Proper fastening of the Mauerlat to aerated concrete - possible options tested in practice. How to properly attach the Mauerlat to an aerated concrete wall? Which ones are better to put the Mauerlat on the armored belt?

The roof is one of the important and responsible parts of the house. And the strength of the connection between the roofing system and the walls largely determines the ability of the house to withstand the effects of natural elements: snow and wind loads.

Mauerlat - definition

Mauerlat- a structural element of a building that connects together all the elements of the roof truss system with each other and with the walls of the building. Main functions of the Mauerlat:

• keeps the roof from moving in relation to the wall;
• evenly distributes and transfers to the walls the load concentrated at the support points of the rafters.

The Mauerlat is laid and secured along the entire perimeter of the upper part outer wall buildings with a slight indentation from the outer edge. Each element of the Mauerlat is firmly connected to two neighboring ones.

Together with the rafter system it creates a reliable, stable spatial design roofing system. Provides a strong connection between the roofing system and the walls of the building, evenly distributing the load from the roof along the entire perimeter of the wall.

Selection of material and calculation of parameters

To manufacture the Mauerlat, timber with the following cross-section is used:

• 100x100 mm;
• 100x150 mm;
• 150x150 mm.

It is common to use boards with a cross section of 50x150 mm. However, for a wall made of aerated concrete without a reinforcing belt, it is advisable to avoid this option. A board laid flat does not have sufficient rigidity to absorb and distribute point vertical loads from rafter legs on the wall.

To create a solid structure capable of withstanding the load transmitted by the rafters, the edges of the beams are connected in series using a direct lock. The Mauerlat bars are strengthened closer to the inside of the wall so that the distance to the outer edge remains at least 50 mm.

The top of the Mauerlat should be located at a distance of 300 to 500 mm from the top of the ceiling. Such a gap provides sufficient conditions for ventilation of the under-roof space and does not impede access for periodic inspection and repair of the Mauerlat and the lower part of the rafter legs.

The strength and reliability of the connection between the roof and the walls largely depends on the correct choice of design, the method of fastening to the walls and the accuracy of calculating the dimensions of the Mauerlat.

Let's consider the main factors influencing the choice of Mauerlat cross-section:

• shape and area of ​​the building covered by the roof;
• type of roof structure (hanging or layered rafters, pitch size and angle of inclination of rafter legs);
• material and weight of the rafter system and roofing;
• presence or absence attic floor in the house;
• calculated snow and wind load roof determined climatic conditions region.

When choosing the design and cross-section of the Mauerlat, it should be taken into account that a wall made of aerated concrete weakly resists horizontal loads (thrust). The presence or absence of spacer forces at the lower ends of the rafter legs is determined by the design of the rafter system.

Non-thrust structures include:

• hanging rafters using tie rods;
• layered rafters with an upper freely rotating fastening, and a lower freely rotating and movable fastening in the direction of the beam axis.

Rafter systems that create horizontal loads (thrust) in the walls:

• hanging rafters without tightening;
• layered rafters with rigidly fastened supports.

The horizontal forces transmitted to the wall by the spacer structures of the rafter systems must be absorbed by the reinforcing belt. Attempts to compensate for these efforts only by increasing the cross-section of the mauerlat beam are a construction mistake and lead to negative results.

The volume and mass of the timber for making the Mauerlat is calculated using the formulas:

• (Volume of the Mauerlat) = (Section of the timber) x (Perimeter of the house);
• (Mass of timber) = (Volume of Mauerlat) x (Density of wood).

Types of fastening the Mauerlat to aerated concrete

Aerated concrete, how wall material, has a whole range of positive properties:

• easy;
• perfectly processed;
• has good thermal insulation properties;
• the blocks have a clear geometric shape.

But it also has its own characteristics. Aerated concrete is a fairly fragile material. It copes well with moderate compressive loads, but the application of tensile or shear forces easily leads to the formation of cracks.

Accordingly, when choosing a method for attaching the Mauerlat to the wall, you need to take this into account.

Mauerlat for aerated concrete without armored belt

In construction practice, sometimes it becomes necessary to attach a Mauerlat to a wall made of aerated concrete without installing a reinforcing belt. The fragility of aerated concrete imposes a number of restrictions on the choice of fastening method, but does not exclude this possibility.

