihood of such unforeseen situations.
If you make a rounding, then such voids will not form and the vapor barrier will be protected. And some random blow will not do anything to her. The vapor barrier will not tear, since there is a rigid base underneath it.
Therefore, when the base has been formed and the vapor barrier is soldered to the walls, gluing it to the screed simply does not make sense. It is enough to solder the joints. That is, to ensure the integrity of the layer. And then it is simply loaded from above.
Of course, if the screed is completely dry, then the vapor barrier can be fused. The concrete is first primed with a bitumen primer, and then a layer of vapor barrier is fused. The labor intensity will be an order of magnitude higher, but it will be soldered to the base. There will be a reason to be proud of yourself and sleep peacefully at night.
But in general, as soon as the concrete screed can support the weight of a person, you can begin laying a vapor barrier. The main thing is to solder it to the walls and be sure to solder all the joints. And the canvas can simply lie on the concrete.
One of the frequently asked questions is: “To what height should I waterproof floors on the ground?”
Euroroofing felt is usually used as insulation. It is heated on one side with a burner to create a kind of built-up waterproofing. It also needs to be laid not only flush against the wall, but also overlapping the wall. In this case, you can protect yourself from various accidents, such as moisture leaking along the wall. As a result, the entire floor patty is protected from possible moisture penetration.
Accordingly, after laying the waterproofing, you can lay extruded polystyrene foam 30-50 mm thick as insulation. Some people think that this is not enough, that much more is needed, but in reality this is not the case.
If the base is insulated, then there simply cannot be freezing. And the ground temperature is usually about +5-10 Celsius. Therefore, in a thermal engineering calculation, assuming even a heated floor with a temperature of 20-25 degrees, the difference will be no more than 15 degrees. In this case, the wall operates at differences of up to 50 degrees. Therefore 30-50 mm. Polystyrene will be quite enough for protection.
Returning to laying the floor, after waterproofing and laying insulation, a screed is performed. It must be reinforced. The fact is that when laying concrete on a non-rigid base, for example, insulation, polystyrene foam, mineral wool or sand, it is advisable to reinforce it. This will help compensate for all possible nuances of unevenness.
It is up to the top of the screed that it is necessary to carry out a vapor barrier. Waterproofing is carried out a few centimeters higher. It is laid on a layer of insulation to protect it from wet concrete. It must be taken into account that PSB foam is afraid of an alkaline environment. And cement is precisely an alkaline medium. Accordingly, upon contact it will be destroyed. But if you use extruded polystyrene foam, then it does not need film at all. This material is much more reliable in quality and is made using more expensive technology. Therefore, there is nothing to worry about if the film is not installed. Even during subsequent dismantling after a long period of time, no signs of corrosion or incompatibility were ever observed.
Accordingly, this film is completely unnecessary. Moreover, euroroofing felt is currently covered with a film on both sides so that its layers do not stick together and it can be stored longer. And after its installation, this film retains its integrity, so there is no need for additional coating. It is enough to lay extruded polystyrene foam on a vapor barrier made of euroroofing felt, and you can stop there.
Moreover, the additional film will certainly be damaged by the fittings or pipes that will be laid in the screed.
Wall insulation with polystyrene foam
The thermal insulation layer is 50 mm of expanded polystyrene, simply laid and there is no need to additionally fasten or glue it, and absolutely not. The fact is that when the screed is made on top, about 5 cm, its weight will be about 400 kg per square meter. So nothing can happen. Expanded polystyrene foam will not fall lower than the vapor barrier. The tie presses it so tightly that any additional fastenings are simply not needed.
Laying insulation on the wall is not always required. Usually quite enough external insulation base But in some cases, it is possible to lay polystyrene foam not only on the floor surface, but also to the level of the screed. This will extend the path of cold air along the wall. Accordingly, it will have more time to warm up. Its use depends solely on the project and external insulation. If it does not provide for this, then there is no need to use polystyrene foam.
But it’s worth laying damper tape along the edges. Moreover, even before laying polystyrene foam. It will compensate for deformation of the screed due to temperature differences. This is especially important when laying heated floors. They heat up to 25 degrees, accordingly the screed will increase in size. The damper tape compensates for these changes, but polystyrene foam does not fully compensate. It may shrink, but it will no longer be able to regain its previous volume. Foamed polyethylene or damper tape is able to restore its volume. This is important so that no debris gets between it and the concrete.
Therefore, you should definitely check the project to check whether additional insulation is required. If yes, then it’s better to lay polystyrene foam, if not, then you can do without it.
Is it necessary to weld (bond) reinforced mesh? When laying concrete screed on the insulation, a mesh with a cell size of 100x100 and a diameter of 3 mm is used. There is an opinion that it must be welded or tied and then filled with solution.
