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How to make an armored belt for the Mauerlat. Armored belt under the Mauerlat: yes or no? Armopoyas under the Mauerlat minimum height

Mauerlat is an element of the roofing system of a building, which is usually made to support rafters on the roof. It is worth noting that professional builders advise attaching the Mauerlat to a special armored belt, which will keep the Mauerlat in place. An armored belt under the maeurlat will add rigidity to the structure and give it the role of reinforced support.
Armored belt is a very important component in construction. So let's figure out what it is actually intended for.
If our building consists of aerated concrete, then you need to know that aerated concrete blocks extremely negatively transfer point loads to their surface and therefore, when drilling holes for studs inside the block, they can crack or simply burst.
The next point for which the armored belt is intended is that hanging rafters from the walls installed directly on aerated concrete blocks will create different weights from different sides, which in turn will lead to the possible movement of the blocks and deformation of the entire roof and walls.
And finally, if you put the rafters on aerated concrete blocks, then at the slightest deviation of the roof level from the design norm, a point load will appear and the blocks will crack.
The solution to all these problems is a protective armored belt under the Mauerlat!
Installing an armored belt for the Mauerlat is very simple. To do this, we install special studs over the entire area of ​​our wall; the studs must be placed evenly approximately every 60 cm from each other. By the way, you can buy studs about 2 meters in size and cut them into equal parts, this way we will save on these elements. After installing the studs, we directly put our beam on the studs, having previously measured and drilled holes for the studs in it, then we tighten the beam to the reinforced belt with bolts.
It is best to wrap the studs in polyethylene so as not to damage them during the concrete pouring process.

When building a house, every stage of work is important, and when creating a roof, special attention should be paid to the strong and reliable fixation of the Mauerlat. This element is the basis of the roof and performs the same role as the foundation for the house. When installing the Mauerlat directly on the wall, point loads may occur, which is especially dangerous for porous materials such as foam concrete or aerated concrete. To prevent loads from the roof from damaging the walls, an armored belt is created before laying the Mauerlat, and rafter beams are mounted on it.

Purpose, characteristics and main functions of the armored belt for the Mauerlat

When the rafters are supported on the wall, a point load is created in the places where they are placed. Mauerlat allows you to distribute it evenly and ensures a reliable connection between the roof and walls of the building. It is firmly attached to the walls, and rafters are mounted on top. For the manufacture of the Mauerlat, the same material is usually used as for the rafters themselves - timber, logs or channels.

For the manufacture of the Mauerlat, the same material is usually used as for the rafters

The roof has a certain weight, in addition, it is subject to snow and wind loads. Therefore, it transfers significant forces to the walls of the house. Loads can be both vertical and bursting. Although modern materials such as foam or aerated concrete have good heat and sound insulation characteristics, their strength will not be enough to withstand the loads from the roof. If the mauerlat can be attached to wooden or brick walls immediately, then in houses made of porous materials, an armored belt is first made, and then rafter beams are installed.

The armored belt performs the following functions:

• allows you to maintain the geometry of the walls during shrinkage of the house and seasonal deformations;
• ensures horizontal alignment of the wall surface;
• gives the structure the necessary rigidity;
• evenly distributes the load from the roof onto the walls of the house;
• has high strength, so not only the Mauerlat, but also other elements can be securely fastened to it.

If a situation arises when it is impossible to make an armored belt on the walls from porous materials, and the roof is quite light, then the Mauerlat can be fixed with chemical anchors directly to the walls.

Armored belt sizes

Calculating the armored belt is not difficult, so you can handle it yourself, without the help of specialists. If you plan to do the work yourself, you must adhere to the following rules:

• the minimum height of the armored belt should not be less than 15 cm (usually it is 20–25 cm) and should not exceed the width of the wall. The optimal ratio of width and height is 1:1;
• the width of this element cannot be less than 2/3 of the wall thickness;
• the total length of the armored belt is equal to the perimeter of the load-bearing walls of the building on which the roof rests.

When creating such an element, its structure must be uniform and continuous. Only by pouring concrete at one time will a monolithic structure with equal strength be obtained. For reinforcement, rods with a diameter of at least 10 mm are used, from which a frame is created, fastened with knitting wire.

The size of the armored belt for each building will be different, as it depends on the thickness of the walls. For example, if the wall of a building has a thickness of 400 mm, then the minimum width of the armored belt should be 2/3 ∙ 400 = 267 mm.

It is better that the Mauerlat beam is slightly narrower than the armored belt, since it is convenient to install insulation in the remaining space

When creating a wall of aerated concrete for the last row, you can use special blocks in the form of an inverted letter “P”. The walls of such blocks act as formwork, so all that remains is to lay reinforcement in them and pour concrete. If the walls are brick, then several rows of half a brick are laid out on the outside, and formwork is made of wood from the inside. After this, reinforcement is laid and concrete is poured. To simplify the work, you can immediately make wooden formwork for the entire width of the building wall.

