Building a house after a reinforced belt. Armopoyas: what is it, why is it needed, types and cost. The sequence of preparatory operations

The need to create an armored belt under the Mauerlat during the construction of the roof is not always obvious to novice builders. They often create a misconception about the reinforced strengthening of the foundation for the construction of the roof as something unnecessary and superfluous. However, the armored belt is an important intermediary that distributes the load of the roof on the walls of the building. Consider why an armored belt is needed under the roof, what functions it performs and how to do it yourself.

In this article

The need for an armored belt

Let's start the consideration of the reinforced base under the roof with its main functions.

Load transformation

The rafter legs transfer the load to the Mauerlat, the main concentration of which is in the places where the rafters rest on the walls of the house. The task of the Mauerlat and armored belt is to transform this load, making it uniform. Mauerlat is affected by two types of loads. This is the weight of the roof itself, the snow accumulated on it, the impact of wind gusts on the roof and other natural phenomena.

Another load is associated with the bursting of the walls of the building by the rafters. With an increase in the weight of the roof, it increases significantly. Modern materials for the construction of buildings, such as expanded clay concrete, aerated concrete, with a number of positive characteristics unable to withstand such a bursting load. Before mounting a Mauerlat on them in without fail it is necessary to create a reinforced belt.

Brick walls have greater resistance to point loads, therefore, to mount a 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 built in an earthquake-prone region.

Roof fastening to the house

The most important and main task of the Mauerlat is the strong fastening of the roof to the house. Thus, the Mauerlat itself must be securely mounted to the building.

The main tasks of the reinforced base under the roof can be reduced to the following points:

Maintaining the strict geometry of the building in all situations: seasonal fluctuations in the soil, earthquakes, shrinkage of the house, etc.;
Alignment of walls in a horizontal projection, correction of inaccuracies and flaws made during the construction of walls;
Ensuring the rigidity and stability of the entire structure of the building;
Uniform and distributed distribution of the load of the roof on the walls of the building;
The possibility of a strong attachment to the reinforced base of important elements of the roof, primarily the Mauerlat.

Calculation of the reinforced base under the 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 a width 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 form of the letter U, which creates the formwork. It is necessary to lay reinforcing elements in it and pour the entire structure with a cement solution.

Before actually starting construction works it is also necessary to prepare the necessary tools and Construction Materials. To create a reinforced base under 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 voids from the air 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 for the masonry to dry completely.

Creation of formwork and laying of reinforcement

The first stage is the construction of formwork. In buildings made of aerated concrete blocks, the last row of masonry is made from blocks in the form 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 is made from boards. Installation is carried out with strict observance of the horizontal level.

A frame of reinforcement is laid in the formwork. Its longitudinal part is formed from 4 reinforcement bars with a diameter of 12 mm or more. Cross mounts are made of rods of 8 mm in diameter, subject to a step of no more than 25 cm. In the 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 a knitting wire. similar in solution reinforced frame exists as a monolith.

Laying the frame provides for compliance with certain rules:

The thickness of concrete from the frame to the formwork is not less than 5 cm;
To comply with this rule, stands made of bars of the desired height are placed under the frame.

An important part of the work is the strengthening of the formwork frame. If this is not done, then it will be crushed by the weight of concrete. This can be done in various ways:

Installing fasteners for Mauerlat

After working with the formwork and laying the reinforcement, you can proceed with the installation of 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 2-2.5 cm above the Mauerlat.

Installation of studs is carried out taking into account:

There is at least one hairpin between two rafters;
The maximum installation step is no more than 1 meter.

Pouring with cement mortar

The main feature of the reinforced base under the Mauerlat is its strength. It can only be reached by pouring concrete mortar at once.

Concrete not less than M200 is used to create a concrete mix. The best blend for filling the belt is prepared according to the following proportions:

1 part of cement M400;
3 parts of washed sand and the same amount of rubble.

