If a house is built from block materials, it is often exposed to natural influences. In particular, the building settles, the soil around it swells, etc. well and strong wind and long rainfalls - negatively affect the integrity of the structure. To protect against such influences, an armored belt is created with your own hands from concrete on top of the walls. In our article we would like to talk about the manufacturing technology of the reinforcing belt, as well as its purpose.
Purpose and design of armored belt
Reinforcing belt (seismic belt) - increases the reliability of the house and prevents the appearance of cracks. They, in turn, are formed when the soil moves or is exposed to precipitation. Such an element helps to evenly distribute the loads from heavy structures located above it.
For example, concrete floors laid just on top of the reinforcing belt. Many people make the mistake of thinking that wooden floors do not need. This is far from true - this element is needed to close the walls of any house. In this case, the type of overlap does not matter. After all, as you know, houses are built to last for many centuries, and not for a short time.
Construction of an armored belt: stages of work and their features
The need to create an armored belt under the Mauerlat when constructing a roof is not always obvious to novice builders. They often have the wrong idea about reinforced reinforcement of the base for the construction of a roof as something unnecessary and superfluous. However, the armored belt is an important intermediary that distributes the load of the roof onto the walls of the building. Let's look at why an armored belt under the roof is needed, what functions it performs and how to install it yourself.
In this article
The need for an armored belt
Let's start reviewing reinforced base under the roof with its main functions.
Load conversion
The rafter legs transfer the load to the mauerlat, the main concentration of which is in the places where the rafters support the walls of the house. The task of the Mauerlat and armored belt is to transform this load, making it uniform. The Mauerlat is subject to two types of loads. This is the weight of the roof itself, the snow accumulated on it, the effect of gusts of wind on the roof and other natural phenomena.
Another load is associated with the bursting of the building walls by the rafters. As the weight of the roof increases, it increases significantly. Modern materials for the construction of buildings, such as expanded clay concrete, aerated concrete, with a number of positive characteristics are not able to withstand such a bursting load. Before installing the Mauerlat on them, it is imperative to create reinforced belt.
Brick walls are more resistant to point loads, so to install the Mauerlat on them, it is enough to use anchors or embedded parts. However, experts recommend the use of an armored belt for brick walls, if the building is being erected in an earthquake-prone region.
Attaching the roof to the house
The most important and main task of the Mauerlat is to firmly attach the roof to the house. Thus, the Mauerlat itself must be securely mounted to the building. 
The main tasks of a reinforced roof base can be reduced to the following points:
- Holding strict geometry buildings in any situation: seasonal variations soil, earthquakes, house shrinkage, etc.;
- Alignment of walls in horizontal projection, correction of inaccuracies and flaws made during the construction of walls;
- Ensuring rigidity and stability of the entire structure of the building;
- Uniform and distributed distribution of the roof load on the walls of the building;
- Possibility of strong attachment to a reinforced base important elements roofing, primarily Mauerlat.
Calculation of a reinforced base for a roof
The process of reinforcing the base under the Mauerlat begins with planning and calculations. It is necessary to calculate the dimensions of the armored belt. By building standards it should be equal to the width of the wall, and not less than 25 cm. The recommended height of the reinforced base is around 30 cm. The armored belt and the mauerlat laid on it should encircle the entire house.
If the walls are built from aerated concrete, then the top row is made of stone in the shape of the letter U, which creates the formwork. It is necessary to lay reinforcing elements in it and fill the entire structure with cement mortar. 
Before the actual start construction work it is also necessary to prepare necessary tools And Construction Materials. To create a reinforced base for the roof you will need:
- Concrete mixer for high-quality mixing of cement mortar;
- A specialized vibrator that accelerates cement mortar in the formwork, preventing the creation of air voids in the structure;
- Materials for the construction of formwork;
- Fittings.
Installation technology
Installation of the armored belt begins after masonry work. It is necessary to wait until the masonry is completely dry.
