Is a Mauerlat necessary? Mauerlat for a gable roof: we make the right base for the rafter system. How is the gable truss system calculated
On the structure of rafters, lathing and roofing material many forces are at work. The lingering snow presses with its whole mass, the wind tries to tear it off. To prevent the roof from “driving” at your house, there is a time-tested building technique - the Mauerlat device.
Mauerlat - what is it and is it always needed? Photo
Builders, like most professionals, have a lot of tricky words that often confuse ordinary people. Almost everyone knows what a "base" is. But what is a Mauerlat and why is it needed - to a few. So let's tell you a secret: Mauerlat- this is what the roof rests on, more precisely, its entire truss system. In fact, this is the foundation, the foundation of the roof, which combines all its elements into a single structure.
Mauerlat performs two functions:
- Compensates for the bursting force from the rafters.
- Holds the roof on the wall.
If there is snow on the roof, especially melted snow, then the force of gravity generated by it is weakened by the value of the sine roof pitch angle. In addition to reducing the perceived load, the slope also changes the direction of the force acting on it. It becomes not vertical, but directed slightly to the side, outward. This is the pushing force.
Its value can be so significant that if the wall is made of discrete material (brick, aerated concrete blocks, concrete panels), then a rafter tree fixed directly on it can destroy the masonry. The solution to the problem is to fix a long beam on the upper edge of the wall - Mauerlat. The roof truss system is attached to it. For reliability, the mauerlat is laid around the entire perimeter of the upper edge of the main wall, forming a solid frame.
The slope of the roof, in addition to reducing the pressing force, also reduces and roof windage. However, not enough to be absolutely sure that the roof will not be blown away by a gust of wind. To compensate for the tearing force, the Mauerlat must be firmly fixed to the wall.
Mauerlat is being done from the same material as the entire truss system. Therefore, it can be not only made of wood, but also of iron. The main condition is that the rafter should be (ideally) a single inseparable structure, in extreme cases - securely docked.
Mauerlat arranged as a separate structure only in houses whose main walls are made of brick, aerated concrete blocks, rubble stone, adobe and other "discrete" building material. In wooden houses, the Mauerlat can be the last crown, especially firmly fixed on the previous ones. There is no need to arrange such a special design in frame houses.
How to arrange?
For the Mauerlat device, beams must be used, the cross section of which is equal to thirds of the thickness of the main wall. Usually a bar with a section of 150 or 200 mm is suitable for this. You should not take it thicker, since this is an additional load on the wall, and it is quite difficult to lift bars of such a section to a great height.
If the Mauerlat beams are joined, then the length of each part should be as large as possible. To illustrate this, the following example can be given: the standard length of any lumber is 6 meters. If the wall on which the rafters will rest is 8 meters long, then for the Mauerlat you need to take two beams of 4 meters each. Using a six-meter beam and a two-meter saw-off would be a mistake.
Before strengthening the beam on the wall, it must protect from moisture. To do this, it is enough to wrap it with roofing material and fix it with a construction stapler (the height of the staple is at least 10 mm).
Mauerlat beam laid on the inside edge main wall or exactly along the center line. Otherwise, you will not be able to securely fasten it. At the junction with the cross beam, a half-tree is washed down, a hole is drilled and a dowel is clogged. The connection angle is fixed with a construction bracket. It must be hammered so that the hypotenuse of an isosceles right triangle is formed.
How to fix on the wall?
In order for the Mauerlat to hold securely, all fasteners must be placed in the thickness of the masonry of the main wall. The easiest way to strengthen in masonry is long soft steel wire staples. It wraps around the Mauerlat, twists tightly, and the rest is bent. Bolts fixed in the masonry are more reliable, but marking and drilling holes in the beam is a long and painstaking task.
It is possible with building brackets, if wooden inserts are installed in the masonry under it (saw-off bars). They must be installed so that the bracket is hammered into the end, otherwise there is a risk that the liner will burst.
Mauerlat can be made from three boards 150 mm wide and 50 mm thick. The first of them is fastened with an anchor screw, the next two are nailed on top with nails 150 mm long. This method is convenient because the boards are easier to lift to a height. In addition, the anchor bolt can be installed already in the finished masonry, for example, if the installation of the roof is already done by you personally or by another construction team, and the previous builders did not install fasteners.
In conclusion, I would like to say that Mauerlat- an important and necessary detail in the design of the house. It is not worth neglecting her device. There are only two unshakable rules: use as long solid beams as possible and securely fasten them to the wall masonry. Otherwise, you can be guided by a sense of proportion and common sense.
And as it turned out later - in vain! Let's see what's what.
In general, the Mauerlat has two main purposes.
The first is to take on the load from the beams and distribute it evenly on the wall. And in the second case - to transfer the load from the "spread" of the rafters. This is during the construction of a simple roof, when the rafters abut each other from above, and the bottom cuts into the Mauerlat, and there are no additional fights and puffs. In general, not my case. Therefore, I consider here the first purpose of the Mauerlat.
The mass at the roof is huge! It is necessary to take into account everything: the floor beams, the entire truss system, the ceiling, the insulation, the crate, the roof itself, the mass of rubbish that will be stored in the attic, the snow on this roof. In general, it runs decently, and all this presses pointwise on my gas silicate, trying to push through and destroy it.
When I started building the roof, I roughly figured out what was what.
