What is a Mauerlat, its size, cross-section and methods of fastening. How to attach the Mauerlat to the walls. Is it possible to attach the Mauerlat with wire?

The roof is one of the most important architectural structures of any building; the duration of operation and comfort of living depend on its reliability. Only experienced builders should design and assemble a rafter system; any mistake can have very dire consequences.

It is much easier to make the right decision about the optimal methods for attaching the Mauerlat if you have information about the role of the element in the rafter system. Mauerlat is a lower strapping belt, present only on sloping roofs.

Mauerlat is an element of the roofing system of a building. It is a beam or log laid on top along the perimeter of the outer wall. Serves as the extreme lower support for the rafters

Made from timber with a cross-section of approximately 200×200 mm, the element performs important tasks in the rafter system.

1. Serves as a platform for fixing rafter legs or trusses. During the calculation of the rafter system, the loads on the rafter legs are determined, the specific values ​​change taking into account the maximum dynamic and static loads, the design features of the roof and the physical parameters of the roofing materials. The legs rest against the power plate and transmit vertical and horizontal forces to it. He must withstand them and not allow fluctuations. Taking into account these loads, the cross-section of the beam is selected.

   

   The Mauerlat is necessary to distribute the concentrated load transmitted by the support points of the rafters over the entire area of ​​the upper part of the wall

2. Gives stability to the rafter system. The lower stop points of the trusses must be rigidly connected to the Mauerlat and prevent them from moving during operation. An exception is the rafter system of a cobblestone house. It shrinks, and therefore the connection of the rafters with the mauerlat is floating, allowing you to compensate for changes in the height of the log house during its drying.

   

3. Evenly distributes loads along the entire perimeter of the facade walls. The larger the support area of ​​the Mauerlat, the smaller the point loads on the walls, the safer the structure of the structure.

   

Prices for various types of timber

General requirements for mounting the Mauerlat

The main requirement is that the physical parameters of the element should not deteriorate throughout the entire period of operation of the house. To achieve this goal, a set of special construction measures is used.

1. Selection of beam sizes for the Mauerlat with a margin of safety. This makes it possible to ensure design stability regardless of the presence of various hidden wood defects.

   

2. Protection from rotting processes. Achieved in two ways. The first is antiseptic impregnation. Modern two-component compositions not only prevent wood from being damaged by pests and rot, but also protect it from open fire.

   

   The second is that reliable waterproofing is provided between the wooden beams of the Mauerlat and brick or concrete walls. As a rule, roofing felt or modern non-woven waterproofing materials are used for these purposes.

   

3. Choosing the optimal method of fixation to facade walls. There are quite a few options here. The roofer chooses a specific one, taking into account the characteristics of the building.

   

It is desirable that methods for attaching the Mauerlat be provided at the design stage of the house; this greatly simplifies the process of constructing the rafter system. In addition, some methods of fixing an element are possible only at the stage of laying facade walls.

Methods for attaching the Mauerlat

The table will show the widest possible list of possible options, some of which are currently rarely used. New building materials and technologies make it possible to attach the Mauerlat easier, faster and more reliably.