Technology for constructing an armored belt made of concrete

Before you begin work, you need to purchase all the necessary tools and materials:

• ready-made concrete (purchased directly at the time of pouring) or components for its creation: sand, crushed stone, cement, water;
• concrete mixer;
• fittings;
• knitting wire;
• boards for formwork;
• building level to control the horizontalness of the surface.

The presence of a properly made reinforced belt allows you to save on door and window lintels, since they are subject to insignificant load and therefore can have minimal dimensions and a small amount of reinforcement. You can immediately install a mauerlat on the reinforced layer or lay floor slabs, and then attach rafter beams to them.

It is impossible to weld the reinforcement cage for the reinforced belt, as this reduces the strength of the structure - in the places of welding inside the concrete, the metal will begin to be damaged by corrosion over time.

Installation of formwork

Formwork is a structure that prevents concrete from flowing beyond the future reinforced belt. Depending on the type of formwork, unedged boards, plywood, old furniture panels and special U-blocks are used for its production.

Removable formwork

The sequence of performing removable formwork will be as follows.

1. Prepare boards or wooden shields.

   For formwork, you can take edged or unedged boards, as well as plywood or wooden panels

2. The formwork is fixed to the walls of the building. It is attached to the side of the wall using wire or a piece of reinforcement, and on top the sides are connected by transverse stiffening ribs. To do this, use bars or boards, which are installed in increments of 120–150 cm.

   Wooden formwork is fixed to the walls and reinforced with transverse lintels

3. All gaps between the boards are sealed so that concrete does not spill out through them during pouring.
4. A frame is made from reinforcement with a cross-section of 10–12 mm, and the elements are connected to each other with knitting wire.

   The armored belt is made from reinforcement with a diameter of 10–12 mm, which is fastened with knitting wire

5. The frame is installed on plastic stands or small wooden blocks so that it does not come into contact with the end surface of the wall.
6. Concrete is poured.

   All concrete needs to be poured at one time, so it is better to purchase it ready-made at the factory

7. Remove the formwork. In summer, this can be done one day after pouring concrete, and in the cold season - after three days.

The disadvantage of this method of creating formwork is that concrete has a much higher thermal conductivity, so it can only be poured if the outer walls are fully insulated, otherwise the wall in the armored belt area will constantly freeze.

U-block formwork

To minimize heat loss at the junction of concrete and walls, permanent formwork is used. To create it, they use U-shaped blocks made of the same material as the walls.

In this case, there is no need to create additional formwork and then dismantle it, so the work will be completed faster, but you will have to spend money on purchasing special blocks.

Combined formwork

This method combines both previous methods. It can be used when the width of the walls is large.

Video: creating an armored belt using combined formwork

Installing studs

For the manufacture of the frame, reinforcement with a cross section of 10–14 mm is usually used. Such a frame consists of four longitudinal rods, which are connected to each other by transverse elements. Tie wire is used to fasten all parts together. The pitch of the crossbars should be about 40–50 cm. The cross-section of the finished frame should be rectangular or square. The frame must be laid on stands - it is better if they are plastic, but you can also use wooden blocks 30 mm thick.

For more reliable fixation of the studs, cross members are welded to them from below.

When creating a reinforcement frame, it is necessary to install threaded rods with a diameter of 12–14 mm into it, onto which the Mauerlat will be attached. There should be no less of them than rafter legs. To ensure the strongest possible fixation of the studs, a cross member must be welded to their lower part, which will prevent them from moving after pouring the concrete. Before pouring concrete, the threads on the studs are covered with masking tape so that they do not become clogged or damaged.

For pouring, you can purchase factory-made concrete or make it yourself. To construct an armored belt, concrete grade M200 or M250 with crushed stone filler is sufficient. Since the entire volume must be filled at one time, it is better to purchase the required amount of ready-made solution. If the size of the reinforced belt is small, then the material can be produced directly at the construction site.

During pouring, the concrete must be compacted, for which a piece of reinforcement or a trowel is used, which is used to pierce the thickness of the solution and release the air trapped in it. It’s easier and more convenient to do this with a special vibrator, if you have this tool at your disposal. If the work is carried out in the summer, the concrete is covered with a film and periodically watered with water so that the moisture evaporates from it evenly. You can begin further work after the armored belt has completely hardened.

In summer, formwork can be removed one day after pouring concrete, and in winter - after three days

If there is not enough concrete when pouring the reinforced belt, make a vertical cut-off, and the gap should not be located above the door or window opening. But it is still better to avoid such situations.