Creating formwork and laying reinforcement
The first stage is the construction of formwork. In buildings from aerated concrete blocks The outermost row of masonry is made from blocks in the shape of the letter U. If these are not available, then the outer part of the formwork is created from sawn 100 mm blocks, and the inner part from boards. Installation is carried out in strict compliance with the horizontal level.
A frame made of reinforcement is laid in the formwork. Its longitudinal part is formed from 4 reinforcement rods with a diameter of 12 mm. Transverse fastenings are made from rods of 8 mm diameter, maintaining a pitch of no more than 25 cm. In projection, the frame looks like a square or rectangle. The frame parts are mounted with an overlap of up to 20 cm. The joints are connected with knitting wire. In solution, such a reinforced frame exists as a monolithic one.
Laying the frame requires compliance with certain rules:
- The thickness of the concrete from the frame to the formwork is at least 5 cm;
- To comply with this rule, place stands made of bars of the required height under the frame.
An important part of the work is strengthening the formwork frame. If this is not done, then it will collapse from the weight of the concrete. This can be done in various ways:
Installation of fasteners for the Mauerlat
After working with the formwork and laying the reinforcement, you can begin installing fasteners for the Mauerlat. We recommend using threaded rods. It is convenient to purchase studs with a diameter of 12 mm. The length of the studs is calculated taking into account the fact that their bottom is attached to the frame, and the top protrudes above the Mauerlat by 2-2.5 cm.
Installation of studs is carried out taking into account:
- There is at least one stud between two rafters;
- The maximum installation step is no more than 1 meter.
Pouring with cement mortar
The main feature of the reinforced base for the Mauerlat is its strength. This can only be achieved by pouring the concrete solution at a time.
To create a concrete mixture, concrete of at least M200 is used. The best mixture for filling the belt is prepared according to the following proportions:
- 1 part cement M400;
- 3 parts of washed sand and the same amount of crushed stone.
The use of plasticizers will help increase the strength and speed of hardening of the mixture.
Since creating an armored belt requires a lot of mixture at once, it is advisable to use a concrete mixer and a special pump to supply the solution. In the absence of equipment, the help of several people will be required to prepare and continuously supply the finished mixture.
After pouring concrete into the formwork, it is important to expel all air from any possible air pockets. For this it can be used special device a vibrator and simple fittings with which the mixture is pierced along the entire perimeter.
Mauerlat installation
Removing the formwork from the armored belt is possible as soon as the concrete has hardened sufficiently, and installation on the Mauerlat structure can begin no earlier than 7-10 days after pouring the armored belt.
Before laying, the Mauerlat parts must be specially prepared:
- The Mauerlat timber is treated with antiseptics;
- Connecting it individual elements performed using the direct lock method or oblique cutting;
- The Mauerlat is applied to the armored belt and the places for the pins are marked. Holes for fastenings are drilled.
Laying the Mauerlat is preceded by covering the reinforced base with a layer roll waterproofing As a rule, roofing material is used for these purposes.
The Mauerlat is secured with a large washer and nut; locknuts are used for security. After tightening all the fasteners, the remaining tops of the studs are cut off with a grinder.
Let's sum it up
A reinforced base for the Mauerlat is more of a necessity than a luxury. Roof structure has a rather large impact on the walls of the house, which, although distributed evenly thanks to the Mauerlat, can negatively affect the strength of the entire building.
The creation of an armored belt is necessary in buildings made of gas and expanded clay concrete due to the fragility of these materials, in areas with high seismic activity. It is also advisable to strengthen the walls under the Mauerlat when creating heavy roofing structures.
Reinforcement of the upper part of the walls is not difficult work, requiring the involvement of specialists. If you follow a number of rules and involve assistants, it can be done on your own.
What is an armored belt and why is it needed?