Mounting method	Brief description, advantages and disadvantages
	The oldest method, today it is used extremely rarely. Fixation is done with wire rod Ø 5–6 mm. The wire is embedded in the facade walls; it must be laid at least three rows before the end of the masonry. The length of the wire is chosen such that its free ends can be twisted around the Mauerlat. After fastening, the excess ends can be cut off. The method has many disadvantages: it is impossible to accurately adjust the tightening force, the wire damages the beam, the reliability of the fastening decreases over time due to the gradual stretching of the metal. For reliability, wire was embedded near each rafter leg, and this had a negative impact on the appearance of the facade. Even if the houses were subsequently plastered, rust from the wire could appear on the outer surface of the walls.
	And this method today is considered outdated and is used very rarely. The Mauerlat was attached with forged metal brackets to wooden inserts that were embedded in the wall of the house. The bars were impregnated with waste machine oil to prevent rotting; the size of the plugs corresponded to the size of the bricks. This method has two big drawbacks. First, the tree can get wet or dry out over time, these processes change the linear dimensions. As a result, the plugs begin to wobble, and their vibrations are inevitably transmitted to the Mauerlat. The second drawback is that the method is quite labor-intensive and requires increased care from the mason.
	Fixation with studs is much more reliable than the methods described above. The studs are embedded in the walls, the number of rows of brickwork on top is at least three. Thread sizes are selected taking into account the parameters of the Mauerlat. This method provides the most reliable fixation of the element; it can be used on very complex and loaded roofs. The disadvantage is that it is labor intensive; vertical metal pins complicate the bricklaying technology.
	All characteristics satisfy most buildings and types of roofs. The industry produces special long anchors of large diameter with reinforced metal fixation elements in the wall. After installing the Mauerlat in place, recesses for anchors are drilled in it and the wall. The elements are driven into the holes and the nuts are used to tighten the Mauerlat to the wall. The only drawback is that this method can only be used on solid brick. The hollow one is not suitable due to the low anchor fixation strength - the voids do not allow the required stability to be achieved. In these cases, you need to use special chemical anchors, we will talk about them a little below.

For example we will take option for attaching the Mauerlat to studs.

Step-by-step instructions for attaching to studs

Before laying, you should prepare the studs. To increase the reliability of fastening, it is recommended to weld a base made of a metal plate at the bottom of the stud. It can be made square, the side length is approximately 6–8 cm. If it is not possible to weld, then you can simply bend the end at a right angle. The length of the stud should take into account the height of the brick belt, the thickness of the mauerlat and the size of the nut. In our case, the armored belt will consist of four rows of bricks. The diameter of the pin is 10 mm.

Step 1. Mark the location of the studs. It is necessary to follow general recommendations: the distance of the stud from the corner of the house is within 35–40 cm, the pitch of the studs is ≈ 1.5 m.

One of the elements that no roof can do without is the Mauerlat. Its functions are so important that the strength of the entire roof structure may depend on the quality of its manufacture, as well as the method of fastening. How can you attach the Mauerlat to the armored belt with anchors? This, as well as its purpose and design features, will be discussed in the article.

Why do you need a Mauerlat?

Installation of the rafter system is not possible on a bare wall. This is due to the fact that the building block is not designed for such a load. In order for it to withstand it, it will need some kind of gasket. The Mauerlat plays its role. It allows you to distribute the load evenly over the entire plane of the wall. That is why it is important to know the features of its design and plan everything well before installation. An excellent option is not just to install the Mauerlat on a bare wall, but to mount it on a reinforced belt. The latter further strengthens the plane and extends the service life of the Mauerlat.

It is worth understanding that the building is constantly experiencing vertical and thrust forces. The first load is explained by the large weight of the roof, which presses on the walls. This weight can be increased by the snow layer, as well as wind loads. This pressure creates a thrust force. It means that the walls are constantly trying to move apart in opposite directions. This force also increases with increasing roof pressure. If such a load affects modern types of aerated concrete or foam concrete blocks, they will simply crumble under the rafters. This also applies to cinder blocks, monolithic walls made of expanded clay concrete and others. For such products, a reinforced belt is not a wish, but a necessity.

Note! There are times when it is impossible to install an armored belt. In this case, they resort to the use of special chemical anchors.

Brick walls are more resistant than the materials listed above. If the building is built on one floor, then the use of a reinforcing belt may not be necessary. You can attach the Mauerlat to the walls with anchors. In some cases, the embedded fastening method is used. In this case, studs are used that were previously laid in the seams of the wall. But it is worth understanding that if the construction of a house is carried out in an area where seismic activity is possible, then the installation of an armored belt will also be required on brick walls.

The main functions of the reinforcing belt under the Mauerlat include:

• protection against wall deformation;
• alignment of the upper end of the walls;
• additional rigidity;
• uniform load distribution;
• possibility of attaching other elements.

