Roof installation is a complex multi-stage process. In order to independently assemble and install the rafter system, it is necessary to carefully study the methods of connecting the elements, calculate the length of the rafters and the slope angle, and select the appropriate materials. If you do not have the necessary experience, you should not take on complex structures. The best option for a small residential building is a do-it-yourself gable roof.
A standard roof of this type consists of the following elements:
Mauerlat is a timber laid on top of the walls along the perimeter of the building. It is secured with threaded steel rods or anchor bolts embedded in the wall. The beam should be made of softwood and have a square section of 100x100 mm or 150x150 mm. The Mauerlat takes the load from the rafters and transfers it to the outer walls.
Rafter legs- these are long boards with a section of 50x150 mm or 100x150 mm. They are attached to each other at an angle and give the roof a triangular shape. The structure of their two rafter legs is called a truss. The number of trusses depends on the length of the house and the type of roofing. The minimum distance between them is 60 cm, the maximum is 120 cm. When calculating the pitch of the rafter legs, one should take into account not only the weight of the coating, but also the wind load, as well as the amount of snow in winter.
It is located at the highest point of the roof and is most often a longitudinal beam connecting both slopes. From below, the timber is supported by vertical posts, and the ends of the rafters are attached to the sides. Sometimes the ridge consists of two boards, which are nailed to the top of the rafters on both sides and connected at a certain angle.
Racks - vertical beams with a section of 100x100 mm, located inside each truss and serving to transfer the load from the ridge run to the load-bearing walls inside the house.
The braces are made from scraps of timber and set at an angle between the uprights and the rafters. The braces strengthen the lateral edges of the truss, increasing the load-bearing capacity of the structure.
Tightening - the beam connecting the lower parts of the rafters to the base of the truss triangle. Together with struts, such a beam serves to strengthen the truss, increases its resistance to loads.
A bed is called a long beam with a section of 100x100 mm, laid along the central load-bearing wall, on which the vertical posts rest. Lezhen is used when installing layered rafters, when the run between the outer walls is more than 10 m.
The lathing is a board or timber stuffed onto the rafters. The lathing is solid and with gaps, depending on the type of roof. It is always fastened perpendicular to the direction of the rafters, most often horizontally.
If there is no more than 10 m between the outer walls and there is no load-bearing wall in the middle, arrange hanging rafter system. With such a system, the upper ends of the adjacent rafters are cut at an angle and connected together with nails, excluding the installation of racks and a ridge bar. The lower ends of the rafter legs rest on the outer walls. Due to the absence of racks, the attic space can be used to equip the attic. Very often, the function of puffs is performed by floor beams. To strengthen the structure, it is recommended to install the top tie at a distance of 50 cm from the ridge.
In the presence of a central retaining wall, arrangement is more justified layered rafter system... A bed is laid on the wall, support posts are attached to it, and a ridge bar is nailed to the posts. This installation method is quite economical and easier to perform. If the ceilings in the interior are designed at different levels, the racks are replaced with a brick wall dividing the attic into two halves.
The process of installing the roof includes several stages: fastening the Mauerlat to the walls, assembling the trusses, installing the rafters on the floors, installing the ridge, fastening the lathing. Before assembly, all wooden elements are carefully treated with any antiseptic compound and dried in air.
For work you will need:
- timber 100x10 mm and 150x150 mm;
- boards 50x150 mm;
- boards 30 mm thick for lathing;
- roofing material;
- metal studs;
- jigsaw and hacksaw;
- hammer;
- nails and screws;
- square and building level.
In wooden houses the functions of the Mauerlat are performed by the logs of the last row, which greatly simplifies the workflow. To install the rafters, it is enough to cut grooves of the appropriate size on the inside of the logs.
In brick houses or in block buildings, the installation of the Mauerlat is as follows:
The bars of the Mauerlat should form a regular rectangle and be in the same horizontal plane. This will facilitate further installation of the roof and provide the structure with the necessary stability. At the end, markings are made on the beams for the rafters and grooves are cut along the thickness of the beam.
