home / Interior decoration/ Correct fastening of the Mauerlat to aerated concrete - possible options tested in practice.

Proper fastening of the Mauerlat to aerated concrete - possible options tested in practice.

The ridge beam, in turn, rests on capital structures walls (pediments) and (optional) on racks. Layered rafters do not require transverse ties and struts, which can significantly reduce the useful volume of the attic floor under the roof. When the width of a house with a gable roof is from 8 to 10 meters, either a rafter structure with additional purlins, struts, or in the form of three-hinged trusses is used. However, the installation of layered rafters requires some experience and proper design in order to avoid the occurrence of bursting loads. The majority of self-builders, cobblers and guest workers in Russia usually prefer the construction of classic spacer rafter schemes, where the top and bottom of the rafters are connected by a hinge with one degree of freedom (or rigid pinching), the main load is transferred to the external counter of the walls of the house made of aerated concrete, and accordingly, applied to walls are subject to bursting loads. In this case, it is necessary to install a rigidly fixed mauerlat, directly connected into a single contour along the perimeter of the building, or rigidly tied to a single contour of the supporting monolithic reinforced concrete piping circuit. Therefore, we recommend that when independently designing and building a house from aerated concrete, in all cases, make a monolithic reinforced concrete strapping belt along the upper edge of aerated concrete walls (not only external, but all internal walls), in which T- or L-shaped anchors with threads are laid along the outer contour M12 in increments of 1 meter for a rigid connection with a wooden beam (100 x 150 mm, or 150 x 150 mm) on which the rafters will rest.

This design will allow you to avoid problems with wall expansion, even if you or your builders assemble the rafter system incorrectly, and it will create expansion loads on the walls. Below we will look at how to properly arrange rafter system, which does not create bursting loads on the walls of a house made of aerated concrete.

Diagram of the installation of a monolithic reinforced concrete strapping belt for fastening the Mauerlat

Before installation, the Mauerlat is treated with antiseptics (ХМ-11, ХМББ) and laid on waterproofing made of bitumen-polymer roll waterproofing material(not roofing felt). According to the pitch of the anchors, holes are drilled in the Mauerlat and the Mauerlat is installed in place. A washer and nut are placed on the threaded rods of the anchors and tightened until they stop. If you use a common "tree" for Russia natural humidity"(that is, raw - which no self-respecting consumer would buy in any civilized country), then you need to provide access to the Maueralt fastening in order to tighten this nut once a year for 5 years (the most intense shrinkage is observed in the first year), until the wet wood will dry out and shrink.In the case of a spacer rafter structure or if you do not know whether the rafter structure will be spacer or non-spacer, it makes sense to build a buttress from a sawn aerated concrete block (through a waterproofing gasket) on the outer side of the mauerlat. The diagram below shows the method of fastening rafters for a traditional spacer scheme, with one degree of freedom for the end of the rafter leg.

What does this mean? The rafter leg in this case is fixed by two steel plates (a steel angle and a strip connecting element) and a wire tie, which prevent rotation in the Mauerlat-rafter hinge. Sliding in this hinge is also impossible due to the rigid fastening of the rafters with an angle and flat metal, coupled with a support bar hemmed from the bottom of the rafters. If the top of the rafters with such a fastening unit is tightly pinched, or the rafters rest against each other, then with this design the thrust load will be transferred to the walls of the house.

Constructive ways mounting the maueralat on the wall of a house made of aerated concrete

When arranging a roof with one or more slopes, it becomes necessary to install a rafter system. However, it is impossible to lay rafters directly on the walls - for this purpose they use a Mauerlat, which redistributes the load. If the walls of a building are constructed from a porous material such as aerated concrete, it is not always possible to lay a reinforcing belt under the Mauerlat. In this article we will talk about how to secure the Mauerlat to aerated concrete without an armored belt using various methods, we will describe in detail the technology and subtleties of this process.

Why do you need a Mauerlat?

So, the Mauerlat is a very important structural element, which takes the main weight of the rafter system and distributes it evenly over the entire plane of the load-bearing walls. As a rule, it is made of a material similar to rafters - most often wooden beams. However, a steel rafter system will require a Mauerlat made from an I-beam or channel.

The following materials are used to make the Mauerlat:

Wooden beams with a cross section of 100x100 mm, 150x150 mm, and also 200x300 mm. IN in this case you can take hardwood that has passed antiseptic treatment. The timber is laid around the perimeter of the building. The logs are joined using the locking method or using nails. Wooden roof frames are most often erected in private construction.
Rolled profiles - I-beams in the shape of the letter H or channels in the shape of the letter P are used somewhat less frequently. In this case, the height of steel profiles can vary between 7-12 cm.

Whatever material you choose, it is attached to the surface of the walls. There can be several ways to attach the Mauerlat to aerated concrete. After fixing this element, installation is carried out rafter legs. It is worth noting that the Mauerlat not only redistributes the load, but also prevents the rafter system from moving in the horizontal plane.

Since aerated concrete is a rather fragile material and does not tolerate increased loads, many craftsmen prefer to pour a reinforcing belt along the upper edge of the walls. At the same time, to reduce costs and labor costs, there are some methods for securing the Mauerlat without an armored belt.

Please note that there must be at least 30-50 cm from the ceiling to the upper edge of the Mauerlat, so that the space under the roof can be well ventilated, and access to the load-bearing roof structures for maintenance and repair is provided.

Methods of fastening to aerated concrete

It is worth noting that laying the Mauerlat on aerated concrete is much more difficult than, say, on a brick wall. Usually it is laid at a distance of 5 cm from the outer edge of the wall.

The following elements can be used to lay and fix the Mauerlat:

steel wire;
anchor bolts;
chemical anchors;
steel studs.

The Mauerlat is fixed to a reinforcing belt or to a brick wall using anchor bolts.