The use of plasticizers will help to increase the strength and hardening rate of the mixture.

Since a lot of mixture is required to create an armored belt at once, it is advisable to use a concrete mixer and a special pump for supplying the solution. In the absence of equipment, the help of several people will be required for the preparation and continuous supply of the finished mixture.

After pouring concrete into the formwork, it is important to expel all air from possible air pockets. For this, a special vibrator device and simple fittings can be used, with which the mixture is pierced around the entire perimeter.

Mauerlat installation

Removal of the formwork from the armo-belt is possible as soon as the concrete hardens sufficiently, and installation on the Mauerlat structure can be started no earlier than 7-10 days after the armo-belt has been poured.

Before laying the Mauerlat parts must be prepared in a special way:

Mauerlat beam is treated with antiseptics;
Compounds it individual elements performed by the method of direct lock or oblique cutting;
Mauerlat is applied to the armored belt and places for studs are marked. Mounting holes are drilled.

The laying of the mauerlat is preceded by the shelter of the reinforced base with a layer of rolled waterproofing, as a rule, roofing material is used for these purposes.

Mauerlat is fastened with a large washer and nut; locknuts are used for safety. After tightening all the fasteners, the remaining tops of the studs are cut off with a grinder.

Summing up

A reinforced base under the Mauerlat is more of a necessity than a luxury. Roof structure renders quite big impact on the walls of the house, which, although evenly distributed due to the Mauerlat, can adversely 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 hard work requiring the involvement of specialists. Subject to a number of rules and the involvement of assistants, it can be done on its own.

correct, competent installation floors - a guarantee of a reliable, long-term service life of buildings. For buildings made of blocks (aerated concrete), additional support is required - reinforcement. The armored belt in a house made of aerated concrete is a special additional structure that is mandatory when installing floor beams and roofs. Production of reinforced belts, for houses from cellular concrete, installation of the ceiling - regulated by SNiP. Here are the brands and characteristics of the beams, the necessary parameters for supporting the walls, from what and how it is made. Compliance with these standards is directly related to the structural stability of building structures.

Armopoyas is an indispensable element in the construction of a house

What is an armored belt for?

Building from aerated concrete material they will not be able to withstand high loads (shrinkage of the building, sedimentation of the soil under it, daily temperature changes, seasonal changes). As a result, the blocks crack, collapse. To avoid various kinds of deformations, monolithic reinforced concrete fixtures are installed. The reinforced belt takes these loads on itself, distributes them evenly, ensuring the reliability of the structure, and binds the walls into one.

It is also needed for distribution vertical load. Giving the structure rigidity, it does not give rise to movement of the overlap ( aerated concrete blocks expands with the movement of moisture, steam). For this, he also received the name - unloading, seismic belt. Another of the purposes of armored belts is to protect the edges of the upper blocks from destruction (installation floors). Remove the point load of beam wooden frames when constructing a roof. Given these qualities, the armored belt is mandatory for beams, floor slabs of the second (subsequent, roof) floor in a house made of aerated concrete blocks.

An armored belt is needed to evenly distribute the load on the foundation and walls

During construction one-story buildings, the question often arises whether an armored belt is needed for one-story house from aerated concrete. This element is simply necessary if:

support beams (Mauerlat) are installed on which the roof rafters are attached, this is especially true for projects one-story houses with an attic;

the foundation is made on unstable ground to bind the entire structure into one (bearing) system.

A prerequisite for houses made of aerated concrete blocks is the complete looping of the belt. The outline of the structure must be without breaks. Refusing to use the armored belt, the appearance of cracks is inevitable. Even despite light wooden floors and masonry reinforcement from aerated concrete blocks.

Unlike brick structures, for a house made of aerated concrete, the reinforcing belt must be made in a single ring

Interfloor reinforced belt

This type of construction is performed for slab or beam floors. The main purposes of ceilings include the perception and transfer of the load of its own weight, interior, people to walls, dividing the internal space of buildings into floors, overlapping spans. This is Basic structure, based on the outer and inner walls around the perimeter.