When choosing a hanging truss system, it is necessary to assemble the trusses on the ground and then install them above the ceilings. First you need to draw up a drawing and calculate the length of the rafter legs and the angle of their connection. Typically, the angle of inclination of the roof is 35-40 degrees, but in open, heavily blown areas, it is reduced to 15-20 degrees. To find out at what angle to connect the rafters, multiply the angle of the roof by 2.
Knowing the length of the run between the outer walls and the angle of the rafter connection, you can calculate the length of the rafter legs. Most often, it is 4-6 m, taking into account the eaves overhang with a width of 50-60 cm.
The upper ends of the rafters can be fastened in several ways: overlap, end-to-end and "in the paw", that is, with cut grooves. For fixing, metal pads or bolts are used. Next, the lower and upper puffs are mounted, and then the finished trusses are lifted up and installed above the ceilings.
The end trusses are attached first: using a plumb line, the rafters are set vertically, adjust the length of the overhang and attach to the Mauerlat with bolts or steel plates. So that during the installation process the farm does not move, it is strengthened with temporary jibs from a bar. After installing the extreme rafters, the rest are exposed, observing the same distance between them. When all the trusses are fixed, they take a board with a section of 50x150 mm, the length of which is 20-30 cm longer than the length of the cornice, and nailed it along the upper edge of the ramp. Do the same on the other side of the roof.
The first option: on the rafter leg, at the point of contact with the Mauerlat, a rectangular groove is cut out to 1/3 of the beam width. Having stepped back from the top of the box 15 cm, a steel crutch is driven into the wall. The rafter is set in level, the grooves are aligned, then a wire clamp is placed on top and the beam is pulled close to the wall. The ends of the wire are securely fastened to the crutch. The lower edges of the rafters are carefully cut with a circular saw, leaving an overhang of 50 cm.
The second option: the upper rows of walls are laid out with a stepped cornice made of bricks, and the Mauerlat is placed flush with the inner surface of the wall and a groove is cut out in it for the rafter. The edge of the rafter leg is cut at the level of the upper corner of the eaves. This method is simpler than the others, but the overhang is too narrow.
The third option: the beams of the ceiling slabs are extended beyond the edge of the outer wall by 40-50 cm, and the roof trusses are installed on the beams. The ends of the rafter legs are cut at an angle and abut against the beams, fixing with metal plates and bolts. This method allows you to slightly increase the width of the attic space.
Layer rafters device
1 shows the cut of the rafter struts in the bed, laid along the intermediate supports, and in Fig. 2 - support of the rafter leg on the Mauerlat
The procedure for installing a layered rafter system:
When the main elements are fixed, the surface of the rafters is treated with fire retardants. Now you can start making the lathing.
A 50x50 mm beam is suitable for the lathing, as well as boards 3-4 cm thick and 12 cm wide. Waterproofing material is usually placed under the lathing to protect the rafter system from getting wet. The waterproofing film is laid in horizontal strips from the eaves to the ridge of the roof. The material spreads with an overlap of 10-15 cm, after which the joints are fastened with tape. The bottom edges of the foil should completely cover the ends of the rafters.
It is necessary to leave a ventilation gap between the boards and the film, therefore, first, wooden slats 3-4 cm thick are stuffed onto the film, placing them along the rafters.
The next stage is the sheathing of the rafter system with boards; they are stuffed perpendicular to the slats, starting from the eaves of the roof. The step of the lathing is influenced not only by the type of roofing, but also by the angle of inclination of the slopes: the larger the angle, the greater the distance between the boards.
After completing the installation of the battens, they proceed to sheathing the gables and overhangs. You can close the gables with boards, plastic panels, clapboard, waterproof plywood or corrugated board - it all depends on financial capabilities and personal preferences. The cladding is attached to the side of the rafters; nails or screws are used as fasteners. Overhangs are also hemmed with a variety of materials, from wood to siding.