Technology for constructing an armored belt made of bricks

In some cases, an armored brick belt can be laid on walls made of porous materials. Typically its height ranges from 4 to 7 rows.

The creation of an armored belt made of brick is carried out in several stages.

1. The wall surface is cleaned of debris and remnants of building materials.
2. The first row is laid on the solution. For a wall 30 cm wide or more, bricks are installed in two rows.

   An armored belt made of brick can replace a concrete one for light types of roofs or under a roof made of hollow slabs

3. A reinforcing mesh is laid on each row of bricks. The thickness of the wire used to create it must be at least 5 mm, and the cell size must be 3x4 cm.

   When constructing a mauerlat, reinforcement of the brickwork is performed in each row

4. The second row is laid offset by 1/3 of the length of the brick, and every third row is made with a bonded ligation.
5. Studs are embedded in the masonry to secure the mauerlat. They are installed every 1–1.5 m, and the embedded part should be twice as large as the one that protrudes.
6. The last laid row is covered with a double layer of roofing material, which will provide reliable waterproofing.

   Roofing felt folded in two layers is most often used as waterproofing.

7. The Mauerlat is threaded onto the installed studs and secured with nuts and washers.
8. Since brick has a higher thermal conductivity than aerated concrete, such an armored belt will be a cold bridge, so it is insulated. You can use mineral wool for this. If the width of the wall allows, a contour of thin aerated concrete blocks is erected from the outside. The distance between the brick and the blocks can be filled with polystyrene foam.

If for the installation of the Mauerlat the armored belt is made of bricks only around the perimeter of the external walls, then for laying the floor slabs it must be done on all walls.

When creating an armored belt, the question often arises: is it worth the risk and make it out of brick instead of a concrete armored belt? Most experts recommend making a full concrete layer. Reinforced brickwork will be only slightly stronger than hollow blocks and will not be as strong as concrete. Several rows of bricks and metal mesh will not be able to evenly transfer the load that comes from the roof, so there is a possibility of cracks and, if the roof is heavy, the wall will collapse. It is better to spend a little more time, make a high-quality and reliable concrete reinforced belt, which will provide greater load-bearing capacity and reliable fastening of the entire roofing structure.

Video: armored belt made of brick and concrete

Methods of attaching the Mauerlat to the armored belt

For a hip roof, the Mauerlat must be laid around the perimeter of the building. If the roof is gable, it is enough to fix it on two parallel walls on which the roof rests. A small indentation is made from the edge of the outer wall, which is then filled with thermal insulation material. There are several ways to secure the rafter beams.

Video: attaching the Mauerlat to the armored belt

Fastening the Mauerlat without an armored belt

For wooden and brick buildings, as well as in some cases for houses made of aerated concrete, it is possible to fix the Mauerlat without an armored belt.

Experts still do not recommend laying Mauerlat without an armored belt on brick buildings and houses made of gas silicate blocks. Only the presence of a reliable and durable armored belt will allow you to fix the Mauerlat well on the wall, ensure reliable fixation of the rafter legs and the entire roof, and also evenly distribute the load from the roof onto the walls of the house.

New building materials are constantly being created for the construction of houses. Recently, porous materials (aerated concrete, expanded clay blocks, foam concrete and others) have become widespread, which have high thermal insulation characteristics, but not very high strength. In order for the Mauerlat to be securely fixed to such walls, experts recommend making an armored belt. Only a strong reinforced concrete frame will be able to evenly distribute the loads created by the roof; it will be possible to securely attach the Mauerlat to it, which acts as the foundation of the roof. Don’t be lazy to make an armored belt, especially since there is nothing complicated in it, and all the work can be done with your own hands.

In order for the Mauerlat to hold firmly at the installation site, it is best to equip it with an armored belt. In this case, the structure becomes more rigid and durable, and can be used as a reinforced support.

Why do you need an armored belt, is it needed under the roof?

The role of this reinforcement in achieving the overall strength of the building is difficult to overestimate. First you need to figure out why exactly the armored belt is used under the Mauerlat.

Any building is subject to a number of loads:

1. Vertical. They are created by the weight of the roof, as well as atmospheric phenomena such as snow, wind and rain.
2. Spacers. They are provoked by rafters resting on the wall. This load acts to move the building apart, increasing as the roof load increases.

Certain modern materials are very poorly resistant to point impacts that destroy them. These include expanded clay concrete walls, for which the installation of an armored belt under the roof is a necessary measure. Therefore, when constructing buildings from such materials, the presence of such a structure is a natural detail. However, there are situations when difficulties arise with its installation. In such cases, the Mauerlat is attached to foam blocks or expanded clay blocks with chemical anchors.