In addition to the fact that the walls are loaded under the pressure of the roof, they can be deformed during the shrinkage of the building. It does not always occur evenly, so cracks can be seen in some buildings. The armored belt allows you to maintain the correct geometry of the building. It is not always possible to achieve their ideal horizontal level when pushing out walls. The Mauerlat cannot be laid on an uneven surface. The armored belt makes it possible to level the end without loss. Thanks to the reinforced belt, the walls receive additional rigidity; in addition, the design of the reinforced belt is quite strong so that various fasteners can be fixed in it. This is exactly what is required for the Mauerlat.

Characteristics of the armored belt

The strength of the armored belt under the Mauerlat directly depends on what its design will be. Each building has its own dimensions, but there are general rules that should be followed. Among them are:

• correct height;
• width corresponding to the size of the wall;
• the length should not be shorter than the walls.

The size of 20 cm is taken as the basis for the height. In some, it is allowed to build an armored belt under the Mauerlat with a height of 15 cm. But it is better to make it larger, not smaller. Also, the height of the armored belt under the Mauerlat should not exceed the width of the wall. The width of the armored belt must correspond to the width of the wall. The minimum cross-section of the armored belt under the Mauerlat should be 25x25 cm.

The armored belt must be monolithic. To achieve this, it must be poured in a short time so that the concrete does not set in parts. The armored belt received this name due to the fact that a metal base is laid inside the structure. The latter is a lattice that is assembled from reinforcement with a diameter of 10 millimeters or more. In this case, the grate should not be flat, but three-dimensional in order to evenly distribute the force.

Installation of armored belt

Installation of the armored belt under the Mauerlat begins with the installation of formwork under it. The latter can be used as an edged board or laminated moisture-resistant plywood. Shields are knocked down from edged boards to a height that will correspond to the height of the future armored belt. The bars that will be used to secure the boards must protrude beyond its edges by a size equal to the height of the shield. With the help of these bars, the shields are attached to the walls. Fastening is carried out both from the inside and from the outside. A trench should form into which concrete can be poured.

You should be careful that there is no gap between the shield and the wall, since the solution will definitely go into this gap. It is also too early to pour the ready-made solution, as it will destroy the formwork. It requires additional strengthening. It can be made with wooden spacers that are nailed to the upper end. You can also strengthen the formwork for the armored belt under the Mauerlat with studs. To make it easier to dismantle the formwork, the studs are placed in metal tubes, which should be slightly larger in diameter than the studs. After this, washers with a large diameter are put on the stud and clamped with nuts.

The next step is laying the reinforcing base. If the walls are made of a material that quickly absorbs moisture, then before pouring it on the wall it is better to lay waterproofing material in the form of roofing material or cover the surface with bitumen mastic. Next, concrete is poured. To fill all the voids, you will need a deep vibrator. It will bring all the air bubbles to the surface.

Mounting the Mauerlat

An anchor bolt is a common fastener. It is used in various installation works. It is a threaded rod, which is placed in a kind of tubular body. At the lower end of the pin there is a small seal, which will subsequently increase the diameter of the tube and fix it in the hole. There is a nut on top, which lifts the rod by squeezing. Before laying the Mauerlat, you will need to waterproof the armored belt. This is done due to the fact that moisture can rise through the pores of the concrete, which will lead to rotting of the Mauerlat and destruction of the roof structure. Waterproofing is carried out with bitumen mastic, roofing felt or similar material.

A timber is laid around the perimeter of the walls, which will be used for the Mauerlat. It is fixed in the corners using a tenon method or another method. It must be placed closer to the outer part of the wall. When the Mauerlat is in place, it is necessary to drill holes in it, the diameter of which will match the diameter of the anchors. Additionally, the upper part of the hole in the mauerlat is widened so that the anchor head can be flush. The distance between holes should not exceed one meter.

Note! Some craftsmen prefer to attach the Mauerlat to the armored belt using pins. To do this, when pouring the armored belt, studs are inserted into the concrete. They must be located in the same plane. After this, holes are drilled in the Mauerlat through which the pins are passed.

Mandatory holes are corner ones, which will additionally secure the logs together and secure the entire structure of the Mauerlat to the walls. After the holes in the mauerlat are ready, you need to drill holes in the brickwork. The length of the anchors must be at least 50 cm, and the diameter must be M12 or M14. The holes for them must be appropriate. When everything is ready, the anchors are inserted into the holes and tightened with a wrench until they are completely secured. You can clearly see the installation process of the Mauerlat in the video below.

