Installation of the roof on aerated concrete blocks without armored belt. We fix the Mauerlat to the aerated concrete wall, all ways

Good day or evening!

I see that you carefully approach the solution of the problems of each issue, I really liked it, so I decided to apply!
So there is no such problem, but there is psychological discomfort (about it a little later), due to the fact that there is no armored belt.
More.
The house is built as follows.

The soil on which the foundation stands is sand and clay (because when the piles were drilled, this mixture (light in the form of sand) came out).
According to groundwater, the water in summer is somewhere around 4 meters (according to the person who sold the site), but when the piles were made to a depth of about 2.4 m, there was no water; a ditch was dug behind the site to collect spring water and lead out to the road, 1.5 meters deep.
The site is flat (a slight slope of 10-5 cm by 8 meters), but 300 meters in front of it is a mountain, and 200 meters behind it is a railway (the highway to Moscow through Perm), sometimes a slight vibration is felt.
Foundation 7.15 m by 8.12 m with a lintel in the form of a cross inside the house, grillage 60 cm (height) * 40 (width) cm (40 in the ground + 20 above it), piles were made every 1.1-1.3 from each other (from edge to edge of the pile) with a diameter of 40 cm by 2 m from the bottom point of the grillage, not excluding the lintels (an approximate view of the foundation is attached), reinforcement was used 10 ".
Poured in October last year (2012), concrete grade M200, (diagram attached).
This year he began to build walls (June 2013).
Then roofing material was laid out in 2 layers, a basement in three M150 bricks (with 2 pieces of air per room).
Next we went gas block (600 * 188 * 300). The first floor of 13 rows is somewhere 2.4 m, floor beams (10 pieces) are laid on them, since the first floor of 5 walls, the beams were located as follows: the back of the house (where there is no bay window) beams 150 * 150 somewhere then 4 meters each, leaning on a wall and a partition of 30 cm each (for the entire width of the block), the front of the house (with a bay window) beams 100 * 150 5 meters each, well, one from the bay window to the partition of 6 m, everyone rests on each side 30 cm (wrapped with roofing material).
Next, an attic was erected, side walls of 1.2 meters each, and a high pediment of 2.3 m each.
The blocks were glued.

Here is the most denouement.
I began to think about how to put the mansard roof, what to attach it to, well, I got into the Internet to read what and how. I read that an armored belt was needed (I hadn’t heard about this before, I thought the gas block was laid like a brick, and therefore I didn’t climb the Internet and the builders said the house would stand for 100 years) and the neighbors didn’t make it and they screwed the beam to the block, but here on you, the armored belt it was needed between the first and second floors and at a level of 1.2 from the second floor before erecting gables, luggage reinforcement between the rows of the gas block. What a miracle material, how to shake over a child. But it's too late, everything is built. "Here he is an elbow, but you won't bite" Well, I began to ask on the forums what and how, but everyone screams at me, it will fall apart, take everything apart and do it again. Decided to ask you for advice. There is no extra money to break everything and do it all over again.

Here is the psychological moment. They scared me with all sorts of horror stories. I was thinking of erecting a broken armored belt (along the sloped surfaces of the gable walls) in 3 fiberglass reinforcements of 8 with a dressing of 1 m, the width of the belt is 25 cm and a height of 20 cm, on it a beam of 100 * 150 mm with a step of studs of 1.5 meters, then erect an attic with a rafter foot step of 600-700 mm (board 50 * 150). A view of the rafters is attached and an approximate view of the roof. What can you say about this situation, maybe something needs to be strengthened, maybe not? How to build an attic from a gas block 600 * 188 (height) * 300 (width)?

Mounting a Mauerlat is not a difficult task, but it requires some skills and accurate calculations. A competent owner may well cope with this on their own. Let's try to figure out what and how best to attach the Mauerlat to aerated concrete, and also talk about the importance of waterproofing.

What is the Mauerlat mount

In the process of building a house, Mauerlat is given special attention - it has an important mission in the roof structure. The rafter system gives a very large load on the walls, in order to avoid this, bars are installed around the perimeter, and rafter legs are already attached to them - thus, the load is evenly distributed on the walls of the house.

Mauerlat can be fixed in three ways, using studs, anchors or steel wire. Usually the method depends on the overall dimensions of the building or house. Experts have long come to the unanimous opinion that the fastening of the Mauerlat to aerated concrete should be accompanied by the creation of an armored belt. Then the structure will be ideally strong and rigid, less prone to shrinkage.

Since the Mauerlat wooden logs are responsible for the reliable fixation of the rafter beams, they must be fixed as efficiently and powerfully as possible. Otherwise, they will not be able to take on part of the load properly.