- 8 cubes of wood (mass of dry pine 650-700 kg) - 5600 kg;
- about 70 sheets of OSB (about 16 kg each) - 1120 kg;
- soft roof 210 square meters (weight of one square of roof 8.5 kg) - 1615 kg;
- insulation 22 cubes (37 kg each) - 814 kg
Here, I think, it is necessary to understand a little. We are looking for SNiP by any search engine. I don’t cite the link because it’s harmful, but because today the link is SNiP, and tomorrow it’s not known what. Clause 5.2 of the SNiP says: the calculated value of the weight of the snow cover Sg per 1 m 2 of the horizontal surface of the earth should be taken depending on the snow region of the Russian Federation. This is not the area of the roof, but the area of the horizontal surface of the roof. In other words, this is the area of land covered by the roof. For example, if you cover with a roof 100 m2 of area
and make a gable roof at an angle of 60 degrees, then the roof area will increase exactly 2 times, and the area of \u200b\u200bthe horizontal surface of the earth under this roof will remain as it was 100 squares.
And snow will fall on this roof like on 100 squares of land. This seems to have been sorted out.
The dimensions of my house are 12x13.5, the roof protrudes 30 cm on each side. The horizontal surface is 12.6x14.1 \u003d 177m 2. On map number 1 (Zoning the territory of the Russian Federation according to the calculated value of the weight of the snow cover of the earth), we are looking for our settlement, we find out the snow region,
put in the table.
The number in brackets, in my case 180, will indicate the load per 1 m 2 to us. We multiply 177x180, we get almost 32 tons. If you add everything (both the snow and the roof), you get an impressive colossus - 41 tons in weight !!! My poor blocks...
We look at the picture and count the points where the beam lies on the block. I counted 126 points.
Our block has a width of 20 cm, the width of the beam is 5 cm. We multiply one by the other, we get the area of \u200b\u200bone point of 100 cm 2. We divide 41000 kg by the number of points, we get 325 kg of pressure on each point, or 3.25 kg per cm 2.
We find out the compressive strength of the material. In my case, according to the manufacturer, destruction occurs at a load of 27 kg / cm 2, which, you see, is much more than 3.25? It was for this reason that I decided that I did not need a Mauerlat.
All with your own hands
Do you need a Mauerlat?
I somehow omitted this question when writing an article about beams, and as it turned out later - in vain! Let's see what's what.
In general, the Mauerlat has two main purposes.
The first is to take on the load from the beams and evenly distribute it on the wall. And in the second case - to transfer the load from the "spread" of the rafters. This is during the construction of a simple roof, when the rafters abut each other from above, and the bottom cuts into the Mauerlat, and there are no additional fights and puffs. In general, not my case. Therefore, I consider here the first purpose of the Mauerlat.
The mass at the roof is huge! It is necessary to take into account everything: the floor beams, the entire truss system, the ceiling, the insulation, the crate, the roof itself, the mass of rubbish that will be stored in the attic, the snow on this roof. In general, it runs decently, and all this presses pointwise on my gas silicate, trying to push through and destroy it.
When I started building the roof, I roughly figured out what was what.
- 8 cubes of wood (mass of dry pine 650-700 kg) - 5600 kg,
- about 70 sheets of OSB (about 16 kg each) - 1120 kg,
- soft roof 210 square meters (weight of one square of roof 8.5 kg) - 1615 kg,
- insulation 22 cubes (37 kg each) - 814 kg
Here, I think, it is necessary to understand a little. We are looking for SNiP by any search engine. I don’t cite the link because it’s harmful, but because today the link is SNiP, and tomorrow it’s not known what. Clause 5.2 of the SNiP says: the calculated value of the weight of the snow cover Sg per 1 m 2 of the horizontal surface of the earth should be taken depending on the snow region of the Russian Federation. This is not the area of the roof, but the area of the horizontal surface of the roof. In other words, this is the area of land covered by the roof. For example, if you cover with a roof 100 m2 of area
and make a gable roof at an angle of 60 degrees, then the roof area will increase exactly 2 times, and the area of \u200b\u200bthe horizontal surface of the earth under this roof will remain as it was 100 squares.
And snow will fall on this roof like on 100 squares of land. This seems to have been sorted out.
The dimensions of my house are 12x13.5, the roof protrudes 30 cm on each side. The horizontal surface is 12.6x14.1 \u003d 177m 2. On map number 1 (Zoning the territory of the Russian Federation according to the calculated value of the weight of the snow cover of the earth), we are looking for our settlement, we find out the snow region,
put in the table.
The number in brackets, in my case 180, will indicate the load per 1 m 2 to us. We multiply 177x180, we get almost 32 tons. If you add everything (both the snow and the roof), you get an impressive colossus - 41 tons in weight. My poor blocks...
We look at the picture and count the points where the beam lies on the block. I counted 126 points.
Our block has a width of 20 cm, the width of the beam is 5 cm. We multiply one by the other, we get the area of \u200b\u200bone point of 100 cm 2. We divide 41000 kg by the number of points, we get 325 kg of pressure on each point, or 3.25 kg per cm 2.
We find out the compressive strength of the material. In my case, according to the manufacturer, destruction occurs at a load of 27 kg / cm 2, which, you see, is much more than 3.25? It was for this reason that I decided that I did not need a Mauerlat.