But the mesh is not a load-bearing element in the full sense. It is necessary to compensate for deformation in the screed, so that in the event of concrete deformation and cracks, shrinkage, the screed does not resemble drifting ice floes. That is, reinforcement is required to ensure that the screed always lies flat. And even if microcracks appear, you won’t have to worry about anything.
Laying pipes in floors on the ground
What to do if pipes are laid in the screed? How to secure them? Is it worth attaching them to the reinforcing mesh or maybe they need to be strengthened much better? On the Internet there is even advice to break through all layers, including hydro- and vapor barriers and install fasteners in concrete preparation.
A completely natural question arises. How will these layers perform their functions in this case? The answer is also simple - not at all. Therefore, you should not listen to crazy tips. Even 15 years ago, when floors on the ground were just becoming popular, all materials were imported from Germany. Then a film was laid as a vapor barrier, and white foam plastic was placed on top. There were pimples on it and pipes were laid between them. In case of smooth surface Plastic fasteners were used, but they were fastened so as not to reach the water vapor barrier. Apparently, such advice arises when someone sees the process of laying floors on the ground, but does not understand exactly how it is done. No one ever fastens pipes through all layers.
Pipe fasteners are required solely to secure the pipes while pouring the screed. It is necessary that the pipes do not move away from the positions specified in the design. There are no large loads there, so no special effort is required to secure the pipes.
As for heating and water pipes, they must be covered with mirilon. The fact is that these pipes are much larger than underfloor heating pipes and they change their size not only from temperature changes, but also as a result of water hammer. As soon as the taps are opened, a micro-water hammer occurs through the pipe, and accordingly the pipe increases in size. Therefore, she should have this opportunity. Otherwise the pipe will burst weak point. This is especially noticeable after a long absence of residents in the house, and as soon as the hot water is turned on, the pipe will expand significantly.
But in this case, there remains a small space above the pipe to the top of the screed. To prevent a thin layer of screed from being destroyed by walking and other loads on the floor, it is worth laying plaster mesh over the pipes, preferably in two layers. In this case, it will protect the concrete screed from destruction.
It is considered necessary to make a 5 cm thick screed on top of the heated floor pipes. Not really consensus about this question. If we consider the physics of the operation of heated floors and the vectors of heat distribution, then the following situation arises. From each pipe, heat covers a specific floor surface. At the same time, it is good when the heating sectors overlap each other. In such a situation, the floor warms up evenly, making it very pleasant to walk on.
But if you reduce the thickness of the screed, the so-called “zebra effect” occurs. In essence, it consists of alternating strips of cold and warm floors. The fact is that the pipes do not heat the entire floor, but only the surface directly above the pipes. As a result, walking on the floor becomes a game of “find a warm spot.” One step is warm, the next is cold.
This effect is strongly manifested exclusively during the first stages of using the floor. When the heating system operates for a long time, this zebra is leveled due to the horizontal distribution of heat and temperature changes are felt much less.
A certain thickness of the screed is necessary precisely in order to minimize areas of temperature changes. If there is a distance of 15 cm between the pipes, then the screed should be about 4 cm thick. On top, for example, there will be another centimeter ceramic tiles and that will be quite enough. If the pipe pitch is larger, then the thickness of the screed should increase. But even if this condition was not met, the temperature difference will disappear over time.
On the other hand, if you make a concrete screed that is too thick, it will require much more energy to heat it up. This will increase the inertia of the floor and its warm-up time. But if people live in the house permanently, then over time a certain temperature is reached, sensors are triggered and the system turns off. So the thickness of the screed on the floor should not exceed 7 cm.
There is an opinion that before pouring the solution it is necessary to heat the underfloor heating pipes to maximum temperature. In this case, the pipes will be expanded as much as possible. And subsequently, when the screed hardens, the pipes will not break through the floor, expanding due to temperature. But this is also advice from the category: “I heard a ringing, but I don’t know where it is.” It is necessary that the floor is constantly under pressure. But there is no need to warm it up. The fact is that cement dust can get anywhere. Therefore, at first they use a temporary boiler or even wood heating. Accordingly, there can be no question of starting a heated floor system. It's just not mounted. Work may still continue in the boiler room. So what about starting up the equipment during the general construction work there is simply no question.
This is why it is wrong to start a heated floor system before all construction work is completed. Also, do not forget that too high a temperature is by no means beneficial for a concrete screed. It will not gain maximum strength and will lose moisture too quickly. Therefore, a sauna will be created in the room and this will not lead to anything good.