After the beam is installed, the rafter leg is pulled to it and wound with twisted steel wire with a cross-section of 3 mm. 6 cm below the beam you need to install a short piece on which the rest of the wire will be fixed. Alternatively, the wire can be wrapped around the floor slabs for secure fixation.

If we're talking about about the roof complex design, then it is recommended to fasten the Mauerlat beam to aerated concrete using a reinforced concrete belt. It will provide not only greater reliability of the structure, but will also allow the load to be evenly distributed.

The Mauerlat bars are secured to each other using an oblique cut and then secured with nails or bolts. Staples or steel plates attach corner connections additional rigidity.

Fixing the Mauerlat using wire

Before attaching the Mauerlat to aerated concrete using steel wire, it must first be fixed in the thickness of the wall. This should be done during installation. last rows gas blocks - the wire is placed under them.

The installation technique in this way looks like this:

A couple of rows before the end of the masonry, a twisted wire of several thinner wires with a cross-section of 6 mm is placed between the blocks.
In this case, the central piece of wire will be placed in the thickness of the masonry, and the ends will hang down on both sides of the masonry. The length of the ends is made such that they are enough to wrap freely around the beam.
There should be so many pieces of wire that it is enough to tie all the rafter legs.

How to secure with studs

It would be advisable to attach the Mauerlat to aerated concrete without an armored belt on studs only in cases where it is planned to use lightweight roofing materials for the ceiling in small houses. Therefore, the expected load on the walls will be small.

In addition, in this situation, the Mauerlat beam itself will serve as an armored belt. Although there are conflicting opinions regarding this type of installation of a Mauerlat on aerated concrete, practice shows that it has a right to life. This technique ensures a sufficient level of reliability and stability of roofing structures.

To work you will need the following components:

metal studs SRT-12, which are also called “ dovetail»;
timber beam with a cross-section of 20x30 cm - although the thickness depends on the size of the constructed wall of the building.

The sequence of work for laying the Mauerlat on aerated concrete without an armored belt looks like this:

Along the entire length of the load-bearing wall, notches are drilled in its upper part at a distance of 100-150 cm.
Studs are placed in the finished holes and secured with non-shrink mortar or cement laitance.
Waterproofing from a double layer of roofing felt is laid on the block wall. At the locations of the pins, holes are pierced in the material so that it tightly covers the surface of the metal. This stage helps protect the wood from rotting due to moisture.
Next, recesses are drilled in the Mauerlat along the diameter of the studs with a pitch that coincides with their location.
Now the mauerlat beam is put on the studs and secured with nuts and washers.
After installing the beams, the abutting end parts are tightened with metal staples.
Next, the rafter legs are installed directly.

The process of attaching the roof to aerated concrete will look somewhat different if the studs are mounted into a reinforcing belt.

The sequence of actions is as follows:

Before pouring cement mixture Studs are installed in the formwork under the armored belt in increments of up to 1 m.
They are fixed to the frame with knitting wire or plastic ties.
Align the location of the studs along all axes.
The formwork with reinforcement and studs is filled with a cement composition.
After the reinforcing belt has completely hardened, the Mauerlat beam is placed on the protruding studs and tightened with nuts.

Application of chemical anchors

By chemical anchor we mean a liquid injection mass made on the basis of a polymer resin, which quickly hardens and firmly fixes the metal rods in the thickness of the Mauerlat.

The advantage of this material is the absence of bursting stress, so fragile aerated concrete does not collapse. If mechanical anchors fix parts by expanding the dowel, then the adhesive composition of a chemical anchor fills the pores of aerated concrete and holds the rod motionless.

The process of attaching liquid dowels looks like this:

A recess for the anchor is drilled in the gas block. The size of the recess should be larger than for a regular anchor bolt.
Remove dust and debris from the hole, for example, with a vacuum cleaner.
Poured into the hole adhesive composition.
Next, a threaded metal rod is inserted into the glue - an M 12-14 pin or a piece of reinforcement.
Complete crystallization of the polymer composition occurs in 1/3 hour if the ambient temperature is above 20 ℃.
Once the glue hardens, the pin will be securely fixed. It is noteworthy that such fasteners are stronger than mechanical ones.

Installing a roof Mauerlat on a wall made of aerated concrete using liquid dowels has a number of undoubted advantages:

The fastening does not lose strength for more than 50 years.
Due to the polymer structure of the glue, this method of fixation is widely used at the edges of walls, where there is a risk of the gas block splitting.
The chemical anchor has good chemical resistance.
Even damp weather and wet surfaces of the joining elements do not prevent the installation of these fasteners.
The installation of the roof mauerlat on aerated concrete blocks can be carried out without pouring an armored belt, since the reliability of fastening a chemical anchor is much higher than that of a mechanical one.
The chemical composition of the anchor is ideally combined with the porous structure of aerated blocks.
To install liquid dowels, holes of a shallower depth are required than in the case of mechanical anchors - there the depth is 2-3 rows.

However, welding work cannot be carried out on anchors installed by this method - overheating of the metal rod will lead to disruptions in the polymer structure of the material, causing it to lose strength.

Fastening on mechanical anchors without armored belt

Finally, the last way to attach the Mauerlat to aerated concrete is the use of traditional mechanical anchor bolts.

The anchor consists of:

internal steel rod with applied thread;
outer casing - the spacer part of the mechanism.

The principle of operation of the anchor is the gradual deformation of the outer body as the nut on the bolt is tightened. In this way, the bolt is firmly fixed in the drilled hole.

Installation of anchors occurs as follows:

Along the last row of blocks, beams are laid out along the walls.
Holes for mounting bolts are made along the entire length of the beam in 1 m increments. Please ensure that the anchors are placed at the corners of the building and at the junction of two pieces of timber.
Using a special drill, a hole is made through the laid Mauerlat in the gas block to the depth of the anchor. In this case, the depth of the hole should be no less than the thickness of 2-3 rows of masonry.
An anchor bolt is inserted into the hole made. It is advisable to use products with a length of at least 50 cm and thread M 12-14.
Finally, put a washer on the bolt and tighten the nut as tightly as possible. As a result of compression, the anchor body contracts and expands the material. So the bolt is securely fastened into the thickness of the wall.