Beautiful and reliable do-it-yourself gable roof
What is a gable roof made of?
In order to understand how to make a gable roof, you need to find out what structural elements it consists of. To do this, below is a list of these components and a description - what they are for.
Mauerlat and rafter legs
Rafter legs are boards measuring 50 mm x 100 mm or 100 mm x 100 mm. Outline the outline of the future roof. They distribute the load throughout the Mauerlat, and he, in turn, transfers it to the walls. Keep the roof from falling off during bad weather. The pitch of the rafter legs should be approximately 80 - 100 cm, if the material is heavy on the crate, then reduce to 50 - 60 cm.
Skate, filly and bed
The fillies continue the rafter legs and are the overhang for the roof. They are used when the length of the rafters is less than necessary to form an overhang. The overhang, in turn, protects the walls from rain.
When erecting a gable roof with your own hands, do not forget about the sores. This is a beam that is placed on an internal load-bearing wall. He also participates in the uniform distribution of the load.
Racks and puffs
Puffs - components of the hanging parts of the rafters. They do not allow the legs to part in different directions.
Brace and crate
The final stage in the formation of a gable roof with your own hands is the fastening of the crate. Fastened perpendicular to the rafter legs. Roofing sheets are laid on it and screwed.
Building a roof without a Mauerlat can lead to the following disadvantages:
- loss of rigidity, which is necessary for attaching rafter legs,
- will require an increase in material consumption.
Mauerlat affects the mechanical strength and is the basis of the future roof. It is desirable to mount it to the walls with the help of anchors.
When it became approximately clear what components will be needed for the manufacture of a gable roof frame, you should proceed to installation.
Installation of a gable roof
Frame Position Calculation
If the construction of a gable roof takes place in an area of \u200b\u200bhigh rainfall, the slope should be done at 45 °. This will ensure that snow and rainwater slide off unhindered.
How to lay a mauerlat for a gable roof
If the house is made of timber, then the last upper timber will serve as a Mauerlat.
Under it, a waterproofing layer of roofing material is necessarily laid. It is connected to the wall with the help of studs for a wooden house, for a brick house knitting wire and fittings are used.
Installation of rafters
The better the fastening, the less the roof will be subject to drift during strong winds.
The upper strapping of the stacks of a gable roof is made by mounting "on the mustache". The ridge beam is laid after the installation and fastening of the extreme rafter legs to the wall of the building.
After the rafters have been leveled, it is recommended to check each leg again with a level. Rafter legs should firmly rest against the Mauerlat.
After the rafters are exposed and the Mauerlat is securely fastened, it is recommended to proceed to the assembly of the roof truss.
roof truss
The way the beams are attached when building the roof of a house is important. It is recommended to use self-tapping screws, nails, tightening boards.
Before installing the pediment, it is necessary to check the perpendicularity of the structure, to ensure that the rafters have the same height. A ridge beam is attached to the top of the pediment.
It is necessary to sew up the gable after the completion of roofing work and laying the sheets on the crate.
For the manufacture of the pediment, a board measuring 50 x 100 is used. Sheathing is carried out vertically or horizontally.
After the base under the roof is ready, bars measuring 400 x 400 are laid on the rafters in a perpendicular position. They tighten the rafter legs and at the same time are the base to which the profile sheet or metal tile will be screwed.
The crate is of two types:
To insulate the roof, mineral wool insulation is used. It is obligatory to lay a waterproofing film between the rafters and the lathing beams. This will protect the roof from collecting condensation inside. And condensate, if it is a frequent guest, can lead to the death of wooden products, their swelling, mold. Create favorable conditions for the development of pathogens for the tree.
On the lower lath of the crate, before laying the roofing material, it is recommended to put a cornice strip. It will serve as a guide for rainwater to run down the drain.
Advantages of a gable roof
If all instructions for the construction and operation of the roof are followed, then it will serve the owner of the house:
- protection from rain and snow,
- cold and heat
- snow and water will easily come off it,
- the wind will never tear off a properly laid roof,
- The roof will last for many years.
If the owner does not have enough knowledge on the construction of the roof, it is recommended to contact the experts.
Rafters without Mauerlat
Good afternoon.
I am generally an inexperienced builder, building for the first time. Built a brick box. The stage of construction of the roof approached. Hozblok in the country. In half a brick. 4x10. I'm going to make a gable roof 45 degrees covered with shingles.
Puff - boards 50x150. Rafters 50x100. What fasteners would you recommend rafters and puffs. I'm going to fasten the rafters in the ridge area with triangles of 16-18mm plywood, but I think the rafters and tightening with bolts, but not at an angle, as is usually shown on the internet, but vertically.
RUS34 wrote:
Is this possible or is it wrong?
And if you post a sketch (a photo of a sketch in pencil), then it is possible and correct.
Here I drew a drawing. The vertical cylinder is a bolt recessed into the rafter and tightened.
RUS34 wrote:
Is this possible or is it wrong?
This is not clear. Do you have a brick floor wall 10 meters long or what? What is the height? Smells extreme, though.
The building is 4 meters wide, 10 meters long. There are 2 main partitions overlapping with the main walls. For a summer kitchen with a bathhouse, a dressing room, a barn and a toilet, I see no reason to build a more massive building. So no extreme
Height 2.5 meters.
Here is a more clear structure.
RUS34 wrote:
So no extreme
The spirit of adventurism hovers near the bolt at a height of 2 and a half meters.