Video - Do-it-yourself gable roof
The structure of the roof of a frame house is one of the simplest, so its independent construction will not take much time and effort.
This article will help you if difficulties arose during the work. In it we will consider the features of installing the roof, give practical recommendations on the choice of material, structural elements, and compliance with the necessary standards and requirements in the process.
What to do before starting work?
Before starting the construction of the structure, you need to decide:
- With roof type and slope angle
- Type of roofing material
- Length, cross-section of rafters and distance between them
- Length, step and cross-section of the elements of the lathing and counter-lathing
- Insulation type
Type of roof frame houses
Roofs are:
- Flat
- Pitched (with one, two or more ramps)
- Mansard (with two and four slopes)
- Pliers, tapered, multi-pinned, etc.
The choice of a roof is made not only on the basis of the conditions of its appearance. It is important to consider the functionality of the design. The main advantages and disadvantages of different types of roofs are given below.
Frame house with flat roof
Flat roofs are not popular in private construction. Their construction does not cause difficulties, but the disadvantages cover everything. They require careful maintenance. After rain, water remains on the roofs; in winter, you have to remove the snow yourself. This increases the likelihood of moisture penetration into the room. On houses with pitched roofs, you can use the attic as an additional room.
But when installing a flat roof, you can significantly save on building materials and sunbathe on it in the summer.
During installation, it is necessary to maintain a slope angle of 2-3 degrees with respect to the horizon.
Multi-slope and single-slope roof of a frame house
The slope angle of the slopes starts from 10 degrees. The number of skates is from 1 to 4.
Pitched roofs are very popular and are widely used. In the spring, the snow does not linger on them for a long time, the water calmly flows down the gutters, there is a lot of additional space in the form of an attic space, where you can arrange an additional room. The stress on the structure is also reduced, and with it the possibility of leaks.
Roof roof
It can be half-hip (gable with two small slopes) and hip (four-slope). This type of roof is also widely used.
The advantages are as follows: additional space under the roof, the possibility of installing windows, the unique appearance of the house, low load on the structure in winter. Disadvantages - high costs for material, heating, a lot of snow on window structures in winter, faster destruction of roof structures due to insufficient ventilation.
Multi-gable roof
The multi-gable roof is considered one of the most popular. It differs from others in a large number of stingrays and the presence of valleys. Installed if the house has a complex layout.
Advantages - the structure can withstand significant loads, it becomes possible to arrange an additional room, a unique appearance. Disadvantages - a large consumption of material, while leaving a lot of waste, the complexity of DIY installation, large cash costs.
Conical roofs
The conical roof is installed when the building is made in the shape of a circle. Few people build such roofs in Russia.
Advantages - interesting appearance, ease of maintenance. Disadvantages: the complexity of calculations and installation.
We suggest choosing a roof with two slopes. In this case, it will turn out to significantly reduce the costs of material and maintenance, while the appearance of the structure will not be affected.
It should be understood that the more slopes, the more beautiful the roof, but also more expensive. But if you are not used to saving money and want the best, then install a roof of any type.
Slope
The ideal slope for safety and durability is between 30 and 45 degrees. In this case, the load on the roof (wind, snow) is optimal.
At the same time, outwardly, a roof with such a slope looks more advantageous.
The choice of material for the roof
The choice of roofing material depends on the slope of the slopes. In this case, the necessary safety requirements will be met and the service life of the roof will be increased.
Below are the main types of roofing materials and the slope angle that must be observed during installation:
- Decking - from 10 degrees
- Slate - 12 to 60 degrees
- Euroslate (ondulin)- from 6 degrees and above
- Ceramic roof tiles- 18-60 degrees
- Polymer shingles- 18-60 degrees
- Bituminous shingles- from 12 degrees without limiting the maximum slope
- Metal tile- from 15 degrees
When choosing the type of roofing material, the following recommendations must be observed:
- The material must match the roof configuration
- The service life of the material should be as close as possible to the shelf life of the roof itself
- The material chosen must meet the aesthetic and economic criteria of the owner. It is necessary to take into account the complexity of the masonry and the cost of the roofing material, the complexity of the roof scheme, etc.
