How to fasten the rafters. Fastening the rafters to the mauerlat without cutting Hip roof with hanging rafters

Any modern roof begins with a Mauerlat. It is a base that is fixed along the perimeter of the top of the external walls. The device serves to support the roof and prevent its windage. Thanks to the uniform distribution of the load over the area, the Mauerlat seems to “tie” the roof to the house.

Mauerlat - what is it and what is it for?

The classic Mauerlat is a dried timber or log fixed on top of the external walls. Fastening is carried out using an armored belt or simply around the perimeter of the house. The structure is the support for the entire rafter system. This is a kind of foundation that unites all the elements of the roof.

Why the device is needed:

• ensuring roof levelness;
• preventing tilts and distortions;
• elimination of windage;
• uniform load distribution;
• tying the roof to the house.

The size of the element is calculated based on the area of ​​the house, roof type, roofing material, climatic conditions, and the presence of an attic.

What materials can it be made from?

The structure is often made of wood, using wooden beams or boards fastened together. Often a steel profile is used. The choice depends on the weight of the roof.

Wooden beam

The timber is placed under the rafters along the perimeter of the roof. With this arrangement, the load is evenly distributed to each point on the walls of the house. There should be no knots on the timber, and if there are any, their size should not exceed 2/3 of the thickness of the wooden product. When arranging the Mauerlat, knots will interfere with the main structure, so it is better to avoid them. If there are many knots on the beam, then a break may occur in the places where they form.

Boards fastened together

In frame construction, when the roof is light in weight, boards fastened together can be used. This design is not suitable for a heavy structure - the boards will not withstand the high load. This material is suitable for roofing without insulation and additional elements that increase weight. The boards are attached around the perimeter of the building. For the Mauerlat, it is advisable to use durable material that will not crack during use and exposure to external factors.

Steel profile

Instead of wooden products, steel structures are often used. This material is more durable, as it can withstand increased loads. The steel profile is represented by a square section or round metal pipes. The use of steel as a support for the roof implies the presence of metal lining around the perimeter of the external walls. The device is suitable for a gable roof, and beams can also be used. The harness is secured to the outside of the wooden belt.

Mauerlat cross-sectional dimensions SNIP

Recommended parameters in accordance with SNIP rules should be at least 100x100 mm for wooden beams. These are the indicators that are considered average, allowing you to reliably hold the roof on the walls. Builders recommend increasing the dimensions to 150x150 or 100x150 mm to increase the reliability of the structure .

There are several requirements for the section:

• the wood must be treated with an antiseptic not only on the cut, but along the entire length;
• individual elements are secured using a direct lock;
• beams are laid over the entire area of ​​the walls.

If you reduce the cross-section of timber or boards, the structure will not be reliable: the roof may not be resistant to adverse weather conditions.

How to attach the Mauerlat

The main requirement when arranging a support is immobility and precise fixation of structural elements. For this purpose, studs, anchor bolts, wire method and wooden plugs are used.

Special metal pins are embedded in the masonry of the walls, then they are used to fix the mauerlat. This method is ideal for lightweight structures. The stud looks like a metal bolt in the shape of the letter “L”, and can also be welded to a square of metal. The studs are immersed in the brickwork to a depth of 45 cm. They protrude vertically from the wall by 3 cm. The studs must be inserted at the stage of laying the walls, in the final or penultimate row. The optimal distance from the outer part of the wall is 5 cm.

Fastening with anchor bolts

To enhance reliability, the Mauerlat is attached to an armored belt using anchor bolts. The manufacture of a reinforced belt is mandatory when using aerated concrete. Such blocks are soft, so it is impossible to screw bolts into them.

When the armored belt is installed in the formwork, threaded anchors are tied to it. They should be aligned exactly along the line - this will ensure a strong fixation. The fasteners themselves must be strictly vertical for the fastening process to take place accurately. There should be as many anchors as there are rafters or more. Anchors should not be located in the places where rafter legs are attached.

How to attach with wire

The classic way is to use wire fastening. To do this, follow a certain sequence of work:

1. Pieces of wire are placed 4-5 rows before the end of the masonry.
2. The distance between the pieces is maintained at 60 cm.
3. The ends of the wire rise up 20-30 cm.
4. The ends of the wire material are hidden in the solution.
5. The other end of the wire is used to tie timber or boards to the wall.

This option is used everywhere in construction. It is suitable for houses made of brick or other stone, as well as where mortar is used for walls.

Using Wooden Plugs

For small structures, for example, for country houses, wooden plugs are used as fastenings. They also securely fix the Mauerlat. The plugs are the size of a traditional brick; each element is treated with an antiseptic and covered with roofing felt. Sometimes plugs are made from timber impregnated with bitumen for strengthening. The cork is laid below the level of the rafters or at the same level at a distance of 50-70 cm from each other.

Methods for attaching the Mauerlat

The device for tying the roof to the walls can be attached using a reinforced belt, as well as without its use. In the second case, an oblique cut or other materials are used, depending on the raw materials of the erected walls.

Fastening without armored belt

To begin with, it is important to determine what the walls are made of - brick, expanded clay, aerated concrete, gas silicate, foam block or cinder block. Next, use one of the options.

Attaching to a brick wall

First, the preparatory stage is carried out: the bricklaying is completed with a flat horizontal surface or ledge. In the first case, the device for tying the roof is placed on the inside, and at the end it is insulated with blocks of expanded clay. Fastening is carried out in one of the following ways:

• embedded studs;
• wooden plugs;
• wire;
• anchors.

At the final stage of masonry, a waterproofing layer is installed. Roofing felt, roofing felt, waterproofing or linochrome are used as waterproofing.

Fastening to expanded clay blocks

The most reliable method of fastening to expanded clay blocks is chemical anchors. Due to the special structure of expanded clay, other options may lead to its fracture and the structure will not withstand.

Chemical anchors are special compounds that are made on the basis of chemicals. They harden quickly, have a long service life and increased adhesion.

Chemical anchors come in ampoule and polymer types. Ampoules are represented by a small capsule inserted into the block. The substance fills the voids, then an anchor is inserted into the hole. Polymers are placed into the cavity using a dispenser gun.

Fastening to aerated concrete

It is possible to secure the Mauerlat to aerated concrete using steel wire. To do this, perform the following actions:

1. A few rows before the end of laying the blocks, a wire 6 mm thick is placed.
2. The ends of the wire are placed hanging on both sides of the block.
3. The length of the ends should be such that the timber can be tied loosely.
4. The number of segments is selected based on the perimeter of the walls.

Then a beam is applied and tied with a twist. This method is optimal, since aerated concrete has a soft stone structure and other options will not work.

Fastening to gas silicate

To fix the Mauerlat on a gas silicate wall, you will need galvanized studs. With a block size of 375 mm, studs with a diameter of 12 mm and a length of 33 cm are needed. The ends of the studs must have a reinforced washer. To ensure reliable fastening, the studs are installed with the same pitch and depth strictly vertically. Holes are drilled in the timber according to the diameter of the pin, then the wooden product is put on them. For precision fastening, you can make a template from a board, in which you need to make a hole and insert a pin there. 12mm fasteners require a 14mm hole.