Warm water floor pipes must be under pressure. They will indeed increase in size, but thanks to this all the loops will take their places. Moreover, in a situation, if someone punches a hole in the floor, for example, by trying to punch a hole in the floor with a hammer drill to secure something, it will become immediately clear. The pressure gauge needle will immediately drop, signaling low pressure in the system, and the tenant will be able to quickly determine the location of the breakthrough by the trickle of water shooting out of the pipe and the wet spot on the floor. Here are two reasons why pipes must be at operating pressure. But there is no point in deliberately increasing the temperature when pouring the screed.
Laying ceramic tiles and porcelain stoneware
Now there is a general fashion to use the most expensive solutions, especially elastic adhesives, for laying ceramic tiles and porcelain stoneware. But this is absolutely pointless. The fact is that these expensive adhesives expand with temperature in the same way as cheaper ones. All of them are made on the basis of cement, that is, if the cement mortar expands by 1 mm due to heating, then the more expensive glue will also increase in size by 1 mm.
But it is still worth adding a special additive to the cement mortar for screed. It is done in order to perform the functions of a postifier and obtain a higher grade of concrete at the same cost. Here you should work based on the rule - the underlying base must have a higher grade than the upper layers. This will prevent delamination, ensuring a normal ligament. Therefore, the brand of solution should not be lower than M-50 or M-70. This is required so that the tile can be used normally and not fly off the floor. This is the only limitation and there are no additional requirements or additional measures to strengthen the cement adhesive. Even ordinary cement glue will last without complaints for at least 10 years.
Alternatives to ground floors
If you fulfill all these conditions and carefully approach the creation of a floor patty on the ground, then it will become a very reliable basis for all future finishing of the room.
Unfortunately, it is possible that the soils are unstable. In this case, various unforeseen problems may arise. One of the most striking examples is floor subsidence. One has only to imagine how after some time the renovation is completed, the floor sags sharply, and the baseboards remain hanging on the wall. It's unpleasant and scary. Therefore, in some cases it is worth thinking about alternative solutions.
If we go back to the beginning and remember the entire scheme for installing floors on the ground, it turns out that most of all the work is aimed at preparing for laying a water vapor barrier. And insulation, heated floors, communications and cement screed are laid on top of it.
Thus, any subsidence of the floor and any possible problems often associated with improper preparation or soil problems. In order to avoid such situations, you can use monolithic slabs instead of backfill and lean concrete. But unlike round-hollow panels, they are not laid on the base of the foundation, but are part of it. Therefore, there is simply no problem with the anchors rusting and its integrity being compromised. Water vapor barrier and all subsequent work is carried out on top of this slab.
Unlike ground floors, monolithic foundation requires much lower construction costs. Its thickness should be only about 10 cm. Moreover, this coating can be formed directly during the laying of the foundation. Thus, instead of many split slabs, you get a single disk. Its strength and performance characteristics in this case will be much higher.
But how to do that? It's actually quite simple. When laying the foundation at the stage of creating the formwork, it is necessary to make a base for such a slab. The only thing that needs to be left between the soil and the slab is a protective space. The formwork can be made permanent and left under the floor after all work is completed. She can easily rot. On the other hand, soil can play the role of formwork. It can be anything, as long as the builders have the opportunity to walk on it and do their job. But it does not require special layer-by-layer compaction. The only thing is that it is important to ensure that there is a protective layer of at least 20 mm of protective space between the future slab and the ground. A reinforcing mesh is laid on top and everything is concreted.
But this procedure also has its drawbacks. First of all this high consumption boards for formwork. Or you will have to fill a fairly large volume of soil under the monolith. Of course, you can do without soil by sacrificing the board. On the other hand, sometimes it is much cheaper to fill the soil. The only question is which option will be more profitable from a financial point of view. By the way, in order to save money, you can use the formwork boards several times, pouring the foundation in stages. After completing one part of the foundation, you can remove the boards and move on to the next stage. Thus, the consumption of the board, and therefore the money for its purchase, will be several times less.
When pouring the grillage, you can leave reinforcement about a meter long on top of the plane of the slab. Subsequently, after the solution dries, it will bend and become a connection and an additional fastening element of the monolithic slab, precisely in the places that bear the greatest load.
But in this case, as in floors on the ground, it is important to provide for all communications in advance. It is mandatory to pressure check water and sewer pipes. In case any mistake is made, financial expenses for repairs can be very, very large.
In general, which flooring option to choose depends on many different factors. So, if there is free space up to the floor of the first floor and it is possible to install vents, then the best option will be the use of round-hollow slabs. Otherwise, there is no need to save money and it is better to use the technology of flooring on the ground. If the soils are unstable, then to avoid problems it is worth using other technologies. The choice always remains with the client. But a consultation with a specialist will help you avoid making mistakes and perform quality work on the foundation and floors of the house. This is the basis for all future decoration of the room.