The reasons for this approach may be the following:

• Drilling holes for studs in cellular blocks may cause them to break or crack.
• Hanging rafters create different loads in a number of directions: this can lead to the moving of blocks, as well as deformation of the walls and roof.
• When directly laying rafters on foam concrete blocks, an ideal roof level position is required. Otherwise, due to the resulting point load, the foam blocks may undergo various types of destruction. To avoid such phenomena, it is customary to equip the Mauerlat with an armored belt.

Brick walls have high mechanical strength. The Mauerlat is attached to them with conventional anchors and embedded elements. The only exceptions are regions where seismic activity is observed: there the question of whether an armored belt is needed under the roof usually does not arise. In this case, the presence of an armored belt under the Mauerlat is also mandatory for brick buildings.

The purpose of the reinforcing belt in practice comes down to the following functions:

1. The walls do not deform in the event of soil movements, or when uneven shrinkage occurs. The building parameters are maintained within the original limits.
2. Helps to align walls horizontally and correct errors when laying them.
3. The structure becomes more rigid.
4. All loads occurring on load-bearing walls are distributed evenly.
5. The good mechanical strength of the reinforcing belt allows it to be used for reliable fixation of the most important elements, including the Mauerlat.

Parameters and features of the reinforcing belt under the Mauerlat

In order for the structure to be durable, you need to carefully calculate the dimensions of the armored belt under the Mauerlat:

1. When making an armored belt with your own hands, the height for the reinforcing belt is usually 20 cm (at least 15 cm). It definitely should not exceed the width of the wall.
2. If possible, the width of the wall and the belt should match.
3. When calculating the length, measure the distance to the desired walls.
4. The cross-section of the structure must be no less than 25x25 cm.

It is very important that the belt is continuous, with the same strength indicators of the individual component sections. It is most convenient to make a monolithic belt under the Mauerlat from concrete. It should be poured in one go, with insertion inside the reinforcement. Its diameter must be at least 10 mm: the individual elements are firmly fastened and bandaged. An armored belt made of brick under the Mauerlat is used quite rarely.

The parameters of the reinforced belt for expanded clay concrete blocks are based on their thickness. For clarity, it is better to consider an example of the calculation of these structures. As SNiP states, the thickness of the reinforcing layer is 1/3 narrower than the load-bearing wall. Therefore, if we take the wall thickness as 40 cm, then 1/3 of it will be equal to 133 mm: the minimum value of the thickness of the armored belt in this case will be 300 mm (if we round the number 267).

As a result, a wall with a thickness of 400 mm will have the size of the inner part of the U-shaped block within 300 mm, which will also act as formwork. On brick walls, the outer formwork is made of half a brick, and boards are used to make the inner formwork.

Installation of formwork

Several methods can be used for this:

1. Made from wooden boards or slabs. They are fixed to the walls using bars, fastened from above. When dismantling the formwork, the upper parts are dismantled: the lower elements are left inside the fill.
2. Using side stops.
3. U-shaped blocks. To ensure that the belt is continuous, the blocks are cut at the corners of the house.
4. Along the outside of the wall, 100 mm blocks can be laid in one row. Several rows of bricks laid on edge or boards are laid along the inside.
5. Using working longitudinal rods with a diameter of 10-12 mm. There must be at least 4 of them.
6. Intermediate jumpers equipped with reinforcing clamps. The diameter of the products is 6-8 mm, with a placement step of 20-40 cm. It is not recommended to use a large step, since the working rods may shift during concrete pouring. As a result, the integrity of the reinforcing belt is compromised.
7. Fastened with binding wire. Welding connections are prohibited, as this weakens the reinforcement and makes the structure susceptible to corrosion.
8. Threaded rods. They are equipped with holes that are pre-drilled in the formwork. The diameter of the pin should be slightly smaller than the internal cross-section of the tube. When placing a pin inside the tube, you need to ensure that its ends pass through the pre-made holes. The entire product is tightened with nuts, using large washers as spacers. Only the tubes should remain inside the concrete monolith. To achieve this, after pouring and pre-hardening of the reinforced belt, the nuts are unscrewed, the formwork is dismantled, and the studs are knocked out.

It is important to take into account the need to insulate the wall opposite the reinforced belt, especially if the formwork is made of boards. This eliminates the risk of concrete freezing in winter. To orient the upper edge of the formwork, a strictly horizontal plane and water level are selected.

As for laying the mesh, at the corners and at the interface areas it is subject to additional reinforcement using curved reinforcement. The recommended overlap size is 300-400 mm. Such reinforcement is best done with composite reinforcement, which is both cheaper and lighter. In addition, such products do not rot, do not rust, have greater tensile strength and are easy to use.