The service life of the roof largely depends on how firmly and efficiently the Mauerlat is secured. The wooden structure takes the loads from the roof and redistributes them to the load-bearing walls.

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Attaching the Mauerlat to aerated concrete is quite simple. Plays a primary role careful preparation all components: wooden beams, fasteners, reinforcement frame, reliable waterproofing. Let's look at the order of work.

Attaching the Mauerlat to aerated concrete

Before directly attaching the Mauerlat, you should prepare the base. Reinforcing belt- a prerequisite for arranging a roof if the walls are made of aerated concrete or any similar material.

The reinforced concrete strapping belt prevents the pushing of aerated concrete blocks and allows the dynamic and static forces coming from the roof to be evenly distributed completely over the wall area.

Arrangement of a reinforcing belt

The minimum size of the concrete tape is 200x150 m. It is attached with inner surface walls.

Installation steps:

construct formwork around the perimeter of the house. The gables must be treated;
u-shaped blocks create a reinforced concrete belt;
A frame is assembled from reinforcement 10 mm thick. The reinforcement should protrude by 4 cm;
To rigidly fasten the Mauerlt to the aerated concrete, threaded studs are installed at intervals of 1 m. Their diameter is 14mm;
the blocks are filled with concrete grade M-200;
After a week, you can remove parts of the formwork and attach the Mauerlat.

Important: at the stage of preparation for the start of work, builders are required to calculate the number of studs and the future distance between them. The points of attachment of the wooden structure to the rafters and the points of connection with the reinforcing belt should be located in different places. Check that the number of rafter legs and studs is the same.

Preparing a wooden structure

The beams are treated before installation antiseptics, preventing wood rotting. A log or beam with a cross-section of 100x100 mm or 150x150 mm is wrapped in waterproofing material. Bitumen-polymer waterproofing material is suitable for this purpose. Ruberoid is not used.

High-quality materials will allow you to create robust construction. The tree should not have knots or cracks. Humidity must be appropriate building regulations.

If the developer uses “raw” wood, it should be possible adjust the anchor nut.

This operation is performed once a year for 5 years. During this period, intensive shrinkage of wet wood occurs. As the beams dry, you will have to tighten the nut less and less.

In this photo you can clearly see one of the ways to attach the Mauerlat to aerated concrete walls.

How to properly attach the Mauerlat to aerated concrete?

Use an anchor with a washer and nut. Anchor shape: T- and L-shaped. Thread: M12 or M14. According to international building codes, in earthquake-prone areas the distance between adjacent anchors should not exceed 1 - 1.2 m.

Mechanical type of fastener

Procedure:

dowels are inserted into the prepared holes;
screwed in fastener;
the teeth of the harpoon are firmly pressed into the aerated concrete;
the surface expands;
the structure is securely fixed.

Great option Installing a Mauerlat on aerated concrete has only one drawback - high cost. 1 anchor and a special dowel with a harpoon costs more than 3 thousand rubles.

Another video on how to attach the Mauerlat to aerated concrete.

Mauerlat installation

Another method is used to firmly secure the Mauerlat in aerated concrete walls. Will need chemical capsule. Its cost is much lower - 150 rubles. for a unit.

Reliable fixation of the structure is achieved through the penetration of chemicals into the pores of the material. Additionally, the concrete surface receives heat and waterproofing.

Final stage

After installing the Mauerlat on aerated concrete, proceed to installation of truss structure. There are two ways.

First option

the boards are cut to 1/3 of the board depth;
nails and metal corners will allow you to securely fasten the rafters;
nails (2 pcs.) are hammered crosswise from the sides;
an additional nail is driven in from above;
The fastening angles finally secure the joint.

Second option

cutting is not done in the rafters;
a special support block is hemmed from below, resting on the Mauerlat;
nails are driven in as in the first option.

The support beam has a length of 1 m. The second option is suitable for rafters that have a low height.

Fastening the connecting beam can only be done after accurate calculations and procurement of high-quality materials. Purchasing bars of inadequate quality from high humidity may lead to damage to the strength of the structure.

To attach the Mauerlat to an aerated concrete wall, use anchors with special dowels or a chemical installation method. Be sure to follow thermal insulation of a reinforcing belt made of extruded polystyrene foam.

Compliance with the requirements will allow you to securely fasten the Mauerlat and create a strong rafter structure.

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When arranging a pitched roof, the installation of the rafter system cannot be done directly on the walls of the building. An additional element that absorbs 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. In private construction, a wooden roof structure is most often used.
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. In addition, this beam keeps the rafter system from shifting.

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

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 performing the last few rows. In this case, the following sequence of actions is followed:

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.
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.
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, providing high reliability and roof stability.

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

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

We carry out the work in this order:

We drill holes in the aerated block walls in increments of 100-150 cm.
We insert pins into the holes and fix them with cement laitance or non-shrink mortar.
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.
With the same step as the studs were installed, holes of a diameter suitable for the studs are drilled in the Mauerlat.
Then the timber is placed on the studs over the waterproofing, washers are installed and tightened with nuts.
After installing the beam, the ends at which the individual fragments of the beam are joined are tightened with forged steel brackets.
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:

Before pouring the armored belt, studs are placed in it with a pitch of no more than 100 cm.
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.
The accuracy of the installation of the studs horizontally and vertically is checked.
Concrete is poured into the armored belt formwork.
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 a synthetic polymer resin. Thanks to the chemical anchor, it is possible to firmly fasten the metal rod and the base.

Important: unlike other fastening elements, the 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:

First, a hole is drilled along the anchor. However, its size should be slightly larger than for a regular anchor bolt.
Using a special brush or compressed air, dust, debris and metal chips are removed from the channel.
A special chemical adhesive is poured into the hole prepared in the wall.
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.
The adhesive composition gains the required strength in 20 minutes, provided that the ambient temperature is approximately 20°C.
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 this method fixation is that welding cannot be performed with a rod attached to a liquid dowel, since heating destroys the polymer material and reduces the strength of fixation.

