Assembling the gable roof rafters. Installation of rafters on a gable roof Mauerlat

Mauerlat (from the German word Mauerlatte) is a system of beams that are attached to the outer surface of the floor of the house along its entire perimeter. They take the full load of podstropilnyh structures and roofing, and so actually determine the strength of the roof.

Materials for the manufacture of Mauerlat

For reasons of safety and durability of the building, wood is used almost exclusively for arranging the Mauerlat. Sometimes (with metal structures of rafters) and the Mauerlat are also made of steel, using profile rolled metal from 09G2S construction steel, but this case can only occur during the construction of two- or three-story houses. It will require a particularly careful laying of lightning rods and a grounding system.

A wooden Mauerlat is made of hardwood, and the surface of the wood must have normal (up to 8%) moisture content, and must be pre-antiseptic. It is not recommended to use pine for the Mauerlat: its softness and resinous incrustations will not only complicate the work on the construction of truss structures, but will also determine its possible subsequent deformations.

So the answer to the question, what is roof Mauerlat - clear: it is a wooden square or rectangular beam, joined together taking into account the natural shrinkage of the wood. Boards are laid on the outer edge of the wall is indented inward 40 ... 50 mm.

How thick should the Mauerlat be

The cross-sectional dimensions of the beams are determined by the following factors:

1. The size of the perimeter of the house, as well as its number of storeys and design features (for example, it is assumed in the house attic or not).
2. The selected material for the roof.
3. The height and shape of the rafters.
4. The climatic conditions of the construction area.

The minimum thickness of the beams is taken for ondulin coatings, and the maximum thickness is for profiled flooring.

For instance, for classic gable roof Mauerlat parameters are calculated in the following sequence:

• The width of the beam is set - for one-story buildings with a low slope of the slope, a beam with a section of 100 × 100 mm is usually taken, in other cases 150 × 150 mm;
• According to the known cross-sectional area and the length of the perimeter, the mass of the beams is set;
• At a distance of 400 ... 500 mm in the section of the Mauerlat, grooves must be cut for the rafter posts. Their section should be such that the depth of the grooves is at least 50 ... 60% of the thickness of the timber. The specified step values \u200b\u200bcan be adjusted to ensure the uniformity of the relative position of the racks.

Mauerlat laying

Before installing the Mauerlat beams, the roof must be waterproofed. It can be single or double layer. The waterproofing film is placed under the beams, but before that it is necessary to check the geometry of the Mauerlat. This check is carried out by measuring the diagonals of the system: if the values \u200b\u200bmatch, then the work can be continued.

For wooden houses, the beams are fastened to the walls either with steel wire made of ductile steel, or using anchor bolts. The latter method is more reliable because mauerlat protects against displacement during the works on the construction of the rafters.

For houses made of concrete, slag and foam blocks, an armopoyas is laid under the Mauerlat. This is a monolithic reinforced concrete screed that will serve as a support for the beams. The minimum allowable height of an armored belt should be 150… 200 mm. Its styling is made the same as in the regeneration of reinforced concrete foundation. Anchor bolts are placed evenly around the perimeter Laying nets before pouring the concrete.

The fastening of the Mauerlat beams in the corners is carried out using steel pins, for which the extreme beams are performed with a bevel of 45 0.

Is it possible roof without Mauerlat? With a low weight of the roof (along with the rafters), this option is not excluded. In this case, the armored belt should be of the maximum height in order to reliably attach all the rafter structures to it. For fastening use anchor bolts, the number of which should correspond to the number of rafter legs.

You can clearly see what the roof Mauerlat looks like in the video:

The roof of the house consists of two main components - the rafter system and the Mauerlat. Mauerlat is a framework that serves reliable fastening for rafter beams. When building a roof, it is extremely important to calculate in detail the dimensions of the building materials for an accurate and reliable structure. Consider the basic rules and tips for measuring the Mauerlat to obtain the material of the required dimensions.

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Calculation of the size of the mauerlat

The construction of the roof begins with the Mauerlat, it serves as a support for the rest of the roof structure, ensures its stability and evenly distributes the weight of the structure along the walls of the house. That is why it is very important to accurately calculate the size of the Mauerlat.