Sorry, I did not understand
2RUS34 like this is possible.
plus lining
RUS34 wrote:
plywood 16-18mm
on nails, maybe it will be easier?
But it would be better to throw a bar 150 * 50 like a Mauerlat.
Yes, I initially wanted to use overlays, but after looking at the prices for them with us, I got sick of something. Due to the fact that this is still a rarity in our country, the prices for them are high. For example, 1 corner is about fifty dollars worth
But I have little idea of using a Mauerlat on a half-brick building (for example, how to fix it)
If your overlays are expensive, then you can make a plank knot at the hanging rafters.
Maurlat, and in your case the lining leveling board, together with the truss truss, must be tied with soft (annealed) steel wire to the wall. The wire had to be laid in the masonry. If not laid, drill the wall either through and insert the wire or hammer the anchors and tie them to them. A span of 4 meters, this is a bit of a slope of 2 meters, and even at an angle of 45 ° there will be no snow on them. You need to fight the wind, and this is only by tying the farm.
Samar , Arkan60 Thank you very much! I will do according to your advice.
You only fasten the wire lower to the wall, otherwise a strong wind can tear off the roof along with the brick of the wall if you fasten it high. The wall thickness of half a brick is very small, the weight is small.
Okay, I didn't think of that, by the way. Thank you!
By the way, when using a plank knot, is there still a need for a bolted connection?
I will note a few more nuances. It is correctly noted here that it is worth throwing a beam as a Mauerlat. In this case, I would even do it differently, around the entire perimeter I would cast a reinforced concrete armored belt of twenty centimeters thick with four reinforcement bars 8x with a viscous wire “square” with mortgages for bolts, I would tie antiseptic boards to it (an alternative option is to pre-antiseptic boards, break through with 200 nails of them and at the time of pouring concrete, put them on top through a "cushion" of lime mortar. But to these boards I would already be tied in a completely ordinary way, using nails or self-tapping screws. I consider it absolutely necessary to make some roof overhang. That is, your scheme bindings are unsuccessful. Now tin corners with drilled holes are sold everywhere, I forgot what they are called, they are convenient for attaching a tree. IMHO, make a height in the ridge of three meters or a sloping roof at 2.30. It will be more convenient to insulate the ceiling, just walk on top of the rough flooring and fill with expanded clay it is natural to leave windows in order to fix the block for lifting the concrete mixer and materials. Take your time, but hurry up. The rainy season has already begun, in principle there will still be three weeks of Indian summer, and then the season of heavy snow will begin. It is very unpleasant to work in semi-darkness under the November light rain.
We build a simple roof for a house, garage or bath with our own hands
In this article, we will consider common options for roof structures, talk about the important features of their selection and installation.
Types of simple roofs and their main elements
Any roof consists of a supporting frame and a protective roofing.
The framework includes the following elements:
- Rafters - inclined beams (serve as the supporting base of the roof).
- Ridge beam (connects the upper docking nodes of the rafters).
- Sheathing - flooring made of boards or OSB boards, laid on rafters and serving as the basis for roofing material.
- Counter-lattice - used when installing a warm roof (creates an air gap for ventilation of the insulation).
- Mauerlat - wooden beam (mounted on longitudinal walls). The lower parts of the rafters (rafter legs) are attached to it.
- Vertical racks, horizontal puffs and struts (used to reinforce the truss structure).
- Filly - boards nailed to the lower ends of the rafter legs to create a roof overhang.
The design of a simple roof for a house is determined by several factors:
- the width of the covered span,
- the purpose of the attic space (residential or non-residential, passable or impassable),
- type of interfloor ceiling (wooden beams, reinforced concrete panels).
If the width of the building is small (up to 4.5 meters), and it is not planned to equip a living space in the attic, then you can stop at the shed roof option. It is economical and easy to install.
The rafters of such a roof can be leaned directly on the walls. To do this, one of them must be made higher than the other. So we will create a slope necessary for the runoff of rainwater.
If you decide to put a shed roof on the walls of the same level, then to create a slope, you need to include wooden racks in its design. After installation is completed, they are sheathed with siding, OSB board or blockhouse.
For asbestos-cement slate, the angle of inclination of the roof must be at least 22 degrees. For metal tiles, ondulin, bituminous tiles, the slope of the roof is made at least 15 degrees. When calculating a simple shed roof, remember that snow load is a serious factor. To reduce it, the slope of the slope is recommended to be made steeper. Otherwise, you will have to increase the cross section of the rafters and battens, which will lead to an increase in the cost of the structure.
If the width of the span is from 4.5 to 6 meters, then the rafters must be reinforced with braces (tilted racks made of timber). They will reduce the deflection of the rafter legs under the action of a snow load. The lower ends of the braces are embedded in the masonry, and when using vertical support posts, they are attached to them with staples, nails or serrated metal plates.
Shed roofs are most often used for small structures, such as garages, sheds, bathhouses or gazebos. A gable design with a large angle of elevation is the best option for arranging an attic space.
Main docking points
The main condition for the strength of any roof is the competent docking of all its parts. Therefore, when drawing up a sketch drawing, you need to pay attention to the nodes (the connection of the Mauerlat with the wall, the rafters with the ridge and the floor beams).