Attaching to foam block

Before attaching the support to the wall, ensure reliable waterproofing. The best method of fastening is to use wire. On the last row of foam block laying, a steel wire folded in several layers is threaded. Its ends come out freely, and the middle is placed under the block. The length of the material should be such that it can be threaded through the beam and the ends twisted. The number of wire fastenings must be no less than the number of rafters.

Attaching to cinder block

If the house under construction is small, then you can use the method of fixing it with embedded studs. If the house has a large perimeter, using anchors is suitable. Metal pins should protrude from the structure by 20 cm, their pitch should be no more than 80 cm. The distance between the anchors is marked in advance, then the bolts are screwed in and the Mauerlat is installed. Before fastening, an insulating layer similar to roofing felt is used.

Attaching to armored belt

If the house is built from panel boards or cellular structures, then the installation of a reinforced belt for the Mauerlat will be mandatory. Before fastening the roof, it is important to find out the optimal thickness, manufacturing methods and connection with the armored belt.

The thickness of the armored belt under the Mauerlat

The thickness of the reinforced belt ensures the reliability of the structure. The minimum indicators are 15 cm, the optimal ones are 20 cm. The thickness should not exceed the width of the wall. The minimum cross-section of the reinforced belt is 250 by 250 mm. The structure must be continuous and also have the same strength. The concrete belt is often monolithic and is completed in one pour, then a reinforcing layer with a diameter of at least 10 mm is inserted.

According to SNiP, the reinforcing belt should be one third the size of the wall thickness.

How to make an armored belt correctly

The technology for constructing an armored belt consists of the following stages:

1. Installation of formwork: wooden boards, side supports or threaded rods are used. The length and width of the belt should be the same. The upper edge of the formwork is aligned in a horizontal plane using a water level.
2. Installation of reinforcement cage. The reinforcement mesh consists of longitudinal rods with a diameter of 10-12 mm. The distance between them is from 20 to 40 cm.

How to attach to an armored belt

The Mauerlat is fixed using the same methods - with studs or anchors. Sequence of stages:

• holes are drilled in the timber;
• the Mauerlat is placed on studs or anchors;
• perform isolation;
• secure the bolts with washers and nuts;
• secure the connections with locknuts.

The remaining elements are cut using a grinder.

Features of the Mauerlat device depending on the type of roof

Depending on the type of roof - gable, three or four slopes, as well as hip or single slope, the Mauerlat will have fastening nuances.

For a pitched roof

The support beam for the rafter system of this type of roof requires increasing the height of one wall, since there is no slope. To do this, use the formula for calculating a right triangle. The thickness of the Mauerlat depends on the angle of the pitched roof. First, the top layer of the wall is covered with roofing felt, then the beam is fixed to the wall with anchors. The horizontal position is measured with a level, then the bolts are tightened.

For gable roof

In this case, the device is always fixed on two opposite walls - the roof will rest on them. When building a house from timber or logs, such a device will not be needed. If the house has a load-bearing wall in the center, then the Mauerlat captures 3 points of support - parallel and load-bearing. The distance from the outer edge of the wall should be at least 5 cm.

For a gable roof

The support beam in this design is also installed around the perimeter with support on the load-bearing wall. The device involves distributing the load of the roof onto the walls. A timber with a cross section of 100x100 mm or 150x150 mm is suitable here. Coniferous lumber is used as timber. Before installation, it is treated with an antiseptic. Floor beams are installed on top of the Mauerlat.

Mauerlat for a hipped roof

The hipped roof has a rectangular envelope design or 4 identical triangles. The main goal is to prevent the roof from moving away from the axes of the Mauerlat. The structural elements are fixed on 4 sides of the walls. This is done with studs, anchors or wire, sometimes wooden plugs are used - depending on the material of the walls. A hipped roof is considered the most resistant to wind, but its design still requires the installation of a support beam.

Mauerlat for hip roof

The roof support beam is installed around the perimeter of the walls, as well as on the load-bearing elements of the partitions, if present. To relieve the load on the walls and increase rigidity, a diagonal jumper is installed between two adjacent elements of the Mauerlat. The support beam must have a cross-section of 100x150 mm. In hip roofs it is better to choose a soft roof.

Installation and fastening of rafters to the Mauerlat

After arranging and fixing the support beam, the rafters are installed and secured. There are several rules for this:

• Formation of cuts that ensure a tight fit of the elements to each other.
• Linings should not be used at the junctions with the rafter legs - over time they become thinner and deformed.
• To fix the rafters, metal corners, plates, brackets, bolts, nails, and threaded rods are used.

To ensure the sliding of the rafter legs to the mauerlat, a “sled” is used.

Waterproofing and insulation

The work includes two necessary stages - laying waterproofing under the support beam, as well as insulating it from the inside.

Insulation of the roof mauerlat from the inside

The insulation of the support beam is carried out from the inside of the attic. A layer of vapor barrier is laid in the lower part under the beam. This will prevent vapors from escaping from the room. The support beam itself is massive, so it will be warm in the attic.

When purchasing insulation, pay attention to its moisture resistance, non-toxicity, fire resistance and speed of installation.

Expanded clay, pressed sawdust, mineral wool, polyurethane foam and expanded polystyrene are suitable for insulation.

Waterproofing under the Mauerlat

Protection from moisture occurs at the stage of fixing the support beam. Before attaching it in any way, a waterproofing layer is placed on the wall. This way the cold will not penetrate through gaps in the roof structure. Rolled roofing felt or other materials are used as protection.

Mauerlat is used to prevent the roof from sailing, as well as to tie it to the walls. It is attached with or without an armored belt using studs, anchors, wire or wooden plugs. Depending on the type of roof, the fixation features will vary. The Mauerlat is made from timber, steel profile or boards. The support beam must be insulated and a layer of waterproofing laid.

The roof is one of the main elements of the house, along with the walls and foundation. Without its correct arrangement, the house will not be strong enough and comfortable to live in. The result of a bad roof will be dampness, wet walls, all kinds of diseases and additional heating costs.

The preferred type of roof depends on the climate of the area and prevailing weather conditions. The most common in our conditions are gable ones, which are quite simple to construct and maintain, and reduce the load from snow or other heavenly moisture. Aesthetics play an important role in choosing them.

Types of gable roofs

A gable roof is a fairly simple structure, consisting of two slopes connected to each other at an angle. They form something like a triangle. But despite the simplicity of this figure, triangles are different. Gable roofs also differ from each other.

The main difference between their designs is the angle of inclination. Depending on the type of building and other necessary conditions, it may vary. In addition, the angles at which the slopes are installed may differ from each other. As a result, one of the following types is built:

1. Simple symmetrical;
2. Simple asymmetrical;
3. Broken (the break can be either internal or external).

Each type has its own positive and negative sides, forcing you to choose one or the other builder, depending on the circumstances.

Simple symmetrical roof

Simple symmetrical roof

This type of construction is undoubtedly the most common. It is the easiest option to make yourself. His appearance always looks good. In the end, it is also good because under such a roof there remains a lot of useful attic space.