- The roofing material should have the most "beneficial" characteristics: durability, resistance to mechanical and climatic influences, ease of maintenance, frost resistance, sound insulation level, climatic conditions, etc. If you live where hail often occurs, you should not choose roofing material, which after the first rainfall will turn into rags.
Rafters: section, step, length
To calculate the rafters, you can use a special calculator, saving time: 
The cross-section of the rafters is selected taking into account the following parameters:
- The lengths of the rafter legs and the step of their installation
- Roof slope (the smaller it is, the less load on the surface)
- Loads (snow, wind, etc.) that are established in regulatory documents for each region of the country
- The type of material that will cover the roof, as well as its weight and size
You can choose a section in two ways: refer to the construction tables or carry out an independent calculation.
We suggest that you familiarize yourself with the standards listed in the table below. However, it is best to always choose the oversized option. From the table, you can immediately pick up the rafter pitch and length.
| Installation step of rafters, mm | Length of a separate rafter, m | ||||||
| 3,0 | 3,5 | 4,0 | 4,5 | 5,0 | 5,5 | 6,0 | |
| 600 | 40x150 | 40x175 | 50x150 | 50x150 | 50x175 | 50x200 | 50x200 |
| 900 | 50x150 | 50x175 | 50x200 | 75x175 | 75x175 | 75x200 | 75x200 |
| 1100 | 75x125 | 75x150 | 75x175 | 75x175 | 75x200 | 75x200 | 100x200 |
| 1400 | 75x150 | 75x175 | 75x200 | 75x200 | 75x200 | 100x200 | 100x200 |
| 1750 | 75x150 | 75x200 | 75x200 | 100x200 | 100x200 | 100x250 | 100x250 |
| 2150 | 100x150 | 100x175 | 100x200 | 100x200 | 100x250 | 100x250 | _ |
Lathing
Depending on the slope of the roof and the roofing material (in this case, tiles were chosen), you can choose the pitch and dimensions of the lathing according to the table.
The cross-section of the stepped lathing bars can be selected with a size of 50 by 40 mm.
| Roof slope, hail | Lathing step, mm | Tile consumption, pcs / m2 |
| 50 | 375 | 8,9 |
| 45 | 370 | 9,0 |
| 45 | 365 | 9,2 |
| 40 | 360 | 9,3 |
| 35 | 355 | 9,4 |
| 35 | 350 | 9,6 |
| 30 | 345 | 9,7 |
| 25 | 340 | 9,8 |
| 20 | 335 | 10,0 |
| 15 | 330 | 10,1 |
| 14 | 320 | 10,4 |
Counter grill
The size and cross-section of the counter lattice can be made the same as that of the lathing.
The step must match the step of the rafters.
Installation of the roof of a frame house
The installation sequence for a gable roof is as follows:
- Installing the rafter system
- Insulation laying
- Sheathing and counter-battens
- Installation of roofing material and finishing elements of the structure
Installing the rafter system
The installation of the rafter legs begins after the ceiling beams (Mauerlats) are securely fixed. A bar with a section of 50 × 150 mm, or 50 × 200 mm, will act as rafters. Take a more accurate section from the table above.
Rafter preparation
First you need to make a template for the rafter legs. This is done like this:
- Take two boards and overlap them at an angle of 90 degrees, fixing with a nail at the top point
- The template is lifted up and the edges of the boards are installed on the Mauerlats
- By adjusting the location of the boards, they find the desired slope. Moreover, their edges should go 40-60 centimeters beyond the level of the walls, so that in the future it will be easier to arrange a drainage system. If the length of the boards is not enough, you can sew in two on the ground
- When the required slope of the slopes is obtained, it is necessary to nail a crossbar between the rafter legs, thereby fixing the angle. At the same time, it is necessary to mark with a pencil the cut line of the rafters, if they are fixed end-to-end and cuts at right angles at the points of attachment of the legs to the Mauerlat
- All calculations must be taken with maximum accuracy.
