In design small house from aerated concrete blocks with a simple sloping roof, there is no particular need to cast reinforcing tape; it is much cheaper and faster to attach the Mauerlat to aerated concrete without an armor belt. Technology reduces construction time goes faster, but does not make the work easier, since this method of attaching the Mauerlat beam directly to the walls requires accuracy and precision.
Features of fastening the Mauerlat to aerated concrete without an armored belt
Simply put, without knowing technological techniques correct installation, it’s better not to take risks and take advantage in the classic way, with laying reinforcement and concreting the tape. On the other hand, the problem is only in following the technology, there are no secrets in this, and with due patience and accuracy, secure wooden beam without an armored belt it will not be difficult.
First of all, you need to know the conditions under which you can attach the Mauerlat to aerated concrete without an armored belt:
- In the design of the roof frame, the rafters should not create an additional thrust load on the upper edge of the walls;
- The building and the roof are primarily oriented to the terrain so that wind flows create minimal pressure on the roof slopes;
- The roof slope is chosen to be large enough to winter time the heavy snow cover squeezed the rafters and mauerlat beyond the upper edge of the walls.
Advice! The way to secure the Mauerlat without an armored belt must be chosen before the walls are laid out. You need to make a decision before the last three rows of blocks are laid out. It is at the level of the third rows from the top that the penultimate layer of wall reinforcement is laid, which is convenient to use to secure the beam directly to the wall made of aerated concrete.
The situation with the rafters will become clearer if you look at the diagram below.
Hanging rafter beams, after installation and alignment on the ridge and mauerlat, must be connected and tightened with horizontal timber ties.
If the layered beam is placed on a ridge girder using a hinge, then the heel of the rafter, with which it rests on the surface of the mauerlat, must be secured to a sliding connection. Otherwise, the weight of the roof will tear the wooden beam from the surface.
Strong arguments against the armored belt
Most craftsmen involved in the construction of buildings made of aerated concrete are confident that installing an armored belt can solve all problems with installing the mauerlat and roof. In fact, this is not entirely true, for one simple reason - future home It is built from extremely weak aerated concrete. Therefore, it is impossible to transfer the techniques and technologies of the armored belt, which successfully work on brick, block and concrete buildings, to aerated concrete walls.
There are only two fundamental objections to the armored belt:
- First of all, with any manufacturing scheme, the reinforced belt can be secured only to the top row of aerated concrete, so the roof has to be made with the same restrictions, as in the case when this belt is not present. Concrete frame redistributes the thrust load well, but all the forces from the reinforced belt fall only on the top row of aerated concrete, hence the appearance of cracks along the upper edge of the walls;
- Attaching the Mauerlat to an armored belt means creating huge problems with a cold bridge in that part of the roof where aerated concrete is least ventilated. Even laying a layer of EPS insulation helps little; you have to look for ways to install vents to remove condensation from the reinforced belt.
The third argument against concreting is related to costs. The installation of reinforcing tape will cost an amount approximately equal to a third of the estimate for the construction of the foundation. For a house 4x8 m this is approximately 60-100 thousand rubles. It is clear that it is much easier to fasten the Mauerlat and roof frame to a Mauerlat rigidly connected to a concrete reinforced belt. Sometimes master roofers even refuse to install a roof on aerated concrete without an armored belt, but technologically this is quite possible.
How to attach a Mauerlat to aerated concrete without an armored belt
There are several reliable and proven methods for securely fastening mauerlat beams to aerated concrete walls. Recommended options include:
- Use of studs with embedded elements;
- Laying timber using annealed steel wire;
- Schemes that allow you to secure timber using chemicals;
- Use of dowels.
For your information! In addition to the options listed, you can secure the Mauerlat using anchor bolts.
Fastening the Mauerlat to aerated concrete without an armored belt using anchors
This is the only method, the use of which should be immediately and without a doubt; it is better not to take risks without an armored belt.
The anchor fastening works perfectly on an armored belt made of concrete, brick, cinder block, but due to small area the contact surface of the support sleeve can tear the fasteners out of the aerated concrete body with the first strong wind.