Mauerlat dimensions depend on the following factors:

1. The parameters of the area of \u200b\u200bthe house are its perimeter and area.
2. Roof construction type.
3. Material used in the rafter system and for covering the roof.
4. Climatic conditions.
5. Whether the area is attic or not.

The main indicator for calculating the Mauerlat is the type of roof. The roof structure can be different types , here are the main ones:

1. Classic - one-pitched, two-pitched, three-pitched or four-pitched roof.
2. Cruciform.
3. Folded.
4. Flat.
5. Spherical.
6. Hip, semi-oval and hip.
7. Spire-shaped.

So, to calculate the Mauerlat, you need to know what type of roof it will be used for. We will look at how to calculate the dimensions of the Mauerlat for a classic gable roof. But before proceeding to consider the Mauerlat for a specific type of roof, you should find out the design parameters common to all types of roofs.

Formula for calculation

When measuring the Mauerlat, firstly you should measure its length and perimeter... The upper part of the bar should be measured. Minimum cross section Mauerlat - 100 × 100 mm.

• r is the density of the tree;
• V is the volume of the Mauerlat;
• m - as you might have guessed represents the mass of a wooden beam.

The Mauerlat volume is calculated by the following formula:

• S - section of a wooden bar;
• L is its length or perimeter.

1. Whatever the size of the Mauerlat, the main thing is to place it at a distance of at least 5 cm from the outer edge of the wall.
2. For most cases, a 100 × 150 mm antiseptic hardwood bar is suitable.
3. You should lay out wooden beams along the entire length of the walls, from one end of the house to the other.
4. Next, you should take the necessary measurements, making sure that the distance between the bars is uniform along the entire length of the installation.

Also, when calculating the parameters of the Mauerlat, the volume of the roof structure should also be taken into account, mass rafter system .

Calculations for a gable roof

The gable roof is the most popular and simple type of roofing. Due to its inclined design, it provides a natural runoff of precipitation in the form of melted snow or rainwater from the roof surface. Installing a Mauerlat for a gable roof requires considerable costs and time-consuming work, but it ensures the durability and resistance of the roof structure.

Suitable for a gable roof wooden beams 10 × 10 or 15 × 15 cm.The thickness of the Mauerlat should not be less than 10 cm, and the indent from the edge of the outer edge of the wall should be at least 6 cm. waterproofing material, the distance between the layers should be at least 40 cm. You should also install racks cut into the beds. The distance between them should be 3 to 5 meters.

Summing up, we can saythat for the calculation of the Mauerlat, many factors should be taken into account that determine the appropriate parameters of the material for fastening. In conclusion, we present the main parameters of the Mauerlat, suitable in most cases:

1. The width of the Mauerlat should not be less than 10 cm.
2. The optimal section of wooden beams is 10 × 15 cm.
3. A suitable material for mauerlat - antiseptic bars made of hardwood.
4. When calculating the mass and volume of the Mauerlat, be guided by the formula above.
5. The distance of the timber from the edge of the wall should be at least 5 cm.
6. The distance between the bars of the Mauerlat should be uniform on all sections of the structure.

For a secure and long-term roof attachment, it is very important to make accurate measurements of the Mauerlat... By following the above tips, you will be able to get the fastening material you need. Then you can safely proceed with the installation of the roof structure.

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Mauerlat Is a wooden beam that is laid on the walls of a house in order to transfer and distribute the load from the weight of the roof, snow and wind loads from rafters or floor beams on the walls. Due to the difficulty of pronouncing the word "", many builders give it other names, for example, murlat, matitsa, uterus, etc.

The construction of any roof begins with the installation of a Mauerlat. An exception is the construction of a log roof, or frame wooden houses... Here, as the upper crown mauerlat used logs, either the upper beam.

As a Mauerlat, a 150x100 or 150x150 bar is most often used. It is better to lay it flush with the inner surface of the house wall. Outside, there will be more than do for mauerlat protective barrier of masonry. Do not forget to make waterproofing to protect the tree. Two layers of roofing material will be enough.