Note! If the armored belt is missing, then it is attached to a chemical anchor. The process of drilling holes is the same as described above. The prepared holes in the blocks are filled with a special chemical composition and a pin of the required diameter is inserted. The composition hardens and firmly fixes the stud, after which you can fasten the Mauerlat with a washer and nut.

Summary

As you can see, the Mauerlat itself and the process of attaching it are very important. Therefore, they should be approached with the utmost seriousness. In addition, since the work takes place at height, it is important to adhere to all safety rules in order to avoid serious injuries.

When building a house, one of the most critical cycles of work is the installation of the roof. It is important to control thermal insulation, waterproofing and reliable fastening of all structures. It is important to securely fix the mauerlat beam, which can be attached to a brick wall in several ways.

Why do you need a Mauerlat?

A beam with a cross section of 100x100 or 150x150 mm is suitable as this element. It is designed to perform the following functions:

• securing rafter legs;
• ensuring the rafters work together;
• uniform distribution of load from individual elements on the wall.

You can avoid installing a Mauerlat only if you provide a support pad under each inclined beam of the slope, but such installation is too labor-intensive.

Preparatory stage

Position of the Mauerlat in the roof

Before attaching the Mauerlat to a brick wall, you need to prepare. The first stage of preparation is carried out when laying walls. There are two options for finishing the brickwork:

1. The masonry of the external walls of the house ends at one level. This results in a horizontal edge of the wall. The Mauerlat is laid on the inside. After completion of the work, the outer edge is filled with expanded clay concrete or insulated with heat-insulating material.
2. The laying of the external walls ends with a ledge. The outer part is made higher than the inner one. This creates additional resistance to thrust and ensures thermal insulation of the structure. This option is preferable when building a private house.

Scheme of two options for securing walls with Mauerlats

After completing the masonry of the walls, it is necessary to provide a waterproofing layer between materials with different characteristics: brick and wood. To do this, the timber is laid on a previously prepared waterproofing layer. The following materials can be used:

• roofing felt (outdated and ineffective, but cheap material that is not currently used in mass construction);
• roofing felt;
• hydroisol;
• linochrome

The materials are a base impregnated with a bitumen composition.

Mounting methods

The beam on the wall of the house can be fixed in different ways. It all depends on the load and the availability of tools and materials.

Brick walls have a fairly high strength and are able to withstand the load from the roof even without installing a monolithic belt.

Installation can be done in the following ways:

• wire;
• using wooden plugs;
• on construction studs;
• on the anchor.

Fastening to wire

Scheme for attaching the Mauerlat to the wire

In this case, it is easy to attach the timber to the wall of the house. This option is suitable for small buildings. Before starting work, prepare wire with a diameter of 5-6 mm (“rod rod”). It is laid in brickwork at a distance of 3-5 rows to the edge. The length is selected so that it is enough to release from the wall and thread through the Mauerlat.

Next, they wait for time for the cement-sand masonry mortar to harden and begin to secure the mauerlat. The wire is twisted with a crowbar. Holes are drilled in the timber through which the “wire rod” is threaded. Next, tighten the fastener until the beam is securely attached to the wall of the house. For reliability, the pitch of the wire fastenings is taken equal to the pitch of the rafter legs.

Attaching to wooden plugs

For work, it is necessary to prepare wooden blocks equal in size to bricks. The material is treated with antiseptic compounds that prevent rotting and mold formation. The work is performed in the following sequence:

Scheme for attaching the Mauerlat to wooden plugs

1. When laying walls, plugs are used instead of some bricks. It is important to remember that they, like the Mauerlat, require waterproofing. In places of contact with brick, coating with bitumen or laying rolled materials is carried out. The spacing is taken equal to the pitch of the rafters.
2. The Mauerlat is secured to the plugs using metal brackets.

There are three options for the arrangement of wooden plugs:

• 1 row before the cut, closer to the inner edge of the wall;
• directly under the Mauerlat (larger area plugs are required);
• behind the Mauerlat, closer to the outer edge of the wall.