Modern construction technologies are aimed at ensuring the stability of erected buildings and increasing the service life. After all, construction sites are exposed to natural factors associated with wind loads, precipitation, and the reaction of unstable soils. The structure of the buildings under construction requires reliable reinforcement, which is provided by an armored belt - a solid contour of reinforced concrete encircling the walls along a closed perimeter.
The reinforced belt along the load-bearing walls ensures high strength of the structure, increases the stability of the building, and compensates for significant loads. A solid reinforced concrete contour makes it difficult for the building to deform due to shrinkage of the base, temperature and seismic factors, as well as snow cover and wind loads. Creating a concrete belt around the perimeter of the building, reinforced with steel rods, makes it possible to form a monolithic frame, which makes it difficult for cracks to appear and increases the rigidity of the structure.
Remove the reinforced belt from the house and the building will not stand for long
There is no need to ask whether a reinforcing belt is needed. It is required during the construction of any residential and industrial facilities, ensuring reliability, stability and long service life of buildings. Let's go into detail about why ring reinforcement is performed and what materials are required. Let's look at how to make a seismic belt on your own.
On the feasibility of strengthening
What is an armored belt and why is it necessary? What caused the need to form a reinforced concrete ring around the perimeter of the building? What it is? Let's deal with all the questions in order. The reinforced belt along the load-bearing walls represents a monolithic concrete contour, repeating the closed configuration of the building and reinforced with a reinforcement frame. An armored belt is formed to solve the following problems:
- ensuring the horizontal level of the blocks in the masonry;
- compensation of thrust forces created by the rafter system;
- preventing deformation of main walls;
- proportional distribution of current efforts;
- reducing the likelihood of cracks;
- reducing negative factors associated with uneven shrinkage of the building.
Armopoyas is a tape made of monolithic reinforced concrete, which is laid on several levels of a building under construction
There are several factors that a reinforced belt along load-bearing walls can prevent:
- The elements of the truss structure are fixed to the walls of the building using fastening anchors that violate the integrity of the blocks made of cellular concrete. The result of attaching the rafters to aerated concrete blocks without a reinforcement contour – cracks appear, integrity is damaged, strength decreases.
- Located at an angle to the walls, truss structure creates expansion loads that cause deformation of the walls of the building. By forming an armored belt to counteract thrust forces, it is possible to ensure uniform distribution of acting loads along the height of the building.
- The reinforced concrete contour makes it difficult to deform main walls that have window and door openings, which perceive the acting forces differently.
The need to strengthen the perimeter of a building is especially relevant when constructing buildings made of cellular concrete, which are prone to destruction under the influence of bending forces. Knowing how to make a seismic belt, you can form a reliable edging, reinforced with a steel reinforced frame that compensates effective loads, ensuring the integrity of the structure.
Classification and purpose
Information about the types of reinforcement circuits will help answer the question of what an armored belt is and why it is needed. The stability of the structure is ensured by the following types of unloading belts:
Protects foundations and walls from cracks caused by uneven settlement and frost heaving of the soil
- the basic unloading belt, which, according to construction terminology, is called a grillage, is concreted when forming a strip foundation. The concrete belt, reinforced with a reinforcement frame, repeats the location of the main walls. The structure absorbs significant forces from the mass of the structure and the reaction of the soil;
- basement edging is the second level of reinforcement located above the foundation. The width of the contour corresponds to the thickness of the walls, allowing you to proportionally distribute the forces acting on the base. The design features of the belt located between the foundation and the main walls are provided for by the building design;
- the third unloading circuit is located between the upper level of the building walls and the floor slabs located between the floors. The one-piece reinforced structure of the belt ensures the immobility of load-bearing walls and makes it difficult for cracks to form. The belt ensures proportional distribution of loads acting from the interfloor slabs on the building contour. It reduces the likelihood of deformations in the area of openings;
- the last unloading belt is located under the roof of the building and is the basis for the Mauerlat. The rafter system, consisting of parallel roof beams, is fastened with anchor elements at the final level of strengthening of the building. A closed concrete contour compensates for the loads created by the roof, which absorbs the mass of snow cover, precipitation, and wind loads.