After the template is prepared, two pairs of rafters must be assembled along it, which will be mounted along the edges. Legs are extended if necessary. You can dock them in half a tree with thick bolts, which is safer, or with the help of two nails driven in at different angles. A crossbar must be installed between the two legs of one rafter.
Splicing a bar
Overlapping rafters
Splicing rafters by butt joint method
Twin rafters
Rigid connection with a steel corner and a support flange
Driving nails from the sides, at an angle towards each other
Sliding rafter joint
The next step is to lift the rafters to the roof and fix them to the Mauerlats (beams), as shown in the picture. A thrust bar is mounted below.
Once the two pairs of side rafters are in place, pull the rope between them. It serves as a beacon by which the level is checked. Further, the distance between the rafters is measured and divided by 60 or 80, depending on the step with which the installation will be carried out.
After calculations, the required number of rafters is assembled on the ground. Then they go upstairs, and are installed with the selected step along the entire perimeter. Two boards are nailed between the trusses for fixing.
Insulation of the roof of a frame house
In order not to freeze in winter, it is necessary to insulate the roof.
First, a vapor barrier film is attached to the inside of the rafter legs with a construction stapler. Joints are worked out with double-sided tape. Then, insulation plates are placed in the space between the rafter beams.
To protect the insulation from atmospheric precipitation, it is necessary to lay a diffusion membrane on top of it. If you plan to use a reinforced film, then leave a gap of 2 centimeters between it and the insulation.
Here's a great photo that simplifies the process:
- 1 - rafter
- 2 - Insulation
- 3 - Roof wind and water insulation
- 4 - counter rail
- 5 - Lathing
- 6 - Roof covering
Lathing and counter-lathing
The counter-lattice can be made with bars of 25 by 30 centimeters or 30 by 50. The pitch of the bars is the same as that of the rafters, since they are mounted on top of them. In the photo above, this is clearly visible.
A crate is mounted on the counter-batten. For this, boards 25 by 100 mm are used., Or beams 40 by 50 mm. The pitch of the battens depends on the type of roofing to be used. Fasteners are made with galvanized nails, the length of which is three times the thickness of the bars or planks, and in a checkerboard pattern.
In the photo below, select the desired distance for your option.
Installation of roofing material
In our case, consider the installation of metal tiles. It starts from the bottom up.
First, the cornice strip is mounted using self-tapping screws. Further, the first sheet of metal tile rises to the roof. It is attached to the eaves strip with self-tapping screws in each recess. Then you can attach the sheet through one notch. If the length of one shingle sheet is not enough, you can build it up using loose pieces, overlapping them and fixing them with 4.8 x 28 mm self-tapping screws. Further, the remaining sheets are similarly stacked with an overlap.
The lower edge of the shingles should protrude 40 cm beyond the edge of the eaves.
The load-bearing parts are always subject to high demands. The main load-bearing elements are walls, foundations and roofs.
The roof frame plays a very important role. After all, it depends on him how long the roof will stand.
The construction of a rafter system very often causes difficulties for novice craftsmen. This article will help you make a roof frame with your own hands.
There are several types of rafter systems. The choice of one type or another depends on the purpose of the building, the nature of the coating and the type of roof.
The roof frame can be:
- Metallic. Such a rafter system, as a rule, is designed in industrial construction. This is due, first of all, to high costs. Also, the construction of a metal frame implies large areas and volumes;
- Wooden. A frame of this type is used in the construction of residential buildings with a pitched roof. It is the most common type;
- From reinforced concrete slabs. They serve as a load-bearing base for the construction of a flat roof.
Before you start designing the roof frame with your own hands, you need to decide on the type of rafter system. To play the role of a support is the main purpose of any rafter system.