In private homes, floors are usually created directly on the ground; they are quite cheap and simple in design. Ground floors are installed on the first floors of private houses with strip foundations, and clay, cement or concrete can be used for their arrangement. The most popular is concrete flooring on the ground. There are several reasons for this: firstly, concrete is publicly available, secondly, it is cheap, thirdly, a concrete floor has the greatest strength and durability, and everything else, it is quite simple to make. Work on creating such floors can be done without any special skills, the main thing is to know what and how to do.
Conditions for arranging a concrete floor on the ground
The arrangement of the floor on the ground presents certain requirements to the soils themselves. The soil must be dry, the groundwater level must be at a depth of at least 4-5 m, and the soil must not be mobile. It makes sense to make a concrete floor on the ground when the house design includes a basement or ground floor. In addition, the house must be residential and heated during the cold season, since in winter the soil freezes, thereby increasing the load on the foundation and deforming the structure.
Installation of a concrete floor on the ground
Layout of a floor on the ground
We begin all work on installing the floor after the walls have been erected and the roof has been constructed. This will ensure quality execution further work. The process of arranging the floor itself consists of the following stages:
- marking the concrete floor level;
- clearing and compacting soil;
- laying gravel, sand and crushed stone;
- hydro- and thermal insulation;
- reinforcement;
- installation of guides and formwork;
- pouring concrete, leveling and screeding the concrete floor.
Concrete floor level marking
We outline the “zero” floor level
We set the level of the concrete floor to “zero” with the bottom of the doorway and apply it along the entire perimeter of the room. To do this, you need to put marks on the wall at a level of 1 m from the bottom of the doorway. Then transfer the marks to the walls along the entire perimeter of the room and measure from them and mark back 1 m down. The resulting line will be the “zero” level to which concrete must be poured. To make it easier to navigate, you can hammer nails along this line in the corners of the room and pull a cord on them.
Clearing and compacting soil
Now we begin to clear and compact the soil. First of all, we remove all construction waste from the premises.
Then we begin to remove the top layer of soil.
The structure of the floor on the ground is a multi-layer “pie”, about 30-35 cm thick. Therefore, we remove the layer of soil until the total height from “zero” to the ground becomes equal to the thickness of the structure of the multi-layer “pie”.
Then thoroughly compact the surface. This can be done using a special vibrating plate. But if it is not there, then we take an ordinary log, nail handles to it on top, and a board below and begin to compact the soil. The goal is to get a level and sufficiently dense base on which you can walk and not leave indentations from your feet.
There may be a situation when the soil level is below the stated 35 cm. In this case, it is necessary to remove a small part of the fertile layer, compact it tightly, fill it with sand to the required level and compact it.
Important! To increase the waterproofing of a concrete floor, a layer of clay and then sand can be laid on top of the native soil. The clay can be watered a little and compacted; it will prevent the penetration of groundwater.
Once the base layer is compacted, you can begin to fill in the next one - this will be gravel. We fill a layer of gravel with a thickness of 5-10 cm. Water it with water and compact it thoroughly. To make it easier to control the thickness of the layer, we drive several rows of pegs of the required height into the base soil and set them according to the level. After backfilling and compaction, the pegs can be removed.
Fill the sand and tamp it down
After the gravel we add sand. We make the layer thickness about 10 cm and to simplify control we use the same pegs. We water the sand and compact it tightly. It should be noted that ravine sand with various impurities can be used for this layer.
On top of the sand we lay a layer of crushed stone of a fraction of 40-50 mm. We carry out the compaction procedure. Sprinkle the resulting crushed stone surface thin layer sand, level and compact. If there is crushed stone with sharp protruding edges on the surface, it should be removed or placed so that there are no sharp corners on the entire surface.
Important! The base base and all layers of the concrete floor “pie” must be leveled to the horizon. Therefore, at all stages of laying and compacting each layer, it is necessary to monitor the horizon using a level.
Waterproofing and thermal insulation of concrete floors
Waterproofing a concrete floor can be done with plastic film
To create, you can use a 200 micron thick polyethylene film or a waterproofing membrane. We spread the waterproofing layer over the entire area of the room, bring the edges a couple of centimeters above the “zero”, let the sheets themselves overlap and glue them with tape.
To improve the thermal insulation qualities of a concrete floor, you can use various materials, each of which is laid at a certain stage of the work:
- expanded clay;
- Styrofoam;
- stone basalt wool;
- mineral wool;
- expanded polystyrene;
- extruded polystyrene foam;
- perlite;
- thick moisture-resistant plywood;
- cork covering;
- rolled isolon.