The name of the structure shows what its distinctive feature is: the slopes form an isosceles triangle. The symmetry of this figure allows it to look proportional on any home.

Simple asymmetrical roof

Simple asymmetrical roof

The main difference from the previous version is also directly reflected in the name. The ridge of this type of roof is shifted to the side and, as a result, the triangle formed by it turns from isosceles to scalene. This design looks modern, so it is well suited for homes in a modern style.

An asymmetrical roof has two important features:

1. Reducing the size of attic spaces;
2. Unequal load distribution.

As a result, this type of design is good for those who need extra space for rooms that can go right up to the roof. But it requires correct calculations.

broken roof

broken roof

This type of construction is the most complex, so not everyone decides to do it with their own hands. Although, in fact, this is quite possible. It’s just important to carry out the correct calculations from the beginning. After all, the main feature is its irregular shape, where the loads are distributed extremely unevenly.

The main advantage of a sloping roof, in addition to its varied appearance, is that it provides maximum free space underneath. As a result, it is possible to equip a full-fledged residential second floor, an attic. Thanks to this feature, it is also called attic.

Rafter system design

The rafter system is the basis of the roof. There are two main design solutions for gable roof rafters:

1. Hanging.

Design of a gable roof truss system

The first of them is used when the house has internal supports, for example, load-bearing walls. In case of their absence, the hanging type is preferable.

But, regardless of what type of rafter system it is decided to build, everyone who wants to know how to build a roof with their own hands must understand the main elements of the structure. Namely:

• Rafter leg or simply rafters. Rafter legs are the basis of the design of the entire system. They are placed on top, along the building, and connected to each other to form a truss. Since they are the ones that support the roof covering, it is important to use durable wood here too. It is desirable that it be a log or timber. Installation is carried out based on pre-made calculations, since it will be very difficult to change something later;
• Rafter post. This structural element helps distribute the load from the rafters. It is a vertically located beam. Its location depends on the type of structure the roof has and its size. If we are talking about a simple symmetrical roof with a small span, then the rack is installed in the center. If the width is large, then two additional ones are placed on the sides. The asymmetrical version involves the location of this element depending on the length of the rafters, and the broken one - two on the sides. True, if there are more than one rooms, then in the latter case an additional rack in the center is needed;
• Run. The main task of the purlins is to connect the rafters, while simultaneously giving them rigidity. The purlins can be ridge or side. The first is located at the very top of the roof, in the area of ​​its ridge. They make purlins from timber. Sometimes boards are used. The most common section is 50 by 150 mm. If the girder is made not only with a ridge, but from several beams or boards on the sides with a large length of the roof, then they are supported by a stand coming from the ridge and resting on the beam. The side purlins are connected to it by means of struts;
• Strut. They are a structure made of beams located at a certain angle and resting on a bench. Their main task is to serve as supports for racks. Can be diagonal or longitudinal. The latter are used most often; they are on the same plane as the rafters. At the same time, the former are necessary if there is an increased snow or wind load in the area. With it, it is also advisable to choose a brace angle of 45 degrees;
• Sill. Located at the very bottom of the structure. If possible, it is placed on an internal load-bearing wall. Its main purpose is to serve as a support for racks. Slopes are attached to it;
• Puff. This element connects the rafter legs, located perpendicularly under them. At the same time, it provides greater structural rigidity;
• Rigel. It also connects the rafter legs, but unlike the tightening, not from below, but from above. Installed with overlap. They make a crossbar from a board of the same cross-section as the rafters themselves;
• Lathing. This element is installed at the final stage of assembling the truss structure, since it is the basis for the covering. It consists of beams and boards that parallelly connect the rafters from top to bottom. In addition to the fact that it serves to secure the roof, the sheathing helps to redistribute the load from it. Therefore, the distance between the elements depends on the material that will be used for coating.

A general understanding of the meaning of each structural element will greatly facilitate the task of building a gable roof with your own hands.

Calculations

Calculating the load on various roof elements is the most important step, since the strength and safety of the structure depends on it. It must be remembered that the triangle is its toughest part.

Loads on rafters can be of three types:

1. Permanent. These are the loads that the rafters feel constantly. For example, the weight of finishing and roofing materials, sheathing, etc. In order to recognize it, it is enough to add up all these weights. Typically the constant load is about 40 kg/m2;
2. Variables. They act at different times with different strengths. These include, for example, wind. In order to calculate the wind load or the load from precipitation, you need to look at the SNiP;
3. Special. We are talking about loads associated with increased seismic activity.

When calculating the load exerted by snow, its weight is multiplied by a set correction factor that takes into account wind pressure. A coefficient depending on the angle of inclination of the roof is also introduced - the lower it is, the greater the load. If the angle exceeds 60 degrees, it is not taken into account.

Tilt angle

The correct calculation of the angle of inclination depends on certain features. Firstly, a lot depends on the chosen material. So, ondulin, corrugated sheets, metal tiles, slate require an angle of 20–45 degrees. And soft roofing - up to 20 degrees.

Secondly, the angle of inclination depends on the climate in which the roof is being built. If there is little precipitation, then you can make it insignificant. And with a large number, it’s the other way around. But it is worth remembering that large angles are subject to large wind loads.

Rafter length

Calculating the length of the rafters is not particularly difficult. It is based on the Pythagorean theorem. The length of the rafter is taken as the hypotenuse of the triangle. And the role of the legs is played by the height of the roof and half the width of the house. It’s worth adding a few tens of centimeters to the resulting value.

Rafter foot step

Their choice depends on the weight of the structure used to cover the roof and the material used. Usually it varies between 60-100 cm.

Rafter section

Calculating the correct required cross-section of rafters is one of the most important points, since this indicator greatly affects the reliability of the structure. This takes into account:

• Loads;
• Rafter length;
• Rafter pitch;
• Material used;
• The type of wood used in the construction of the house.

The higher the pitch of the rafter legs, the higher the cross-section.
The video provides a detailed description of the calculation of the rafter system.

Types of rafter systems

There are two main types of rafter systems from which to choose when erecting a gable roof. We are talking about hanging and layered rafters. Each type is designed for different structures.

Hanging structure

Hanging rafter system

Hanging ones are designed for small houses whose width does not exceed 6–6.5 linear meters. They are not suitable for houses with a wide roof. They are also not used where there is a middle load-bearing wall.

Design features

A design feature of hanging rafters is that they rest on the two outer load-bearing walls. As a result, the system is subject to a strong bursting force. If necessary, it is reduced using a bolt-bolt attached at the bottom.

Attaching to the Mauerlat

The design feature of hanging rafters also dictates how they are attached to the “foundation” of the entire system - the mauerlat. The only mounting option is to use a unit with a zero degree of freedom. Hinges, for example, cannot be used.

Layered system

Layered rafter system

Layered rafters are the only option when it comes to a large roof. But they either require an internal load-bearing wall or specially installed intermediate supports. A support is laid parallel to the Mauerlat, which takes on part of the load from the structure.

Differences between hanging and layered rafters

Hanging rafters do not require intermediate supports or an internal load-bearing wall, but their bursting force greatly influences the structure. At the same time, due to the fact that they also rest on a beam in the middle, layered rafters are easier, including in assembly. They are better suited for larger roofs.