The last option for fastening the timber is suitable if the method of fastening was determined after the completion of the masonry of the walls of the house.

Stud mount

This option is suitable if you need to secure the timber under fairly large loads. There are two options for attaching studs to the wall:

• directly into the masonry;
• into a monolithic reinforced concrete belt.

Scheme for attaching a mauerlat beam to a brick wall with studs

The second option is more labor-intensive, but allows you to further strengthen and connect the brick walls into a single whole. Suitable if the load from the rafter system is very large. In most cases, the first method is sufficient. The work is performed in the following order:

1. Prepare L-shaped studs. The diameter is taken depending on the load. The most common cross-section for roofing is 10-14 mm.
2. Fasteners are laid in the masonry. The length of the recess is approximately 450 mm, the bent end faces down and hooks onto the brick course.
3. Lay waterproofing. To do this, it is pierced and put on stilettos.
4. Perform markings for holes on the beam. The Mauerlat is laid on studs and tapped with a hammer at their locations. Using the resulting marks, drill holes for the studs.
5. Mounting timber. Nuts are screwed onto the studs.

The option of placing studs in a concrete belt is similar to installation on anchor bolts, and therefore is not considered separately.

Anchor mounting

Suitable for heavy load knowledge. The presence of a concrete belt increases the labor intensity and cost of the work. The work is performed in the following order:

Scheme of fastening the Mauerlat to the anchor

• installation of formwork under the belt;
• laying the reinforcement frame;
• installation of anchor bolts (section 10-14 mm);
• filling the belt at one time;
• waiting for the time for concrete to gain strength (depending on temperature conditions and the binder on which the concrete is made, but on average it is 28 days);
• removal of formwork (if necessary);
• laying a waterproofing layer;
• marking holes on the timber and drilling them;
• securing the Mauerlat, screwing the washers.

It is important to note that according to regulatory documents, it is allowed to begin stripping work once the concrete reaches 70% of its brand strength (50% under special conditions).

The disadvantages of this method include:

• high labor intensity;
• increased cost;
• increase in construction time due to concrete hardening.

Splicing the Mauerlat along the length

Most often, wooden beams are 6 m long. If the walls of the house are longer, then the mauerlat will need to be increased in length. There are several connection options:

• ends, secured to metal plates (unreliable);
• “tooth” (beams are cut halfway in height, connected with an overlap and secured with bolts or studs).

The second option is more reliable and desirable.

Proper fastening of the Mauerlat will ensure high reliability of the structure. If mistakes are made, and there are hurricane winds in the construction area, the roof can simply be torn off the wall, so this stage of work must be taken very seriously.

The Mauerlat is laid directly under the rafters, or over the entire surface of the wall. The second option is more effective, as it ensures rigidity and reliability of the structure. Short about the advantages of using a Mauerlat:

1. Efficiency - the roof fastening will be more reliable and durable.
2. Load distribution on the walls of the house.
3. Low consumption of materials, correspondingly low costs.

Before considering the mounting methods and operating instructions for each of them, you should choose the shape and type of structure.

For small houses built with brickwork or other lightweight materials, the best option would be to use a continuous mauerlat structure along the entire perimeter of the building. More massive masonry requires laying the mauerlat flush with the inside of the wall. For buildings of this type, wooden beams are used, which are fastened together with a direct lock.

For larger homes, with an area of ​​200 sq.m., fastening with concrete pads is used. Fastening methods will be discussed below.

Also, before securing the Mauerlat should be considered and the material from which the wall is built. The following methods of fastening the Mauerlat are suitable both for walls made of silicate block or foam block.

Methods for attaching the Mauerlat to the wall

Attaching a wooden beam to the wall happens in three ways:

1. Fastening with steel wire.
2. Fastening with anchors.
3. Fastening with studs.

Let's consider each fastening method separately.

Fastening with steel wire

How to attach a power plate to a wall using steel wire? This fastening method is quite simple: steel wire 4-6 mm wide, twisted several times, is laid in the brickwork, at a distance of 5-6 rows from the level of the mauerlat. After the brickwork has become stronger, the wire is threaded through wooden beams and its ends are twisted, pressing the mauerlat to the wall. The wire should be long enough to go completely through the beam, or wrap around it, and also to have ends left for reinforcement.