In order to secure the Mauerlat with anchors, you will need three times as many attachment points, each of which will have to be glued with expensive adhesive composition. The cost of such fasteners will be no less than the cost of a traditional armored belt, and there are practically no advantages over concrete.
Fastening with studs
The easiest way to build a building made of aerated concrete without a reinforcing belt is to secure a wooden beam using an embedded element and a stud with a thread of at least M16. The method is very similar to the option with an anchor, but differs in the depth and diameter of the threaded rod, which will need to be fixed in the aerated concrete block.
There is one caveat to this method of fastening. Before laying the last three rows of box blocks, it is necessary to mark the planned installation lines for the future threaded fasteners of the Mauerlat. Usually they simply draw vertical lines on the walls. Further under the laid steel reinforcement embedded elements are placed, most often these are steel plates, 5 mm thick, with a welded M16 nut. The remaining rows of aerated concrete are laid out on the walls in the usual manner.
In order to secure the studs in the wall, you will need:
- Drill a vertical hole with a diameter of 20-25 mm to the level of the plate embedded in the aerated concrete; usually you have to drill with a drill up to a meter deep;
- Screw the threaded rod into the nut with the plate;
- To properly fasten the pin, it will need to be leveled and wedged in the hole;
- After all the rods have been aligned and secured, the free space is filled with concrete or adhesive mixture.
After a day, you can put the Mauerlat directly on the aerated concrete. This is the only way to mount the Mauerlat on a wall with minimal costs and maximum degree of reliability. Another option for installing a Mauerlat on aerated concrete without an armored belt is shown in the video
Mounting the Mauerlat on dowels
It is clear that it is not always possible to prudently lay plates in walls made of aerated concrete, and it is simply not possible to punch horizontal holes for laying fasteners. If the aerated concrete box is small in size, then you can fasten the Mauerlat without an armored belt using carpentry, using dowels.
The technology is practically no different from the previous method. Initially, centering holes are drilled in the mauerlat laid on aerated concrete, and the timber is secured to the surface of the walls with ordinary self-tapping screws. This allows you to correctly align and splice the Mauerlat until the moment of final fastening.
Waterproofing is successively applied under the timber, roofing felt is laid, after which 25-30 mm holes can be drilled for oak dowels to a depth of 70-80 cm. All that remains is to pour in the glue and secure the rods. The tops of the rods are cut off, a carpentry screw is turned inside, allowing the dowel to be wedged out and thereby firmly securing the Mauerlat. At first glance, this method gives the impression of being the most unreliable, but the practice of installing a Mauerlat suggests the opposite. Especially if you remember that most timber houses assembled using dowels.
Fastening with chemical anchors
Relatively new way allows you to fix a beam or board almost anywhere on an aerated concrete wall. To hold the Mauerlat, threaded anchors are used, but they are not wrapped in the body of aerated concrete, but in a special cavity filled with quick-hardening resin.
First, markings are carried out on the walls of the points where it is planned to fix the timber. Next, the Mauerlat boards are dismantled, and holes are drilled in the aerated concrete for installing chemical plugs. In order for the anchor bolt to hold firmly in the thickness of the aerated concrete, it is necessary that the diameter of the plug cavity be at least 35 mm.
The cavity for filling the self-hardening resin is cut out using special device. An oblique cutter is a drill bent at an angle of 15° cutting edge. The nozzle is installed on a drill and sequentially, in several passes, a cavity is drilled in the aerated concrete for a conical plug.
Before fixing the anchor, the hole is purged with air. Can be used hand pump for inflating tires or any similar device. Next, you need to attach a plastic nozzle to the hole, through which the resin mixed with the hardener is pressed with a syringe.
After 10 minutes, it is necessary to tighten the anchor bolt, align it vertically and temporarily secure it until the plastic is completely cured. Before installation, the anchor must be thoroughly cleaned of dust and degreased with a solvent. After another hour, the Mauerlat can be fixed to aerated concrete. The advantage of chemical anchors is simple technology and high reliability of fastening, without the use of an armored belt. The downside remains high price self-hardening resin and the inability to fix the Mauerlat at temperatures below 15 o C.