Do-it-yourself gable roof installation

As already noted, a gable roof is especially popular due to the fact that its design allows you to build it yourself. Which is naturally quite attractive for those who like to build themselves or want to save a lot.
The construction of a gable roof structure consists of several large stages, each of which is important to perform correctly. In this case, the roof will stand for a long time and will not collapse.

Installation and fastening of the Mauerlat

Formally, a gable roof can be made without a Mauerlat. In this case, the rafters will rest on the floor beams. But it is not recommended to do this for one simple but important reason - the beams will have to take on additional load from the roof.
The Mauerlat is installed along the wall on which the rafters will rest, parallel to the ridge of the house, as shown in the photo.

Mauerlat

Mauerlat connection

The ends of the beams that will be connected are sawn at an angle of 90 degrees. After the ends are applied to each other, they are fastened with bolts and only with bolts. It is important not to use any other material, such as nails or wire, instead of bolts.

Fastening

The methods for attaching the Mauerlat are based on the fact that it is installed on top of the wall. At the same time, it can be located either strictly in the center of the wall or offset to one of the edges. But it is important to maintain a distance of five centimeters to the outer edge.

A layer of waterproofing is placed between the wall and the timber. A simple roofing material is quite suitable for this.

This will protect the wood from the influence of moisture that may fall on the walls. The mount itself must be as strong as possible, because it will have to withstand wind loads. There are several ways to fix the Mauerlat to the wall.
The methods of attaching the Mauerlat to the walls largely depend on what material the house is being built from.

• If the building is being erected from a monolith, then the best solution is anchor bolts;
• If the house is being built from timber, then the usual solution is wooden dowels. They can be strengthened with additional fastening;
• A fairly common fastening option is staples. They are loved because they are quite versatile, although they are not the most durable solution;
• If the building is constructed from porous materials, such as foam concrete, then the right choice would be to attach the Mauerlat to the reinforcement;
• The hinged fastening, due to the fact that it is sliding, is suitable primarily for those houses that are built from materials that give noticeable shrinkage;
• As an additional fastening, you can use strong, for example, knitting wire. It is not used as an independent option.

The correct choice of fastening will allow the roof to survive the blows of even the strongest winds.

Installation of rafters and racks

There are two options for assembling rafter legs. They can be collected either from above, on the roof, or below, on the ground. The second option is easier to do with your own hands, but it takes more time. The second will require the use of mechanisms, since it is difficult to lift the structure of the rafter system upward manually.

But, one way or another, the manufacture of rafters must be done strictly according to the markings. Special templates that are made from plywood after all the calculations have been made are well suited for this.

Rafter fastening scheme

Before attaching the rafter legs to the mauerlat, you need to make a gash in them. Only rafters can be sawed, since such procedures on the Mauerlat weaken it. Three nails are used for fastening. Two of them are driven in at the edges, and the third must be driven through the upper plane of the structure in the center. Thanks to the use of three nails driven in this way, the rafter leg is well attracted to the mauerlat and does not move.

As for the upper fastening of the rafters to each other, there are three main ways to do this.

1. Without support beam. Rafters can be spliced ​​end-to-end or overlapped. In the first case, the ends are cut so that equal angles are formed. After applying the ends to each other, they are connected using a metal or wooden strip. In addition, a nail is driven in at the top. When joining with an overlap, the ends are cut as required and connected with bolts;
2. Using a support beam. This method is necessary if we are talking about a large roof. The rafters at the ridge are also attached end-to-end or overlapping, but in addition they rest on a beam, which in turn also serves as a support for the racks;
3. Cutting method. It involves cutting the rafter legs into the support beam.

The ridge support is mounted after the two outer rafter legs are installed. Then the racks are attached. And then, the remaining rafters. You can see all this in the photo or video.

Insulation and protection from water

Proper insulation and waterproofing are very important in the domestic climate. Especially when it comes to a roof that is constantly and heavily exposed to the environment. And the moisture that accumulates in the house itself also rises to the attic in the form of steam.

Based on the above, it is important to choose insulation that has a vapor barrier function. Otherwise, its type does not matter. But as for waterproofing, roll types are considered the most suitable. For example, a special film. It can be easily laid directly on the rafters. You can see how this is done in the video.

Installation of sheathing

The sheathing is installed last, but it plays an important role.

Without it, it is inconvenient to move on the roof, and the roofing material puts unnecessary pressure on the rafters. In addition, it allows an air cushion to appear between the roofing material and the insulation.

The design of the sheathing and its pitch depend on what material will be laid on the roof.

1. The lattice sheathing is laid under slate, tiles or metal tiles, and corrugated sheets. In the case of metal tiles, the distance should be 350 mm, and for slate and corrugated sheets - 400 mm;
2. Solid sheathing is used for soft types of covering.

Installation of sheathing

It is made from timber or boards, and if we are talking about soft ones, from plywood, OSB sheets or the same board. They are laid on a beam located along the rafters, as shown in the photo and video.

Calculation of roof area

A gable roof often has a simple shape, so calculating its area is not difficult. But it is extremely important to do this accurately, because the consumption of materials depends on knowledge of the area.

Calculation of roof area

When calculating the roof area, in order to avoid confusion, you should not pay attention to the parameters of various ventilation openings, roof windows or chimneys. You just need to know the height from the ceiling to the ridge and the length of the ridge run. These parameters are multiplied. If you divide the roof area by the sine of the rafter angle, you can find out the area of ​​one slope.

Typical parameters

A design feature that distinguishes a gable roof is that it can be divided into separate standard parts. By calculating the area of ​​each such element separately and adding everything together, you can get the required amount of materials.

Since the roof is made with a slope, you need to know its angle.

The cosine of the angle is needed to determine the exact area of ​​almost all elements.

Typical elements are the rafter legs that form the base of the trusses. In addition to them, there are braces, struts, supports, purlins.

Roofing: selection and installation

Installation of metal roofing

Installation of the roofing is the final stage of the work. But it is preceded by the selection of suitable material. Nowadays, manufacturers offer a huge selection of roofing materials, each of which has its own pros and cons. The choice is always up to the consumer and depends on his aesthetic preferences, financial capabilities and climate.

• Natural tiles. This is a very beautiful, traditional, but at the same time expensive material. Its high price is compensated by a very long service life, unless, of course, it is deliberately damaged or it is exposed to extremely unfavorable weather conditions;
• Metal coating. This roofing is also a fairly traditional solution. Today, manufacturers offer many options for metal roof sheets, differing not only in strength, but also in appearance;
• Wooden roof. A shingle or spindle roof certainly has many aesthetic benefits. But it is quite expensive and susceptible to rotting without special treatment;
• Self-leveling coating. It is considered quite inexpensive and reliable. Belongs to the category of soft coverings. The disadvantage is that it can only be used on roofs with not very steep slopes.

Each type of material is installed in its own way and different fastenings are used for them. Information can be obtained from the video or from the manufacturer. Then the eaves overhangs are installed.