Fastening with construction pins

How to secure the Mauerlat using construction pins. In a situation with small houses, when a strong impact on the roof surface is not expected, the Mauerlat is attached to the wall special construction pins. Such studs are L-shaped and are embedded in the brickwork. The optimal immersion depth of the stud is 450 mm, and the minimum height of the protrusion above the Mauerlat is 30 mm.

When using construction studs, you can strengthen the fastening using a concrete support pad. The length of the pillow should not exceed 400 mm and the height – 220 mm. When pouring concrete, it is important to ensure that the threads of the studs do not become dirty and do not make it difficult to screw on the nuts.

For precise marking Mauerlat, you need to put it on the tip of the pins and hit it with a massive object, preferably with a special hammer. Marks will appear at the impact site, the marked areas can then be drilled with a feather drill.

Also, it is necessary to take into account waterproofing layer, which must be placed on the wall. You can secure it by pinning it with pins.

We offer you to watch a video about the installation (installation) of the Mauerlat.

Fastening the Mauerlat with anchor bolts

In this way, the Mauerlat is attached directly to the armored belt. This is one of the most reliable and durable fastenings. Anchors for fastening the Mauerlat are fixed in the armored belt while it is being poured. Holes are pre-drilled in the Mauerlat for its subsequent attachment to the anchor.

It should be noted that it is almost impossible to lay perfectly even bolts. Therefore, to mark the holes, you should select a flat board, place it on the bolts and mark. Then the board should be applied to the bottom edge of the Mauerlat, and holes should be drilled in it corresponding to the markings on the board.

The finished Mauerlat is carefully placed on the bolts. Then a washer is screwed onto them or a piece of reinforcement is welded.

Main disadvantage fastening with anchor bolts - their high price. Therefore, to reduce costs, you can use the following method: using a drill, drill through the Mauerlat and to a depth of 200 mm, enter the armored belt. Take the scraps of reinforcement and hammer them into the reinforced belt with a sledgehammer, so that the scrap goes in to its full depth. To strengthen it, you can bend the ends of the reinforcement with the same sledgehammer.

Comparing the methods of fastening the Mauerlat, we can list main indicators for choosing the appropriate method:

1. Availability, low price of materials.
2. Reliability and durability of fastening.

Main– choose the optimal method suitable for a particular situation.

Do-it-yourself Mauerlat installation

Sequence of action for attaching the Mauerlat depends on the mounting method you choose. Here are a few steps required for all methods of attaching the Mauerlat to the wall:

1. Before installing the timber, it would be a good idea to clean the wall surface from dirt and unnecessary objects.
2. To avoid rotting of the wood, place a special waterproofing material between the timber and the wall surface, for example rubyroid, polyethylene or some other material with waterproofing properties.

If you use construction pins or anchors to attach the Mauerlat, you must perform the following steps:

1. Prepare holes for the nozzle.
2. To prepare the holes, it is necessary to use a flat board to mark the places for drilling, since it will not be possible to align the fasteners perfectly level.
3. Next, as described above in this article, you should attach the board to the Mauerlat and drill holes in it.
4. Then you should carefully place the beam on the bolts.
5. The last step is to strengthen the Mauerlat fastening using washers and nuts.

If using wire everything is much simpler:

1. Two holes should be drilled in the Mauerlat at a distance of 250 - 300 mm.
2. The ends of the wire, which must be previously fixed in the wall, are threaded through the holes and twisted together as tightly as possible.

By following these simple tips, you can easily strengthen the Mauerlat with your own hands.

Price

For installation companies, the cost of installing the Mauerlat depends on the height of the mark for the work, the type of material from which the Mauerlat is made, the base for installing the Mauerlat and many other factors. Average price for installing a Mauerlat one linear meter - from 450 to 800 rubles.

The cost of 1 m3 of wooden beams starts from 5,000 rubles. The price of timber depends on the type of wood from which it is made, as well as on its area.