Fastening with steel wire

The simplest mounting option.
It has become widespread due to the low cost of materials.

Sequencing:

• several rows (at least three) before the completion of the masonry, pieces of soft steel wire with a diameter of 6 mm are laid across the wall;
• the mauerlat is laid after the wall is laid and the glue has set its strength;
• by twisting the ends of the wire, the mauerlat beam is firmly pressed against the wall.

The length of the ends of the wire must be sufficient to cover the upper rows of the wall, the mauerlat beam and twist.

The laying pitch must coincide with the pitch of the rafters.

Fastening with anchor bolts

An anchor bolt (mechanical anchor) consists of:

• from an internal rod with a threaded part;
• external spacer part.

When the nut is screwed onto the inner rod, the spacer part is deformed and fixes the anchor bolt in the channel of the wall hole.

Sequencing:

• Mauerlat beam laid out along the entire perimeter of the wall.
• Holes for anchor bolts are drilled along the entire length of the Mauerlat.. The distance between adjacent holes is no more than 1 meter. It is necessary to strive to ensure that the locations of the anchors necessarily fall on the corners of the building and the joints of the beams.
• Through the holes in the Mauerlat using a drill, drilling into the masonry wall is the length of the anchor, but not less than 2 - 3 rows.
• An anchor bolt is inserted into the hole length of at least 500 mm and M12 or M14 thread.
• The washer is put on. The nut is tightened with force. The plastic or metal dowel included in the anchor design is expanded, pressed into the channel walls and securely fixes the anchor bolt in the wall.

Fastening the Mauerlat using mechanical anchors has become widespread. Limited relatively high cost fasteners.

Chemical anchor

Modern technologies The manufacture of mechanical anchors for fastening in aerated concrete has reached perfection. However, the main drawback inherent in the principle of operation remains. An anchor is attached to aerated concrete by creating bursting forces. As the load on the anchor increases, the aerated concrete block may split.

The so-called chemical anchor. Instead of dowels, a synthetic adhesive composition is used. It penetrates deeply into the pores of aerated concrete. When hardened, it firmly fixes the metal rod in the wall material.

Sequencing:

• a hole is drilled as for a mechanical anchor bolt, but with a slightly larger diameter;
• by using compressed air or a special brush is used to remove dust and crumbs of material from the hole channel;
• the hole channel is filled with adhesive;
• a threaded rod M12 - M14 or a piece of reinforcement of a similar diameter is inserted into the hole;
• at a temperature environment 20 degrees Celsius the composition gains strength in about 20 minutes.

TO positive qualities chemical anchors include:

• The fastening strength is significantly higher than that of an anchor with mechanical fixation.
• Absence of bursting stresses in aerated concrete. Mounting on the edge of the wall is allowed.
• Chemical resistance.
• Can be attached to wet material and work in the rain.
• Long service life (more than 50 years).

Disadvantages of chemical anchor:

• The adhesive composition does not withstand high temperatures.
• Cannot be produced welding work directly with the metal anchor rod.

Arrangement of a reinforcing belt

And yet, if the design of the house allows you to make a reinforcing belt, it is recommended to take advantage of this opportunity. Attach the Mauerlat to aerated concrete wall through an armored belt is much easier and more reliable. In addition to making it easier to attach the Mauerlat, the armored belt also has other positive qualities.

• Armored belt, like a hoop in a tub, tightens the upper part of the walls of the building and preserves its geometry during uneven shrinkage of the foundation and seasonal soil movements.
• Increases rigidity and the strength of the entire building.
• Distributes evenly point loads from rafter legs on the walls of the building.
• Is the best(and in the case of gas concrete walls and the only) means of counteracting thrust loads on the walls during the expansion structure of the rafter system.
• Changing the thickness of the armored belt It is convenient to align the top cut of the building walls horizontally. Level errors made during laying are leveled out.

The armored belt is made in the form of a concrete strip along its entire length load-bearing walls building.