Fastening parts

The ability to correctly fasten the smallest details is the most important in making a roof with your own hands. There are several basic methods for connecting and fastening parts of a roof structure.

So, a groove connection is used to fasten diagonal parts. If we are talking about connecting perpendicular elements, then it is suitable only for those of them where strength is not so important.

Metal corners and plates are also quite popular. They are distinguished by good strength. But the disadvantage is the danger that some screws will turn out from the load. To minimize risks, a combined fastening method is used.

Cost of a gable roof

The cost varies greatly depending on whether the roof is done with your own hands or with the help of craftsmen. In the latter case, it will be significantly more expensive and the price can reach several hundred thousand. In the first case, the main costs will go to materials.

The total price of the structure includes:

• Materials;
• Installation of the Mauerlat;
• Installation of rafter system;
• Installation of waterproofing;
• Installation of sheathing;
• Roof installation.

Carrying out any of these elements yourself reduces the cost of construction.

Finishing the gable with siding

The gable is a prominent part of the house. Therefore, it is customary to use attractive materials for its cladding. This could be a board that matches the roof, plywood or siding. In the case of wooden houses, the pediment can be cut out in advance. This is explained in more detail in the video.
Thanks to the simplicity and accessibility of the design, which allows you to install it yourself, the gable roof has become a truly universal solution. Knowledge of individual features will make it easy to avoid the main problems during its construction.

The question of how to secure a Mauerlat to aerated concrete without an armored belt is quite rare, because such a connection is rather nonsense in construction. To understand this, you need to understand why the armored belt is needed, and what the Mauerlat is and its purpose.

Is this aerated concrete?

But first of all, let us note that the construction of houses from aerated concrete is at the peak of popularity, and the demand for this building material is growing. This means that many people encounter it when building their own houses. What you need to know about aerated concrete:

• belongs to the category of porous materials;
• good thermal insulation qualities;
• not the lowest moisture absorption;
• good load-bearing capacity;
• low strength.

It is the latter characteristic that determines the possibility or impossibility of laying the Mauerlat on aerated concrete. Because the porous structure of the material does not allow it to be heavily loaded, especially pointwise.

As for the Mauerlat itself, it is a structure that is laid on the upper surfaces of the walls. In fact, it performs the functions of a strip foundation, evenly distributing the loads from the roof onto the walls of the house. They are made mainly from wooden beams with a minimum cross-section of 100x100 mm. It should be added that this roofing element simplifies the fastening of the rafter system to the walls.

Armopoyas: design features

Now about the armored belt. Its main task is to fasten the Mauerlat. And if it is not included in the structure of the house being built, then certain problems arise specifically related to the fastening of the mauerlat beam. There are several mounting methods. They are perfectly used by builders if houses are built from more durable materials: brick, stone, concrete blocks.

Mounting methods

So, we are familiar with the main elements indicated by the question of how to attach the Mauerlat to aerated concrete. It remains to figure out the methods and understand one important idea. But the idea is that the proposed fastening options must be accepted with a large number of reservations. Because installing a Mauerlat on aerated concrete blocks without pouring a reinforcing belt is a rather dubious undertaking.

And no matter how much you look for technologies, they will all turn out to be at least of little use. And with each option there are a huge number of contraindications. And although some portals contain a lot of information that it is possible to lay the mauerlat on aerated concrete and secure it, everyone unanimously assures that there are certain criteria that must be taken into account.

Eg:

• you can use this method (without an armored belt) if the structure being constructed is small in size;
• if the roof is a simple structure covered with lightweight roofing materials;
• if the design of the rafter system uses hanging rafters, which are tied together with reliable ties;
• if layered rafter legs are installed, supported along the axis of laying the ridge beam.

By the way, the last option is best suited to this situation. Because part of the load from the roof will fall on the supports under the ridge, this will reduce the load on the walls. And yet, before attaching the Mauerlat to aerated concrete, you need to think carefully about whether it is worth carrying out this process without pouring an armored belt.

Option #1

Fastening the Mauerlat to aerated concrete without an armored belt is best done using steel wire with a diameter of 4–5 mm, which is twisted into 2–4 layers. This method is often used when laying mauerlat timber on brickwork. How this process is carried out. There are several strict requirements:

• the wire must be laid in the masonry of aerated concrete stones in the third or fourth row before the end of the masonry, that is, 3–4 rows of blocks must be laid above the wire;
• the length of the twist should be such that on both sides it reaches the laid mauerlat, overlaps it and twists, creating a fastening;
• The step of laying wire twists is equal to the step of installing rafter legs.

An example of fastening a mauerlat beam using wire

Before laying the Mauerlat without an armored belt on walls made of aerated concrete, the ends of the walls must be waterproofed. The easiest way is to spread the roofing material in two layers. After which the timber itself is laid. It must be aligned either with the outer surface of the wall or with the inner one. Horizontal alignment is required. Then the wire braids are tightened using a pry bar. The main thing is that the screed is strong and tight.

Example of correctly tightened wire braids using a pry bar

It seems that this is the solution to the problem. But let's think sensibly. Strong tightening of gas silicate blocks can lead to cracking of the material, this will be especially noticeable during the operation of the roof, when wind loads act on it. They will make the wire work like a saw. But it is with this tool that blocks are trimmed when it is necessary to adjust them to the required dimensions.

That is, this option, although seemingly correct in use, raises serious doubts. And the more you tighten the Mauerlat with wire, the faster it will cut the blocks.

Option No. 2

Installation of mauerlat timber without reinforced belt using anchors and dowels. For fastening, they suggest using anchors with a length of at least 30 cm, preferably 50. They look like this:

How this process is carried out:

1. After waterproofing their upper ends, a mauerlat is laid on the walls.
2. Every 1-1.2 m in it, as well as simultaneously in aerated concrete blocks, holes are made with a drill and a drill, the diameter of which is selected to match the diameter of the dowel for the anchor.
3. The dowels get clogged.
4. Anchor bolts are screwed into them.

To attach the Mauerlat to aerated concrete without an armored belt, it is better to use anchors with a diameter of at least 12 mm. And one more thing - select a washer of a larger diameter under the nut.

So, can this method really be considered reliable? If this concerned the reinforcing belt made of concrete mortar, then there would be no doubt. This is a one hundred percent reliable mount. With aerated concrete, even if long anchors are used, there is no certainty that this type of fastening will be able to withstand the serious loads emanating from the roof structure. It’s one thing to attach a shelf, cabinet or TV to aerated concrete; it’s another thing when the load from the roof is more than one ton of different materials.

Option #3

Fastening the Mauerlat to an aerated concrete wall using studs. A pin with a diameter of at least 12 mm is used here. It is laid across the wall in a masonry of blocks below the last row by 2-3 blocks. It will turn out that the threaded ends of the studs will stick out from the wall on both sides. Therefore, its length is chosen according to the width of the aerated concrete wall.