That's all. In conclusion, I would also like to note that in order for the roof to perform its functions well, all requirements for attaching the Mauerlat must be carefully followed, and even better - contact specialists.

An integral part of the technology for constructing pitched roofs is the installation of a Mauerlat. Today we will look at why a Mauerlat is needed, what it is and how to install it correctly.

What is a Mauerlat

Mauerlat is a long beam fixed along the upper edge of the wall. The main tasks for which this element is needed:

• redistribution of the point load transmitted from the rafters and floor beams along the entire length of the wall;
• tying the roof to the walls of the building.

For multi-pitched roofs, it may look like a closed perimeter; for a gable roof, a beam laid along each slope is sufficient. This difference is due to the fact that the rafter frame of a gable roof rests on only two walls.

This roofing element is made from the same material as the rafters, so the most common type is a wooden Mauerlat (and it must be treated with an antiseptic). For roofs with a metal frame, channel bars, I-beams and other types of rolled products are used.

Types and size of Mauerlat

The cross-section of the Mauerlat depends on the expected loads - most often it is timber with dimensions of 100x150, 150x150 and 150x200 mm. The rectangular shape of the beam gives it stability, but a log will also work if you cut it flat on one side.

Instead of timber for the Mauerlat, you can take several boards 150 mm wide and 50 mm thick and connect them together. This method is convenient because it is easier to build up boards if you need to extend them, and it is easier to carry and lift to a height. Usually they take two or three boards, but sometimes builders make do with one.

This option is applicable only for light and small roofs. With significant wind and snow loads on the roof, such a thickness of the Mauerlat will be clearly insufficient.

In wooden houses, the top row of logs or beams serves as the mauerlat, so the cross-section corresponds to the parameters of the material from which the walls of the building are constructed.

Attaching the Mauerlat to aerated concrete

The main methods of attaching a Mauerlat to aerated concrete are the use of embedded pins and anchor bolts. In addition, you can attach the Mauerlat to aerated concrete using perforated anchor plates, concrete screws and binding wire.

Important! Before attaching the Mauerlat, it is necessary to install an armored belt on top of the wall - its absence can lead to the destruction of the walls of the building.

Armored belt device

Armopoyas is a monolithic reinforced concrete belt, poured to increase the strength of the upper part of the wall when absorbing horizontal thrust loads from the roof, which are especially strong in the winter season. Thus, the main thing for which an armored belt (also called a seismic belt) is needed is to protect block masonry from cracks.

Installation of the armored belt begins with the installation of formwork. There are three options:

Then, a frame of steel or fiberglass reinforcement with a diameter of 8–12 mm is tied directly into the formwork. A cell is cut out of the masonry mesh or a frame is made from a rod, and reinforcement is attached to it with knitting wire at the corners.

After installing the formwork and frame, the armored belt is poured, and if necessary, studs are installed (if the Mauerlat is planned to be fastened in this way). Recommended composition of concrete mortar when doing the work yourself:

• cement - 1 bucket;
• sand - 3 buckets;
• crushed stone - 4 buckets;
• water – 8–10 liters;
• liquid soap – 30 grams.

The first method is to install studs

To secure the Mauerlat to aerated concrete, you will need studs with a diameter of M10 or more, preferably M12–M16. The length of the studs is chosen in such a way that after installing the armored belt, there is still the necessary margin for installing the Mauerlat and screwing on the nut. You should be careful in your calculations, since after filling the armored belt it will no longer be possible to correct the mistake made. Usually a meter-long hairpin is taken and cut in half.

The cut part of the stud is immersed in the solution, and the flat end is left for the nut - then when screwing it on, you won’t have to clean off the burrs.

The studs are installed at equal distances in increments of approximately 0.6–1 m in the spaces between the rafter legs, aligned along the same line, as well as vertically, so that the beam sits easily after drilling holes in it.

The embedded pin can be installed both before laying the mortar and at the concreting stage:

To prevent the pin from being pulled out of the armored belt, it is stopped. The most common methods:

• a plate (heel) at the end, which is also a support, the approximate size of the heel is 100x100 mm;
• bending the end of the pin at an angle of 90 degrees;
• screwed nut with washer;
• welded piece of reinforcement.