Fastening the Mauerlat to aerated concrete with wire
In order to fix the Mauerlat on walls made of aerated concrete, you do not need any expensive materials or special tools. It is enough to have an electric drill with long drill with a nozzle, scissors for cutting wire and construction rod with a diameter of 5 mm. Sometimes 2 mm thick wire is additionally used to tie the reinforcement.
Advice! If the walls made of aerated concrete were laid by other craftsmen, and the location of the reinforcement is unknown, then it will also be useful to use a hand-held device to find hidden wiring.
The advantage of this method is the exceptional simplicity of the process. In order to secure the Mauerlat timber to the wall, it is enough to tie a wire loop and pull the wood to the supporting surface, as in the video
Before you begin installation, you will need to solve two problems. Firstly, you will need to immediately install a thick and very heavy beam on the walls and splice the individual parts of the Mauerlat into one run.
Secondly, you will need to select the line and drilling locations through holes. The best option is to drill holes below the level of laying the last reinforcing layer. Sections of walls above window and door openings are definitely not suitable.
Before fixing the Mauerlat, the wire is cut and annealed to make it softer and more flexible. The material is passed through the hole and wrapped onto corner edge Mauerlat using a mount, the remaining mustache is cut off with scissors.
Some craftsmen, before securing the beam, put a spiral spring wound from pieces of wire rod 2 mm thick onto the wire. An improvised tube is inserted into drilled hole in aerated concrete to avoid cutting the wall material when the fasteners are under strong tension. The method does not guarantee the absolute safety of aerated concrete if the rafters are not balanced correctly, but it does not allow the wire pigtail to cut the wall like a hacksaw during gusts of wind.
Since there is no durable concrete reinforced belt under the Mauerlat, special attention must be paid to the correct and uniform tightening of the nuts on the studs or anchors. Usually the fasteners are tightened with a wrench, following the diagonal rule. That is, each subsequent point for the nut should be located on the opposite side of the wall from the previous nut.
Conclusion
The choice of how exactly to fasten the Mauerlat to aerated concrete without an armored belt must be made taking into account the thickness of the walls, the size of the building and the roof structure. For the bath the best option There will be wire fasteners; for a small cottage in the country, you can use chimankera or hairpins. It is better to build two-story buildings with a reinforcing reinforced belt made of rolled steel.
For people uninitiated in the nuances capital construction It is hardly known on the roof why the 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 structure is made of 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;
Mauerlat can be made not only from wooden beams, but also from metal channel 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 beams so that they evenly cover the entire upper part of the 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 regulatory 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 an L- or T-shape with a thread size of 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. Construction 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 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 serves essential protection from 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, choose a light one, but more large timber 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 taking place is not harsh and there are snow or wind loads, but they are of insignificant force.
- 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 reliable protection from external and weather factors. This work should be entrusted to experienced developers and roofers.
For correct installation and assembly rafter system roofs, competent distribution of strong loads on the building, builders resort to using important element- Mauerlat. Mauerlat is a wooden or metal mount, which is fixed at the top of the walls. In this case, it should be securely fastened.
If builders use metal rafters, then there is a need for an I-beam Mauerlat. It is attached to a wall made of aerated concrete without an armored belt and performs two functions:
- distributes loads that are transferred to the walls of the building;
- attached to a metal Mauerlat rafter elements roofs.
Selection of building materials
In the manufacture of wooden mauerlat, beams are used. In this case, experts advise making fastenings from deciduous trees, processed with special antiseptics. The beams should be laid around the perimeter of the wall. To connect them together, specialists install a lock, which must be secured with nails. This will help make a strong, solid wooden structure.It is important that its size be smaller than the width of the aerated concrete walls. The timber must be secured to the inner surface in such a way that there is a gap of five centimeters between the outer cut and the fastening. Sometimes builders use brick for a protective belt on outside walls. Before starting installation work, waterproofing should be provided between the walls and beams.