Manufacturing of formwork

• Convenient to use U-shaped blocks. With their help, a continuous gutter is formed in the top row of the masonry, which performs the functions permanent formwork. With this manufacturing method, cold bridges are not created. The wall will not freeze.
• The top row on the outside of the wall is made of blocks 100 mm thick. From the inside - brickwork"on the edge." More labor intensive compared to using U-shaped blocks. Thermal insulation properties somewhat worse. The cost of the material is lower.
• The entire width of the wall is made of boards or OSB boards removable formwork is formed. The method is often used due to the low cost of materials. Cold bridges form. Measures must be taken to additional insulation walls in the armored belt area.

Belt reinforcement

Four - six threads of reinforcement with a diameter of 10 - 12 mm are used to make a frame in the form of a spatial box. Cross connections are made with wire with a diameter of 6 mm. The connection of frame elements to each other should be done using soft steel wire twists or plastic ties.

It is advisable to fill the armored belt with M200 grade concrete at one time, avoiding long interruptions in work. Using a vibrator to compact concrete significantly increases strength and durability reinforced concrete structure.

Fastening with metal studs

Threaded metal studs are rightfully considered the simplest and most convenient element for attaching the Mauerlat to the armored belt. The diameter of the pin is from 12 to 14 mm. The length is sufficient for the upper edge of the pin to protrude 4–5 cm above the surface of the Mauerlat. The lower edge of the pin is bent in the shape of the letter “G”.

Bolts may be used. In this case, they are welded to the caps metal plates in the shape of a rectangle.

Sequencing:

• studs with a pitch of no more than 1 meter are placed in the armored belt formwork before the concrete pouring operation is completed;
• attached to the reinforcement frame using binding wire or plastic ties;
• the accuracy of installation vertically and horizontally is controlled;
• After the concrete hardens, the Mauerlat beam is put on the protruding ends of the studs with holes and tightly pulled with nuts to the surface of the reinforced belt.

The importance of waterproofing during installation

Regardless of the chosen method of fastening, the Mauerlat and the wall surface must be securely separated from each other by a layer of waterproofing. Condensation formed when there is a temperature difference at the junction various materials, leads to wetting and destruction wooden beam Mauerlat.

Exists big choice materials for waterproofing during installation. Usually two layers of roofing material or one layer of waterproofing are laid. It will not be unnecessary to treat the wooden beams with an antiseptic composition.

Building a house is a long and difficult journey. Regardless of whether you are building a house with your own hands or have entrusted the work to third-party specialists, you need to clearly understand how to correctly take EVERY step along this path. Only personal control of the correctness of the chosen decisions and the quality of the work will allow the house to serve for a long time and bring joy to you and your children.

When settling in pitched roof installation of the rafter system cannot be done directly on the walls of the building. Additional element, which absorbs the loads from the rafters and transfers them to the walls, will be the Mauerlat. Usually this is a special beam that is laid around the perimeter of the walls. Since it takes a serious load from the roof, it is very important to securely fix the Mauerlat to the wall. In the case of brick or concrete walls, everything is simple and clear. But how is the Mauerlat fastened to aerated concrete without an armored belt, since the aerated block itself is quite loose and porous, and therefore cannot provide a strong fixation of the fastener? This is exactly what we will talk about in our article.

Functional purpose of the Mauerlat

Typically, the same material is used to make the Mauerlat as for the rafter system. Most often it is made from wooden beams. However, if the rafter system is made of metal, then this structural part can be made of a channel or I-beam.

Typically this element is made from the following materials:

• Wooden beam with a section of 100x100 mm, 150x150 mm or 200x300 mm. The timber is made from hardwood and undergoes mandatory antiseptic treatment. The product is laid around the perimeter of the walls of the structure. The joints are fixed with nails or a straight lock. Most often used in private construction wooden structure roofs.
• Less commonly, rolled profiles are used for these purposes - a channel with a U-shaped section or an I-beam with an H-shaped section. The profile height is determined by calculation and can be in the range of 70-120 mm.

A beam or steel beam is attached to the walls. In this case they can be used different ways fastenings Next, the rafter legs rest on the mauerlat. They exert a load on this element, which in turn, evenly distributing it, transfers it to the walls of the building. Besides this timber holds rafter system from displacement.

Important: since aerated concrete does not tolerate long-term point loads and gradually collapses, it is recommended to erect a monolithic reinforced belt along the top of the walls before laying the Mauerlat.