In this case, the Mauerlat is laid on aerated concrete in exactly the same way as in previous cases. But the fastening is done with twisted wire. Loops are made at the ends of the steel “braid”, which are put on the ends of the hairpins. That is:

• first, one loop is put on, for example, on the outer end of the fastener;
• it is tightened with an M12 nut with a wide washer placed under it;
• twisted wire is thrown over the wall, and so is the Mauerlat;
• the free loop at the opposite end is inserted into the free end of the hairpin;
• tighten with a nut and washer;
• You will need a pry bar, which is used to tighten the twist on top of the mauerlat beam, that is, to pull the latter to the wall.

We must pay tribute to this method of attaching the Mauerlat to a wall built from aerated blocks. In many respects it is more reliable. Firstly, the wire does not come into contact with the aerated concrete material. This means that there is no load from twisting it that could cut it. Secondly, the stud is laid without violating the integrity of the blocks, which is very important for aerated concrete material. But even this option does not guarantee 100% reliability of the fastener.

Option No. 4

Today we need to talk about innovative fastening methods, because scientific and technological progress does not stand still and offers us new materials that increase the strength of fastening. These are so-called chemical anchors. Essentially, this is the same metal device that is inserted into the wall. But instead of a metal dowel, a two-component adhesive composition is poured into the hole made, which, when in contact with air, quickly polymerizes, forming a strong connection. A steel anchor is inserted into it while the material has not yet become hard.

Today, manufacturers offer two types of chemical dowels:

1. A ready-made two-component composition in a can, onto which a pistol nozzle is attached for ease of supplying the mixture.
2. The composition is in a glass capsule, which must be inserted into the prepared hole. Then an anchor is inserted into it, which breaks the capsule, thus mixing the two components with each other and creating conditions for their contact with air.

The process of attaching the Mauerlat in this way exactly repeats the technology with conventional anchors and metal dowels, which was considered in option No. 2. Only instead of a steel dowel, either a capsule is inserted into the prepared hole, or a composition from a spray can is poured. The most important thing in the latter case is to insert the anchor immediately after filling the mounting hole with a two-component chemical composition.

It should be added that manufacturers of chemical anchors today offer varieties specifically for aerated concrete materials. These are the ones that should be used for fastening.

Now, as for the reliability of the fasteners. This is one of the most reliable options. But there is no information that anyone has already used it. Therefore, we can only speculate. Although theoretically everything should work.

Option #5

The same studs are used here, only they will be installed vertically and serve as anchors. Steel strips with a thickness of 5 mm, a width of 50 mm, and a length equal to the width of the wall are welded to them. The device is installed at the stage of wall construction 2–3 blocks below the upper plane of the end. Therefore, it is important to accurately determine the length of the hairpin. The installation orientation is a strip across the wall. This option is best used if the walls are raised from two blocks, so the studs will be between the blocks without violating their integrity.

A good mounting option, one of the best, but on one condition - the weight of the roof should not be large. In this case, the load on the walls is oblique, so the fasteners work in bending. The wider the strip in the fastening structure, the better.

Generalization on the topic

Several options have been proposed for attaching the Mauerlat without filling the armored belt. It is difficult to say how the entire structure will behave and whether the fasteners will be reliable. Therefore, you should not take risks and avoid expenses. Fill the armored belt and all your problems will be solved instantly.

Correct and strong fastening of rafters when building a house is one of the key points of the entire construction process. Therefore, it is important that all components of the system are accurately selected, installed in place and firmly fastened into a single structure. It is not advisable for a builder to begin installing rafter elements without a pre-drawn diagram and calculation of the quantity and range of required materials and fittings.

The roof truss system is the frame and skeleton of the roof.

Structural basis of the system

The rafters, i.e. the supporting base of the pitched roof, are log or block beams on which the so-called roofing pie is laid. The latter includes a vapor barrier layer, waterproofing material and the final roofing covering. The soles of the rafters, i.e. their lower part, are attached directly to the wall of the building or to the mauerlat. At the top, rafter beams are laid by building them up from separate parts in a straight line, or at the required angle, and are attached to the roof purlin or its ridge.

Hanging rafters can experience deformation loads, including compression and bending, which creates a significant bursting force. This is due to the fact that the fastening is carried out without additional support. This is permissible for the walls of a house, the distance between which does not exceed 6.5 m. Otherwise, a horizontal beam is installed - a tie designed to evenly distribute the load. Very often it is used as the basis of the ceiling.

Figure 1. Elements and connection of layered rafters.

The roof structure with intermediate columnar supports requires the installation of layered rafters. The rafter soles are fixed to the Mauerlat, and the top - to the roof ridge. In the middle, such rafters rest on supporting pillars or intermediate walls. This significantly reduces deformation and overload and makes the fastening of the rafter system strong and durable.

An important part of the load-bearing base of the roof is the Mauerlat. It is made from timber, with a minimum cross-section of 15 x 15 cm. For log cabins, a mauerlat may not be made, but permanent structures made of concrete and brick cannot be built without it. The Mauerlat is installed parallel to the roof ridge on the walls along the length of the house. Why is it necessary to make a reinforced concrete base on the walls with vertical embedded screws. The Mauerlat fits onto these screws and is secured with nuts. (Fig. 1: Rafter fastening diagrams.)

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Accessories for rafters

Metal fasteners are used for the rafter system. It includes:

• steel corner;
• perforated tape for tightening system elements;
• nails, staples, screws, bolts, studs, binding wire;
• metal plates;
• fastening “sleds” to prevent deformation during shrinkage of the structure.

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Connection methods

It is necessary to determine how to fasten the rafters when designing the fastening points. For example, they are attached to the Mauerlat in a rigid way.

For such fastening, “saddles” are cut out on the soles of the rafters according to a template. With their help, the beams are placed on the Mauerlat, which remains solid. The joining of the “saddle” and the Mauerlat is done with nails: one is driven vertically in the middle, and the other two are driven at a slight angle to the supporting beam. You can also use metal corners, for fixing which nails with special spikes on the leg are used. Another fastening option is a support beam installed under the sole of the rafter with a stop.

Elastic fastening of rafters is used in buildings made of beams or logs, since structures made from them experience significant shrinkage in the first years after the construction of the house. Lack of the required fastening play can lead to failure or collapse of the roof. For sliding fastening, a steel angle with elliptical holes for a nail or special fastening “sleds” is used.

To secure the structure, the following tools are required:

• roulette;
• building level;
• square;
• hammer;
• adjustable wrenches;
• electric drill;
• saw;
• screwdriver;
• pencil.

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Roof installation without Mauerlat

If the rafters are fastened directly to the floor beams, a point distribution of the roof's weight results. Therefore, the beams must be elongated and protrude 40 cm beyond the line of the walls. To maintain the same angle when fastening across the beams, it is necessary to tighten the string. It will become a guide when cutting out grooves for the soles of the rafters.

The rafters are attached to the beam in the following ways:

• spiked tooth;
• persistent tooth;
• emphasis at the end of the beam.

The required number of teeth (1 or 2) is determined by the angle of inclination of the rafter base. Having inserted the rafter ends into the grooves, they are additionally fixed to the beams using a bolted connection or steel angles.