Types of fastening
There are ways by which you can securely fasten the Mauerlat to aerated concrete. It is necessary that the fastening be installed as securely as possible - this will help to avoid the roof moving. In the construction industry, it is customary to fix an element using the following means:
Waterproofing during installation
Waterproofing is needed between the Mauerlat and the wall of the building. For this purpose, you can use polyethylene, building materials in rolls, or modern waterproofing products. Such work is extremely important during the construction of a building, otherwise liquid may condense in the area of contact of materials, which can destroy the Mauerlat. Protection against moisture penetration is the final stage of installation.
Nuances of installation work
The base is made from timber measuring from 10x10 to 15x15 cm. Experts believe that it is preferable to install a solid wooden structure around the perimeter of the wall surface. In this case, you need to fasten the wooden blocks into a single Mauerlat using a lock. Its dimensions will depend on the characteristics of the bar. After you decide on the type of fastening of the structure to aerated concrete, calculate the location and number of elements, you can begin installation. First of all, workers need to prepare workplace, ensuring insulation of the space between the Mauerlat and the concrete masonry. It is important to remember that the contact areas between the wooden beams and concrete surface wood rotting occurs. Waterproofing building materials laid under the Mauerlat structure will help to avoid the destructive effects of moisture. For good waterproofing, two dense layers of material are used. You can use roofing felt or more expensive means.
In addition, it should be taken into account that when using studs or anchors, you need to make holes in the surface of the aerated concrete in advance. But this problem is more difficult to solve than it might seem at first glance. The difficulty is that using building level It is impossible to install the fasteners exactly in a vertical position, especially in a liquid concrete mixture. Therefore, the first step is to determine where the bolts will be located and how much they will deviate from the concrete. For this purpose, experts use a flat wooden board. The exact location of the bolts is marked on it. To do this, apply the board to the outer bolts and mark where the others should be. After this, the builders transfer the points directly to the block and drill holes according to the marked points. Then place the holes on the fixed bolts and tighten wooden block using nuts. With metal wire the work is much easier. To do this, 2 holes are drilled in the block, the distance between which should be about thirty centimeters.
Workers thread metal wire into the prepared holes, twisting the ends.
Rafter fastening scheme
Mauerlat is a part of the roof of any structure, which is a beam that is laid on top outer wall around the entire perimeter.
Its purpose is to uniformly distribute the load from the roofing system over the entire surface of the load-bearing walls. It can be made of wood or metal. In the case of using a metal Mauerlat, take finished goods: I-beam, channel, corner.
To perform its function, the Mauerlat must be securely fastened. There are two ways: attaching the Mauerlat to aerated concrete without armored belt and with an armored belt.
Fastening the Mauerlat with an armored belt
Using aerated concrete as the main material for laying walls, you need to understand that it will not be able to withstand the load of the rafter system and roof, so the creation of an armored belt is mandatory.
Purpose and dimensions of the armored belt
Armopoyas is a closed structure made of reinforced concrete, running along the perimeter of the structure. Purpose of the armored belt:
- preventing deformation of load-bearing walls;
- giving additional rigidity to aerated concrete structures;
- uniform distribution of load on the surface of the walls.
The armored belt is essentially the foundation for the roofing system. The dimensions of the armored belt depend on the width of the walls; for aerated concrete, the width of the armored belt is approximately 25 cm, while the outer row is laid out with U-shaped blocks, which will later act as formwork for pouring concrete mortar.
Important! The armored belt must be a continuous monolithic structure!
Prepared formwork before concreting
Armored belt device technology:
- Construction of formwork around the perimeter of the building.
- Creating an armored belt from concrete blocks.
- Assembling a frame from reinforcement.
- Installation of studs for fastening.
- Pouring blocks with concrete mortar.
- Removing the formwork after the concrete has hardened.
After the armored belt is ready and the formwork has been removed, you can proceed directly to attaching the Mauerlat.
How to attach a Mauerlat to aerated concrete
From him correct fastening to the load-bearing walls and rafter system of the building depends on its resistance to external influences, service life, noise and waterproofing characteristics and strength.
