Building standards for the construction of structures of different parameters provide for separate structural solutions. Their implementation is not always necessary, since some designs can be replaced by others, and taking into account third factors, the need to use the recommended tool completely loses its relevance. But when it comes to issues of home reliability, then there should be no compromises. One of the structural elements, whose function is aimed at increasing the strength of walls, ceilings and foundations, is a monolithic belt. It is laid under the floor of the building in cases where the base parts of the frame cannot fully accept the imposed loads. If we omit this nuance, then during operation, the formation of cracks at the joints of walls with ceilings is not excluded.
Technology overview
The need to implement this technical solution is due to the fact that in the case of thin walls, the loads from the floors used will exert excessive pressure on the overall structure of the building. In such situations, additional reinforcement is practiced through a balanced distributionmechanical effort. Actually, the foundation is used first in such equipment, the monolithic belt of which goes to the basement walls. It should be noted that these walls are constructed simultaneously with the ceilings. However, the sequence to a large extent depends on the material from which the foundation itself is made. So, if the foundation of the building is being built on the ground without geological restrictions, then the belt may even be superfluous. However, a monolithic belt is usually arranged along the upper intersection of the above-ground part of the foundation walls. This is especially true for houses that are built from such masonry building materials as cellular concrete or expanded clay concrete.
Belt composition
As the name implies, the basis is a monolithic beam made of concrete. The cement mixture itself acts as the basis of the belt, forming a reliable support. If we are talking about construction in a home construction site, then you should also prepare means for creating formwork. A niche is formed from the beam for the subsequent pouring of concrete. The formwork can be made from boards 2.5 cm thick. The better the wood, the better the geometry of the structure will turn out - accordingly, the monolithic belt will fit more neatly into the frame of the house. Special attention is devoted to the reinforcement of the structure. Reinforcement with metal bars is the key to the strength of the beam itself, so you should also prepare for the introduction of reinforcing bars, possibly using a welding machine or a specialized tool for knitting iron bars.
Execution of the plank base
The wall or foundation is immersed in plank formwork. As a rule, the belt has a height of 30 cm. As for the width, it corresponds to the masonry material, taking into account the thickness of the heat insulator. These parameters should be taken into account when constructing the formwork. First you need to fix the board with the bottom side to the wall with self-tapping screws. Both sides of the formwork are connected by transverse fasteners. By means of the level, the horizontal of the lower part of the structure should be controlled so that the monolithic belt is evenly installed and does not require further adjustments. The same must be done at the top. In the created structure, the basis for the reinforced belt will be laid. It is important to note that the most problematic areas of this box are the corner places where the boards form joints. These points should be further strengthened and, if possible, sealed with special compounds so that the solution does not seep through.
Reinforcement of the monolithic belt
In strengthening the structure, metal reinforcement is used, the size of which is selected depending on the parameters of the ceiling. Usually, a rod with a large diameter is used to strengthen the span above the foundation. The standard diameter is 12 mm. Two lines of such rods are used in conjunction with the walls. Typically, installation is carried out in a ladder configuration. That is, the elements are introduced obliquely in increments of 100 cm. For the lower levels with the same foundation, four contours are usedrods. Reinforcement is introduced into a monolithic belt not separately, but in the form of a formed rectangle. For this case, you will need a welding machine, although you can limit yourself to strapping. Also in modern houses, fiberglass reinforcement is used, which is distinguished by its lower weight and overall dimensions, while maintaining the same strength indicators. It is quite possible to prefer this reinforcement option, but it costs more. If there are doubts about the bearing capacity of the foundation, then this option will justify itself even taking into account the overestimated estimate, since plastic reinforcement will reduce the load on the foundation.
Pouring concrete
There are no special requirements for the concrete mixture for the reinforcing belt. For it, if desired, you can turn on the crushed stone filler, if we are talking about a large area of filling. Also, before performing the procedure, the formwork should be checked for reliability and tightness. In extreme cases, you can bring the solution to the optimum viscosity - so that it does not spread when placed in a frame. Some technologies provide for the installation of a monolithic belt with the laying of mesh reinforcement in an already poured solution. However, this solution is only justified if the position of the external reinforcement elements is to be monitored. After the event is completed, the structure should be expected to harden. It usually takes about 4-5 days to fully achieve strength properties.
Introducing communications
Even before pouring, you can place everythingthe necessary communications that will take place in the belt laying section. For laying pipelines, special sleeves are used through which the contour is passed. Chimney and air duct structures are immediately installed at the place of use, and later they can be connected to indoor and roof systems. All plugs are recommended to be fixed through with self-tapping screws. The flight of stairs is the most difficult element that can be laid through a monolithic belt. A formwork is also installed under a monolithic slab with a march, and its corners are additionally reinforced with diagonal reinforcement bars. That is, the possibility of introducing this communication should be considered at the reinforcement stage. To fix the stairs, the rods of the lower reinforced belt are passed through the formwork.
Technology Implementation Tips
When laying a belt in single-layer walls, inexperienced craftsmen often ignore the heat transfer performance of the structure, which is why the heat-insulating function suffers during the operation of the house. You can correct the error by insulating the outer side of the wall with mineral wool or expanded polystyrene. The optimal layer thickness is 10 cm. You should also correctly calculate the position that the monolithic belt will take relative to ceilings and walls. Typically, the beam is lowered below the floor level by 4 cm. In this configuration, the elements of the supporting structure will not rest on the walls, but just on the intermediate concrete belt. Due to its base and the reinforcing elements placed in itdistribution of floor loads will be more even and reliable.
An alternative in the form of a prefabricated monolithic slab
Despite the function of unloading the gravity transmitted from the ceiling to the walls, the monolithic beam itself acts as a rather serious load element due to its mass. And if for the walls this part acts as a load weakening factor, then for the foundation, in any case, the pressure rises. Therefore, sometimes prefabricated monolithic belts are used on weak foundations. The presence of cavities in them eliminates excess weight, and in terms of thermal conductivity, experts note more favorable characteristics from the point of view of operation. On the other hand, a monolithic reinforced concrete belt has an undeniable advantage in terms of strength. Still, massiveness and heavy weight endow the overall frame with reliability and resistance to ground shifts and external influences.
Conclusion
The function of the reinforcing belt is still perceived ambiguously among professional builders. The need for this design is obvious when it comes to thin walls and, in general, to a weak bearing part. On the other hand, the monolithic belt of the house does not at all relieve the supporting elements from loads, but only redistributes the mass of the upper part of the building with ceilings. Practice shows that the introduction of this beam also does not cause serious negative consequences. And even if we exclude the function of the belt as an optimizer of loads on walls and foundations, then it acts as a useful intermediate link in a house withfrom the point of view of laying engineering communications.