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:

Prepared timber is laid along the perimeter of the walls.
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.
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 of the 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.
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.
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.

When building a roof for a house made of foam blocks, you must strive to reduce its weight so that the load on the walls is small. However, if the house has a reinforced concrete frame, then you can deviate from this recommendation.

Why is that?

Foam blocks have a cellular structure. This suggests that the material is inferior in strength to some others. Under a certain force, foam blocks are prone to gradual destruction. And we don’t need such a fate.

How to make the roof lighter?

First, you need to use lighter lattice forms. Secondly, wooden crossbars must be hollow. It is better to use a channel based on OSB.

The choice of roofing material must also be approached wisely. The less its weight, the better.

Among the roofing materials for a house made of foam blocks are:

Corrugated sheet
Sheet copper
Metal tiles
Galvanized iron

Features of installation of overhangs and slopes

When constructing a roof for a house made of aerated concrete, the truss and the angle of inclination of its slopes play an important role. Especially if the building is being built in regions of the country with a cold climate.

If you do not maintain a certain angle of inclination, snow will linger on the roof for a long time, placing a strong load on the structure. This will soon lead to destruction roofing and other dangers.

The sharper the angle at which the rafters are installed, the less load the walls will experience, The snow on the roof will disappear faster. And the overhangs will no longer be subject to constant pressure.

Construction of an attic roof for a house made of aerated concrete

Let's briefly look at the process of installing an attic roof.

Construction of an attic rafter system is a complex process. Before starting work, remember some installation features:

For rafters, beams of 10×10, 15×15 or 20×20 centimeters are used
It is mandatory to lay a waterproofing layer between the walls and the Mauerlat
It is better to fasten the assemblies of the attic structure with thick metal brackets
Wood used for structural elements must be well dried and treated with an antiseptic and fire-retardant compound
It is better to give preference to coniferous trees, since the influence of humidity on them is the least

Stage 1 - waterproofing the junction of the Mauerlat with the wall

There must be a layer of waterproofing between the wall of the house and the mauerlat. For these purposes, you can use ordinary roofing felt. It is laid along the entire perimeter of the walls and is not fixed in anything.

Stage 2 - installation of the Mauerlat

Mauerlat- a wooden beam that is attached along the perimeter of the walls of the house.

It should be fixed using anchor bolts whose diameter is at least twelve millimeters. Holes are pre-drilled for them.

The ends of the anchors are bent into a hook to prevent them from being pulled out further. However, there are anchors with a spacer system at the bottom. The fastening step is 10-15 centimeters. The mounting location is between the rafter legs at an equal distance.

If mansard roof If a house made of aerated concrete has two slopes, then two mauerlats are needed; if it has four slopes, then four.

A beam with a cross section of 15×15 or 20×20 centimeters is used as a Mauerlat.

Stage 3 - construction of the rafter system

The rafter system must be assembled perfectly, because it is the skeleton of the roof. And all loads (wind, rain and others) fall on it. Therefore, it is important to correctly make calculations with a slope of climatic features your region. It is difficult to make a calculation, so you can turn to professional workers.

It is better to make a rafter system from coniferous wood. Usually it is pine or larch. Humidity should not exceed 23 percent.

To protect yourself in the future from negative consequences associated with the proliferation of microorganisms and the attack of rodents, it is necessary to thoroughly impregnate the wood with special compounds, including fire-fighting ones.

Rafter design

Rafters can be hanging or inclined.

When the span between the walls is no more than six meters, then inclined rafters can be installed. If the span is twice as large, then inclined rafters are used only if additional support is installed.

Hanging rafters are installed when the span between the walls reaches 12 meters. In this case, the installation of additional support is not provided.

Preparing rafter legs

We will install the rafters in increments of 60 centimeters, leaving holes for the windows. Let’s take the bars for the “legs” with a cross-section of 10×10 centimeters. The length is determined taking into account the slope of the slopes and the size of the building (individual for each case).

Installation of floor beams

For beams, you can use logs, timber, or a board that is laid on the edge. Beams are installed with a selected step into pre-prepared grooves in the wall. Their ends are waterproofed with two layers of roofing material. After the beams are laid, they are additionally secured with anchor bolts.

Construction of vertical racks

If the roof on a house made of aerated concrete is broken, then first support vertical posts are erected. They will serve as the frame of the walls.

The height of the racks must be at least two meters to make it comfortable to be on the floor.

Vertical posts are inserted into grooves on the floor beams and are additionally fixed with metal corners and brackets.

Select the beam section from the table.

An attic floor beam is installed between the posts. Additionally, it is secured with bolts or another method.

A certain number of racks are assembled with a previously selected step U-shaped. A cord is pulled between them and checked for level. If the height is different, dismantle one of the arches and then adjust it in height. The racks are sewn together with bars of the same section.

Installation of ridge posts

You can immediately install ridge racks. The ridge itself will be mounted between them, but you can do without them.

Installation of lower rafters

Now you need to install the rafters between the Mauerlat and the upper floor beam. To do this, the distance between the corresponding supports is determined, and the rafter legs are prepared. required length. In the lower part, cutouts are made on the legs of the rafters, with which they rest on the Mauerlat and are additionally fixed with brackets.

Installation of the upper rafters

We need to prepare the upper rafters. To do this, a template is sewn from boards. It is installed at the ends of the attic floor beam, the size is taken and the slope angle of the slopes is determined. Based on this size, the required number of rafter legs is prepared, which are then securely fixed to the horizontal beams.

Installation of sheathing

From what roofing material selected, whether continuous or sparse lathing is laid. Continuous is done when installing heavy roofing coverings.

Installation of roofing material

The selected roofing material is mounted on the prepared sheathing, after which additional roof elements are installed - gutters, protective drains, etc.