The supporting surface serves as the basis for pouring the armored belt. bearing walls, which perceives the entire mass of the future structure. General requirements:

installation is carried out on the entire perimeter of the future building, taking into account internal walls;

for external load-bearing walls, blocks with a density of at least D-500 are used;

height, made according to the height of aerated concrete, or less is allowed (200-400 mm);

belt width - 500 mm (reduction by 100-150 mm is possible);

the reinforcing cage lies on stands (brick, pieces of blocks, plastic clamps) 3 cm high so that it does not touch the walls, thus creating a so-called protective concrete layer;

for pouring, concrete not lower than grade B-15 is used.

Formwork for pouring concrete mortar with reinforcing mesh

On our website you can find contacts construction companies that offer a foundation repair service. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

Armopoyas for aerated concrete under floor beams, poured into a pre-prepared formwork. This frame is made from:

Plastic.

aluminum.

Blocks of aerated concrete.

This type of formwork is used most often. This is the cheapest and most popular option. Installing double-sided removable wooden frame(sewn from wood), it is fixed with self-tapping screws on both sides of the wall (to aerated concrete blocks). Top part is pulled together with wooden jumpers (step 800-1000mm). This is necessary so that the concrete does not push the structure apart when pouring.

Wood formwork is the most common option due to its availability.

The reinforcing cage (reinforcement diameter 8-14 mm), made in the form of a "ladder" (connection with jumpers with a step of 5-7 cm), fits into the prepared space. The rods are knitted together using a knitting wire (every half a meter), forming square shape. It is not recommended to use welding, because of the rusting of the welds in the concrete. For beam ceilings (if not high load), a frame of two rods is enough, with a monolith height of 30 cm. For overlapping with slabs, an armored belt with increased reliability is used (4 rods and a monolith - 40 cm).

After removing the formwork, outer wall insulated together with the armored belt. If during finishing the outer walls are only plastered, then to remove the “cold bridge”, the formwork is moved deep into the wall. And in the resulting niche, then a heater is installed.

You can use one-sided removable formwork. In this case, aerated concrete blocks (10 cm thick) perform the external function. They are stacked on the bottom row, using glue. With inside a wooden frame is attached. After that, insulation (5 cm) and fittings are laid. The top is also pulled together with jumpers.

Video description

How to make a wooden formwork for an armored belt:

Belt using blocks

The manufacture of such formwork requires additional additional blocks or ready-made U-shaped aerated concrete products. In this case, on the glue (on top of the previous row), internal (thickness 5 cm) and external (10 cm) or U-blocks (with walls - 5 and 10 cm) are installed. In inner space, fittings and insulation are placed (to the outer wall). After that, the concrete is poured. For openings (doors, windows), at the level of the top of the previous row of masonry, wooden lintels are installed. They are fixed with vertical supports.

This type of formwork is relatively easy and quick to install. But it is not very popular due to the need to purchase additional material, and as a result, an increase in the cost of construction.

An armored belt with the help of concrete blocks will be more expensive, but with their help the place of reinforcement will not be noticeable

Mauerlat belt

This armored belt is installed from below attic space, both for one-story and for two or more storey buildings. It is necessary for installing fasteners under the Mauerlat, and takes the main load from truss system(vertical, tensile forces) and load from snow, wind. Installed mounts for a beam simply into aerated concrete, will not withstand these loads. They will loosen (due to the low strength of the blocks) and the Mauerlat will move from its place, which will inevitably lead to negative consequences. It also acts as an additional reinforcement of the walls, preventing them from cracking.

Such a belt can be made of reduced dimensions due to the thickness (having correctly calculated the load) and two reinforcing bars can be used for the frame. hallmark such armored belts are vertical studs with nuts. They are installed together with the reinforcing cage, before pouring concrete. It is on these mounts that the Mauerlat will be installed, which is fixed on top with nuts. This is the future basis for the roof truss system.