Frankly, I had not paid enough attention to the mounting mauerlat walls of the house. I thought the roof was so heavy, well, where will it go. And there are no tornadoes like in America in our region. But one day, about six years ago, after another summer hurricane, I saw such a picture on one of the streets of our city. There is a house, and next to it, literally five meters from it, lies the already dilapidated roof of this house. It got me thinking.

There are several ways to attach the Mauerlat to the walls:

1 way: wooden blocks are embedded in the brickwork two or three rows below the top of the wall and the Mauerlat is attached to them with staples;

Method 2: when building walls from cellular blocks (foam concrete, etc.), it is necessary to make a reinforced concrete belt under the roof. So, directly when pouring this belt, threaded rods are laid into it. Then, holes are drilled in the Mauerlat beams for these pins and the beams are installed on them, after which they are attracted to the wall with nuts and washers. Studs can be used with a diameter of 12-14 mm. They must be installed every 1.5-2 meters, at least.

Method 3: similar to the second method, during construction brick walls build into the studs directly into the brickwork to a depth of at least 3 rows of bricks.

By the way, in order to save money, you can use simple fittings instead of studs, and weld the nuts to it by welding.

Method 4: a thick (3-4 mm) steel wire is also inserted into the brickwork 3 rows below the top of the wall, the ends of which go out and in and have a length sufficient to tie the Mauerlat.

Often, when installing a Mauerlat, it is necessary to splicate the bars. This is done by cutting the beams into a half-tree and fastening them either with bolts or nails.

All of the above methods, at the request of the customer, I had to use, some more often, some less often. But in last years I do it my own way more and more often. In general, I always try to simplify and facilitate the work as much as possible. We use 50x150 mm edged boards as Mauerlat. First, lay out one row of boards on the walls. We fix them with anchor screws (propellers precisely - under the bonnet screwdriver, bolt heads will interfere). Length of anchors not less than 20 cm. Holes in brickwork or a reinforced concrete belt we do using a perforator, having previously drilled a board with an ordinary drill.

After that, lay out another row of boards and nail them to the first one with simple nails 100 mm long. We make the joints of the boards in other places, thereby carrying out the dressing. In the corners of the board, we also put it with a bandage. Thus, we get a Mauerlat 100 mm thick, which is, in principle, sufficient.

We use this method for several reasons. First, it is easier to lift the boards to a height than the parallel bars. Secondly, there is no need to cut into a half-tree. Well, there is also such a moment: it happens when, for example, the walls were laid out by other builders, and we are making the roof. Of course, bricklayers most often do not lay any kind of studs, embedded bars or wire. We have to work with what we have.

In conclusion, I want to say once again that the roof is like a large sail, so it is better to spend a little time and fix it more securely so that in a strong wind it would not even be able to move along the walls.

Or any other) of a modern private house starts with a Mauerlat. Mauerlat for roof - this is the base, the beam, which is fixed along the perimeter of the top of the outer walls. It serves to evenly distribute temporary and permanent loads from the roofing system to the walls and ensures the rigidity of the roof, "ties" it to the bearing walls.

Some builders prefer to lay the Mauerlat directly under the rafters, or do without it, but both options are not correct, since the strength and rigidity of the roof structure is lost. further in our article, we will try to tell you what a roof Mauerlat is and consider how does the Mauerlat mount to the wall building.

1. Mauerlat device: its dimensions and material

Figure 1. Variants of the maurlat device

Used by roof Mauerlat not only for gable roofs, it is also used for single-pitched and flat versions. Depending on the roof structure, mauerlat devices and mounts use a bar with a dimensional section of 100 × 100mm.

There is an unspoken rule - the section of the bar is equal to 1/3 of the thickness of the wall on which it will rest.

The timber should have a moisture content of no more than 20%, preferably with a preliminary impregnation with an antiseptic in order to remove the likelihood of insects in the wood. The Mauerlat is laid only on those walls on which the rafter system will rely, that is: if the roof structure provides only a standard gable version with gables, then the Mauerlat is mounted only on longitudinal walls, perpendicular to the gables, if the roof type is four-pitched, along the entire perimeter.