However, there are ways to install this structural element on aerated concrete walls without an armored belt. It is also worth remembering that the upper edge of the Mauerlat should be located at a height of at least 30-50 cm from the surface of the ceiling. This will ensure effective ventilation under-roof space, and will also facilitate inspection and repair of roof structures.

Mounting methods

Attaching a Mauerlat to aerated concrete is much more difficult than to a brick wall

Attaching the Mauerlat to aerated concrete is much more difficult than to a brick wall. As a rule, this product is laid at a distance of 50 mm from the outer edge of the wall. The following fasteners can be used to secure the Mauerlat:

• steel wire;
• anchor fasteners built into the masonry;
• special chemical anchors;
• steel studs.

Important: to attach the support beam to a reinforced belt or brick walls anchors are used.

After installing the beam, the rafter leg is pulled to the wall using a twist made from twisted metal wire with a diameter of 3 mm. To fix the wire 6 cm below the beam, a steel short is mounted. Instead, the wire can be fixed to the floor slabs. During installation complex roof It is recommended to make sure to use a reinforced concrete belt, which will give the building additional rigidity and more evenly distribute the load from the roof onto the walls of the house.

To connect individual parts of the Mauerlat into a single structure, an oblique cut is used, followed by fastening with nails, screws or bolts. To strengthen the corner parts of the structure, steel plates and brackets are used.

Using wire to secure beams

If wire is used to fasten the Mauerlat, then this must be taken care of at the stage of laying the walls. The wire must be laid in the wall tub when completing the last few rows. In this case, the following sequence of actions is followed:

1. When laying aerated concrete blocks, two or three rows before the end of the walls, a steel wire with a cross-section of 6 mm is laid between the elements, which consists of several thinner wires twisted together.
2. In this case, the middle part of the fastener is inserted into the masonry. Its ends should protrude from the walls. The length of these ends should be such that the wire can be freely wrapped around the timber being laid.
3. The number of wires used must be equal to the number of rafters being installed.

Fixation with pins

Fastening the Mauerlat to a wall made of aerated concrete with studs is allowed when installing light roofs on small houses. Materials used for formation roofing pie, must be as light as possible and not transfer significant loads to the remaining structural parts of the building.

This technique is ideally suited in cases where it is not possible to arrange an armored belt. In such a situation, the timber itself will serve as a reinforcing belt. This method causes rather controversial reviews from experts, but in practice it has proven itself very well, ensuring high reliability and stability of the roof.

To fix the timber to aerated concrete you will need the following elements:

• studs marked SRT-12, called “dovetail”;
• wooden beam with a cross section of 20x30 cm (the dimensions of this element depend on the thickness of the external walls).

We carry out the work in this order:

1. We drill holes in the aerated block walls in increments of 100-150 cm.
2. We insert pins into the holes and fix them with cement laitance or non-shrink mortar.
3. Next you need to perform waterproofing. To do this, two layers of roofing material are laid on the walls. At the location of the studs, holes must be pierced in the material to ensure a tight fit to the walls. Waterproofing will protect the wooden beam from saturation with moisture and subsequent rot, which can come from the walls.
4. With the same step as the studs were installed, holes of a diameter suitable for the studs are drilled in the Mauerlat.
5. Then the timber is placed on the studs over the waterproofing, washers are installed and tightened with nuts.
6. After installing the beam, the ends at which the individual fragments of the beam are joined are tightened with forged steel brackets.
7. Now you can begin installing the rafter system.

If the studs will be mounted in an armored belt, then we carry out the work as follows:

1. Before pouring the armored belt, studs are placed in it with a pitch of no more than 100 cm.
2. They are attached using a knitting wire to the reinforcing frame of the belt. Instead of wire, you can use plastic ties to secure the studs.
3. The accuracy of the installation of the studs horizontally and vertically is checked.
4. Concrete is poured into the armored belt formwork.
5. After it hardens, the prepared timber is put through the holes onto the protruding ends of the studs and pulled to the surface with nuts.

Chemical anchor

This product is also called liquid dowel, injection mass or glued-in anchor. Essentially, it is an adhesive with high adhesive characteristics, which is made on the basis of synthetic polymer resin. Thanks to the chemical anchor, it is possible to firmly fasten the metal rod and the base.