In the same way, you can make an armored belt in a house made of aerated concrete and under wooden floors. Prefabricated fasteners for wooden structures, will avoid subsequent drilling of concrete for installation of anchors.

Pouring concrete

To fill the belt, after completing all preparatory work, ready-mixed concrete (M200) is used or is made on site in a ratio of 3-5-1 from:

cement (M400).

Filling is carried out not in parts, but completely around the entire perimeter. If such a process is impossible, the necessary jumpers are made in advance. Before pouring the next batch of concrete, temporary lintels are removed, the joints are wetted with water and poured with concrete. The solution is sealed with an iron pin, removing air bubbles from it. During the hardening process (approximately 5 days), the concrete is poured with water to increase strength.

Video description

Preparation of a solution for pouring an armored belt:

Conclusion

Made according to all the necessary parameters and rules reinforced concrete monolithic belt, will give the house of aerated concrete blocks the necessary strength and durability. It will protect the walls from premature cracks, will make a reliable roof.

Any developer, having decided to build a house from aerated concrete, is faced with the need to manufacture an armored belt (it is also called a seismic belt). Armopoyas on aerated concrete is a monolithic reinforced concrete tape, poured around the entire perimeter of the walls (between the first and second floors, etc.). This element is necessary for uniform distribution of the load and connection of the walls together. This reduces the risk of cracking due to uneven shrinkage of the building. Also, the armored belt is laid under the Mauerlat when constructing the roof.

Maxim Pan FORUMHOUSE user, Moscow.

It is impossible to fasten a beam (Mauerlat) directly to aerated concrete on studs. If this is done, then over time, under the influence of wind load, the fasteners will loosen. On device attic floor armored belt on aerated concrete with wooden floor redistribute the point load from the beam to the entire wall.

An illustrative example is a forum member with a nickname madmax, which fully answers the question, when you need an armored belt in a house made of aerated concrete . He did not have time to pour an armored belt under the Mauerlat, and the house went into "winter". Already during the cold arched openings under the windows in the house cracked exactly in the middle. At first, the cracks were small - about 1-2 mm, but gradually they began to increase and for the most part opened up to 4-5 mm. As a result, after the winter, the member of the forum filled in a belt of 40x25 cm, in which, before pouring the concrete solution, he installed anchors under the Mauerlat. This solved the problem with growing cracks.

mad-max FORUMHOUSE User

I would like to add to this that the foundation for my house is tape - monolithic, the soil is stony, there were no movements in the foundation before I started building the house. I believe that the reason for the appearance of cracks was the lack of an armored belt under the Mauerlat.

An aerated concrete house, and even more so a house with two floors, needs an armored belt. When making it, remember this rule:

The main condition for the correct "work" of the armored belt is its continuity, continuity and looping around the entire perimeter of the walls.

There are several options for the armo-belt device in aerated concrete house. The manufacture of the armored belt begins with the calculation of its cross section and the choice of the type of formwork - removable or fixed, as well as the "pie" of the entire structure.

eyeonenow FORUMHOUSE User

I am building a house of aerated concrete 37.5 cm thick, with a brick cladding and a ventilated gap of 3.5 cm. special U-blocks I don’t want factory-made for filling the armored belt. I saw on our forum the following scheme when building a house, how to insulate an armored belt - on wall block installs a partition block 10 cm thick, then comes the insulation (EPS), and a removable formwork is mounted from the inside of the house. I also saw an option when the insulation is pressed close to brickwork. With this scheme, a belt of greater width is obtained.

To understand which option to choose, let's turn to the experience of FORUMHOUSE experts.