Remove from wooden barrel steel hoops and it will fall apart. Remove the reinforced belt from the house and the building will not stand for long. This is a simplified but very clear explanation of the need to strengthen walls. Anyone who is going to build a durable house will benefit from information about the purpose, types and design of armored belts.
What is this structure and what functions does it perform? Armopoyas is a tape made of monolithic reinforced concrete, which is laid on several levels of a building under construction.
The reinforced belt is poured in the foundation, under the floor slabs and under the mauerlats (supporting beams of the rafters).
This amplification method performs four important functions:
- Increases the spatial rigidity of the building.
- Protects the foundation and walls from cracks caused by uneven settlement and frost heaving of the soil.
- Prevents heavy floor slabs from pushing through fragile gas and foam concrete.
- Connects securely rafter system roofs with walls made of light blocks.
Reinforced concrete has been and remains the main material for increasing the rigidity of walls. For small outbuildings, you can use a less powerful brick armored belt. It consists of 4-5 rows of brickwork, the width of which is equal to the width of the load-bearing wall. In the seam of each row, a mesh with a cell of 30-40 mm made of steel wire with a diameter of 4-5 mm is placed on the mortar.
Reinforcing walls with a reinforced belt is not always required. Therefore, there is no need to waste money on its device in the following cases:
- under the base of the foundation lies a strong soil (rocky, coarse clastic or coarse sand, not saturated with water);
- the walls are built of brick;
- under construction cottage, which is covered with wooden beams rather than reinforced concrete panels.
If the site contains weak soils (pulverized sand, loam, clay, loess, peat), then the answer to the question of whether a reinforcing belt is needed is obvious. You cannot do without it even when the walls are built from expanded clay concrete or cellular blocks (foam or aerated concrete).
These are fragile materials. They cannot withstand ground movements and point loads from interfloor floor slabs. The armored belt eliminates the risk of wall deformation and evenly distributes the load from the slabs onto the blocks.
For arbolite blocks (the wall thickness is not less than 30 cm, and the strength grade is not lower than B2.5), an armored belt is not needed.
For Mauerlat
The wooden beam on which the rafters rest is called the Mauerlat. It cannot push through the foam block, so someone may think that an armored belt is not needed under it. However, the correct answer to this question depends on the material from which the house is built. Fastening the Mauerlat without an armored belt is allowed for brick walls. They securely hold the anchors with which the Mauerlat is attached to them.
If we are dealing with light blocks, then the armored belt will have to be filled. In aerated concrete, foam concrete and expanded clay blocks anchors impossible to securely fix. Therefore, a very strong wind can tear the Mauerlat from the wall along with the roof.
For the foundation
Here the approach to the amplification problem does not change. If the foundation is assembled from FBS blocks, then an armored belt is definitely necessary. Moreover, it must be done at two levels: at the level of the sole (base) of the foundation and at its upper cut. This solution will protect the structure from intense loads arising during the rise and settlement of the soil.
Rubble concrete strip foundations also require reinforcement with a reinforced belt, at least at the level of the sole. Rubble concrete is an economical material, but not resistant to soil movements, so it needs reinforcement. But a monolithic “tape” does not need an armored belt, since its basis is a steel three-dimensional frame.
There is no need for this design for a solid foundation slab, which is poured under buildings on soft soils.
Under what types interfloor ceilings do you need an armored belt?
Under the panels that rest on expanded clay concrete blocks, gas or foam concrete, a reinforced belt must be made without fail.
For monolithic reinforced concrete floor it does not need to be poured, since it evenly transfers the load to the walls and firmly connects them into a single spatial structure.
Armopoyas under wooden floor, which rests on light blocks (aerated concrete, expanded clay, foam concrete) is not required. In this case, it will be enough to pour concrete support platforms 4-6 cm thick under the beams to eliminate the risk of pushing through the blocks.