Rafter legs or rafters are wooden beams with a cross section of 150 × 50 millimeters. On top of them, a crate is attached, and then - a roofing material.
There are two types of roof frames: layered and suspended. They differ from each other in the way the rafters are connected. Both of these types are used in the construction of private houses. They differ in that the Mauerlat is used in the hanging rafter system - a longitudinal beam with a section of 100X100 mm.
The top should rest on the center load-bearing wall and not be connected to each other.
The structural and planning characteristics of the building being erected play an important role when choosing the type of rafter system.
It is advisable to use a rafter system if the distance between the supporting walls is too large. In this case, an “intermediate” wall is erected in the center of the building, which serves as an additional support. As a result, the rafters will not sag.
Otherwise, a hanging rafter system is usually used. But if the roof frame is made of metal, then additional walls are not needed.
Installation features
When designing a rafter system, the following points should be considered:
- If the living area has a humid climate, then it is better to choose a roofing material that has the best water resistance;
- It is necessary to provide ventilation of the attic space. If this is not done, then after a while the supporting elements of the structure will fail;
- The structure must support not only the own weight of the roof with its elements. It must withstand under a layer of snow, fallen leaves, and also withstand the pressure created by the wind;
Required materials and tools
When designing a roof frame with your own hands, you will need:
- Hammer;
- Drill;
- Plane;
- Level;
- Saw;
- Self-tapping screws for wood;
- Roulette;
- Gloves;
- Brackets;
- Fire retardants;
- Staples;
- Antiseptics for wood;
- A bar with a section of 150 × 50 mm (for rafters);
- Studs 8 mm and 10 mm (for rafters);
- A bar with a section of 100 × 100 mm (for Mauerlat);
- Mounting studs (for Mauerlat);
- Slats with a section of 40 × 40 mm (for battens).
Wooden structural elements must be treated with an antiseptic and fire retardant. This will extend the life of the structure and also minimize the risk of fire.
Roof frame with two slopes
You need to start the installation of the frame after:
- all instruments are prepared;
- the necessary materials were purchased;
- treated wooden elements with antiseptics and fire retardants.
Mauerlat laying is the initial stage in the construction of a gable roof frame. distributes and transfers the load from the rafters to the load-bearing walls.
It is important to note that wood can draw moisture out of the concrete base, after which it will crumble. In order to avoid this, it is necessary to lay roofing material under the beams in several layers.
The device of the rafter system
Installation of the rafter system includes the following steps:
- Determine the distance between the rafter legs. It is usually 80 - 90 centimeters. This distance corresponds to the size of the batten;
- We make holes in the Mauerlat to secure the rafters;
- The construction of the roof frame usually begins at the gable of the building. End rafters must be installed at both ends of the roof. After that, we pull the cord between their skates. This cord will help align the intermediate elements;
- We fix all the rafter legs on the Mauerlat using steel brackets and brackets. The overhang of the rafters beyond the perimeter of the building should be approximately 40 centimeters.
- To fix the lower part of the rafters, you must use the harness, which rests on the Mauerlat. If the rafter is not long enough, then it needs to be increased. To do this, lay another beam on the rafter with an overlap of at least 100 centimeters. Such a large overlap is needed so that the roof does not lose its rigidity;
- It is necessary to install additional braces between the rafter legs if the roof frame has a six-meter span. They are attached between the support rafters;
- After the installation of all the rafters has been completed, we proceed to fix the rafters in a strictly vertical position. For these purposes, a ridge bar is used. It is attached to the top of the roof frame;
- When using soft roofing materials, you need to make a continuous sheathing. To do this, use moisture resistant plywood or OSB - plates. If the roof is made of metal, slate, corrugated board, then the crate should be thinned. To increase the strength of the roof, regardless of the roofing material used, a continuous sheathing is made near the ridge part.