Floor reinforcement
You can reinforce a concrete floor with a frame made of metal rods
To give concrete floor It must be reinforced for additional strength. For this purpose, metal or plastic mesh, reinforcing rods or metal wire are used. The reinforcing frame must be laid on stands 2-3 cm high. This way it will be inside the concrete floor and create a single whole with it.
Important! If we use plastic mesh, then we pull it onto the pegs hammered into the base. You can weld a reinforcing frame made of reinforcement and metal wire yourself, having certain skills.
Installation of guides and formwork
To facilitate pouring concrete and maintain the “zero” level, it is necessary to lay guides. We mark the room into equal sections up to two meters wide and divide them using guides. They are usually made from a board or block, the main thing is that the height of the guides is level with the “zero” mark. We fix the guides themselves using a thick mortar of cement, sand and clay.
We install the formwork for the concrete floor between the guides. It forms so-called “cards”, which are subsequently filled with concrete. This is done in order to simplify the filling process and maintain a “zero” level. For formwork we use moisture resistant plywood or boards.
Important! The guides and formwork must be brought to “zero” and leveled horizontally using a level in order to obtain a level floor when pouring. We treat the formwork and guides with special oil to easily remove the boards from the concrete solution.
Pouring concrete, leveling and screeding a concrete floor
We pour the concrete floor in one, or maximum two, passes. This is necessary to create a monolithic and durable structure. To do this, you can order concrete at the factory, and it will be delivered to large volume, but if this is not possible, you will have to do everything yourself. Then you will need a concrete mixer and a shovel, M400 or M500 cement, river sand, crushed stone and a partner.
To prepare concrete, take 1 part cement, 2 parts sand, 4 parts crushed stone and 0.5 parts water. Mix in a concrete mixer and use the resulting mixture to fill the floor. We start pouring from the opposite corner from the door. It is necessary to pour several “cards” in one or two times, then level and stretch the mixture with a shovel. To ensure dense shrinkage of concrete, we use a special vibrator, which helps compact the concrete and fill all voids with it.
We set the rule on the guides and pull towards ourselves
After filling out several “cards” we begin the rough draft. To do this, we install a rule more than 2 m long on the guides and pull it towards us. With its help, we remove excess concrete that fills the still empty “cards”. In those “maps” where the alignment was carried out, we remove the formwork and guides and fill the voids with concrete. Once the entire floor area is filled with concrete and leveled, it is covered with film and allowed to sit for 3-4 weeks to harden. During this time, the surface is constantly moistened with water.
Fill the floor with self-leveling mixture
At the final stage, we screed the concrete floor with a self-leveling mixture. This will smooth out all the small flaws and create a perfectly smooth surface. We start from the opposite corner from the door. We apply a solution of a self-leveling mixture to the surface and stretch it using the rule. The resulting surface must stand for 3 days.
The crowning achievement in creating a concrete floor on the ground will be the laying of the floor covering, which, thanks to a carefully prepared base, will be strong and durable. The design of a concrete floor on the ground, due to its simplicity and reliability, can last for decades; the main thing when creating it is to follow the concrete pouring technology.
Construction of a private house implies the possibility of laying the floor directly on the ground. This is a popular installation method that does not require large financial expenses from the property owner - only spending on clay, cement or concrete. In buildings with strip foundations, a concrete floor is often installed on the ground - its material is available for purchase, has a wide variety of types and is strong enough to perform load-bearing functions. The installation work can be done with your own hands, but for a high-quality result you will need the recommendations of professional builders.
Before you begin installing the floor system, you need to check the soil for compliance with technical standards. The soil at the construction site must be dry and motionless, and groundwater must not approach the surface closer than 4-5 meters.
Concrete floors are best made for buildings with basements or ground floors. The final quality of the work performed also depends on the degree of heating of the home.
In poorly heated private houses, the soil under the floor freezes strongly, which leads to deformations and increased load on the foundation.
The concrete floor surface matches the bottom doorways. It should maintain a uniform thickness over the entire area of the room. Marks on the walls made a meter from the bottom of the door will help achieve this. After placing the first marker in such a place and distributing the marks along all the walls of the room, meter-long lines are again measured down from them.
By connecting these lines with perpendicular segments, you can determine the boundary up to which you need to pour the concrete mixture. For ease of orientation, nails are driven into the corners of the room, along which the cord is pulled.
Clearing the base
Before removing the top layer of soil in the room, you need to clean it, getting rid of construction waste and large items. Since the concrete floor consists of several layers with a total thickness of about 40 centimeters, a similar volume of soil will need to be removed to lay it.
Finishing work is carried out only on a flat surface, and therefore the soil after excavation must be compacted with a special vibrating plate. In case of absence necessary equipment you can use a simple log, nailing handles to its upper part, and to the bottom - wooden board suitable size. To prevent the base from being washed away by groundwater, the treated soil can be covered with clay.