The Mauerlat must be made of the same material as the rafter system. If metal structures are used, then they are used as a Mauerlat. metal beams, channels, corners. For a wooden rafter system, the Mauerlat will be made of wooden beams. The cross-section of the beams depends on the design load, the type of roof and the diameter of the rafter beams.
Before installing a wooden mauerlat on aerated concrete blocks, it is necessary to treat the wooden beams with an antiseptic solution that protects the wood from insects and rot. It is also advisable to wrap the beams with a layer of waterproofing material. For this you can use hydroisol, elastoizol, hydrostekloizol, steklomast. These materials will not weigh down the structure and will create a layer of additional moisture insulation.
The Mauerlat is attached to aerated concrete walls using anchors, studs or metal wire. When laying beams, it is necessary to connect them at the joints with metal brackets.
Fastening diagram using studs (right) and staples (left)
Next, you need to attach the rafters to the Mauerlat. The connection occurs by cutting, tapping, sawing, but it should occupy no more than 25% of the timber. Fastening is done using self-tapping screws, bolts, angles, metal plates and polyurethane foam.
The main methods of fastening, starting with the most preferable:
- Fastening with studs. This type of fastening can be used in construction as simple one-story buildings, and auxiliary structures: baths, summer kitchens, garages, outbuildings, small country houses. This stud fastening method is preferred for most buildings.
- Fastening with chemical anchors. The beams are attached to aerated concrete using a special chemical adhesive composition: “liquid dowel”, glued-in anchor, etc. The composition is made on the basis of polymers and contains adhesives in the form of synthetic resins. IN aerated concrete wall A hole is made as for a regular anchor, which is filled with adhesive, then a rod (reinforcement) is inserted into the prepared hole, onto which the Mauerlat is then installed. The strength of this design is quite high, however, with a large perimeter of the Mauerlat, this method will be expensive.
- Fastening with steel wire. This method can be used if still at the stage of laying walls between aerated concrete blocks a metal wire was pushed through. Holes are made in the Mauerlat, where the wire is inserted and the strapping is made. It is very important that the number of wire ties is no less than the number of supported rafters.
Fastening the Mauerlat to a wall made of aerated concrete without an armored belt
In accordance with SNiP, fastening without preliminary installation of an armored belt is allowed only in exceptional cases. Aerated concrete is not enough durable material, and will not withstand the spacer snow load, as well as dynamic wind load, so an armored belt is required!
In some cases, fastening the Mauerlat to walls made of aerated concrete blocks is possible without installing an armored belt. This significantly reduces the cost and speeds up construction. However, this is possible subject to the following conditions:
- a light wooden beam with a cross-section of no more than 20 cm is used as a base;
- the beam will be strengthened metal elements: locks, nails, metal profiles;
- snow and wind loads in your region are insignificant;
- The design of the rafter system eliminates thrust loads.
The Mauerlat is located at a distance of 0.5–1 cm from the outer edge load-bearing wall, and to secure it to aerated concrete, studs are used, chemical anchors or steel wire.
Mauerlat is a design designed accept and evenly distribute the load, created by the roof and perceived by the walls. With its help, the stability of the roof is ensured, provided that the Mauerlat is fastened according to all the rules. To do this, you need to know what a Mauerlat is, how it is attached to the aerated concrete wall, and also in what sequence the work should be performed.
Do you need a Mauerlat?
Without a Mauerlat it is possible to install roofing systems on frame houses, as well as buildings erected from timber and logs. They have this function structural element can perform the upper crown of logs or top beam . For buildings made of aerated concrete, this is unacceptable, and therefore the installation of a Mauerlat must be done without fail.
With it you can:
- significantly strengthen the building box;
- increase the rigidity of the installed roof;
- align the upper crown of the wall in a horizontal plane;
- provide fastening roofing structure and the walls of the building.
The thickness of the Mauerlat depends on design features mounted roof. Most often, timber with dimensions of 150 x 150, 150 x 100 or 80 x 180 mm is used for its manufacture. It is also acceptable to use logs that have been cleared of bark and cut on one side. Trimming is done to ensure maximum adherence of the structure to the wall surface.