Parameters of a suitable timber for the role of Mauerlat

The bars of deciduous trees (most often oak) are well suited for this. The recommended size is 10x10, if possible more - 15x15. Be sure to treat the wood with an antiseptic to protect it from rotting. With the help of a direct lock and additional nails for reliability, the Mauerlat is fastened together, evenly covering the top of the walls.

Important: it happens that you have to take “raw” wood, in such cases, do not forget that for 5 years you will need to tighten the anchor nut annually due to frequent shrinkage of the wood - take care of the possibility of adjusting it. Over time, this will not be necessary.

Before installing the Mauerlat, the top of the walls must be covered with a layer of waterproofing, otherwise, upon contact with the wall surface, the wood will begin to deteriorate. To do this, you can use the usual roofing material, but modern builders still do not recommend it - it is better to choose a high-quality bitumen-polymer material. It will provide more reliable waterproofing.

Fastening with anchors

It is this mount that is used with the armored belt - together they create
very strong and reliable construction. The armored belt is a kind of frame made of 12 mm reinforcement, which fits into a special chute.

What you need:

Reinforcement with a thickness of 10-12 mm to create a frame.

Rods 6 mm thick, for cross-sections of the armored belt

Concrete brand M-200
U-shaped blocks - they will be the container for reinforcement and concrete

U-blocks will help you lay out the groove on the surface of the walls without resorting to chasing aerated concrete - just install the blocks along the top edge of the walls.

You should get a continuous "ditch" - for this you need to put blocks with sawn sides in the corners.

Then, in the resulting gutter, install a reinforced belt.

Attach a threaded anchor to the belt, use a wire for this, and pull a fishing line or thick thread as guides.

Now you can fill it all with concrete.

After the concrete has dried, apply a waterproofing layer.

Important: the anchors should protrude beyond the concrete - you will put on the Mauerlat on them. The pouring of the concrete mixture should take place without interruption, so to speak, in one go at once the right amount.

Despite the existence of other methods of fastening to aerated concrete, the use of a reinforced belt cannot be compared with any other in terms of quality and power.

Metal studs - where this type of fastening is appropriate

This option is good for very small houses or other buildings where there is no heavy load on the walls of aerated concrete. Well, or for some reason it is not possible to build an armored belt. In other cases, metal studs are rather weak and do not withstand excessive pressure, so experts do not recommend using them to mount the Mauerlat on the walls of large buildings.

Stages of work:

To insert studs into aerated concrete, you must drill holes in it with a distance of one to one and a half meters.

Insert CPT 12 studs into aerated concrete.

Then the hairpin must be filled with a solution.

Before putting on the Mauerlat studs, install a layer of waterproofing - roofing material is possible, but as mentioned above, it is better to use more modern material.

Lay the Mauerlat beam on the insulation, pushing it onto the washers.

Tighten nuts.

At the junction, the Mauerlat is pulled together with brackets.

Important: it happens that during the work there are already gables - it is better to remove them. Lay the bars along the edges of the walls, then file the rafter legs - in this way, it will be possible to redirect the thrust from the rafters to the timber.

Mauerlat fastening with wire without armored belt

This method is much simpler than the first two, but less resistant and strong - it is well suited where you need to fasten the Mauerlat to aerated concrete as quickly as possible. It is used in the construction of small, simple buildings. If in the method with construction studs an armored belt is installed if necessary, then everything happens without it in any case. Its advantage can be considered that for the work you only need steel wire.

Work process:

At the stage of building walls when laying aerated concrete blocks, you need to put the wire between the joints of the bricks and wall it in. This should be done so that its middle is tightly fixed with blocks. It is advisable to start mounting the wire somewhere three or four rows before the completion of the wall.

Steel wire should be long. Keep in mind that part of it will be under the bricks, and the ends must penetrate the hole in the beam, braid it, and then they must be tightly tightened and secured. Thus, the mauerlat will be able to quite confidently hold the entire structure of the truss system, taking part of the load from the walls onto itself.

Do not forget that the Mauerlat should be fastened in such a way that there is at least 5 cm free space between the bars and the outer edge of the wall.

Wooden boards must be sanded well so that there are no cracks or knots.

Waterproofing is one of the important points - if it is not laid, then moisture forms between the wood and aerated concrete, and it will very quickly ruin the timber.

"Raw" wood is allowed, but it must comply with building codes.

As you can see, attaching a Mauerlat to aerated concrete without an armored belt or with it is not so difficult as it might seem at first glance. But in any case, it would be useful to consult with an experienced builder.

Video

For a user uninitiated in capital construction, it is unlikely that it will be known what a Mauerlat is, what role it plays in building a structure, and so on. Therefore, the question of how the Mauerlat is attached to aerated concrete is generally misunderstood.

However, the use of such technology is a relevant and very effective solution. With it, you can solve a number of significant problems that can reduce the durability and strength of the structure.