Laying bulk material
The previously prepared soil is covered with a layer of gravel 5 to 10 centimeters thick, watered and compacted. Sand is placed on top of it in the same amount. The next layer is crushed stone 4-5 cm in size, which also needs to be compacted and sprinkled with sand. Stone fragments with sharp edges that come to the surface will need to be removed or placed on their side, otherwise it will interfere with the future screed.
Thickness control is ensured using several rows of pegs driven into the base soil and leveled. At the end of the work they can be removed.
Installation of film covering
After making sure that each layer of material is backfilled and leveled, the future concrete floor will need to be waterproofed. A 200 micron thick polyethylene film or similar waterproof membrane is suitable for this.
The laying technology involves placing it along the entire perimeter of the building with the edges raised 10-20 centimeters above the zero level. They will be trimmed after the finishing screed is completed. Separate sheets are laid overlapping, gluing along the joints with mounting tape. If waterproofing work cannot be carried out at this stage, water protection is carried out by coating the rough floor screed.
Laying a concrete floor on the ground involves strengthening it with a mesh of metal or plastic, reinforcing rods or thick wire. The frame for reinforcement is laid on wooden coasters height from 2 to 4 centimeters. If you pour it there building mixture, it will pass through the mesh, coat it and harden to form a durable surface.
If a plastic base is used for reinforcement, it must be pulled over pegs driven into the base. To save money, you can make frames from reinforcement or wire yourself.
After installing the frame, guide bars are laid to create a layer of reinforcement to facilitate pouring. They divide the entire space of the house into equal parts two meters wide. The material for them is identical pieces of boards or construction timber, aligned horizontally to the zero mark. They are fixed using a cement-sand mortar with the addition of clay.
Formwork is also installed between the guides, dividing the floor in the room into separate cells, where concrete will need to be poured in the future. It is easy to make from thick plywood, impregnated with special oil for ease of removal from the frozen mixture.
Concrete works
To create a durable and uniform surface, all concrete must be used in one go. High quality mortar You can order it at the factory, but if this is not possible, you will have to prepare it yourself. The optimal composition for the subfloor of a private house will be a solution of lightweight concrete B7.5 (M100) or B10 (M150) with the addition of crushed stone of fraction 5-20.
If a waterproof bedding was used for compaction, concrete grade M50-M75 can be used. It must be thoroughly mixed in a concrete mixer and kept until installation begins.
Coating liquid concrete starts from the side opposite the entrance opening. Several cells are filled with the mixture at a time, after which the solution is smoothed with a shovel and leveled with a special rule that is installed on the guides and pulls towards itself. The removed excess concrete, in turn, fills the free cells.
The resulting rough screed should be five centimeters thick. The permissible horizontal difference is 4 millimeters. To make a floor with tight shrinkage, you will also need to use a construction vibrator. It will compact the concrete and ensure its solidity.
Further technology for the work being carried out requires the removal of guides and individual parts formwork from areas that have been leveled. The voids created during this process are also filled with the building mixture.
After the concrete is evenly distributed over the entire area of the future floor, you need to check its slope with a bubble level and cover it with a layer of polyethylene. The period for complete hardening of the rough screed is about a month, and during this period the concrete must be constantly moistened.
Vapor barrier
To prevent the screed from being exposed to the harmful effects of moisture, the concrete floor will need to be protected from steam and condensation. A polymer-bitumen membrane, polyester or fiberglass film is well suited for this. PVC sheets will be more expensive, but their cost is justified by their high durability and resistance to rotting. Insulation can be done using polyethylene, but under a layer of insulation and finishing screed it will be subject to heavy loads and may lose its integrity.
Coating concrete with a layer high-quality insulation will reduce the cost of heating your home by a quarter. Popular insulators are polystyrene foam derivatives. To give the material additional strength, it is covered with layers of polyethylene, laid overlapping.
You can make high-quality installation using extruded polystyrene foam. It has low compressive deformation and can be freely used in rooms where the floor is subject to heavy loads.
Another insulation option could be mineral wool. Due to its vulnerability to water, such an insulator will need to be protected with a polymer film and laid in a pre-created frame.
Finish floors
Finish concrete screed is carried out after completion of all concrete work. It is used to level the floor surface, improve heat absorption in a private home, and also create the desired slope on the floors. Before you begin reinforcing and pouring concrete, you will need to clean the subfloors from dirt and construction debris. Cracks in the supporting layer are covered cement mortar, and large cracks at the joints of surfaces are isolated with damper tape.
To strengthen the structure, it is necessary to reinforce it by installing a metal mesh 3 mm thick and 10x10 cm in diameter at the bottom of the floor. This mesh is installed from below with a rise of 2.5 cm on the walls. When the reinforcement is completed, you need to prepare guides for pouring concrete. They are seated on the plaster and checked with a bubble level. The final slope of the floor depends on the correctness of their fastening.