The moisture content of the wood used must be appropriate regulatory requirements. When using “raw” wood, it must be provided possibility of adjusting the anchor nut once every five years. After the timber has dried, the shrinkage of the wet wood will occur less intensely, and therefore the nut will need to be tightened less frequently.
The prepared wood is subjected to special treatment antiseptic composition to protect the structure as much as possible from rotting and insect damage. Before laying the log should be wrapped waterproofing material, for example, bitumen-polymer. It is better to avoid using roofing felt.
If mounted metal carcass, for the manufacture of the Mauerlat, rolled products are used: channel or I-beam. It can be treated with anti-corrosion compounds.
Features of installing the Mauerlat
The Mauerlat must be laid in such a way that there is some distance left to the outer edge of the wall. As a rule, about 5 cm. Sometimes it is provided protrusion into which the mounted structure should rest. Subsequently roofing system will have to be attached to this structure.
To increase the service life of a structure made of wood, waterproofing must be provided. For this, roofing felt or any other waterproofing material is used.
Methods of fastening to aerated concrete walls
The preferred option is to install the element along the entire perimeter of the wall. For connection individual elements it is advisable to use it as a whole straight lock, the dimensions of which directly depend on geometric parameters the timber used. For reliability, nails are additionally driven into the lock to form a rigid, integral system, to which the rafters are subsequently attached.
To secure the Mauerlat, you can use several methods:
- chemical;
- mechanical.
In the first case it is used special fastening capsules. Chemical substance, penetrating inside the material, ensures reliable fixation of the Mauerlat. At the same time, the condition of the top layer improves and the degree of heat and waterproofing increases. The capsules used for fastening are affordable.
To make the Mauerlat, you must use only high-quality materials. The wood should not have knots. The waterproofing layer must not be damaged, which is achieved by using a special tool.
When mechanically fastening it is necessary to observe certain order actions:
- dowels are inserted into holes prepared in advance;
- the fastening element is screwed in;
- the teeth of the harpoon are firmly pressed into the aerated concrete;
- surface expanded;
- fastening has been done.
The Mauerlat must be fastened in such a way that adjacent links were not connected to each other. This improves the stability of the structure. However, mechanical fastening involves the creation of an expansion force, which can cause some problems at the edge of the structure.
Fastening with anchor bolts and armored belt
For buildings built from aerated blocks, armored belt is required, since this one construction material not strong enough, which can cause certain difficulties when installing fasteners, especially anchor bolts. Therefore, the question of whether a Mauerlat is needed is not relevant in this situation: you simply cannot do without it.
Fasteners for the Mauerlat must be laid in advance. To construct a reinforced belt, it is advisable to use U-shaped blocks, with which you can form a characteristic gutter along the entire perimeter of the outer wall. To avoid the formation of gaps, the corner blocks are sawn through.
The reinforcement frame is assembled using 12 mm reinforcement, which is tied with 6 mm jumpers. Threaded anchors are attached to the frame placed inside the gutter. They must take a certain spatial position, which is controlled using a stretched fishing line or cord. The anchors are placed at right angles to the mauerlat as close as possible to the top beam.
Fastening points should be located along the entire perimeter of the wall. Their number directly depends on the number of rafters: at least there should be the same or more. The fastenings must be positioned in such a way as to avoid contact with the rafters in the future. In order to reduce financial costs it is possible to fill not a solid armored belt around the entire perimeter of the wall, but only individual concrete pads.
After the reinforcement cage along with anchor bolts will be placed in a pre-formed trench and concrete will be poured. To form monolithic design The filling process cannot be interrupted. Work must be carried out continuously along the outer wall. The gutter must be filled with concrete in one pass.
After the concrete has completely dried, the anchors will be securely fixed in the specified spatial position. At the same time very it is important to ensure their precise positioning during the solidification of the solution.
As soon as the concrete gains the necessary strength, the beams are laid on the concrete belt and anchors, which should be inside the holes pre-drilled in the wood. Then the nuts are tightened to secure the beams.
To determine the location of the holes in the timber, it is first laid on top of the bolts, and then force impact sufficient to cause dents in the wood. In these places holes are drilled for anchors.