Important: unlike others fastening elements liquid dowel does not create expansion stress in the material, which is especially dangerous for fragile aerated concrete at the edges of walls.

Unlike mechanical anchors, the fixation of which is based on the use of friction forces and expansion of the dowel made of polymers, a chemical anchor is fixed due to the fact that the glue penetrates into the pores of aerated concrete to a considerable depth and firmly secures the rod in the wall.

Installation of a chemical anchor is performed in the following sequence:

1. First, a hole is drilled along the anchor. However, its size should be slightly larger than for a regular anchor bolt.
2. Using a special brush or compressed air, dust, debris and metal chips are removed from the channel.
3. A special chemical adhesive is poured into the hole prepared in the wall.
4. After this, a steel rod is inserted there - a threaded rod M 12-14. You can also take a piece of reinforcement of a suitable diameter for these purposes.
5. The adhesive composition gains the required strength in 20 minutes, provided that the ambient temperature is approximately 20°C.
6. After the chemical composition has hardened, the rod is securely fixed in the wall. Moreover, the fastening strength is much higher than that of the mechanical method.

Advantages of using liquid dowel:

• The service life of such fasteners is more than 50 years.
• This method of fixation can be used on the edge of walls without fear that it may crack.
• The fastener has fairly high chemical resistance.
• Fastening can be carried out on damp material, that is, installation can be carried out even in rainy weather.
• Work on installing the Mauerlat and arranging the roof can be carried out without the use of a reinforced belt, since a chemical anchor is fixed much more firmly in a fragile material than a mechanical dowel.
• This method is ideal for working with aerated concrete.
• The depth of the hole may be less than when installing a mechanical anchor, which must be buried 2-3 rows of masonry.

The only drawback of this method of fixation is that welding cannot be performed with a rod attached to a liquid dowel, since heating polymer material is destroyed, the fixation strength decreases.

Mechanical anchor (anchor bolt)

This is a fairly common way of fixing timber to walls. The anchor bolt consists of the following parts:

• external spacer;
• internal threaded rod.

Fixation occurs due to the fact that when the nut is screwed onto the rod, the spacer structure is deformed in such a way that it reliably fixes the product in the hole drilled in the wall.

The installation of a mechanical anchor is carried out in the following order:

1. Prepared timber is laid along the perimeter of the walls.
2. Next, holes are drilled along the entire length of this product for installing anchor bolts. The pitch of the holes is 1 m. It is important to ensure that the installation sites of the anchors always fall on the corners of the building and the junction of the two ends of the beam.
3. After this, using a drill, holes are drilled in the walls through the holes prepared in the Mauerlat to a depth equal to the length anchor. At the same time, it is not allowed to make the depth of the anchor less than 2 or even 3 rows of masonry.
4. An anchor bolt is installed in the hole. For these purposes, it is better to take products with a length of at least 50 cm with an M 12 or 14 thread.
5. After this, put on the washer and screw the nut tightly. As a result, the steel or plastic dowel expands so that it is firmly pressed into the material and fixes the bolt in the wall.

The Mauerlat is attached to aerated concrete or foam concrete, as a rule, using a reinforcing belt located in the upper part of the wall structures. It is this that becomes the support for the Mauerlat and provides greater strength to the entire house.

Why do you need an armored belt?

As is known, aerated concrete is characterized by high sensitivity to local loads. That is, if the permissible pressure of the drill used to create holes in the block is exceeded, there is a high probability that it will become cracked or even crack. To prevent such changes, an armored belt is installed; it also helps to avoid sliding and deformation of the blocks, which is caused by uneven pressure of the total weight.

What you need to know

The functions of the Mauerlat are to connect the frame of the building and also to distribute the load along all walls. Mostly wood is used to make fasteners. The best option is a timber made of hardwood, the surface of which is coated with an antiseptic composition.

It is desirable that the fastening of the Mauerlat to the aerated concrete wall be continuous along the entire perimeter of the wall structures. For fixation individual elements a straight lock of suitable size is used. To ensure rigidity, nails are driven in, ultimately forming the beams unified system for the installation of rafters, connected to adjacent elements. The beams must be located on the inside of the masonry, while they must be at least 5-6 cm from the outside. To support the Mauerlat, a brick parapet is made along the outer edge of the wall, the individual parts of which are fastened with a direct lock.