Figure 2. Variants of joining (connection) joining of maurlat beams

In the case of a difference in the size of the Mauerlat and the wall, the Mauerlat device is arranged so that its pieces fit together with the maximum length of each part. That is, at standard size lumber - 6m, and the length of the wall is 7m, use 2 beams 3.5m long, but not 6m and 1m. connections of mauerlat bars produce washed down on half of the beam section. The junction of the Mauerlat is nailed with nails 150 mm long in an amount of at least 6 pieces, and fixed in the masonry.

When joining the beams in the corners, the same gash is made with hammering staples with reinforcement with a diameter of at least 10 mm into both beams.

It is necessary to hammer in the bracket so that it is the hypotenuse of an isosceles right triangle.

The Mauerlat is located closer to the inner edge (indentation is at least 5 cm from the edge), or along the central axis of the wall. This is done for further ease of installation of the roof system and a secure fit most beam in the thickness of the masonry.

2. Methods for attaching the Mauerlat to the wall: basic mounting options

Figure 3. Methods for attaching the Mauerlat to the wall

Before installing the Mauerlat, it is necessary to arrange waterproofing for it. Although there is a huge variety of mastics, an ordinary sheet roofing material is suitable for this, which can be laid directly on the mounting surface, and also wrap the Mauerlat itself with it, securing the material with a stapler.

Figure 4. Roof Mauerlat: construction of a waterproofing layer

Fastening the Mauerlat beam to the wall can be completely different, the only requirement is the rigidity of the fasteners. This can be wire strapping, laid in the wall during laying, or fixing the beam with a bracket nailed to the bars previously left in the masonry, it can also be drilled into the holes in the beam and wall, into which the reinforcement is hammered with a further bend.

But the most reliable are two options mounting the Mauerlat to the wall :

• the first one is to drill holes in the timber and masonry, hammer anchor pins into the hole and fix it with a nut and washer (without an armature belt device);
• the second is the installation of the Mauerlat on the anchors previously left in the masonry (using an armature belt).

Both versions of their labor-intensive, but the probability of "slip" timber is almost equal to zero. The step of attaching the Mauerlat to the wall is at least 1m. The hole depth is not less than 200mm in the thickness of the masonry. The diameter of the anchor to be driven in must be from 10mm.

Mauerlat for the roof is the foundation on which a huge number of loads act: wind, snow, the load of the roofing system itself from the influence of these factors. But all this is compensated by the reliably and firmly installed Mauerlat. Do not neglect the basic rules set forth above when installing it and the comfort in your home will be provided for many years.

The Mauerlat for the roof is like the foundation for the entire building. It is this bar that is considered. It takes on the load transmitted by the rafters and distributes it evenly along the walls of the building. This function is important for the strength of the house and its longevity. Also, the mauerlat is called a mother log, mother or uterus and, as a rule, it is made from a bar with a large section. When self-erecting housing, users may encounter a number of problems. In particular, questions such as: how thick should the Mauerlat be, or how is this element correctly mounted? To answer them, it is worth considering in detail the technology for installing the matrix, the parameters on which the specific choice of a log or bar depends, as well as the sizes recommended by the standards for the Mauerlat.

Mauerlat features

We can say that it is the Mauerlat that is one of the main elements of the roof. This beam is part of the rafter system and the base of the entire roof. If you build a house without it, then the point load from the rafter legs will exert pressure only in certain places on the wall and over time the strength of the entire structure will noticeably deteriorate. In addition, the Mauerlat beam is necessary to fix the roofing structure, that is, the mat is firmly mounted to the walls, and the rafters are already fixed to it, read more:. The element is laid with a small indent from the edge of the wall, which means that the thickness of the Mauerlat cannot be wider than the wall itself. Such a detail is necessary for buildings made of a wide variety of materials, while depending on the type of building, the design and fastening of the Mauerlat may change.