Video about the step-by-step construction of the roof of a house made of foam blocks

Start of roof construction

People uninitiated in the nuances of capital roof construction are unlikely to know why a Mauerlat is needed, what kind of structure it is. And the question of how to make a Mauerlat on aerated concrete causes complete misunderstanding. In fact, it attaches simply. The main thing is to prepare all the components: reinforcement cage, fasteners, timber beams and competently carry out waterproofing and wood processing.

Mauerlat - description in detail

This design is made from wood beams. Performs the function of additional support for the load from the roof, with further uniform distribution along the entire perimeter of the walls.

If we summarize all of the above, we come to the conclusion that the Mauerlat is responsible for two important tasks:

uniform distribution of the weight of the rafters on the walls;
fixing the rafters to the frame of the building;

The Mauerlat can be made not only from wooden beams, but also from metal channels or beams.

In this option, the rafter system also needs to be made of steel. But this option is used extremely rarely due to the high cost of the material and difficulties in installation.

Materials and calculations

The strength and reliability of the roof depends on how securely the Mauerlat is attached to the aerated concrete. Therefore, everything needs to be calculated correctly. The minimum cross-sectional dimensions of wood beams must be no less than 10×10 cm. experienced craftsmen and designers recommend using higher values.

When using wooden logs for the mauerlat, one side should be hewn. This is necessary for a tight fit to the surface of the upper aerated concrete wall.

As for the type of wood, it is better to choose hardwood. Before installation, be sure to treat it with an antiseptic. Arrange the bars so that they evenly cover the entire top part walls Fasten adjacent parts with a straight lock and reinforce with nails.

The width of wooden beams is smaller than that of gas blocks, so they must be installed by moving them towards the inner edge, not reaching the end by 5 centimeters.

Ultimately, a solid structure with high levels of rigidity and reliable support for the rafter structure should be formed.

Preparing wooden beams before installation

As already mentioned, the beams should be treated with antiseptics before installing the Mauerlat on aerated concrete. They will prevent putrefactive processes in wood. Take logs with a section of 100 by 100 mm, but it is better to choose stronger ones 150 by 150 mm. Wrap them with waterproofing material, for example, bitumen-polymer. Ruberoid is not used for these purposes.

A durable structure can only be created quality materials, there should be no knots in the logs. Special attention the moisture content of the wood deserves - it must meet standard indicators. If wet material is used (meaning beams), then the anchor nut must be adjusted.

The nut should be tightened once a year for 5 years. This is necessary because in the first few years the wood is subject to intense shrinkage. And as the material dries, the nut must be tightened all the time. After 5 years, this procedure will have to be done less and less often. The Mauerlat is secured with special anchors with a nut and washer. They must have G- or T-shape with thread size M12 or M14.

According to European and international standards, the distance between two adjacent anchors should be no less and no more than 1-1.2 meters. This is especially true for earthquake-prone regions.

Attaching the Mauerlat to gas blocks without and with an armored belt

To complete this task, you need to ensure that the power plate is installed correctly and not securely fastened. There are two fastening technologies used by developers: with or without a reinforced belt.

Method of fastening a structure with an armored belt

When choosing aerated concrete for building walls, you need to understand that the frame of a house made from it will not cope with the weight of the roof placed on it. The construction of a reinforced belt will help her cope with this problem.

Dimensions of the armored belt and its purpose

An armored belt is a reinforced concrete closed structure that envelops the building perimetrically (that is, around the entire building). Tasks put forward to him:

protection against wall deformation;
additional rigidity for aerated concrete buildings;
adjusting the load on all wall surfaces evenly.

An armored belt is a kind of foundation intended for the roof of a building. Its dimensions are selected in accordance with the width of the walls and are approximately 25 cm. The outermost row should be laid out in blocks like English letter U. They will subsequently perform the task of formwork when pouring concrete.

It is extremely important that the Armopoyas is produced in a continuous monolithic structure.

Installation of armored belt

The step-by-step technology for producing armored belts is as follows:

First, formwork should be built around the perimeter of the house.
Next, an armored belt is made from monolithic blocks.
Then the frame is assembled from reinforcing bars.
Studs are installed for fastening.
Now everything needs to be filled with concrete mortar.
When it hardens, the formwork must be removed.

After completing the construction of the armored belt and removing the formwork, it will be possible to begin installing the Mauerlat.

How to properly install and secure the Mauerlat

This element and the rafter system must consist of the same materials.

Before installing the Mauerlat on aerated concrete, you must remember to treat it with antiseptic substances. Then wrap it in a layer of waterproofing material such as: hydroisol, steklomastelastoizol.

The Mauerlat is fixed to the wall structure with studs, iron wire or anchors. If it is made of wood, then it can be secured with special metal brackets.

After this, it will be necessary to fasten the Mauerlat to the rafters. The connection is made by tapping, tapping or sawing down to no more than 25% of the thickness. It is fixed with bolts, self-tapping screws, special angles, and steel plates.

The construction of a reinforced concrete armored belt will be able to prevent unwanted punching in aerated concrete blocks. It will contribute to the uniform distribution of gravity on the house box and the influence of dynamic and static forces pressing on the walls.

Installation technology without armored belt

The SNiP requirements state that installing a Mauerlat on an aerated concrete house without a reinforced belt is in principle unacceptable. This is allowed to be done only in rare cases. This can be explained by the fact that an aerated concrete structure is not able to cope with the thrust snow load, dynamic and wind. The armored belt provides significant protection against deformation. As an exception, the Mauerlat is allowed to be mounted on a building without an armored belt.

This construction option will speed up and reduce the cost of the construction process. But in this case, you should adhere to the following requirements:

for the base, a light but larger beam is selected, having a cross-section of at least 20 cm;
it should be reinforced with steel elements: metal profile, nails or locks;
the climate where construction is carried out is not harsh and snowy or wind loads There are, but of insignificant strength.
The Mauerlat should be positioned in relation to the outer edge in the load-bearing walls at a distance of 0.5 - 1 cm. The Mauerlat is fixed with chemical anchors, steel wire or special pins.