When fastening to a beam is carried out by cutting, a single tooth is sufficient. For this method of fastening, you must adhere to the following rules:

1. The beams are connected to the rafter system if an angle of 35° is formed between them.
2. A protrusion with a spike is made at the base of the rafter sole, and a corresponding socket is made in the supporting beam.
3. The depth of the socket should be less than 25 - 30% of the width of the sole.
4. To avoid chipping the end under the pressure of the rafter leg, the notch is made at a distance of 25 - 40 cm from the cantilever end of the beam.
5. Teeth with stops or spikes can prevent lateral displacement;

A hollow roof with an angle of inclination not reaching 35° requires cutting, carried out in the following ways:

1. B 2 spikes;
2. Point blank without spikes or with 1 spike;
3. In a lock with 2 spikes.

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Attaching the ends to the roof ridge

The question of how to attach the rafters to the top beam of the roof is solved using 1 of 3 schemes:

1. Directly with nails or plates, cutting the upper parts of the rafters according to the template at the required angle.
2. For overlapping fastening, long bolts, nails or studs are used.
3. A butt fastening to a roof ridge requires sawing out a “saddle” at the bottom as well as at the top end to support the ridge beam.

Extension of rafters.

To increase the length of the rafters to the size of the roof, you need:

1. Make an oblique cut and connect the segments with a bolt with a diameter of 10-12 mm or more;
2. Connect end-to-end and secure with overlay beams, which are fixed with nails;
3. Connect with an overlap of at least 1 m to the cutout, placing the fasteners on both sides.

The Mauerlat belt is the basis for the rafters. The lifespan of the entire roof depends on how strong you make it, how you secure it and think through the connection with the rafter system. So what is a Mauerlat for a gable roof, what is it made of, how to mount it on a brick, frame wall and wall made of hydrophobic gas blocks? What pitfalls might there be and what mistakes should you avoid? It is precisely in order to answer all these questions that we have prepared this useful article for you.

By the way, if you heard from builders or a foreman you know such a word as murlat, this is the same mauerlat, only in common parlance. This is exactly what we will be talking about.

Mauerlat is a stable structure that is laid around the perimeter of the walls and serves as the basis for attaching the rafters. The main task of the Mauerlat is to distribute the loads of the roof overhangs as evenly as possible and firmly tie the roof itself to the overall structure of the house. In other words, this is the very connecting link between the walls and the roof, and therefore its production must be started with special responsibility.

The secondary task of the Mauerlat is to reduce to a minimum the so-called windage of the roof, i.e. its ability to be torn by the dashing wind.

But why then, if this is so important, are there roofs without any Mauerlat at all? Yes, such a practice exists. The rafters are simply attached to the floor beams, if they are strong enough. But in this case, all the concentrated loads of the roof fall on the places where the rafters support, whereas the Mauerlat would distribute them over all the walls. What do you think is better and safer?

What materials can it be made from?

This roofing element is made of wooden beams, I-beams, channels or metal.

Option #1 – durable timber

So, depending on the future weight of your roof, use timber with the following cross-section as the material for making the Mauerlat: 10x10, 10x15, 8x18, 15x15 or 20x20 cm. You just need to place it under the rafters along the entire perimeter of the roof to evenly distribute the load on walls of the house.

So, if you have already chosen wood for the mauerlat, pay attention that the knots on it in no case exceed two-thirds of the thickness in their length. What's the catch? The fact is that knots are dangerous not because of the release of resin, as many people think. It’s just that these places on the beam will ultimately work poorly in tension, and yet the Mauerlat is the one that experiences the heaviest loads of all other roof elements. What are the consequences of a poor choice of wood for this purpose? Cracks!

Option #2 – bonded boards

But, if you are building a light frame house and no special loads are planned on the roof, then save money and instead of a heavy solid beam, use fastened boards as a mauerlat.

Option #3 – steel pipes

Often, additional beams made of steel pipes are used when constructing the Mauerlat. It looks like this: the wooden Mauerlat no longer protrudes beyond the perimeter of the building, but pipes are attached to its ends, which serve as the main support for the gable roof. Moreover, there are a number of serious requirements for pipes:

• Small section. The pipes pass through holes in the rafters.
• Exceptional strength. The whole roof is on them!
• High quality steel. It is important that such a supporting element does not deform over time.

Make holes in the rafters strictly along the axis, with a diameter 10 cm less than the height of the rafter leg. If this does not work, attach additional steel elements. Steel pipes work well for bending, and the fact that they require small round holes is also good. Such “damage” has almost no effect on the strength of the rafters themselves.

The main advantage of this design is that here the wooden Mauerlat is hidden under the roof, and is already more protected from smudges and melting snow.

Mounting the Mauerlat on the wall: 2 ways

So, we selected the material and made the Mauerlat. Now let's decide whether he needs a reinforced belt. They are usually built on walls that are not strong enough so that the future roof has something to rest on:

Method #1 – installation without armored belt

But even for a strong overall building, a reinforced belt will not be superfluous, because It’s convenient to make special fastenings for the Mauerlat through it.

Method #2 – installation on an armored belt

The most difficult thing is to make a mauerlat on aerated concrete - the most fragile wall material. We advise you to make a structure on it for this purpose from more durable brick or concrete, because... the Mauerlat needs a solid base. But just an armored belt will do. Moreover, you can easily cope with this important construction task:

Calculate the thickness of the reinforced belt based on the loads that will affect your roof: both permanent, in the form of the weight of the rafter system and roofing, and temporary, in the form of winds and snow. But in any case, the width of the armored belt should not be less than that of the load-bearing wall. The minimum limit is 25x25 cm. And do not forget that the pressure on the main walls of the house is exerted not only by the Mauerlat, but also by those posts and ridge beams that rest on the internal floors. And for them, too, you need to build an armored belt.

To make the reinforced belt strong, use a concrete grade of at least M400 and pour the entire belt in one go. Of course, for this it is advisable to use a concrete mixer with a pump. To prepare the mixture, take cement, washed sand and crushed stone in a ratio of 1:3:3. Additionally, add modern plasticizers to reduce the amount of water used in the mixture and thereby increase the strength of the future belt.

Additionally, this short video will help you understand everything:

We construct the formwork

It is important that the armored belt is continuous on both sides of the external walls of the house. And special U-shaped blocks can serve as a kind of formwork for constructing an armored belt. You can also complete the outer row with sawn blocks up to 10 cm wide, or build formwork from OSB boards. Even ordinary wooden boards will help. But, no matter what formwork you make, be sure to check its upper edge with a water level.

If, due to some design feature of the building, you still have to interrupt the reinforced belt, then do it according to the same successful principle as in this project:

Choosing a mount

On frame walls and walls made of logs or timber, the Mauerlat is attached with screws, self-tapping screws and even ordinary nails. For greater strength, special perforated connectors are used.

Also, if the area of ​​your house is large and the roof is at least 250 m2, then you need to attach the Mauerlat to the walls with studs. Studs are long metal pins with threads, which are distributed at the place where the Mauerlat is attached so that it happens at least every 2 meters, plus always at the ends.

First, an armored belt is poured around the perimeter of the walls - a concrete screed, and then the studs are embedded vertically, one after another. The height of each should remain greater than the thickness of the Mauerlat, and remain at least 3 cm higher. This is the only way you can firmly tighten the Mauerlat with nuts and a washer.