Methods for attaching Mauerlat to aerated concrete walls

It is possible to use several techniques suitable for different conditions:

• fixation with studs built into the masonry;
• anchoring based on armored belt;

In the latter option, the wire is laid between the bricks so that the middle part is located under them, and external sides were outside. The length should be sufficient to freely thread through the beam and then tighten it. The number of strappings must correspond to the number of rafters. Using metal wire, the Mauerlat is then secured to the wall.

Reinforced belt

Fastening the Mauerlat to aerated concrete with an armored belt is the most preferable, since the blocks have an insufficiently dense structure and the difficulty of installing fasteners of any kind. It is worth noting the advantages of using a reinforced belt. First of all, this is leveling the upper part of the walls and strengthening the entire structure of the house; when arranging it, clamps for the Mauerlat are created in advance. The easiest way to implement it is to use U-shaped block elements in the form of a gutter along the perimeter of the wall external structures, and there should be no interruptions. Next, a cut is formed on the corner parts. To assemble the frame, reinforcement with crossbars, then it is placed in the gutter followed by pouring concrete mixture. To ensure solidity, the mass is poured in one go. Before that on reinforced belt anchors with wire are secured. Special meaning has careful level matching. The studs are also fixed on the frame along a line in accordance with the tensioned cord, in vertical arrangement. Just as in the case of use, the number of rafter legs and anchor clamps must match. It is necessary to first determine the optimal location of the elements in order to avoid coincidence with the places where the rafters are fixed.

Fastening the Mauerlat to aerated concrete using studs

This option is optimal for small buildings and roofs that have a lightweight structure, when there are no significant loads on the roof and walls. There are two types of studs: these are bolts that form a single structure with a steel square, or L-shaped elements. They are secured in a course several rows before the top, and the length should be enough for the locknut and the thickness of the bars. The process is similar to the anchor method: the timber is put on studs when the masonry hardens and is fixed with nuts. There are also other methods of attaching the Mauerlat to aerated concrete, but they are used less frequently due to their lower reliability.

Sufficient rigidity and reliability of fastening is achieved by tying the bolts to the frame and additionally walling them up with concrete. It is enough to put the power plate on the studs and tighten it to the blocks using nuts.

If it is necessary to attach the Mauerlat to aerated concrete without an armored belt, monolithic plugs and pillows in the walls are used. Their dimensions should be within 400 mm, they are recesses with a structure made of thin reinforcement or metal rods, and it is on this that the anchors are fixed.

Peculiarities

The use of anchors and studs requires preliminary creation of holes. A number of difficulties may arise here. For example, the fasteners may not be level enough, even if a cord and level are used; the most difficult thing to work with is liquid concrete. First of all, the exact location of the fasteners is set on the board with flat surface The points of the upper parts of the bolts are marked, subsequently they are transferred to the Mauerlat, in which the corresponding holes are drilled. Next, the beam is fixed to the wall. The base of the rafters is fixed with bolts; washers and nuts are additionally used.

Fastening the Mauerlat to aerated concrete should be carried out after selecting the fastening method and preliminary planning of the number and locations of the fasteners. First of all, reliable insulation is formed between concrete and wood. This is necessary due to the development of intensive wood decay, to prevent this process waterproofing material is used, laid in two layers. It can serve as modern options, and the usual ones, such as polyethylene or roofing felt.

When using wire, it is enough to make holes at a distance of no more than 35 cm for all fasteners, thread the wire, and twist the ends in such a way as to obtain the maximum connection between the wall and the Mauerlat.

It is worth noting that they should not be used with an angle grinder, since this tool not suitable for wood. Non-compliance of this rule may cause injury during operation.

Sliding Mate

The installation of the rafters is carried out after the Mauerlat is tightly secured. Rafter structure can have hinged or rigid fixation, selection suitable option depends on the requirements that must be met by the attachment points of the Mauerlat to aerated concrete, general configuration and type of construction (hanging or layered).

The hinged version can have different interfaces. The most common is a rigid mount, with no possibility of displacement or rotation. A sliding coupling is also used to ensure the beam moves and rotates in relation to the beam. Last option reduces thermal expansion of wood and shrinkage of the building, all of which prevents the transfer of thrust loads to wall structures.