The following video demonstrates the technique of laying studs (for both a brick wall and aerated concrete):

After the armored belt has hardened, the mauerlat is placed on the studs and tapped on top with a mallet - due to which marks will remain on it along which holes can be drilled (necessarily strictly perpendicular to the plane of the beam). Then the Mauerlat is placed on the studs, the washers and nuts are put on and tightened, the remaining excess part of the stud is cut off, leaving a small tip above the nut.

The upper part of the studs while pouring the concrete (and until the Mauerlat is secured) must be wrapped with stretch film or tape to protect it from the solution, so as not to have problems later with seating the beam and tightening the nuts.

The second method is to attach the Mauerlat to an anchor

When anchoring, it is necessary to correctly install the Mauerlat on the reinforced belt, mark and drill holes in the beam with further penetration into the concrete.

The anchor is driven into the hole and tightened. To increase the anchor support area, a washer is used.

Fastening the Mauerlat to aerated concrete with anchors is used less often than with studs.

While the reliability of fastening using each of these methods can be debated, the cost of the studs will be much cheaper. The method of fastening with anchors will be a good way out of the situation if, when arranging the armored belt, the studs were not laid or they were installed incorrectly, and also if it was decided to make a mauerlat from several boards.

This method is covered in great detail in the video below:

Attaching the Mauerlat to a brick wall

Fastening the Mauerlat to a brick wall can be done using the same methods as described above for aerated concrete, or using:

• wires;
• staples to wooden plugs.

Using wire

When installing masonry, a steel wire is laid under one of the bricks at a distance of several rows from the upper edge of the wall (usually 3-4 rows), the ends of which are brought out and in. The wire is taken thick enough, and the length should be such that it is enough to tie the Mauerlat. It is recommended to make the number of such wire inserts equal to the number of rafter legs.

For fastening, the ends of the wire are twisted on top of the Mauerlat, pulling it to the wall. To make a strong connection, the wire must be tightened using a pry bar or crowbar. Otherwise, it may turn out like the would-be builders in the video below:

Using staples

The wooden plug is made from a block, which is laid in the brickwork several rows below from its upper edge, with the end facing outward. To fix the structure, one end of the bracket is driven into a wooden plug, and the other into the Mauerlat.

The thickness of the block must be greater than the length of the short end of the bracket (otherwise it will rest against the masonry), and the length of the bracket must correspond to the distance between the mauerlat and the embedded block.

How to increase the Mauerlat

Ideally, the Mauerlat beam should consist of a solid beam, but since the size of the house does not always allow this, in some cases the Mauerlat can be extended.

To do this, the ends of the extendable parts of the Mauerlat are sawed down to half the thickness of the timber and must be treated with an antiseptic. It is advisable to make the joint so that it falls on one of the embedded studs (which will significantly increase the strength of the connection), or it is fastened with anchors, fastening plates, or nails.

The beam is spliced ​​from parts of timber of approximately equal length, and not from a long piece and trimmings, i.e. the connection should be made approximately in the center, and not at the edge of the wall.

A similar connection is used to join the cross beams at the corners of the building. A dowel is driven into the hole drilled in the joint, and the ends of the beams are tightened with staples driven diagonally, giving the entire perimeter additional rigidity. Another option is to use a hairpin.

The need for underlay and waterproofing

With direct contact between the wall and the Mauerlat, condensation forms due to the different thermal conductivities of the materials, so cut-off waterproofing must be installed (otherwise the wood will begin to rot).

In practice, waterproofing of Mauerlat is most often made from roofing felt or any other rolled bitumen-guided material in two layers. Ruberoid can be rolled out on the surface of the wall or attached to the Mauerlat using staples and a stapler; a strip of the required width is marked and sawed off from the roll with an ordinary hacksaw.

It is recommended to lay a linen or jute inter-crown sealant on top of the waterproofing for a tight fit and additional thermal insulation.

Another possible option is to install the Mauerlat on a substrate made of foamed polyethylene, which has both insulating and waterproofing properties.

That seems to be all I wanted to talk about in this article. As always, I invite readers to discuss nuances in the comments.