As you can see, nothing complicated:

And another way:

Strong metal brackets for attaching the Mauerlat are also convenient to some extent:

And also do not forget about anchors and twisted wire, which works great in tension:

Using wire rod - thick wire - is the easiest method of all. So, between the rows of bricks, 3-4 rows before the top masonry, a piece of wire is placed in the middle so that the ends are enough after finishing the masonry to tie the entire mauerlat. Then the remaining ends are hidden in the thickness of the wall between the bricks.

They do it differently. It is not the studs that are embedded vertically into the reinforced belt, but the pins of the reinforcement itself so that they are lower than the height of the mauerlat. And studs of only 4-5 cm or long bolts with pre-cut heads are already welded to them.

Another popular method is that pins or studs are embedded in the brick wall during the laying process. But this technique is only suitable for small roofs, and for greater reliability, take longer studs.

We reinforce the belt

So, if you don’t use any of the things proposed to attach the Mauerlat, then simply leave the protruding rods from the reinforcement, and put the beam itself on them after the concrete has hardened. So, even on the shortest wall, the armored belt should have at least four metal rods of 12 mm in diameter - for attaching the Mauerlat. Moreover, with such rods you can not only string the Mauerlat, but also secure it from the outside:

But in any case, even if you chose pins or wire, there should be reinforcement in the belt.

Fill with concrete

When making such an armored belt, make the thickness of the concrete at least 5 cm. As soon as the concrete is laid, make sure that no air cavities form in the armored belt - you will notice them by bubbles. Why is this bad? All this reduces the strength and uniformity of the structure, but on the belt you still have to install a mauerlat - the foundation of the roof. Therefore, simply pierce the concrete with a reinforcing bar along its entire length, and the air lenses will disappear.

The formwork must be removed on day 10-12, when the concrete has already gained its strength.

We put waterproofing

But this point is required!

Place a layer of roofing felt as insulation or other similar waterproofing material on the finished armored belt. A tree is a tree, and it is better for it not to come into contact with wet wood.

All the subtleties and nuances of installation

Your most important task when installing the Mauerlat is to constantly check the horizontal position with a building level. If you find an unevenness, even a small one, correct it immediately: cut off the protruding parts, and raise those that are below the level using linings.

Now prepare a beam that will serve as a mauerlat. Treat it with a disinfectant and fire retardant (against fire), and dry it well. Attach the beam to the future location of fastening and make marks where the holes will then be drilled. Connect the individual parts of the Mauerlat with a straight lock and additionally secure them with nails at the places of such connections.

Fasten the timber at the corners with a straight lock or an oblique cut - whichever is more convenient for you. Attach the Mauerlat to these boards using corners, dowels or metal brackets. But for the sake of economy, just don’t use the board that was fixed in advance in the upper groove of the SIP panels (if you are building from this very material) - this is completely unreliable and is fraught with future distortion of the roof, destruction of the panels themselves under the weight of the roof and other disastrous results.

And finally, secure all connections on the Mauerlat with locknuts, and cut off all protruding studs with a grinder.

We build a “bench” on the Mauerlat

As soon as the Mauerlat is laid, we proceed to the construction of the so-called “bench”:

• Step 1. Measure the distance between the opposite Mauerlats.
• Step 2. Divide this distance in half and mark the middle of the span.
• Step 3. Connect the marks so that you get the axis of the future “bench”.

It is along this axis that you will lay the bottom run. The most convenient option is to make the “bench” with the bottom girder immediately intact, in a horizontal position, and then lift it and secure it vertically along the axis of the floor.

Fastening the rafters: all popular methods

Because The main task of the maueralat is to distribute the loads from the roof; be sure to pay special attention to attaching the rafters to it. The fact is that it depends on whether the roof will move over time, whether it will begin to sag or create stronger loads on one of the walls. This is serious!

There are two technologies for tying rafters to the Mauerlat:

• Tough. Here, any displacement of the rafter leg, bends or shifts is completely eliminated. For stability, a hemming block is used, which prevents the rafter leg from slipping. And the metal corners prevent the rafters from moving to the sides.
• sliding. Such fastening is necessary if the house was built from logs or timber, which noticeably settle over time. And the Mauerlat itself is usually not used here - only the upper crown of the log house. If you use a rigid rafter fastening system, then the next year the roof will lose up to 50% of its strength - it will simply fail.

And now about everything in more detail.

Most often, when constructing a roof, wooden rafters are used, as they are the most affordable and easy to process. But wood is bad because it quickly absorbs moisture and swells just as quickly, although it returns to its previous size after drying. And it is especially important to correctly fasten the wooden rafters to the mauerlat in order to prevent the formation of the so-called expansion force during a wet hike. Which, in turn, can significantly reduce the durability and reliability of the entire structure.

The main task of rigid fastening is to completely eliminate the possibility of rafters moving in any direction. Here, the saddle of the cutout on the rafter is rested against the Mauerlat and firmly fixed with nails driven at an angle. But it is extremely important that all such cutouts on the rafters are the same, according to the same pattern and no more than 1/3 of the width of the rafters.

The second method is single fastening with a special fastening plate. Additionally, in some cases, a meter-long beam is hemmed under the rafter, which also serves as a stop, and the fastening is done with a metal corner.

A sliding mount is also called a hinged mount, and for good reason. Keep in mind that different wooden houses shrink differently. So, laminated veneer lumber sags the least over time, and the most is a fresh log house, which drops to 15% in just a year! Moreover, the shrinkage itself always occurs unevenly, which has an even greater impact on the distortion of the entire rafter system - if you have not installed a sliding fastening.

Roof distortion also occurs during the operation of the house itself. Thus, during prolonged rains, wood swells greatly, and in winter it loses a large percentage of moisture and dries out noticeably. Moreover, they settle in completely different ways:

• south and north side;
• the side that constantly receives moist river or sea air, and the drier side;
• the side blown by the winds and the one in front of which there is a utility building;
• hidden from the sun by a tree and open.

During all this time, the geometric parameters of the log house are constantly changing. Moreover, even the central wall of the house, on which the racks and beams of the rafter system rest, changes its parameters. Especially during the winter heating period, when it dries out noticeably. Therefore, if the rafters on the mauerlat or the upper crown of the log house are firmly secured, then in winter the snow load will cause the rafter system to bend.

Therefore, the knot needs to be a little loose, for which you will need a fastening element such as a “sled” or “slider”, as people like to call it. This is a special metal part that looks like a loop. When the geometry of the log house naturally changes, it moves along the guide, and the rafters settle a little without any harm to the entire system.

Here's more detail about the process itself:

By the way, some roofers still perform sliding angles using more traditional methods. To do this, they make a cut in the rafter leg, place the beam with a cut on the upper crown and secure it in the following ways:

• With staples.
• Crossing nails in the mauerlat.
• One nail driven vertically.
• Stylish fixing plates.

Also, as a good alternative to a modern sliding support, use strong forged wire, twisted twice (we talked about it in the paragraph on attaching the Mauerlat to the wall). It works well in tension and gives a certain degree of freedom to all elements of the roof structure.

As you can see, everything can be sorted out!