Three techniques are used to create a sliding mate:

• the use of a special metal fastener to connect the rafters;
• moving the beam beyond the walls and fixing it with a plate;
• creating a groove in the rafter board and installing it on the mauerlat using a corner, staples or nails.

Hard pairing

Concrete and wooden buildings, as well as structures made of timber. Due to the fact that both frame and timber houses are characterized by noticeable shrinkage, in the absence of the possibility of simultaneous displacement of the building frame and roof, there is a possibility of significant stress causing damage to the structure of the walls and rafters. To create a rigid connection, support bars with a length of within 1 meter are required, secured to nails and steel corners. with a beam should rest against the structure of the mauerlat in accordance with the pressure line. This helps prevent perpendicular displacements. Angles and nails eliminate lateral movement, and the latter must be driven in at an angle on both sides, so that they intersect in the beam. A third nail is driven through the beam, which should have a vertical direction.

Conclusion

Attaching the Mauerlat to aerated concrete has its own characteristics, which must be taken into account when arranging, in this way problems with the operation of the roof can be prevented. In the absence of experience and relevant knowledge to create a project and subsequent installation of a rafter system, it is advisable to contact professionals who guarantee reliable roof, which long years will protect the house from cold and precipitation. When building, you shouldn’t skimp on at this stage work, as this may cause additional financial investments and time costs.

How to attach the Mauerlat to aerated concrete without an armored belt?

On manufacturers' websites there are conflicting statements regarding the need for building a building from aerated concrete blocks. Some argue that they are quite capable of withstanding the expected load. Others, on the contrary, suggest playing it safe. However, all manufacturers and builders are confident that porous materials react negatively to point loads.

Therefore, it is necessary to distribute it evenly. If for any reason the installation of an armored belt is not possible, it is necessary to use. This will extend the life of the building.

The Mauerlat is most often made from the same material as the rafters - metal (channel, I-beam) or wood (timber)

What is a Mauerlat

This is a special design that is used to distribute the weight of the roof evenly across the walls. As a rule, it is made of wooden beams. It is to the Mauerlat that the rafters are attached to make the roof stable. The durability and reliability of the entire structure depends on the quality of installation.

The Mauerlat can be metal, but only if steel rafters are used. However, such structures are rare, since the cost of construction increases significantly. In addition, fastening steel parts is much more difficult than wooden ones.

• Mauerlat functions:
• uniform distribution of the weight of the roof over the walls;
• reliable fixation of the rafter system;

protection and prevention of point loads on aerated concrete blocks. The minimum size of timber used as a mauerlat should be 10*10 cm. However, to ensure best quality

For clutches, it is advisable to use a material with a larger cross-section. It is permissible to use a log, but it is necessary to cut off the side that will be adjacent to the aerated concrete.

Hardwood timber performs these functions best. In order for it to last longer, it must be treated with antiseptics and impregnations that prevent rotting and insect damage. The beams must completely and evenly cover the walls. They are fastened together with nails or a straight lock. Due to the fact that the cross-section of the wooden material is smaller than the width of the gas block, the Mauerlat is placed along inside walls

The distance to the outer edge must be at least 5 cm. Laying bricks on the outside of the building is also permissible. Between aerated concrete wall

and the wooden mauerlat should be a waterproofing layer.

Methods for attaching the Mauerlat The Mauerlat can be attached directly to aerated concrete or using an armored belt. There are such connection methods wooden beam

• with wall:
• using steel wire;
• using anchors;

stiletto heels.

When using any of the above methods, you must ensure that the fastening is of high quality and reliable. Also, during installation, structural shifts should be avoided.

In private housing construction, wooden beams are the main material used to work on the mauerlat

Private and public construction requires the use of structural elements of varying complexity. When constructing houses from aerated concrete, a special element is used - Mauerlat. There is a special technology that describes fastening the Mauerlat to aerated concrete without an armored belt. This construction method significantly increases the reliability and service life of the future structure.

Design Features

The technology for building houses from aerated concrete is being improved for objective reasons - in the materials market, the demand for aerated concrete blocks is growing every day. The peculiarities of constructing houses from this material allow for high-quality construction in the shortest possible time. House built from cellular concrete, has beneficial thermal insulation characteristics, and also has a relatively small structural mass.