Filling the armored belt

To make the structure as strong as possible, pouring must be done in one step. For this purpose, concrete grade of at least M200 is used. Usually it is necessary to pour a significant amount of solution, so it is best to prepare a concrete pump in advance.

When preparing the solution yourself, take one part of M400 cement, three parts of washed sand and three parts of crushed stone. The formwork can be dismantled 4-5 days after pouring; Full maturation of concrete occurs in 3-4 weeks.

When pouring concrete, you should adhere to the following recommendations:

1. It is impossible to do without the formation of internal voids. To remove them, piercing the solution using reinforcement or vibration is used.
2. It is important to moisturize concrete. This way it becomes stronger. This procedure is carried out every day while the concrete hardens.

Attaching the Mauerlat to the armored belt

Before attaching the Mauerlat to the armored belt, in order to avoid rotting or burning of the support beam, it is treated with special impregnations. To achieve solidity of the Mauerlat, straight locks or oblique cuts are used to splice it.

This is done as follows:

• The support beam is equipped with holes.
• The Mauerlat is attached using pins or anchors.
• During the installation process, it is necessary to go through a layer of roofing felt.
• Large washers and nuts are used for fastening.
• It is recommended to secure the tightening using locknuts.
• To cut off protruding parts, use a grinder.

Embedded studs

Sometimes, in order to secure the Mauerlat, studs with a diameter of 12 mm or more are pre-installed on the armored belt, protruding 3-4 cm above the Mauerlat. The installation step of such studs is 100 cm: they are attached to clamps with knitting wire.

As for the question of the feasibility of making a Mauerlat in the presence of a reinforcing belt, then indeed, theoretically, the rafters can be fixed to the belt. However, in practice this will require a significant number of additional measures. So it’s much easier to go the traditional route of using a reinforced belt under the Mauerlat.

When planning to fill an armored belt under the Mauerlat, it is important to consider the dimensions and characteristics of the fastening system. - This is an intermediate beam through which the rafter system is connected to the walls with anchors, studs or wire. After laying the Mauerlat, it is important to securely fasten the roof of the house. When making walls from cellular blocks, you should consider attaching the Mauerlat to expanded clay blocks without, as well as together with it. Let's consider how to install the Mauerlat so as not to destroy porous concrete. After all, if fastened incorrectly, the blocks can crack.

How to attach the Mauerlat - fixation options

Builders use the term “mauerlat” in their vocabulary, meaning a special frame fixed to the end surface of the main walls. Regardless of whether brickwork is used for the construction of load-bearing walls or porous blocks are used, a mandatory element of the building is the Mauerlat. It is made from channel or wooden beams. Mauerlat combines the roof structure and the frame of the house into a general scheme. The damper frame ensures uniform distribution of loads on the walls and reliably connects the roof truss to the frame.

One of the elements that no roof can do without is the Mauerlat

Depending on what materials are used for the construction of walls, various methods of fastening the Mauerlat are used:

• installation of the Mauerlat on the end plane of the walls without filling the reinforced belt. This fastening option allows you to firmly fasten the support beam to the surface of an aerated concrete, brick or expanded clay concrete wall. During the process of laying the top level of blocks, a wire is installed between them, which is threaded through holes in the frame. Then the ends of the wire are twisted;
• installation of the Mauerlat on a reinforced belt constructed around the perimeter of the supporting surface of the house frame. This method is used to fix the Mauerlat to walls built of brick or composite blocks. The installation technology involves pouring a reinforced concrete belt in which pieces of reinforcement with a diameter of 8-10 mm are concreted. Steel rods are used to fix the Mauerlat.

The method of fastening the load frame is indicated in the building design.

Attaching the Mauerlat to expanded clay blocks without an armored belt

When deciding to use a building for the construction of walls, you should take into account their load capacity. Porous expanded clay concrete is not able to withstand significant loads. However, if the weight of the roofing structure is small, it is permissible to install a Mauerlat on the end surface of expanded clay concrete walls.

To do this, follow these steps:

1. Cut pieces of steel wire.
2. Lay the wire between the blocks of the upper rows of masonry.
3. Complete the laying, ensuring that the free ends of the wire come out.
4. Lay the wooden beam on the surface of the expanded clay concrete walls.
5. Tighten the Mauerlat with wire through the pre-made holes.

The strength of the armored belt under the Mauerlat directly depends on what its design will be

The number of connections made must correspond to the number of rafter supports.

All types of porous concrete are characterized by insufficiently high strength. This must be taken into account when choosing a fastening method. Let us next consider how to secure the Mauerlat to aerated concrete without an armored belt.

Installation of a Mauerlat on aerated concrete without an armored belt

The technology for installing the Mauerlat on the surface of aerated concrete walls that are not equipped with an armored belt is similar to the method of attaching to expanded clay concrete blocks.

