Building codes for the construction of structures of various parameters provide for individual 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 relevance. But when it comes to issues of reliability at home, then there should not be any compromises. One of the structural elements, whose function is to increase the strength of walls, floors and foundations, is a monolithic belt. Under the ceiling of the building it is laid in those cases when the base parts of the frame cannot fully accept the assigned 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 used ceilings will exert excessive pressure on the general structure of the building. In such situations, additional reinforcement is practiced through a balanced distribution of mechanical forces. Actually, the foundation is the first to use such equipment , the monolithic belt of which goes to the basement walls. It should be noted that these walls are being constructed simultaneously with ceilings. However, the sequence to a large extent depends on the material from which the foundation itself is made. So, if the base of the building is constructed on the ground without geological restrictions, then the belt may be superfluous. However, a monolithic belt is usually arranged along the upper intersection of the aerial part of the foundation walls. This is especially true for houses that are built from masonry building materials such 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 building site, then you should also prepare means for creating formwork. A niche is formed from the timber for subsequent pouring of concrete. Formwork can be made of boards 2.5 cm thick. The better the wood, the more perfect the geometry of the structure will be - respectively, and the monolithic belt will fit neatly into the frame of the house. Special attention is devoted to reinforcing the structure. Reinforcement with metal rods is the key to the strength of the beam itself, so you should also prepare for the introduction of reinforcing bars using, possibly, a welding machine or specialized tool for knitting iron rods.
Doing boardwalk
A wall or foundation is immersed in a 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 using 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. The created structure will lay the foundation for the reinforced belt. It is important to note that the most problematic areas of this box are the corner places where the boards form the joints. These points should be further strengthened and, if possible, sealed with special compounds so that the solution does not leak out.
Reinforcement of a monolithic belt
In reinforcing 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 over 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 staircase configuration. That is, the elements are introduced obliquely in increments of 100 cm. For the lower levels with the same foundation, four contours of the rods are used. In the monolithic belt, the reinforcement is introduced 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 homes they use fiberglass reinforcement, which is less weight and overall size, while maintaining the same strength indicators. It is possible to prefer this option of reinforcement, but it costs more. If there are doubts about the bearing abilities of the built foundation, then this option will justify itself even taking into account overstated estimates, since plastic reinforcement will reduce the load on the base.
Concrete pouring
There are no special requirements for concrete mix for the reinforcing belt. For him, if desired, you can turn on the aggregate of crushed stone, if we are talking about a large filling area. Also, before performing the procedure, the formwork should be checked for reliability and tightness. In extreme cases, you can bring the solution to the optimal viscosity indices - so that it does not spread when it is laid in the frame. Some technologies include the installation of a monolithic belt with laying mesh reinforcement in an already poured solution. But this solution justifies itself only if the position of the external elements of the reinforcement is to be monitored. After the implementation of the event, one should expect hardening of the structure. The complete achievement of strength qualities, as a rule, takes about 4-5 days.
Implementation of communications
Even before pouring, you can arrange all the necessary communications that will take place in the belt laying section. For laying pipelines, special sleeves are used through which the circuit is passed. Designs of chimneys and ducts are immediately installed at the place of use, and later they can be connected to indoor and roof systems. All plugs are recommended to fix through with self-tapping screws. The flight of stairs is the most complex element that can be laid through a monolithic belt. Under the monolithic slab with a march, formwork is also installed, and its corners are additionally strengthened by diagonal reinforcement bars. That is, the possibility of introducing this communication should be considered at the stage of reinforcement. To fasten the stairs through the formwork, the rods of the lower reinforced belt are passed.
Technology Implementation Tips
When laying belts in single-layer walls, inexperienced craftsmen often ignore the heat transfer indicators of the structure, because of which the heat-insulating function suffers during the operation of the house. The error can be corrected by warming the outer side of the wall with mineral wool or polystyrene foam. The optimum layer thickness is 10 cm. You should also correctly approach the calculation of the position that the monolithic belt will occupy with respect to ceilings and walls. Typically, the beam is lowered below the level of overlap 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 it, the distribution of loads from the overlap will be more uniform and reliable.
The alternative in the form of a precast monolithic slab
Despite the function of unloading the gravity transmitted from the overlap to the walls, the monolithic beam itself acts as a rather serious load element due to its mass. And if for walls this part acts as a factor in easing loads, then for the foundation, in any case, the pressure rises. Therefore, sometimes on weak foundation foundations, prefabricated monolithic belts are used. The presence of cavities in them eliminates excess weight, and in terms of thermal conductivity, experts note characteristics that are more favorable from the point of view of operation. On the other hand, a monolithic reinforced concrete belt has an obvious advantage in terms of strength. Still, massiveness and heavy weight endow the overall frame with reliability and resistance to soil 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 about a weak bearing part. On the other hand, the monolithic belt of the house does not relieve the supporting elements from the load at all, 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 the loads on the walls and foundation, then it acts as a useful intermediate link in the house from the point of view of laying utilities.