How to make an armored belt correctly?
The technology for constructing a reinforced stiffening belt is no different from the method of pouring a monolithic foundation.
IN general case it consists of three operations:
- Manufacturing of reinforcement frame;
- Installation of formwork;
- Pouring concrete.
Certain subtleties and nuances in the work appear depending on the area where the armored belt is located.
Reinforced belt for the foundation
Answering the question of how to make a reinforced belt under the foundation (level 1), let’s say that its width should be 30-40 cm greater than the width of the supporting part of the main concrete “ribbon”. This will significantly reduce the pressure of the building on the ground. Depending on the number of storeys of the house, the thickness of such a stiffening belt can be from 40 to 50 cm.
The reinforced belt of the first level is made for everything load-bearing walls buildings, and not just for external ones. The frame for it is made by knitting reinforcement clamps. Welding is used only for preliminary connection (tack welding) of the main reinforcement into a common spatial structure.
Armoyas of the second level (on the foundation)
This design is essentially a continuation strip foundation(rubble concrete, block). To reinforce it, it is enough to use 4 rods with a diameter of 14-18 mm, tying them with clamps with a diameter of 6-8 mm.
If the main foundation is rubble concrete, then there are no problems with installing the formwork under the armored belt. To do this, you need to leave free space in it (20-30 cm) for installing the reinforcement cage, taking into account the protective layer of concrete (3-4 cm).
The situation with FBS blocks is more complicated, since formwork is not installed for them. In this case, wooden spacers should be used, which support the formwork panels from below. Before installation, cut boards are stuffed onto the boards, which protrude 20-30 cm beyond the dimensions of the formwork and prevent the structure from moving to the right or left. To connect the formwork panels, short crossbars are nailed to the top of the boards.
Option for attaching armored belt formwork to foundation blocks
The fastening system can be simplified by using threaded rods. They are placed in pairs in the formwork panels at a distance of 50-60 cm. By tightening the studs with nuts, we get a sufficiently strong and stable structure for pouring concrete without wooden supports and crossbars.
This system is also suitable for formwork, which requires an armored belt for floor slabs.
The studs that will be filled with concrete need to be wrapped in glassine or a little machine oil applied to them. This will make it easier to remove them from the concrete after it has hardened.
Armobelt for floor slabs
Ideally, its width should be equal to the width of the wall. This can be done in the case when the facade is completely lined with slab insulation. If for decoration it is decided to use only plaster mortar, then the width of the armored belt will have to be reduced by 4-5 centimeters in order to leave room for foam plastic or mineral wool. Otherwise, a through cold bridge of very substantial dimensions will appear in the area where the stiffening belt is laid.
When making an armored belt on aerated concrete, you can use another solution. It consists of installing two thin blocks along the edges of the masonry. A steel frame is placed in the space between them and concrete is poured. The blocks act as formwork and insulate the belt.
If thickness aerated concrete wall 40 cm, then for this purpose you can use partition blocks 10 cm thick.
If the wall thickness is smaller, you can cut it yourself in a standard masonry block cavity for an armored belt or buy a ready-made aerated concrete U-block.
Reinforced belt under the Mauerlat
The main feature in which the armored belt under the Mauerlat differs from other types of reinforcement is the presence of anchor pins in it. With their help, the beam is firmly fixed to the wall without the risk of tearing off or shifting under the influence of wind loads.
The width and height of the reinforcement frame must be such that after embedding the structure between the metal and the outer surface of the belt, at least 3-4 cm of a protective layer of concrete remains on all sides.
A reinforced concrete belt is constructed around the perimeter of the building. The basis is a frame assembled from reinforcement. It is filled with a liquid concrete solution. And so that concrete mixture did not spread, the formwork is assembled under the armored belt. Let's figure out how to assemble this structure correctly.
Why do you need to build an armored belt?