When performing work, you should pay attention to a number of points:

• laying rolled wire between aerated concrete blocks a couple of rows before the top of the wall;
• selection of the length of the wire sections to ensure reliable tying of the Mauerlat;
• ensuring the horizontality of the upper plane of aerated concrete for laying timber;
• correspondence of wire laying areas and fixation points to the total number of rafter beams.

Wire fasteners securely attach the support beam to the aerated concrete walls.

Ensuring structural strength when fixing the Mauerlat with an armored belt

To increase the reliability of fastening the Mauerlat and prevent deformation of the building frame, a reinforced belt is constructed.

The width of the armored belt must correspond to the width of the wall

It allows you to solve a number of serious problems:

• form a solid horizontal base along the contour of aerated concrete or brick walls;
• prevent local pushing of porous concrete in places where rafter beams are attached;
• give an additional reserve of rigidity to the aerated concrete or expanded clay block frame of the building.

Carry out work on the construction of the armored belt in the following order:

1. Mount the formwork structure along the contour of the box.
2. Assemble and install the reinforcement cage inside the formwork.
3. Place and attach threaded rods to the reinforcement to secure the Mauerlat.
4. Keep the threaded part of the studs clean after concreting using polyethylene or a rag.
5. Fill the formwork with concrete mixture.
6. Dismantle the formwork elements after the concrete has hardened.

It is easy to attach a wooden Mauerlat beam to a frozen armored belt with threaded rods.

How to securely fix the Mauerlat - proven methods of fastening rafters

When constructing a support structure for fastening the roof, it is important to ensure that the beams are securely fastened.

Anchor bolt is a common fastener

The following methods of fastening rafters are used:

• steel corners. Metal elements of an L-shaped section are attached to opposite planes of the rafter beams using self-tapping screws, ensuring reliable fastening to the supporting frame;
• knitting wire. After annealing, the wire becomes softer and can be easily deformed. With a knitting wire diameter of 0.5-0.6 mm, the reliability of the connections of the elements of the truss is ensured;
• curved staples. The use of U-shaped fasteners allows you to securely fasten the rafter beams to the support beam. The staples are driven in with a hammer and cover the surface of the beam;
• metal plates. Steel fasteners are used when assembling truss structures made of metal profiles. Fastening is carried out using threaded rods or metal screws;
• metal brackets. Self-made brackets or purchased products are used. When the bracket thickness is at least 2 mm, the reliability of anchor and self-tapping fastening is ensured;
• mounting tape. This is a proven fastening method that provides the necessary rigidity of fixation. This method does not cause weakening of the supporting structure at the fixation points.

The choice of fastening method is carried out individually. In this case, it is necessary to take into account the design features of the building, as well as the materials from which the walls and roof truss are made.

To attach the Mauerlat to the frame of the building, the following technological methods are used:

• fastening with annealed wire;
• installation using threaded rods;
• fixation using chemical anchors.

Some craftsmen prefer to fasten the Mauerlat to the armored belt using pins

When choosing the optimal mounting method, you should consider a number of factors:

• overall dimensions of the building box;
• roof truss design;
• weight of the truss structure;
• rafter beam material.

Let us dwell in more detail on the features of various fastening methods.

How to reliably install a rafter structure on a wire?

Steel wire is traditionally used to fasten the Mauerlat. This is a budget solution that allows you to securely fix the support beam. The wire is fastened at the final stage of wall construction.

To ensure fastening of the timber, a number of requirements must be met:

1. Cut the annealed wire into pieces of the required length.
2. Twist the wire several times and secure it inside the masonry.
3. Thread free lengths of wire loop through the holes in the beam.
4. Twist the wire carefully, avoiding breaking it.

In the binding areas, strong clamping of the timber to the supporting surface of the box is ensured. When performing work, it is important to correctly calculate the length of the wire sections, which allows for tight coverage of the Mauerlat. The advantages of the wire fixation method are ease of work and low cost.

As you can see, the Mauerlat itself and the process of attaching it are very important

Fastening the belt under the Mauerlat with threaded rods

Using pins bent at an angle of 90 degrees, the Mauerlat is securely fixed to the upper level of the wall. At the end of the stud, intended for fastening the beam, there is an M8-M10 thread. The curved end of the fastening element, which has a smooth surface, is located inside the wall masonry or in an armored belt. The length of the curved part is 0.35-0.4 m.

Having decided to mount the Mauerlat on threaded rods, pay attention to the following points:

• the height of the threaded part at a distance of 0.3-0.4 m from the top level of the box;
• the interval between the threaded rods corresponding to the distance between the rafters;
• reliable protection of the threaded part of the studs using masking tape or polyethylene during concreting.