The device of a simple roof begins with the laying of a horizontal wooden beam - Mauerlat, on which the rafters will rest. It is attached to the masonry through threaded steel anchors (in brick walls) or to studs concreted in the armored belt (gas silicate masonry, expanded clay concrete, foam block).
The floor beams are fixed to the wall with anchor studs, and the Mauerlat is attached to them with nails or long self-tapping screws.
We also note that the roof of a small house, barn or garage can be installed without a Mauerlat, fixing the lower ends of the rafters directly to the floor beams.
The next important knot is the fastening of the upper ends of the rafters to each other and their connection with the ridge beam.
There are several ways to create this node. The rafters can be connected with a bolt and tightened with a nut (node 1). You can use an overlay from a piece of OSB board (knot #2) or fix them with a metal toothed plate (knot #3). For closer contact between the rafters and the ridge beam, notches are made on them.
It should be noted that the ridge beam, which increases the rigidity of the structure, is most often used on large roofs. It is also placed in buildings with pediments made of bricks, blocks or logs, which serve as supporting walls for it. When building a small bathhouse, a garage or a country house, you can do without this element. For a small roof, OSB sheathing or flooring will provide sufficient rigidity.
If you are going to make a simple roof with your own hands, you should familiarize yourself with the recommended sections of the rafter legs (table No. 1).
The cross-sectional dimensions of other elements of a simple roof can be taken from table No. 2
Features of the construction of a simple roof
The installation of the roof is started after the completion of the construction of the walls, the installation of beams or floor slabs. Having set the extreme rafters according to the level, they are attached to the beams or Mauerlat and fixed with temporary connections. After that, a beacon cord is pulled between them. Ordinary rafters are exposed along it and alternately fastened with the help of a crate.
In the presence of a capital pediment, installation is simplified, since the ridge beam laid on it serves as a support and beacon for the installation of rafters.
Mounting a roof frame at a height is a laborious task. When erecting a small roof, it is more convenient to assemble roof trusses on the ground. In this case, on the walls you will only have to connect them with the help of a crate into a single structure. Having assembled one truss, it can be used as a template for marking and cutting rafters, puffs and beams.
When preparing for the construction of the roof, be sure to make a detailed diagram indicating the dimensions of all elements and a detailed study of the nodes. It will come in handy for you to calculate the purchased lumber and help you complete the installation efficiently and quickly.
If the attic is residential, then the roof structure must include not only insulation, vapor barrier, but also a counter-lattice - a wooden block with a section of 30x50 mm. It is nailed to the rafters over a vapor barrier film to create a ventilation gap, and the main crate is attached on top. Without this “little thing”, the insulation in the cold season will get wet from diffusion moisture, and the wooden parts of the structure will begin to rot.
If a solid OSB flooring is used when installing an insulated roof, then a counter-lattice is placed under it.
To protect the walls from rainwater, any roof needs overhangs. For a shed construction, they are made not only in the lower, but also in the upper part. If the length of the rafter legs is not enough to form cornice overhangs, then they are increased by nailing the “filly” boards.
The minimum value of roof overhangs should be at least 20 cm. To protect the gables from moisture, the length of the roof on each side is increased by 20-30 cm, creating frontal overhangs. The ends and lower planes of the overhangs are sheathed with a wind board.
The roof is one of the main elements of the house, along with walls and foundations. Without its proper arrangement, the house will not be strong enough and comfortable enough 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, the prevailing weather conditions. The most common in our conditions are gable, fairly simple to build and maintain, and reduce the load from snow or other heavenly moisture. Aesthetics plays an important role in choosing them.
Types of gable roofs
A gable roof is a fairly simple structure consisting of two slopes connected at an angle to each other. They form something like a triangle. But with all the simplicity of this figure, triangles are different. The 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 types is erected:
- Simple symmetrical;
- Simple asymmetrical;
- Broken (kink can be both internal and external).
Each of the types has its positive and negative sides, forcing builders to choose one or the other, depending on the circumstances.
Simple symmetrical roof
Simple symmetrical roof This type of construction is undoubtedly the most common. It is the easiest option for making your own. His appearance always looks good. In the end, it is also good because under such a roof there is a lot of useful attic space.
The name of the design shows what is its distinguishing feature: the slopes form an isosceles triangle. The symmetry of this figure allows it to look proportional on any home.
Simple asymmetrical roof
simple asymmetric roof The main difference from the previous version is also directly reflected in the title. The ridge of this type of roof is displaced to the side and as a result, the triangle formed by it turns from isosceles to versatile. This design looks modern, so it is well suited for houses in a modern style.
The asymmetric roof has two important features:
- Reducing the size of the attic space;
- Unequal load distribution.
As a result, this type of construction 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, it is quite possible. It's just important to make the right calculations from the start. After all, the main feature is the irregular shape, where the loads are distributed extremely unevenly.
The main advantage of a sloping roof, in addition to its diverse appearance, is that it gives a maximum of free space under it. As a result, it is possible to equip a full-fledged residential second floor, an attic. Due to this feature, it is also called the attic.
Construction of the truss system
The truss system is the basis of the roof. There are two main design solutions for gable roof rafters:
- Hanging.
The design of the gable roof truss system The first of them is used when the house has internal supports, for example, load-bearing walls. In their absence, the hanging type is preferable.