Aerated concrete has a disadvantage associated with the difficulty of attaching structural elements to each other. The porous base of the walls is difficult to connect to the main frame, and builders have to look for additional paths solutions. Mauerlat is a structural element connecting the walls of a building and the roof. An armored belt made of reinforced concrete helps solve the problem, but some homeowners use the method of attaching the Mauerlat to aerated concrete without an armored belt.

The peculiarity of aerated concrete structures is that it is difficult for porous concrete to withstand the point pressure of pressing elements. Mauerlat represents an important structural element, performing the load function. Unlike the foundation, the Mauerlat carries the load exerted only by the roofing part of the building - the roof, the inside of the slope and the thermal insulation layers.

Working with a metal or wooden Mauerlat helps in redistributing pressure on the walls. Mounting the Mauerlat also makes it easier installation work related to the installation of rafter elements.

Calculation algorithm

Work on installing the desired material can be performed using the following modules:

• Wooden supports;
• Metallic profile.

The cross-section for wooden beams is selected within the format of 10 cm * 10 cm. If the roof has particularly large dimensions, then it is recommended to use modules bigger size(10 cm*15 cm, 15 cm*15 cm, 15 cm*20 cm). There is a certain proportion in accordance with which the Mauerlat is fastened for work - the thickness of the material should be equal to 2 thicknesses of the rafter supports.

The production of a mauerlat from logs is possible, but does not justify the effort expended - the cross-section of the log is difficult to adjust to the configuration of the rafter components. The characteristics of the wood selected for the job must also meet high standards. The Mauerlat is fastened using wood, which is tested for wear resistance and absence of mechanical damage.

The best option is considered quality wood hardwood, processed special compounds. It is also possible to use a metal profile for roof fastening work. Carrying out such work is accompanied by the use of a channel or I-beam impregnated with anti-corrosion substances.

Basic values

A specialist installing a Mauerlat without an armored belt must carry out correct calculation main parameters. The following values ​​are taken into account during operation:

• Built-up area;
• Type of roofing system;
• Features of roofing material;
• Seismic activity of the zone;
• Climate influence.

There are various structural forms of the roof, but the most common is considered gable roof. As an example, it is beneficial to make calculations for work on this type of roof. The volume of the Mauerlat is measured using the formula V=P*S, Where P– perimeter of the flooring, and S- section of timber or V= N/R, Where N is the mass of the beam, and R– wood density.

Fastening methods

Fastening the Mauerlat to aerated concrete without an armored belt can be carried out in accordance with several technologies. Fastening works to aerated concrete blocks pass with the help of special elements.

Chemical anchors

This method is based on the use of chemical resins with adhesive properties. Liquid dowel or other chemical paste perfectly connects the porous surface of aerated concrete and metal profiles. In small buildings, corners can be fixed using ties, brackets and screws. Anchoring increases the level of protection of the structure.

Work with chemical compounds implies the following list of actions:

• Filling the hole with adhesive;
• Fixation of the metal frame;
• Control of composition hardening.

It is noted that corners strengthened in this way are distinguished by great durability and long service life (up to 50 years). It is prohibited to carry out welding work with fixed metal profiles, since chemical anchors are sensitive to high temperatures.

Studs for fastening

Construction studs are perfect for small-sized buildings, where the Mauerlat is fastened so that it serves as a reinforced belt.

Working with pins involves the following list of actions:

• Drilling holes at a distance of 1.5 m;
• Fixing the stud with cement;
• Installation of a waterproofing layer;
• Installation of the Mauerlat;
• Fastening the timber with forged brackets;
• Installing a roofing system on top of a structure.

Steel wire

Using steel wire of a certain thickness, you can achieve a similar result in installation work. Using this method involves the following sequence of actions:

• Embedding twisted wire into the walls of a building;
• Control correct position wires in aerated concrete;
• Control of free passage of wire through the beam;
• Calculation of the required number of components in accordance with the number of rafters.

Supporting rafters on walls made of small blocks of porous concrete can be done using special reinforced beams - brackets. The brackets are made of metal with anti-corrosion coating. Fixation occurs using wire ties, self-tapping screws, plates and perforated tape.