The Mauerlat is fastened to threaded rods using nuts, under which washers of increased diameter should be placed.

Fixing the load-bearing frame on an aerated concrete wall using anchors

The method of fastening using steel anchors is similar to the method of fixing with threaded rods. Installation of fasteners is carried out before pouring the reinforced belt with concrete mortar.

When performing work, it is important to comply with a number of requirements:

• make the correct markings in the beam of fastening coordinates;
• maintain an even step between steel anchors;
• make holes in the beam corresponding to the diameter of the threaded part.

In terms of fastening efficiency, this method is more reliable when compared with the use of annealed wire.

How to install the Mauerlat - installation details

When performing installation work, pay attention to the following nuances:

• location of the Mauerlat at a distance of 5 cm from the outer plane of the wall;
• fastening the mauerlat beam parallel to the roof ridge;
• ensuring a horizontal surface for installing timber;
• impregnation of wooden beams with an antiseptic composition.

When joining the Mauerlat bars, the joint parts should be connected with metal staples.

Let's sum it up

To ensure the strength of buildings, it is important to securely fasten the Mauerlat. The technology makes it possible to attach the Mauerlat to expanded clay blocks without an armored belt and to the surface of a concrete reinforcement contour. Various technological methods are used to fix the timber. It is necessary to take a responsible approach to the choice of fastening method to ensure reliable fixation of the roof structure.

The construction of structures made of aerated concrete or foam concrete blocks requires the presence of an armored belt under the Mauerlat, poured along the upper contour of each of the walls. The unloading belt gives the structure a more rigid structure and is a strong support for the fixed Mauerlat.

Why do you need an armored belt under the Mauerlat?

When constructing a building from aerated concrete, it is very important to remember that this material is extremely sensitive to point loads. The block is likely to split or crack if the drill used to make the bearing hole applies too much pressure. An armored belt can reduce the likelihood of cracks.

Another useful property is the prevention of deformation and tilting of building blocks due to uneven weight distribution. Uneven pressure can cause the wall to diverge, aerated concrete or foam concrete blocks can tilt and thereby nullify the entire construction.

Purpose and functions

There are five main functions of the armored belt:

• Fitting and carefully adjusting the stability of the building, preventing cracks and breaks.

• Insurance against possible errors and shortcomings in construction work, protection against additional pressure on gas blocks.

• Strengthening the base of the upper walls, evenly distributing the load.

• Providing additional strength to the walls, protection from crumbling.

• Reliable fastening of the Mauerlat and, if necessary, various hanging structures.

Dimensions and specifications

When calculating a reinforced belt, it is worth considering that it should not be less than one third of the load-bearing wall. Ideally, the width should be equal to the load-bearing wall, and the size should not be less than the limit of 250x250 mm. Special U-shaped blocks are used for laying the last row, since they are a kind of formwork.

The armored belt must be continuous and pass along the perimeter of all external walls of the building. In addition to the rafters, the roofing system of a house may contain various elements: ridge beams or racks resting on the internal main walls. In this case, it is on them that the reinforced belt should be constructed.

Installation of reinforced belt

The need to install an armored belt becomes clear when designing the roof. The installation technology includes the following sequence of work:

• installation of formwork;
• installation of embedded studs;
• filling the armored belt.

Installation of formwork

Upon completion of the masonry work, you can begin the construction of a monolithic belt under the Mauerlat.

The task is greatly simplified by laying the last row of U-shaped blocks that form the formwork. Or the outer row can be completed using sawn blocks 10 cm wide, and the internal component of the formwork can be made from OSB boards or wooden boards. The upper edge of the formwork must be strictly horizontal, which can be easily adjusted with a water level.

When it is finally ready, a strong reinforcement frame with a longitudinal part of at least four metal rods and at least 12 mm in diameter is placed inside. Longitudinal reinforcement with a pitch of no more than 23-24 cm is fastened with transverse parts made of rods or wire of 8 mm diameter. Such a frame in cross section resembles a square, sometimes a rectangle.

If you do not want to spend extra effort on such labor-intensive work, you can safely contact special enterprises that produce any frames with high quality and in a timely manner using the resistance spot welding method.

The thickness of the concrete when installing the reinforcement cage must be at least five centimeters. The lateral thickness is perfectly regulated by a high-quality laid frame, and stands made of wooden blocks or broken bricks are installed below. There are special plastic stands of suitable height that you can easily find at your local building materials stores.

All components of the frame must overlap each other with a “margin” of at least 200 mm. It is convenient to connect the overlaps with tying wire. The value of such a frame is that, thanks to its strong construction, it acquires monolithic qualities and responds well to pouring concrete.