But, no matter what type of truss system it is decided to build, anyone who wants to know how to build a roof with their own hands must understand the main structural elements. 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 interconnected to form a farm. Since it is they who hold the roof covering on themselves, it is also important to use durable wood here. It is desirable that it be a log or timber. Installation is carried out on the basis of pre-made calculations, since it will be very difficult to change something later;
- rafter rack. This structural element helps to distribute the load from the rafters. It is a vertical bar. Its location depends on the type of structure that the roof has and on its dimensions. 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 are additionally placed on the sides. The asymmetric version assumes the location of this element depending on the length of the rafter, and the broken one - two on the sides. True, if there are more than one room, then in the latter case an additional rack in the center is needed;
- Run. The main task of the runs is to connect the rafters, at the same time giving them rigidity. Runs can be ridge or side. The first is located at the very top of the roof, in the region of its ridge. Make runs from timber. Sometimes boards are used. The most common is a section of 50 by 150 mm. If the run is made not only of a ridge, but of several beams or boards on the sides with a long roof, then they are supported by a stand coming from the ridge and resting on a bed. Side runs are connected to it by means of struts;
- Strut. They are a structure of beams located at a certain angle and resting on a bed. Their main task is to serve as supports for the racks. Can be diagonal or longitudinal. The latter are used most often, they are on the same plane with 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 desirable to choose a strut 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, being perpendicular to them. In parallel, it provides greater structural rigidity;
- Rigel. It also connects the rafter legs, but unlike the puff, not from below, but from above. Overlapped. They make a crossbar from a board of the same section as the rafters themselves;
- crate. This element is installed at the final stage of mounting the truss structure, since it is the basis for the coating. It consists of beams and boards, with which the rafters are connected in parallel from top to bottom. Besides the fact that it serves to fasten the roof, the crate 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 idea of the meaning of each structural element will greatly facilitate the task of building a gable roof with your own hands.
Calculations
The calculation of the load on the various elements of the roof is the most important step, since the strength and safety of the structure depends on it. It must be remembered that it is the triangle that is its most rigid part.
Loads on rafters can be of three types:
- Permanent. These are the loads that the rafters constantly feel. For example, the weight of finishing and roofing materials, battens, etc. In order to find out it is enough to add up all these weights. Usually the constant load is about 40 kg/sq.m.;
- 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 into the SNiP;
- 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 of dependence on the angle of inclination of the roof is also introduced - the lower it is, the greater the load. At an angle exceeding 60 degrees, it is not taken into account.
Tilt angle
The correct calculation of the angle of inclination depends on some features. First, a lot depends on the material chosen. So, ondulin, corrugated board, metal tiles, slate require an angle of 20–45 degrees. A soft roof - up to 20 degrees.
Secondly, the angle of inclination depends on the climate in which the roof is being built. If there is little rainfall, then you can make it insignificant. And with a large number - on the contrary. 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. To the value obtained, it is worth adding a few tens of centimeters for washing down.
Step of rafter legs
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
Calculation of the correct required section of the 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 step;
- 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 shows a detailed description of the calculation of the truss system.
Types of truss systems
There are two main types of rafter systems, from which they choose when erecting a gable roof. We are talking about hanging and layered and rafters. Each of the types is designed for different structures.
Hanging structure
Hanging truss system Hanging 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. Also, they are not used where there is an average load-bearing wall.
Design features
A feature of the design of hanging rafters is that they rest on two extreme load-bearing walls. As a result, the system is under a strong influence of the bursting force. If necessary, it is reduced with the help of a crossbar fastened at the bottom.
Mauerlat mount
The design feature of the hanging rafters dictates how they are attached to the "foundation" of the entire system - the Mauerlat. The only mounting option is to use a node with a zero degree of freedom. Hinges, for example, cannot be used.
Layered system
Laminated rafter system Laminated rafters are the only option when it comes to a large roof. But they need either the presence of an internal load-bearing wall, or specially installed intermediate supports. Parallel to the Mauerlat, a bed is laid, 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 affects the structure. At the same time, due to the fact that they also rest on a bed in the middle, layered rafters are lighter, including assembly. They are better suited for large roofs.
Do-it-yourself gable roof device
As already noted, the 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 this is not recommended for one simple but important reason - the beams will have to take on the additional load from the roof.
A 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 bars that will be connected are cut down at an angle of 90 degrees. After the ends are applied to each other, they are fastened with bolts and only with them. It is important not to use any other material instead of bolts, such as nails or wire.
Fastening
Mounting methods for the Mauerlat are based on the fact that it is installed on top of the wall. At the same time, it can be located both strictly in the center of the wall, and with an offset to one of the edges. But it is important to keep 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 suitable for this.
This will protect the wood from the influence of moisture that can get on the walls. The mount itself must be as strong as possible, because it will have to withstand the wind load. 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 built from.
- If the building is erected from a monolith, then anchor bolts are the best solution;
- If the house is being built from timber, then wooden dowels are the usual solution. They can be reinforced with additional fasteners;
- A fairly common mounting option are staples. They are loved because they are quite versatile, although they are not the most durable solution;
- If the building was erected from porous materials, such as foam concrete, then mounting the Mauerlat on the reinforcement would be the right choice;
- 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 fastener, you can use a strong, for example, knitting, wire. It does not apply as a standalone option.
The right choice of fasteners will make it possible to survive the blows of even the strongest winds.
Installation of rafters and racks
There are two options for assembling the rafter legs. They can be assembled 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 truss system up manually.