It is very important before installing the Mauerlat on aerated concrete , accurately count the number of fasteners, as well as the distance between two adjacent fasteners.

You need to understand that the service life of the roof directly and largely depends on the strength and correct installation Mauerlat. And for this reason, errors, even seemingly insignificant ones, should not be allowed. This is the only way the roof will not cause deformation of the house, but will serve as reliable protection from external and weather factors. This work should be entrusted to experienced developers and roofers.

Mauerlat is a structural element, an intermediate link between the walls and roof, connecting them together. He takes on a high functional load. If you plan to build a house from aerated blocks, the question of how to secure the Mauerlat in the most practical and reliable way becomes relevant.

The Mauerlat is most often made from the same material as the rafters, - metal (channel, I-beam) or wood (timber). The link is firmly fixed on the walls of the object, the rafters and the entire roof are attached to it, connecting the system into a single whole.

The rafter legs at the points of support transfer the load to the mauerlat, which, transforming and distributing it, transfers it to the walls. However, aerated concrete, as a fragile material, is not able to withstand high point loads and gradually collapses. It is recommended to erect an armored belt, especially in those regions where seismic activity is expected. It is possible to skip this stage only in exceptional cases.

How to choose material?

Work can be carried out using the following materials:

wooden beam 15x15, 10x10, 20x30 cm cross-section, deciduous, antiseptic. The timber is laid evenly around the perimeter of the building, secured at the joints with a straight lock and large nails;
channel - metallic profile with a U-shaped section, with a corrosion-resistant coating. I-beam is a standard profile with an H-shaped section.

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

Calculation of parameters

The construction of the roof begins with laying out the mauerlat, so the master must correctly calculate its dimensions.

Factors taken into account:

length of the perimeter and area of the object;
roof type;
roofing material, rafters;
climate conditions;
presence of an attic.

Type of roof structure:

flat;
classic with 1-4 slopes;
spherical;
cruciform;
tent;
spire-shaped;
folded.

Most often a standard one is built gable roof. Therefore, it is advisable to present a calculation for this type of roof. Initially, you should measure the perimeter of the building and the length of the Mauerlat. The measurement is taken along the top of the beam.

We calculate the volume of the Mauerlat:

V = L*S, where S is the section of the beam, L is the perimeter of the object;
M = R*V, where V is the previously calculated volume, R is the density of the material, M is the mass of the beam.

Working methods

A solution to the problem may be to use the following techniques:

steel wire;
anchors embedded in the wall structure;
chemical anchors;
metal studs.

Chemical anchor for aerated concrete

Liquid dowel, anchor, glued-in anchor, injection mass - all these are compositions with high adhesive properties based on synthetic polymer resin. The base firmly binds the base and the metal rod. Unlike mechanical analogues, chemical anchor does not become a source of expansion stress, which is effective when working in areas near the edge of the structure.

In small houses, the Mauerlat can be tied with an oblique cut and secured with nails, bolts or screws. The corners of the structure are reinforced with plates and brackets. Anchoring is provided to the wall

Anchors, which are considered mechanical, are fixed due to the work of friction forces of the base and an expanding polymer dowel. In chemical - the synthetic mass penetrates deeply into the pores of the material and very firmly connects the aerated concrete and the rod.

Sequencing:

the prepared hole is filled with a chemical composition;
a metal rod is inserted (you can use scraps of reinforcement);
after the mass hardens, the fixation strength is higher than that of the mechanical method.

The service life of such fastenings is more than 50 years. This is a durable element that can be successfully used near the edges of the structure, without the risk of breaking off part of it. However, it is not recommended to carry out welding work with a rod fixed with a chemical composition - the polymer will collapse under the influence of high temperatures and lose its strength characteristics.

Chemical anchors for aerated concrete allow you to carry out work without an armored belt, since in fragile materials it holds much stronger than its mechanical counterparts. Fasteners are almost indispensable when working with aerated concrete. For anchors it is necessary to make more holes, at least 2-3 masonry layers deep.

Using studs when attaching the Mauerlat to aerated concrete without an armored belt

Stud fixation is suitable for light roofs and small houses where no heavy loads are expected. Sometimes the method is implemented in exceptional cases, when it is impossible to erect a reinforced belt and the mauerlat itself, made of timber, implements all the functions of the armored belt. Such a system causes mixed assessments by specialists, but in world practice there was not a single case of the roof losing stability.

For fixing you will need:

dovetail studs SPT 12;
timber 200x300 (actual parameters depend on the thickness of the wall).

Work technology:

the gas block is drilled in increments of 1-1.5 m;
the pin is inserted and sealed with non-shrink mortar or cement laitance;
waterproofing is placed under the timber and on the studs, for which roofing felt is successfully used; it effectively separates aerated concrete from the wood;
a Mauerlat is placed on top of the waterproofing and the washers are tightened with nuts through the threads;
when the beam is mounted at the junction points, it is tightened with forged brackets;
Rafters are installed on top of the system.

Very often the owner already has gables installed, at that moment he wants to implement this stage of work. It is recommended to remove the gables and lay the mauerlat around the perimeter of the wall. Then you should cut (sawing) the rafters to transfer the thrust from the leg to the beam. This connection is considered one of the most reliable.

The Mauerlat is attached to the armored belt using anchors. The Mauerlat is attached to a brick wall in a similar way.

The rafter is twisted to a wall made of 3 mm steel wire. To do this, a steel short is inserted in an area 600 mm below the Mauerlat or they work on floor slabs. When designing a complex roof, it is recommended to construct an armored belt. Identical recommendations are given if it is necessary to attach the Mauerlat to the foam block without an armored belt.

Aerated concrete and fastening the Mauerlat with wire

Work begins at the stage of laying the walls. The wire is embedded into the structure shortly before its construction is completed.