In what cases is the installation of an armored belt necessary? The purpose of this structure is to strengthen buildings built from gas or foam concrete, brick and other materials that do not provide sufficiently high structural rigidity. The structure is necessary in the following cases:
- if the house is built on a shallow foundation;
- when constructing buildings on sites that have a significant slope;
- if there is a river or ravine at a short distance from the facility under construction;
- for certain soil characteristics at the construction site;
- during construction in seismically active areas.
The technology for building houses from block materials involves the construction of several armored belts, namely:
- the lowest reinforcing belt is poured into a trench dug under the foundation. The armored belt is installed around the perimeter and at the location of the load-bearing walls;
- the next reinforcing structure is located in the basement of the building, its main function is to distribute the load;
- another reinforcing belt is installed at the floor level between the first and second floors. Its functions are to tighten walls and redistribute the load over window and door openings;
- the upper belt is mounted at the level of the ceiling of the upper floor to redistribute the loads exerted by the roof.
To build an armored belt with your own hands, you must first assemble the formwork. Let's look at how this structure is mounted.
Types of formwork for armored belts
The formwork for the armored belt can be mounted different ways. The main design options are removable and non-removable. In addition, can be used various materials for assembling molds for filling.
Fixed
The simplest installation option is installation Not removable formwork. The disadvantage of this method is the increase in costs, since the molds used are used once and remain in the belt structure forever. For installation they are already used ready-made blocks made of polystyrene foam, the owners just have to install them correctly.
Advice! The use of polystyrene foam blocks is an additional insulation of the house, since bare reinforced concrete structures are bridges of cold.
The blocks are available in a wide range of sizes, so it is easy to purchase material for the construction of formwork for armored belts of any size. Assembling a structure from blocks is as simple as possible, since they have fastenings and are connected to each other according to the “groove-tenon” principle.
Removable
If you do not plan to purchase ready-made blocks for installing formwork, then you can assemble removable systems using boards. This is a removable option; the assembled formwork is disassembled after the solution has hardened and moved to another place.
The use of adjustable structures allows you to save on materials. This option is more labor-intensive, since you will have to install the forms yourself. Carrying out this work requires care and precision.
Installation of formwork
Let's figure out how to make formwork for an armored belt. We will consider the option of constructing removable formwork from boards. Installation of formwork for armored belt is carried out as follows:
- 20 mm wide boards are used for assembly;
- The height of the belt should be 30 cm;
- the width must be equal to the width of the main structure, that is, the width of the foundation or the width of the wall;
- The first formwork board is screwed around the perimeter of the part to be strengthened. Subsequent boards are installed on top, close to each other, the gap between the boards should be minimal. The boards are knocked together into panels using bars. It is better to fasten the structure with self-tapping screws, but you can also use nails;
- to give the shape the necessary rigidity, bars according outside stuffed every 0.7 meters. The bars are placed strictly vertically;
- To further strengthen the structure, wire ties are installed between the parallel panels. The ties should be placed in increments of 0.8-1.0 meters;
- The last stage is checking the quality of installation. It is necessary to make sure that the walls of the formwork are positioned strictly vertically, and that the structure itself is strong enough to withstand the pressure exerted by the concrete mixture;
- in addition, you need to make sure that there are no cracks, otherwise the solution will flow out through them. Wide gaps they are clogged with overhead slats, narrow ones with tow.
Dismantling of formwork
Dismantling of wooden forms should begin after the concrete has hardened. There is no need to wait for the concrete to gain full strength. You can dismantle the forms as soon as the solution hardens on top.
Disassembly is not particularly difficult. First, remove the wire ties, then disassemble the structure into parts. After cleaning and drying, the boards can be used to assemble formwork in another area.
So, in some cases, installation of an armored belt is mandatory. This is a reinforcing structure that increases the reliability of the building. To construct it, you must first assemble the formwork. It can be quickly assembled from ready-made polystyrene foam blocks or knocked together yourself from boards and wooden blocks.