But, one way or another, the manufacture of rafters must be done strictly according to the markup. For this, special templates are well suited, which are made of plywood after all calculations have been made.
Rafter attachment scheme Before attaching the rafter legs to the Mauerlat, they must be washed down. Only rafters can be sawn, since such procedures on the Mauerlat weaken it. Three nails are used for fastening. Two of them are hammered along 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 top attachment of the rafters to each other, there are three main ways to do this.
- Without support bar. Rafters can be spliced end-to-end or overlap. 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 plank. In addition, a nail is driven in at the top. When overlapping, the ends are cut as needed and connected with bolts;
- Using a support bar. This method is necessary when it comes to a large roof. The rafters at the ridge are also fastened end-to-end or overlapped, but in addition they rest on a beam, which in turn also serves as a support for the racks;
- Cutting method. It involves cutting the rafter legs into the support beam.
The ridge support is mounted after the two extreme rafter legs are installed. Then there is the fastening of the racks. And then, the remaining rafters. You can see all this in a photo or video.
Insulation and water protection
Proper insulation and waterproofing are very important in the domestic climate. Especially when it comes to the roof, which is constantly and strongly affected by the environment. And the moisture that accumulates in the house itself also rises to the attic in the form of steam.
Based on the foregoing, it is important to choose a heater that has the function of vapor barrier. Otherwise, its type does not matter. But, with regard to waterproofing, then its rolled types are considered the most suitable. For example, a special film. It can be easily laid directly on the rafters. How this is done can be seen in the video.
Lathing installation
The crate is mounted last, but it plays an important role.
Without it, it is inconvenient to move along the roof, and the roofing material presses unnecessarily on the rafters. In addition, it makes it possible for an air cushion to appear between the roofing material and the insulation.
The design of the lathing and its step depend on what material will be laid on the roof.
- The lattice crate is laid under slate, tile or metal tile, corrugated board. In the case of metal tiles, the distance should be 350 mm, and for slate and corrugated board - 400 mm;
- A solid crate is used for soft types of coverage.
Lathing installation They make it from a bar or board, and if we are talking about soft - 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.
Roof area calculation
A gable roof often has a simple shape, so calculating its area is not difficult. But this is extremely important to do exactly, because the consumption of materials depends on the knowledge of the area.
Roof area calculation When calculating the roof area, for this, in order not to get confused, you should not pay attention to the parameters of various ventilation openings, skylights or chimneys. It is enough just to find out the height from the ceiling to the ridge and the length of the ridge run. These parameters are multiplied. If the roof area is divided by the sine of the angle of inclination of the rafter, then you can find out the area of \u200b\u200bone 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 desired value of the amount of materials.
Since the roof is made with a slope, you need to know its angle.
The cosine of an angle is needed to determine the exact area of \u200b\u200balmost all elements.
Typical elements are the legs of the rafters, which form the basis of the trusses. In addition to them, there are braces, struts, supports, runs.
Roofing: selection and installation
Installation of metal roofing Installation of roofing is the final stage of work. But it is preceded by the choice of a suitable material. Nowadays, manufacturers offer a huge selection of roofing materials, each of which has its pros and cons. The choice is always up to the consumer and depends on his aesthetic preferences, financial possibilities and climate.
- Natural tiles. This is a very beautiful, traditional, but at the same time expensive material. Its high price is offset by a very long service life, unless of course it is specially beaten or it is affected by extremely adverse weather conditions;
- Metallic coating. Such a roof is also a fairly traditional solution. Today, manufacturers offer many options for metal sheets for the roof, which differ not only in strength, but also in appearance;
- Wooden roof. A shingle or spindle roof undoubtedly has many aesthetic merits. But it is quite expensive and without special treatment is prone to rotting;
- Bulk coating. It is considered quite inexpensive and reliable. Belongs to the category of soft coatings. The disadvantage is that it can only be used on roofs with not very steep slopes.
The installation of each type of material is carried out in its own way and different fasteners are used for them. Information can be obtained from the video or from the manufacturer. After mounted cornice overhangs.
Fastening parts
The ability to properly fix 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, the groove connection is used by fastening the 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 have good durability. But the disadvantage is the danger that some screws will turn out from the loads. To minimize risks, a combined fastening method is used.
gable roof cost
The cost varies greatly from whether the roof is made by hand or with the help of craftsmen. In the latter case, it will come out much more expensive and the price can reach several hundred thousand. In the first case, the main costs will go to materials.
The total cost of the design includes:
- materials;
- Mauerlat installation;
- Installation of the truss system;
- Installation of waterproofing;
- Installation of the crate;
- Roof installation.
Performing any of these elements with your own hands reduces the cost of construction.
Finishing the gable with siding The pediment is a prominent part of the house. Therefore, it is customary to use attractive materials for its sheathing. It can be a board to match the roof, plywood or siding. In the case of wooden houses, the pediment can be cut in advance. More about this in the video.
The gable roof, due to the simplicity and accessibility of the design, which allows you to arrange it, including with your own hands, 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 fix the 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 figure out what the armo-belt is for, and what the Mauerlat is and its purpose.
Aerated concrete - is it?