Sequencing:

when laying wall structures, 2-3 rows to the top, steel wire is threaded between the gas blocks, compacted into several layers;
the ends of the wire should extend outward and be placed in the middle under aerated concrete;
the length is chosen so that the ends pass freely through the beam and can be twisted;
the number of elements is selected according to the number of rafters.

Attaching the rafters to the mauerlat

As noted above, the rafters can be fixed using various types cutting Additional elements metal rafter fasteners protrude.

Fasteners that are used for this type of work:

corners;
wire ties;
WB brackets;
plates;
corners of the Kyrgyz Republic;
self-tapping screws;
LK fasteners;
mounting perforated tape TM;
nails;
studs, bolts complete with washers and nuts.

Brackets

The technique does not involve arranging cutting, since there is no weakening of the structure. The brackets are made of steel with a zinc anti-corrosion coating. Fixation is realized using anchor bolts, self-tapping screws, and nails. The use of LK fasteners allows you to connect all elements of the system without the use of anchors.

If wet timber is used for the mauerlat, it will inevitably shrink. Fasteners should be tightened once a year for five years

KR corner and modifications

The fasteners increase the load-bearing characteristics and strengthen the strength of the nodes, eliminating the displacement of the rafters under the influence of high loads. The corner is mounted using nails with special projections or self-tapping screws.

Mounting metal tape

Perforated tape strengthens joints without weakening bearing structures, because it does not violate their integrity. Nails and screws are used for installation.

Fastening the Mauerlat to aerated concrete without an armored belt can ensure a reliable fit, fixation of the roof on the house and uniform distribution of point loads. However, when working with piece materials, such as foam blocks, bricks, gas blocks, it is recommended to build an armored belt, especially if you plan to build a large house with a complex roof.

Fastening the Mauerlat to aerated concrete without an armored belt is shown in the video:

Mauerlat is known as a wooden structure that absorbs forces from the roof and redistributes it to the load-bearing walls. Properly constructed, it is the key to a long service life of the roof.

Aerated concrete and other similar materials are quite fragile in structure, so attaching the Mauerlat directly to aerated concrete is not so easy. In such cases, it is more advisable to install a wooden Mauerlat. How such a structure is attached to an aerated concrete wall is worth careful consideration.

Preparation of aerated concrete walls

This stage precedes the installation of the Mauerlat on aerated concrete. To prevent the walls from pushing through and ensure uniform distribution of dynamic and static loads, laying the Mauerlat on aerated concrete blocks requires the presence of a reinforcing belt laid out along the inner surface of the walls.

Wall preparation is carried out in the following order:
- formwork is constructed along the perimeter of the building, not forgetting about the processing of the gables;
- using u-shaped blocks, they create a reinforced concrete armored belt;
- to increase the rigidity of the fastening, threaded rods (Ø 14) are installed in increments of one meter;
- the blocks are filled with concrete of a “low” composition (grade 200), for which it is necessary to wait at least a week to harden.
The formwork is removed only after the concrete has completely set. Then you can proceed to attaching the murlat.

But what should the Mauerlat be like in such structures, and how should it be attached to the aerated concrete wall?

How to make and secure a Mauerlat on aerated concrete

As a support for the rafter system, it is standard to use either a wooden beam or a log with a square cross-section with a side of 10 or 15 cm. The wood is pre-treated with antiseptics and thus extends its service life, since it prevents its rotting. The timber must be of exceptional quality, it must be free of knots and cracks, and the humidity must comply with SNiP.

Attention!
If the humidity level is higher, that is, for some reason, “raw” wood is used for the wall plate, then the adjusting anchor nut should become a mandatory element of the design, due to which the wall plate is tightened once a year.

Another prerequisite is a waterproofing layer made of bitumen-polymer material, which is used to wrap the timber.

Let us now dwell on how the Mauerlat is attached to walls made of aerated concrete.

Provide reliable fastening perhaps in different ways, since you can attach the Mauerlat to aerated concrete different ways, based on the design features and financial capabilities of the developer.

Mechanical method

This technology involves the use of T- and L-shaped anchors with standard M12 or 14 threads. Special dowels are also required, which are a cylinder equipped with a special harpoon.

In seismically hazardous areas, fastening is carried out in increments of about one meter.
- install dowels into pre-drilled holes;
- screw in the fastening element;
- firmly press the harpoon teeth into the cellular blocks. In this way, taking into account the expansion of the surface, reliable fixation of the anchors is achieved.
This technology is considered the most reliable, however, wedge anchors and special dowels significantly increase the cost of fixing the murlat. That's why mechanical method considered to be quite expensive.

Chemical method

This is a less expensive technology, which nevertheless provides high-quality and reliable fasteners. The method is based on the use chemical substance, tucked into a capsule. An adhesive composition made of polymer resin, penetrating through the pores of aerated concrete, binds the metal rod to the base and reliably fixes the murlat. The chemical method also provides additional heat and waterproofing.

On a note
By the way, if you are wondering whether it is possible and also how to fasten the Mauerlat to aerated concrete without an armored belt, then a chemical anchor will solve this problem.

Mechanical fastening creates a bursting force, which is extremely undesirable for areas along the edges of the structure. A chemical anchor does not create such problems. It works on the following principle: a metal rod, say, a piece of reinforcement, is inserted into a pre-drilled hole filled with a chemical composition. In this case, the rod and the base are connected more firmly than in the case of using mechanical fastening. Note that the holes for chemical anchors should be larger and go deep into at least two or three layers of masonry.

Such an anchor is chemically resistant and can last about half a century. It can be used painlessly around the edges of structures or on damp substrates, even if they are located under water.

Attention!
If the rod is connected chemically, then welding work with it is extremely undesirable. The fact is that the polymer resin under conditions high temperature is destroyed, and this negatively affects the strength of the connection.