If the house is made of brick, then an armored belt of concrete should be mounted to secure the beam. Metal anchors or reinforcement are inserted into this layer, on which the Mauerlat is installed in the future, read more:. If you want to build a roof on wooden structure, then the functions of the Mauerlat are performed by the crown, that is, the upper beam or beam, also fixed to the anchor with several lower beams, or additionally tied into a single system with strong wire. On buildings where the main frame is made of metal, it is recommended to use a metal I-beam or channel for the Mauerlat. The most common Mauerlat section is 15x15 cm. However, in different situations, this parameter may differ significantly. What is important to consider when calculating basic dimensions? Will consider this issue in detail.

Criteria for calculating the Mauerlat

In order for the uterine beams to really reliably cope with their main function, it is important to perform this element in accordance with all the rules and in compliance with the prescribed technologies. Determining the size of the Mauerlat is based on 5 main criteria.

1. The parameters of the house, specifically the perimeter and its area.
2. Materials used for building walls, rafters and roof topcoats.
3. The presence of an attic floor.
4. Climatic features of the region.
5. Roof construction type.

At the same time, the parameters of the Mauerlat will largely depend on the type of roofing system. The roof structure can have a wide variety of varieties, here are just the most popular:

• roof with slopes - one-, two, four-slope and so on;
• hipped or domed roofs;
• hip and half hip;
• flat structures;
• cruciform or broken.

Depending on the specific type, the calculation of the Mauerlat will also change, and the basic values \u200b\u200bof this element will change accordingly. To understand how to make a calculation, you should use special formulas.

General design parameters

The reliability of the entire house and the roof in particular depends on the correct choice of timber for the Mauerlat device. The Mauerlat section can be square or rectangular - these are the most optimal options that allow you to achieve maximum stability of the element. Since, using round logs, it will be necessary to trim one of the sides, which should adjoin the wall. Of course, without special tools, it will not be possible to do it perfectly exactly, which means that there is a possibility of distortion of the rafter system in the future. Therefore, it is optimal to use a ready-made timber, the cross-section of which varies within 10-25 cm.In this case, the size of the Mauerlat should be at least 1/3 of the thickness load-bearing wallsbut not too big. If the beam is massive, then it will create an additional load on the structure of the building, but this will not add strength to the roof. As for the length, it is optimal to use a bar equal to the wall in this parameter. If there is no such possibility and it will be necessary to dock two elements together, then in this case it is important to use segments equal in length or minimally differing. The connection is made by the overlap method, that is, the upper half is cut out at the end of one beam, the lower half at the other, and then the two ends are superimposed and fastened through with bolts or nails.

To understand what the Mauerlat's height, width and other parameters should be, you should calculate the volume of a wooden beam and its weight. To do this, you can use simple formulas. To calculate mass: m \u003d rV, where r is the density of the wood and V is the volume. Accordingly, to find the volume, it is worth using the formulas: V \u003d SL, where S is the section and L is the length. If all the main parameters can be measured independently, then it is quite easy to find out the density of wood from special tables, in addition, many lumber manufacturers describe in detail the characteristics of the goods sold. In particular, such species as Siberian fir, pine, spruce, linden and others have the lowest density. Having all the parameters, it remains only to substitute them in the formulas and get the result of the calculations.

In construction GOSTs and SNiPs, the recommended size of the Mauerlat is described in detail. In particular, the most optimal option is the use of a hardwood bar, the cross-section of which is 10x15 cm.Variations such as 10x10 or 15x15 are also possible. That is, you should not use a beam whose width is less than 10 cm, since it will not be highly durable. A wooden beam more than 25 cm wide will exert tremendous pressure on the walls of the building, and, therefore, also will not make it more reliable and durable. It is important to remember that there must be an indentation of at least 5-6 cm from the edge of the wall. the same number of rafter legs rested. This will allow the most even distribution of the load.

Of course, it is important not only to correctly calculate the dimensions of the Mauerlat, but also to choose the highest quality wood for installation. So experts recommend using lumber conifers, which is compulsorily treated with antiseptic drugs, fire retardants and hydrophobic compounds. This will help protect the wood from fire, water, fungus, insects and other nuisances that can reduce the strength of the material.