It is also necessary to mention a more economical variant of the implementation of the specified method of fastening. If it is necessary to fasten the Mauerlat to aerated concrete without an armored belt, then in this case it is not a continuous armored belt that is poured, but concrete pillows are made in the right places. Such a mount for foam blocks is also quite reliable.

2.3 Metal studs

In the presence of a small house, as well as a slight roof pressure, a lightweight method can be used to fasten the walls of the cinder block with the Mauerlat beam - metal studs embedded in the wall. These are steel fasteners in the form of bolts with a base in the form of a square with sides of more than 5 cm.

If, when laying a cinder block, studs are embedded in the wall, they must be installed one or two rows to the top edge. The length of the stud should be sufficient to pass through the beam.

Subsequent fixation similar to fastening a mauerlat with a cinder block using anchor bolts.

2.4 Waterproofing during installation

Having decided on the method of fastening, it is necessary to calculate the fasteners and their location. If it is necessary to fix the Mauerlat to the gas block without an armored belt, then the first option is suitable - steel wire.

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

Why do you need an armored belt

As you know, aerated concrete is characterized by high sensitivity to local loads. That is, if the allowable pressure of the drill used to create holes in the block is exceeded, there is a high probability that it will become covered with cracks or even crack. To prevent such changes, an armored belt is equipped, it also allows you to avoid slipping and deformation of the blocks, which are caused by uneven pressure of the total weight.

What you need to know

The functions of the Mauerlat are to connect the box of the building and also to share the load with along all walls. For the manufacture of fasteners, wood is mainly used. The best option is hardwood timber, the surface of which is coated with an antiseptic composition.

It is desirable that the fastening of the Mauerlat to the aerated concrete wall be continuous around the entire perimeter of the wall structures. To fix individual elements, a straight lock of a suitable size is used. To ensure rigidity, nails are driven in, as a result, the bars form a single system for mounting rafters associated with neighboring elements. The bars should be on the inside of the masonry, while at least 5-6 cm to the outside. To support the Mauerlat, a brick parapet is made along the outer edge of the wall, the individual parts of which are fastened with a direct lock.

Methods for attaching the Mauerlat to aerated concrete walls

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

fixing with studs built into the masonry;
anchoring on the basis of armored belt;

In the latter version, the wire is laid between the bricks in such a way that the middle part is located under them, and the outer sides are outside. The length should be sufficient for free threading through the beam and subsequent tightening. The number of strappings must match the number of rafters. Using a metal wire, the Mauerlat is then fixed to the wall.

reinforced belt

Fastening the Mauerlat to aerated concrete with an armored belt is the most preferable, since the blocks are characterized by an insufficiently dense structure and the complexity of mounting clamps of any kind. It is worth noting the advantages of using a reinforced belt. First of all, this is the alignment of the upper part of the walls and the strengthening of the entire structure of the house; during its arrangement, fixators for the Mauerlat are created in advance. In execution, the easiest way is to use U-shaped block elements in the form of a gutter along the perimeter of wall external structures, while there should be no interruptions. Next, a cut is formed on the corner parts. To assemble the frame, reinforcement with transverse lintels is used, then it is placed in the gutter, followed by pouring with concrete mixture. To ensure solidity, the mass is poured in one go. Before that, anchors with wire are fixed on the reinforced belt. Of particular importance is careful compliance with the level. The studs are also fixed on the frame along the line in accordance with the stretched cord, in a vertical arrangement. Just as in the case of use, the number of rafter legs and anchor clamps must match. It is necessary to first determine the optimal location of the elements in order to avoid coincidence with the places where the rafters are fixed.

Mounting Mauerlat to aerated concrete using studs

This option is optimal for small buildings and roofs with a lightweight design, when significant loads do not fall on the roof and walls. Studs are of two types: these are bolts that form a single structure with a steel square, or L-shaped elements. Their fastening is carried out in the course of several rows to the top, while the length should be enough for the lock nut and the thickness of the bars. The process is similar to the anchor method: the beam is put on the studs when the masonry solidifies and is fixed with nuts. There are also other ways of attaching the Mauerlat to aerated concrete, but they are used less frequently due to their lower reliability.

Sufficient rigidity and reliability of fastening is formed by tying the bolts to the frame and additionally immuring them with concrete. It is enough to put the Mauerlat on the studs and use nuts to pull them to the blocks.

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

Peculiarities

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

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

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

It is worth noting that they should not be used with a grinder, as this tool is not suitable for wood. Failure to follow this rule can lead to injury during operation.

Sliding mate

Installation of rafters is carried out after tight fixing of the Mauerlat. The truss structure can have a hinged or rigid fixation, the selection of a suitable option depends on the requirements that the attachment points of the Mauerlat to aerated concrete must meet, the general configuration and type of structure (hanging or layered).