A popular method of finishing concrete screed is monolithic pouring. A mortar is prepared for it from one part of cement (Portland cement M400 is usually used) and three parts of sifted quartz sand. The amount of water is determined as the kneading progresses. Its volume should be slightly more than half the volume of cement used (1 to 0.55). The mixture should not be too fluid.
To ensure that the mixture sets well and is homogeneous, it is better to pour it into a concrete mixer rather than knead it by hand. Having ensured that the reinforcement and floor preparation processes are correct, you can proceed to the main concrete work.
The pouring process is similar to installing subfloors, but for maximum effectiveness, the cement must be used within two hours. The period of complete hardening is about thirty days. You cannot force it to accelerate - the internal connections may be broken, and the drying composition will lose its strength.
Strip foundation, lack of a basement, low groundwater level - these conditions are enough to choose concrete floors on the ground in a private house.
Call this solution simple and easy it is forbidden, but it allows you to save money due to the absence of floor slabs and reducing the load on the base unit (hence the foundation can be made “lighter”).
Floors on the ground: we start with protecting the foundation
Most sources cite groundwater occurrence as a mandatory requirement no higher than 4-5 meters(sometimes even two). And this is the level of occurrence perched water, which is seasonal and is located above impermeable layers. That is, these are ordinary sedimentary waters that have not had time to seep into lower and permanent aquifers (“on sand” and “on lime”).
Summer and winter perched water disappears and appears in spring and autumn. Even if the site is located in a “critical” zone, then it can be effectively dealt with (if it is not infiltration water seeping through the ground from a nearby reservoir).
The first condition for preventing flooding by high water is drainage.
It is necessary to “help” sedimentary water penetrate through soil layers that have water-resistant properties (loams). These measures are important for such areas, even from the point of view of protecting the foundation during the period of rain and snow melting. This is not difficult to do - several wells with a diameter of up to 15 cm and a depth below the heel of the foundation are drilled around the perimeter of the house.
Then a drainage pipe is inserted just below the ground level (it is better to wrap it with filter fabric - this will prevent it from silting) and fill it with fine crushed stone. The hole is covered with waterproof material, covered with earth on top or covered with a piece of turf.
There is a more complex option with the construction of trenches, in which the same pipes are laid on a bed of sand and crushed stone and brought down at a slope to the drainage well.
The second condition is waterproofing the foundation.
In conditions of pressure water exposure, the most effective will be a combination of several methods.
First, the outer walls of the base are treated with a bitumen primer, and roll materials are glued onto it. The correct technique is a horizontal arrangement from bottom to top, overlapping, but a simpler one is vertical.
Bonding occurs due to heating blowtorch the inside of the leaf. They protect the waterproofing with a clay castle, which itself serves as a barrier to water. If the impact of perched water is short-lived, and precipitation in the region is not heavy, then you can limit yourself to coating waterproofing.
And of course, to the mandatory measures to protect against water, it is necessary to add a blind area (20 cm wider than the projection of the roof edge) and a drainage system.
Floors on the ground: installation of a base for a concrete floor on the ground
In principle, ground floors are a common technology for basements, basement premises, outbuildings(sheds, garages). The only significant difference can be the installation of a “warm” floor in the screed, and the installation of a reliable foundation, waterproofing and passive insulation is carried out in any case. Floors on the ground
No matter how reliable the foundation waterproofing and drainage measures are, the soil has its own moisture, and water can rise up through natural capillaries. Therefore, it is necessary to protect the floor from these factors.
In cross-section, the device for flooring on the ground represents a multi-layer cake.
The base for the entire structure should be a flat and dense area without any remnants of vegetation, root systems and construction debris. The “reference point” for determining the volume of excavation work is the threshold level.
The thickness is subtracted from it finishing coating and the thickness of all layers of the concrete floor on the ground (for residential premises it is only the base).
After the site has been cleared and leveled, its base must be compacted. The simplest “rammer” is a cut log with a cross handle; a more modern method is a vibrating machine.
Floors on the ground: to improve insulating properties
the next layer can be done made of clay. For wells, the recommended thickness is clay castle not less than 20 cm, for artificial reservoirs 8-12 cm, the same parameters are chosen for adobe floors, but here you can limit yourself to a more modest value of 5-6 cm.
Next comes a layer of sand. Many people, out of inertia, advise choosing river or washed seeded sand, but this is redundant - ordinary quarry sand is suitable for the cushion (this is not the production of concrete and clay impurities do not affect the strength characteristics). This layer is watered and compacted.