44alex FORUMHOUSE User

I built a house of aerated concrete 40 cm thick. In my opinion, a ventilated gap between the wall and the cladding of 3.5 cm is not enough, it is optimal to leave a gap of 5 cm. If you look at the “pie” of the armored belt from the inside out, it was as follows:

removable formwork;
concrete 20 cm;
EPPS 5 cm;
partition block 15 cm.

A reinforced concrete belt is constructed along the perimeter of the building. The basis is a frame assembled from reinforcement. It is poured with a liquid concrete solution. And to concrete mix did not spread, the formwork for the armored belt is going. Let's figure out how to properly assemble this design.

Why you need to build an armored belt

In what cases is the device of an armo-belt a necessity? The purpose of this design is to strengthen buildings built of gas or foam concrete, brick and other materials that do not provide a sufficiently high structural rigidity. The design device is necessary in the following cases:

if the house is being built on a shallow foundation;
when constructing buildings in areas that have a significant slope;
if there is a river or ravine at a short distance from the object under construction;
with certain characteristics of the soil at the construction site;
during construction in seismically active areas.

Technology for building houses block materials provides for the construction of several armored belts, namely:

the lowest reinforcing belt is poured into a trench dug under the foundation. The armored belt is arranged along 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 load distribution;

another reinforcing belt is installed at the level of the ceilings 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 ceiling 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. Consider how this design is mounted.

Types of formwork for armored belt

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 easiest installation option is to install removable formwork. The disadvantage of this method is the increase in costs, since the forms used are used once and remain in the design of the belt forever. Already used for installation ready blocks from expanded polystyrene, the owners just have to install them correctly.

Advice! The use of polystyrene blocks is additional insulation at home because naked reinforced concrete structures are cold bridges.

The blocks are produced in a wide range of sizes, so it is easy to purchase material for the construction of formwork for armored belts of any size. The construction of blocks is assembled as simply as possible, since they have fasteners and are interconnected according to the “groove-thorn” principle.

Removable

If the purchase of ready-made blocks for the installation of formwork is not planned, then removable systems can be assembled using boards. This is a removable option, the assembled formwork is disassembled after the mortar has solidified and moved to another place.

The use of adjustable structures allows you to save on materials. This option is more time consuming, as you will have to mount the forms yourself. Performing this work requires care and accuracy.

Formwork installation

Let's figure out how to make a formwork for an armored belt. We will consider the option of constructing a removable formwork from boards. Installation of formwork for armored belt is carried out as follows:

for assembly use boards 20 mm wide;
belt height should be 30 cm;
the width should 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 reinforced. Subsequent boards are installed from above, close to each other, the gap between the boards should be minimal. Boards are knocked down into shields with the help of bars. It is better to fasten the structure to self-tapping screws, but nails can also be used;

to give the form the necessary rigidity, bars on outside stuffed every 0.7 meters. The bars are placed strictly vertically;
to further strengthen the structure, wire ties are installed between parallel shields. It is necessary to position the screeds in increments of 0.8-1.0 meters;

The last step is to check the quality of the installation. It is necessary to make sure that the walls of the formwork are strictly vertical, 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 gaps, otherwise the solution will flow through them. Wide slots are clogged with overhead rails, narrow slots with tow.

Formwork dismantling

To disassembly wooden forms should be started after the concrete has hardened. No need to wait for the concrete to gain full strength. You can dismantle the molds as soon as the solution hardens on top.

Disassembly is not particularly difficult. First, the wire ties are removed, then the structure is disassembled into parts. After cleaning and drying, boards from boards can be used to assemble formwork in another area.

So, in some cases, the installation of an armored belt is mandatory. This is a reinforcing structure that increases the reliability of the building. For its construction, you must first assemble the formwork. It can be quickly assembled from ready-made polystyrene foam blocks or knocked down from boards and wooden blocks on your own.