But first of all, we denote that the construction of houses from aerated concrete is at the peak of popularity, and the demand for this building material is growing. So, many people face 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 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, this is a structure that is laid on the upper surfaces of the walls. In fact, it performs the functions of a strip foundation, distributing evenly the loads from the roof onto the walls of the house. They are made mainly of wooden beams with a minimum section of 100x100 mm. It should be added that this roof element simplifies the fastening of the truss 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 in the design of the house being built, then certain problems arise that are associated specifically with the fasteners 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 fix the Mauerlat to aerated concrete. It remains to deal with the methods and understand one important idea. And the idea is that the proposed fastener options must be accepted with a large number of reservations. Because the installation of 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 all turn out to be, at least, of little use. And with each option there is a huge number of contraindications. And although there is a lot of information on some portals that it is possible to lay a Mauerlat on aerated concrete and fix it, everyone unanimously assures that there are certain criteria that must be taken into account.
Eg:
- you can use this method (without armored belt) if the building being constructed is small in size;
- if the roof is a simple structure covered with light roofing materials;
- if hanging rafters are used in the construction of the rafter system, which are tied together with reliable puffs;
- if layered rafter legs are installed, supported along the axis of laying the ridge beam.
By the way, the last option is best suited for this situation. Because part of the load from the roof will fall precisely 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 the armored belt.
Option number 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 in 2–4 layers. This method is often used when laying Mauerlat timber on brickwork. How is this process carried out. There are several strict requirements:
- the wire must be laid in the laying of aerated concrete stones in the third or fourth row before the end of the laying, 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 mount;
- the step of laying the wire twists is equal to the step of mounting the rafter legs.
An example of fastening a Mauerlat beam with wire Before laying a Mauerlat without an armored belt on aerated concrete walls, it is necessary to waterproof the ends of the walls. The easiest way is to spread the roofing material in two layers. After that, the beam itself is laid. It must be aligned either on the outer surface of the wall, or on the inside. Be sure to align horizontally. After that, the wire braids are tightened using a mount. The main thing is that the screed is strong and dense.
An example of correctly tightened wire braids using a pry bar It seems that this is the solution to the problem. But let's be reasonable. A 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. From them, the wire will work like a saw. But it is with this tool that blocks are cut when it is necessary to fit them to the required dimensions.
That is, this option, with the seeming correctness of use, raises great doubts. And the stronger the Mauerlat is tightened with wire, the faster it will cut the blocks.
Option number 2
Installation of a Mauerlat beam without an armored belt using anchors and dowels. For fastening, it is suggested here to use anchors with a length of at least 30 cm, preferably 50. They look like this: 
How this process is carried out:
- Mauerlat is laid on the walls after waterproofing their upper ends.
- 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.
- Dowels are clogged.
- Anchor bolts are screwed into them.
For fastening the Mauerlat to aerated concrete without an armored belt, it is better to use an anchor with a diameter of at least 12 mm. And one more thing - pick up a washer of a larger diameter under the nut.
So, is this method really reliable? If this concerned a reinforcing belt made of concrete mortar, then there was no doubt. This is a 100% secure 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 severe loads emanating from the roof structure. It is one thing to fix a shelf, cabinet or TV on aerated concrete, and another thing when the loads from the roof are not one ton of different materials.
Option number 3
Fastening the Mauerlat to the aerated concrete wall with studs. A stud 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 stud will stick out of the wall on both sides. Therefore, its length is chosen according to the width of the aerated concrete wall.
In this case, the Mauerlat on aerated concrete is laid in exactly the same way as in previous cases. But the fastening is made by wire twisting. Loops are made at the ends of the steel “pigtail”, which are put on the ends of the hairpin. 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 laid under it;
- twisted wire is thrown over the wall, respectively, and Mauerlat;
- the free loop at the opposite end is inserted into the free end of the hairpin;
- tightening with a nut and washer;
- a mount is required, which twists the twist over the Mauerlat beam, that is, the latter is pulled to the wall.
We must pay tribute to this method of attaching the Mauerlat to a wall built from gas blocks. In many respects, it is more reliable. Firstly, the wire does not come into contact with the aerated concrete material. So, from its twisting there is no load 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 one hundred percent reliability of fasteners.
Option number 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 the so-called chemical anchors. In fact, this is all the same metal fixture 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 solid. 
Today, manufacturers offer two types of chemical dowels:
- A ready-made two-component composition in a can, on which a pistol nozzle is put on for the convenience of supplying the mixture.
- The composition is in a glass capsule, which must be inserted into the prepared hole. Then an anchor is inserted into it, which by itself breaks the capsule, thus mixing the two components together and creating conditions for their contact with air.
The process of fastening 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 is poured from a can. 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. They should be used for fastening.
Now, as for the reliability of fasteners. This is one of the most reliable options. But there is no information that someone has already used it. Therefore, one can only speculate. Although in theory it should work.
Option number 5
All 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 fixture is installed at the stage of wall construction below the upper plane of the end by 2–3 blocks. Therefore, it is important to accurately determine the length of the hairpin. Installation landmark - a strip across the wall. The 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 mass of the roof should not be large. The load on the walls in this case is oblique, so the fasteners work in bending. The wider the strip in the mounting structure, the better.
Generalization on the topic
Several options for fastening the Mauerlat without pouring the armored belt are proposed. It is difficult to say how the whole structure will behave, whether fasteners will be reliable. Therefore, do not take risks and avoid expenses. Fill in the armo-belt and all your problems will be solved at once.