A chemical anchor provides a much stronger connection than a mechanical one, so attaching the Mauerlat to aerated concrete without an armored belt (video below) is justified.
Nevertheless, it is recommended to resort to this method only in cases where the installation of an armored belt is practically impossible. In any case, you need to accept that fixing the Mauerlat to the armored belt is much more reliable. Moreover, the latter performs more than one important function for buildings made of aerated concrete:
- during shrinkage, especially if it is uneven, seasonal soil movements, thanks to the armored belt, the walls are not deformed and the geometry of the structure is not disturbed;
- a reinforced belt levels it horizontally, smoothing out possible masonry errors;
- provides additional rigidity to the structure;
- thanks to the armored belt, the point forces exerted by the rafters are evenly distributed over all walls of the structure;
- as you know, rafters exert significant pushing forces on the walls of a building, which can increase depending on the weight of the roof, including loads from snow and ice;
- the reinforced belt is strong enough to hold structures attached to it firmly and securely. And this is quite easy to do.
In conclusion, watch the video, which clearly shows the process of attaching the support beam to the armored belt.

When it comes to arranging the roof, methods of how to secure the Mauerlat to aerated concrete without an armored belt begin to interest many future homeowners who have chosen aerated silicate blocks for the walls. A reinforced layer between the roof and the main part of the house is certainly necessary. But it is quite expensive, and it takes a lot of time and effort, since the matter is quite labor-intensive. And if there is a workaround that allows you to do without her equipment, why not use it? You just need to know what to do first.

How to fasten the Mauerlat to aerated concrete without an armored belt, and whether to decide to take this step can only be done by knowing exactly what you are risking and how safe your home will be as a result. And for this you need to analyze some characteristics and recommendations. Therefore, in order not to be unfounded, let’s first understand the terms and purpose of individual elements of the structure.

What is a Mauerlat

Quite far from roofing works people can very vaguely imagine what the roof over their heads consists of. The mysterious term “mauerlat” means nothing to almost anyone except professional roofers. Meanwhile, it is a kind of girdle laid along the entire outer perimeter of the house and located between the erected walls and roof. Its installation has 2 main goals:

point load distribution, which is exerted by the bases of the rafters along all the walls of the house. Without such distribution, the weight of the roofing system, falling on individual areas, will quickly lead to subsidence of loaded areas, cracks in thickness load-bearing wall, skewed roof, and in the future - its possible collapse or collapse of the house itself;
rafter fastening(and with them the entire roof structure) with the rest of the building. Without such fixation, the structure will consist, as it were, of two separate parts, without forming a single whole. As you understand, neither reliability nor protection from external weather conditions, in this case there can be no discussion.

Traditionally, the Mauerlat is made of wood, most often from dried timber (and hardwood) with a cross-section of 10x10 or 15x15 centimeters. Options for using steel beams or channels are acceptable, but in individual construction they are extremely rare: firstly, the load on the walls and foundation greatly increases, since these elements themselves are quite heavy. Secondly, the rafter system will also have to be made of metal, which, again, loads the entire structure, and its cost goes beyond any reasonable price limits.

Why do you still need a reinforced belt?

With all the advantages of some building materials, both modern and long-known, they are certainly accompanied by some shortcomings. The main disadvantage of gas silicate, foam concrete, aerated concrete, shell rock, and expanded clay concrete is fragility and softness.

If you fix the Mauerlat directly into them, they quickly begin to collapse in the places of fixation. However, even when using durable building materials like cinder block or brick, you should not give up the armored belt. Especially for those whose house is being built in seismically active zones. The reasons why you should agree to his equipment (albeit through gritting your teeth) can be mentioned as follows:

shrinkage is characteristic not only of wooden frames, but also of other buildings. It is especially typical for cellular concrete, and often flows unevenly along the walls. Its passage takes place without consequences for the geometry of the structure precisely due to the presence of a reinforcing belt. It also prevents deformation during seasonal soil movements;
the armored belt increases rib rigidity and its strength throughout the entire frame of the house;
if anyone doesn’t know, the rafters exert bursting pressure on the walls. It is especially great in winter, when an additional mass of snow and freezing of ice in the form of icicles are added to the weight of the roof (and these precipitations can significantly increase the weight of the structure). The reinforcing belt helps the walls resist expansion more successfully.
And all these arguments are complemented by the possibility of more securely and simply fastening roofing structures to the walls.

Most often, a reinforcing belt is made by pouring concrete into a pre-constructed formwork. The second option is to lay it out from blocks of different origins. However, it is considered less reliable.

How to do without an armored belt?

If it is absolutely not possible to arrange such a useful gasket, builders can only suggest 2 ways in which this step can be ignored.

Steel wire woven in when laying out the walls largely replaces the reinforcing belt. Rows 3-4 to the top of the wall along the entire perimeter between aerated concrete blocks a wire piece is embedded. It must be fastened starting from the middle, and the length is calculated so that it is enough to attract the mauerlat beam to the top of the wall. To fix the Mauerlat element, a hole is made in the beam. The number of ligaments is not limited, but in most cases corresponds to the number of rafter legs.

Chemical anchor, also called glued, liquid, and also injection mass, is recognized as more durable. In a rough description, it consists of 2 parts: a metal rod and a synthetic-polymer adhesive mass. Its main difference from its mechanical counterpart is the absence of bursting stress created by the hardware itself. A conventional anchor is held in the material being fastened solely due to friction and expansion, while a chemical anchor penetrates the pores of aerated concrete, tightly fastening it to the hardware.

Roughly speaking, even a piece of reinforcement can be used as a rod. The main thing for the success of your undertakings is to drill enough for the anchor deep hole, layers in 2-3 masonry. There is no obstacle to using chemical anchors high humidity- At least carry out work under water. The service life of such fasteners is determined by the manufacturer to be half a century.

The only limitation, if you decide to prefer this method of fixing the Mauerlat to aerated concrete without an armored belt, you cannot weld anything to chemical anchors. Welding a rod with any other object leads to the destruction of the resins that make up the mass, after which it is in vain to expect any strength from the fastener.