When constructing a private house, it is important to choose the constructive solutions of its elements. One of the most important designs can be called overlap. Properly selected thickness of the slab of reinforced concrete floor slabs in the house between floors will ensure its reliability and safety.
Types of reinforced concrete structures and scope
Monolithic slabs are suitable for use in massive buildings made of stone or brick. In a brick house, this overlap creates a disk that gives the building additional rigidity. When laying interfloor reinforced concrete floors, it is important to choose the type of its manufacture:
- monolithic;
- national team.
Both of these methods are common at present, but gradually the first displaces the second. The main disadvantages of monolithic overlapping are the cost of formwork and the need to wait for the concrete to harden. The advantages include:
- high laying speed;
- reduction of financial costs;
- lack of need for complex lifting equipment;
- the ability to fill slabs of complex configuration in terms of;
- reliability and durability.
The advantages of the combined technology include:
- high installation speed;
- no need to wait. until the concrete gains strength;
- reliability and durability;
- simpler manufacturing technology.
The disadvantages of this method are slightly larger than the previous:
- a large mass of individual elements;
- there is a need for lifting equipment (truck crane);
- limited number of sizes, difficulty in overlapping rooms of unusual shapes.
The choice between the technologies by which the overlap between floors will be built depends on the preferences of the future owner of the house and economic considerations. If the distances between the bearing walls are far from the standard, a large number of atypical products will be required, which will increase the cost of construction. In this case, it is better to dwell on a monolithic version.
Plate thickness
Know the thickness of the slab is necessary in order to calculate the total height of the floor and floor. This will be required when calculating the height of the floor, premises and the entire building. The thickness of the overlap depends on the type of construction chosen. If a decision is made to use monolithic technology, it also depends on loads from people, furniture, equipment and floor construction.
Prefabricated plates for PC and PB series
These elements are most often used in construction. PC plates are round hollow. Stacked between floors, both in private homes and in multi-story buildings. PB boards are a fairly new technology that is gradually replacing the PC series. They can be produced in any length, regardless of the sizes given in the regulatory documents. They differ in the manufacturing method - the method of continuous molding. They have some limitations and are not fully understood, but are successfully used both in private and mass construction.
Plate thickness is standard. It is 220 mm. To calculate the total floor height with the floor structure, add to this value:
- the thickness of the concrete screed, about 30-50 mm;
- if necessary, sound insulation or insulation, the thickness of the heat-insulating material (30-50 mm for sound insulation, 100-150 mm for thermal insulation);
- flooring (depending on the type, the highest height will be for a wooden floor, the smallest for linoleum or ceramic tile);
- ceiling design.
In total, the height of the concrete floor in a private house with a floor structure when using plates of the PB or PC series is approximately 300 mm.
Plates of the PT series
In most cases, these elements are applied as additional elements to the PB and PC series. Laying of such plates between levels is carried out in those places where the distance between the walls does not allow to lay large-sized products. They have small dimensions in plan, which allows you to cover small spans. Plates are suitable for laying over corridors, bathrooms, utility rooms and storage rooms. Support can be performed on all sides.
Product thickness 80 or 120 mm. The total height of reinforced concrete floors with floor elements is 150-200 mm, depending on the type of flooring.
When used, align with PC and PB products on the upper edge of the floor.
Irregularities are corrected by the construction of the ceiling.
Overlap according to the professional sheet
A fairly common method for private housing construction. In this case, the profiled sheet serves as the formwork and the supporting element of the monolithic plate. The main structural elements:
- load-bearing beams (I-beams, channel or corners with a large width of the shelf);
- profiled sheet, which is laid on the beams (the waves should be perpendicular to the supporting elements);
- concrete mortar layer.
All thicknesses are selected depending on the payload. For a private house, you can give the average values of a monolithic slab between spaces located in different horizontal levels:
- The height of the beams (I-beam or channel) for spans up to 5-6 meters is approximately 220-270 mm.
- The height of the corrugated board wave plus the thickness of the concrete layer depends on the step between the load-bearing beams and the planned load. As a minimum value for a monolithic slab of a private house, 150 mm can be given.
- Concrete screed with a thickness of 30-50 mm.
- If necessary, add a layer of insulation from 30 to 150 mm, depending on the purpose of its installation.
- Clean floor construction. Thickness depends on the type of flooring.
The profiled sheet can be supported in two ways:
- over load-bearing beams;
- adjacent to them.
In the first case, the full height of the I-beam or channel is taken into account in the thickness, and in the second case, the thickness of the floor reinforced concrete is significantly reduced. The minimum height is for light loads.
According to regulatory documents, the weight that accounts for floors in a private house is 150 kg per square meter.
In the calculation, this value must be increased by a safety factor of 1.2. For more serious loads, reinforced profiled sheet and a large thickness of the concrete layer are used.
Ribbed monolithic overlap
For a private house, you can apply another technology for making the base for the floor. A ribbed concrete slab is a long rib spaced along the long sides of the room and a thin layer of concrete between them. The space between the ribs is filled with insulation (expanded clay, mineral wool, polystyrene foam and the like).
The thickness of the monolithic plate is calculated from the following values:
- Rib height. For private housing in most cases, a thickness of 200 mm is sufficient. Moreover, the thickness of the section between the ribs can be 50-100 mm. The width of the ribs is selected approximately 100 mm.
- The thickness of the cement-sand screed. It is taken in the range of 30-50 mm.
- Floor design. The thickness depends on the floor covering and on average is in the range of 10-50 mm.
Ribbed overlap, as well as according to the profiled sheet, can reduce concrete consumption while maintaining a sufficiently large thickness. Making ribs is a difficult task. Using corrugated board allows you to create an overlap with a ribbed surface without unnecessary labor costs.
Proper selection and calculation of the thickness of the concrete slab will allow you to calculate the height of the premises, the consumption of concrete mixture and determine the financial and labor costs at the design stage of the object. In the case of prefabricated ceilings, the thickness for all elements is standard.