A reinforced belt, also known as a monolithic belt or seismic belt, is a special design designed to solve two problems. First, distribute the load from what will be on top to what will be below. And, secondly, to connect the entire plane on which it is located into a single whole. Both a monolithic, concrete armored belt and a reinforced brick one cope with the distribution of the load. Both of them do an excellent job of distributing the load, say, from floor slabs to walls. If the task is also to tie the walls into a single whole, for example, from the bursting load of the roof rafters on the walls of the house, then a concrete reinforced belt is needed here.

How to make an armored belt with your own hands

We figured out what the armored belt is, let's find out how to make it with our own hands. With a brick armored belt, everything is simple. Usually, it is made of solid red brick of the minimum grade M100 in several rows with reinforcement with masonry mesh. You can also reinforce the masonry with reinforcement with a diameter of 6-8 mm. with concrete, monolithic armored belt the matter is more complicated.

First you need to set the formwork. It could be like wooden formwork, and "tray" or fixed formwork, if we are talking about an armored belt on aerated concrete or foam concrete blocks. You can use factory U-blocks or custom made trays. To do this, it is not necessary to cut a U-block from a conventional gas block. It is enough to make a laying of a thin gas block from the outside and inside. The space between these blocks can be insulated with extruded polystyrene.

After you have made the formwork, a reinforcement frame is placed inside the tray.

Sufficient reinforcement for an armored belt measuring 200 by 200 mm is a frame of 4 threads of reinforcement with a diameter of 12 mm (two at the top and bottom), fastened with transverse clamps with a diameter of 6-8 mm every 30-50 cm.

The standard reinforcement overlap should be 30-40 diameters. That is, if you put 12 mm reinforcement, then increasing it, you need to overlap by about 40 cm.

In the corners, reinforcement is necessary bend so that the corner is connected by solid reinforcement.

It is advisable to put the reinforcement frame on plastic clamps for the thickness of the concrete protective layer. And put the clamps on the vertical clamps. If there are no factory fixatives for the protective layer, you can use pieces of stone, brick, etc.

Studs for Mauerlat or pieces of reinforcement are attached to the reinforcing cage for subsequent fixation of floor slabs.

Now you can proceed directly to pouring the armored belt with concrete.

If you will pour purchased concrete, choose the brand M200-M250. Such a brand of strength is enough for private construction.

If you plan to prepare concrete for pouring the armored belt yourself, then use universal recipe proportions of concrete for armopoyas: 1 part of cement grade 500, 2 parts of sand, 4 parts of crushed stone.

You can also use one of ours to calculate the composition of concrete. Do not forget to add a plasticizer for concrete to the batch. This will make the filling more convenient for you, and the resulting armored belt will be more durable.

After pouring, cover the armored belt with a film to avoid sudden drying. For the same purpose, wet the concrete for the first 2-3 days.

Armopoyas will be ready for loading in a week. Full maturation of concrete will be completed 28 days after pouring.

The most frequent questions on the topic of the reinforced belt.

In what cases is an armored belt needed?

A monolithic reinforced concrete belt is required:

on block foundation
on walls made of aerated concrete, foam blocks, etc. under hollow slabs and wooden beams overlapping (to exclude punching). Here the armored belt can be brick
under the Mauerlat on the roof, the design of which assumes a spacer load on this very Mauerlat

Is it possible to fill in the armored belt in winter, in frost?

Filling the armo-belt in winter time occupation is dubious. However, if you really need to pour it in the cold season, take all measures to protect the concrete. Add special antifreeze additives to concrete. Use as little water as possible to mix concrete. After pouring, be sure to cover the armored belt to protect from the cold. For example, sawdust. AT minus temperature, use a special heating cable. It is sold in any building supermarket.

What is the minimum thickness, height, width, size of the armored belt?

The minimum size of the armored belt is 150 by 150 mm. But not less than the width of the support of the slabs or floor beams.

Armo-belt freezes, what to do?

If you or your employees forgot to insulate the armored belt before pouring, then it will have to be insulated now. They insulate the armored belt from the outside.