Then a layer of medium or fine crushed stone is poured. It interrupts the capillary rise of water from the ground. It is also compacted.
The thickness of each layer is usually selected from 5 to 10 cm, with a total size of up to 20 cm.
It is possible to use expanded clay (it is a good bulk thermal insulation material), but this is only if the possibility of water ingress is excluded - under its influence it swells. For dry soils, you can limit yourself to only a cushion of sand, but for the floor in the basement it is permissible to use a cushion made of two layers of crushed stone - first a coarse fraction, and then a fine one.
A thick polyethylene film is laid on top of the crushed stone, extending onto the walls.
It is not used for waterproofing, but as a necessary condition proper hydration of the first layer of concrete.
First to fill skinny concrete, which does not perform load-bearing functions, but serves as the basis for waterproofing and laying thermal insulation materials. Builders call it “foot concrete” or “rollable” (it is easy to lay). The percentage of cement in it is usually almost 2 times less due to increasing the share of filler- for example, instead of the ratio 1:3:3 (cement, sand, crushed stone), the proportions 1:3:6 are used.
Since this layer is not taken into account when ensuring the overall strength of a concrete floor for a private house, its reinforcement is not necessary.
A layer of 6-8 cm is enough.
Important! When making concrete, you should use river or washed sand.
After pouring, the concrete must be compacted and leveled. Jewelry precision, as for a screed, is not necessary, but alignment with beacons is necessary for high-quality installation of slab insulation. Floors on the ground
Then a break is necessary for the concrete to gain strength. The first week is very important - for hardening (hydration) of the solution it is necessary to create high level humidity. This is why a film is needed at the base - so that water does not go into the sand and crushed stone, and does not get absorbed into the walls. Periodically the surface is moistened with water. Better yet, cover with wet burlap. Ideally (at a temperature of 20°C and normal humidity) in the first 7 days, concrete gains 70% of its design strength, and in four weeks - 100%.
To continue work, it is enough to wait a week.
When using hardening accelerator modifiers, 3 days are enough (sometimes one day, but such additives ultimately significantly affect the quality of the concrete stone).
Floors on the ground: waterproofing.
It is mandatory for the first floors, especially in conditions of flooring on the ground. It is better to leave the use of polyethylene (of any density) for the floors of city apartments (and not in the bathroom or kitchen). The right choice is roll insulation with bitumen impregnation.
The surface, cleared of dust, is treated with a bitumen primer (primer), and roofing material (or one of its analogues) is laid on top. This is done in two layers, with the seams displaced (filled with bitumen) and reaching the walls above floor level.
At this stage, the preparation of the base for insulation and pouring the screed ends.
Concrete floor on the ground: floor insulation
To insulate a concrete floor, three options are most often used - expanded clay, expanded polystyrene, and extruded polystyrene foam.
As already noted, only when reliable waterproofing It is possible to use expanded clay - it swells when exposed to moisture. The thickness of the layer can vary between 10-20 cm.
It is better to insulate with foam plastic in two layers, each of which should move relative to each other. It is advisable to offset the seams between the rows. This will increase the strength of the insulation layer itself, and ultimately the screed - if the seams coincide, the risk of cracks appearing in this place increases. Sheets of foam plastic should be fitted as tightly as possible to each other, and it is best to use foam plastic with ends that have a tongue-and-groove profile.
Treat the joints with adhesive.
The insulation technology of EPS is the same as for polystyrene foam. The difference between the material is its high compressive strength and the almost complete absence of water absorption (it itself is a good waterproofing material).
Important! Floor insulation is effective if the base is insulated.
Floors on the ground: screed
The pouring of the floor over the ground ends with a screed. Next comes the installation of the finishing layer: wooden floors, laminate, linoleum, etc.
Although for office premises(garage, basement, storage room) you can top the concrete surface at the pouring stage (this significantly increases strength and prevents dusting).
The screed over the insulation must have reinforcement.
For residential premises with light surface loads, it is sufficient to install a road mesh with a link size of 10x10 cm and a wire thickness of 3-4 mm.
You can use galvanized steel mesh, but polymer
or composite
behaves better in the alkaline environment of concrete, as well as .
The mesh is not attached to the walls, but a compensation gap of at least 20 mm is left. Can be used wooden block or foam cuttings, which are then removed and the gap is filled with elastic sealant.
The mesh is laid overlapping two cells, and the fastening between the sheets is done with wire.
Floors on the ground: reinforcement
passes at some distance from the floor surface (approximately 1/3-1/2 layer of screed). To do this, you can use pieces of brick or crushed stone, plastic bottle caps or special stands.
The thickness of the screed for residential premises must be at least 50 mm.
You can use both types of concrete (cement-sand) screed - classic or semi-dry.