The hinged version can have a different pairing. The most common is a hard-coupled mount, with no movement or rotation. A sliding interface is also used, which ensures the movement of the beam and rotation in relation to the beam. The latter option reduces the thermal expansion of the wood and the shrinkage of the building, all of which prevents the transfer of bursting loads to the wall structures.

Three techniques are used to create a sliding mate:

the use of a special metal fastener to connect the rafters;
removal of the beam beyond the walls and fixation with a plate;
creation washed down in the rafter board and its installation on the Mauerlat using a corner, staples or nails.

Hard Pairing

Without it, concrete and wooden buildings, as well as structures made of timber, rarely do. Due to the fact that both frame and tree houses are characterized by noticeable shrinkage, in the absence of the possibility of simultaneous displacement of the building frame and the roof, there is a possibility of significant stress causing damage to the structure of walls and rafters. To create a rigid interface, support bars with a length of 1 meter are required, fixed to nails and steel corners. with a beam should rest against the Mauerlat design in accordance with the pressure line. This prevents perpendicular displacements. Corners and nails eliminate transverse displacement, while the latter must be driven in at an angle on both sides, so that they intersect in the beam. A third nail is driven through the beam, which should have a vertical direction.

Conclusion

The fastening of the mauerlat to aerated concrete has its own characteristics, which must be taken into account during the arrangement, so problems with the operation of the roof can be prevented. In the absence of experience and relevant knowledge, to create a project and subsequently install a rafter system, it is advisable to turn to professionals who guarantee a reliable roof that will protect the house from cold and precipitation for many years. During construction, it is not worth saving at this stage of work, as this may cause additional financial investments and time costs.

Why do you need an armored belt

What you need to know

The functions of the Mauerlat are to connect the building box and the truss system, as well as to share the load from the roof structure along all walls. For the manufacture of fasteners, wood is mainly used. The best option is hardwood timber, the surface of which is coated with an antiseptic composition.

Methods for attaching the Mauerlat to aerated concrete walls

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

fixing with studs built into the masonry;
anchoring on the basis of armored belt;
fastening the Mauerlat to aerated concrete with wire.

reinforced belt

Fastening the Mauerlat to aerated concrete with an armored belt is the most preferable, since the blocks are characterized by an insufficiently dense structure and the complexity of mounting clamps of any kind. It is worth noting the advantages of using a reinforced belt. First of all, this is the alignment of the upper part of the walls and the strengthening of the entire structure of the house; during its arrangement, fixators for the Mauerlat are created in advance. In execution, the easiest way is to use U-shaped block elements in the form of a gutter along the perimeter of wall external structures, while there should be no interruptions. Next, a cut is formed on the corner parts. To assemble the frame, reinforcement with transverse lintels is used, then it is placed in the gutter, followed by pouring with concrete mixture. To ensure solidity, the mass is poured in one go. Before that, anchors with wire are fixed on the reinforced belt. Of particular importance is careful compliance with the level. The studs are also fixed on the frame along the line in accordance with the stretched cord, in a vertical arrangement. Just as in the case of using steel wire, the number of rafter legs and anchor clamps must match. It is necessary to first determine the optimal location of the elements in order to avoid coincidence with the places where the rafters are fixed.

Mounting Mauerlat to aerated concrete using studs

This option is optimal for small buildings and roofs with a lightweight design, when significant loads do not fall on the roof and walls. Studs are of two types: these are bolts that form a single structure with a steel square, or L-shaped elements. Their fastening is carried out during the laying of blocks several rows before the upper part, while the length should be enough for the lock nut and the thickness of the bars. The process is similar to the anchor method: the beam is put on the studs when the masonry solidifies and is fixed with nuts. There are also other ways of attaching the Mauerlat to aerated concrete, but they are used less frequently due to their lower reliability.

Peculiarities

It is worth noting that saw blades should not be used with a grinder, as this tool is not suitable for wood. Failure to follow this rule can lead to injury during operation.

Sliding mate

Three techniques are used to create a sliding mate:

the use of a special metal fastener to connect the rafters;
removal of the beam beyond the walls and fixation with a plate;
creation washed down in the rafter board and its installation on the Mauerlat using a corner, staples or nails.

Hard Pairing

Without it, concrete and wooden buildings, as well as structures made of timber, rarely do. Due to the fact that both frame and tree houses are characterized by noticeable shrinkage, in the absence of the possibility of simultaneous displacement of the building frame and the roof, there is a possibility of significant stress causing damage to the structure of walls and rafters. To create a rigid interface, support bars with a length of 1 meter are required, fixed on the rafter legs, nails and steel corners. The rafter beam with the beam must rest against the Mauerlat structure in accordance with the pressure line. This prevents perpendicular displacements. Corners and nails eliminate transverse displacement, while the latter must be driven in at an angle on both sides, so that they intersect in the beam. A third nail is driven through the beam, which should have a vertical direction.

Conclusion