Heavy concrete can destroy the formwork, so it must be properly reinforced. There are several suitable ways:

• The lower part of the formwork can be fastened with blocks, and the same wooden blocks or boards can be nailed at the top. When the concrete has hardened, the upper boards are successfully torn off, and the lower ones remain firmly in the concrete, while the protruding edges are filed down.

• To strengthen the formwork, you can use diagonal stops. At one end they are in contact with the horizontal surface, and at the other they support the formwork itself.

• If the formwork is reusable (made from the above-mentioned OSB boards), It is popular to use fastening using threaded rods. Holes with a diameter of 1.25 cm are made opposite each other on the formwork sheets. A plastic tube is threaded through them, the length of which is equal to the width of the future monolithic belt. A pin with a diameter of 1.2 cm is driven into the holes, then tightened with nuts and large washers. When the concrete has safely hardened, the pins are pulled out, and the penny tubes remain inside the structure.

Installation of embedded studs

After the work on installing the formwork has been completed, it is necessary to install the fastening components to which the Mauerlat will be attached.

The best option is to use threaded rods attached to the frame.

So, you need to purchase threaded rods with a diameter of 1.2 cm, large nuts and washers. The length of the studs should be convenient for attaching to the frame, and the upper end should protrude 4 - 5 cm above the already installed Mauerlat. In places where the rafters do not rest on the mauerlat, threaded rods must be installed. There should be at least one stud between each rafter leg.

The maximum distance between fastenings should be no more than one meter. You can pull the cord along the center line for alignment, and it is convenient to mark the markings with chalk on the reinforcement frame itself. Each stud is individually secured with tying wire to the reinforcement cage.

Be sure to check the vertical installation of each of the studs with a special bubble level.

Pouring the armored belt with concrete

To increase the strength of the reinforced belt, all work on pouring concrete must be carried out continuously and in one go.

The grade of concrete must be at least M200, preferably M600. It is better to use ready-mixed concrete, which is supplied by a concrete pump directly into the formwork. You can prepare concrete yourself if it is not possible to supply it industrially.

To make concrete, you will need M400 or M600 cement, washed sand and crushed stone in a ratio of 1:3:3, respectively. When concrete has been successfully laid, our main task is to avoid the formation of bubbles (air cavities) that reduce the uniformity and strength of the structure. A construction vibration platform is perfect for preventing such misfortune. Or, to make the task easier, simply pierce the concrete over the entire area with a reinforcing bar.

To increase the mobility of the mixture, plasticizers are used. They reduce the amount of water in the concrete mixture, thereby increasing the strength of the finished monolithic belt and the time it hardens.

Attaching the Mauerlat to the reinforced belt

Once the concrete reaches the required strength, the formwork can be removed. After 7-12 days, it’s time to start securing the mauerat. The timber serving as a mauerate is treated with fire retardants and disinfectants. It is fastened with an oblique cut or a straight lock. These connections make it possible to make the structure monolithic. A beam is applied to the future place of fastening, and in places where there are studs, holes are marked and drilled for them.

The Mauerlat is mounted on the reinforced belt only through a layer of rolled waterproofing. It is secured with a nut and a large washer. When all the nuts are tightly tightened, it is better to secure the connections with locknuts. All protruding studs can be cut off with a grinder.

Fastening to aerated concrete without armored belt

Aerated concrete is an extremely fragile material. To successfully mount the Mauerlat, it is necessary to make a structure on it from a stronger material. You can use concrete or brick pillars.

Such supports must be fixed to the wall itself; it is also very desirable that the anchor goes through the support and a couple more rows of aerated concrete blocks. A clear privilege should be given to the chemical anchor. Its peculiarity lies in gluing the stud or reinforcement to the entire depth of the hole, while the length of a conventional mechanical anchor is 0.5 - 0.7 mm.

It is important to know that when using a chemical anchor, you should not weld anything to the reinforcement, because in the process the chemical composition may burn out and stop working.

The thickness of the walls must be sufficient to resist the lateral impact of the rafters. Therefore, if the wall is too narrow, the above design may not be suitable. In this case, you will have to install additional horizontal beams, which will serve as a kind of “ties” and protect the rafters from divergence.

If you combine such a solution with modern materials, you can get the opportunity not to make a reinforced belt on aerated concrete. But, in our subjective opinion, it is better not to skimp on such an important element in the construction of a building for any purpose.

Watch the video to see how to do it yourself.

Let's sum it up

So, we can conclude that the construction of a reinforced belt under the Mauerlat is an integral part of the construction of houses made of aerated concrete and foam concrete, while regarding stone walls it serves as a reliable assistant in strengthening the building.

The most suitable fastening of the Mauerlat to the armored belt is with the help of special pins attached to the metal frame. Work with concrete should be carried out without interruptions, once. The Mauerlat should be secured through a layer of roofing material.