Features of the construction of the roof frame
The construction of a roof is an important step in the entire construction of a house. That is why special attention is paid to the structure of the frame of the upper part of the building. To build a roof frame on your own, you need certain knowledge and experience. Next, we will talk about how to make a roof frame.
Depending on the type of roofing structure, the roof frame has several types:
- Roof frame structure, which are based on wooden elements. It is used in private construction for the construction of pitched roofs.
- Metal carcass. It is made from shaped metal beams and is mainly used in industrial construction.
- Concrete frame. In its device, concrete slabs are used, which create a flat roof mainly in high-rise buildings.
Before starting the construction of the frame structure of the building, it is necessary to decide on the choice of one of the above types and the frame of the rafter system, in which the bearing capacity is fully transferred to the trusses. For the device of the truss, a timber bar is used, which in cross-section must be at least 15.0 × 5.0 cm in size. After attaching the rafters to the building and to each other, the roofing system of the sheathing is fixed to the frame.
The rafter structure is divided into layered and hanging. It is chosen depending on the structural features of the building. Both types of rafters are used in the construction of private houses and differ in that, with a hanging system, the main beams are supported by a Mauerlat, which is arranged around the perimeter of the building and is attached to the surface of the load-bearing walls on the upper row of masonry. In practice, the Mauerlat is a timber bar that has a cross section of 10.0 × 10.0 cm. The rafter legs on the upper side of the truss are fixed to each other using a ridge bar. The slab structure in the upper part is not fastened with rafters between each other. Such a wooden frame is made in a different way.
With a layered system, the trusses at the top of their structure abut against the longitudinal central wall or specially provided columns for the supports.
When choosing the type of rafter structure, the overall dimensions of the structure are of great importance.
Note! Hanging rafters are used in the construction of roofs for houses, the distance between the external load-bearing walls of which does not exceed 6.0 m. If the span is greater than this value and there is a longitudinal central wall with load-bearing characteristics or support columns, then a layered rafter frame is used. In this case, it will not be affected by the increased load from the weight of the roofing material.
You need to know that the Mauerlat is the main support for the frame structure and roofing material of the roof. The task of the Mauerlat is to take the loads from the entire roof structure and distribute them evenly on the load-bearing walls of the building.
- Thanks to this structural element, the durability of not only the roof, but also the entire building as a whole, increases. If this tier from a bar was not used, the vertical loads from the roof would act with a destructive force on the load-bearing walls at separate points. In fact, the Mauerlat performs the main supporting and protective function in the entire frame structure of the top of the structure. Such support is not needed only in the construction of wooden houses, in which the top of the walls ends with the laying of beams or logs. This important structural element must be installed when installing the roof frame in such a way that the inner surfaces of it and the bearing walls are in the same plane. This will make the interior decoration of the house more comfortable.
- From the side of the street, the Mauerlat must be buried with brickwork so that the wood material is not exposed to the effects of nature. Walls lined with blocks or bricks should be leveled at the top with a concrete screed. She, in turn, should be covered with roofing material in several layers. Instead of this material, heated bitumen can be used. Insulation material is used to protect the Mauerlat from moisture that could be transferred to it from the walls. An excess of moisture has a detrimental effect on wood material and reduces its durability.
- The most practical and reliable method of fixing the Mauerlat to the walls of the building is the use of metal studs, which firmly hold the surfaces of both elements. Holes of the required size are made in bricks or blocks. Finished metal studs, which are made from steel reinforcement, are inserted into the drilled holes. Then the support bar is applied to the studs for fitting, marks are made and holes are made along them in the Mauerlat.
Note! When installing, attention should be paid to the length of the studs. They should protrude from the body of the support bar at a distance of 1.5 cm. A thread should be cut at the ends of the metal parts, which is ultimately used for the final fixation of the Mauerlat using large diameter washers and nuts. Welding can be used as an alternative to this fastening.
Installation of the rafter frame
At the next stage of work, the roof truss frame is being installed. Before installing the trusses, you need to purchase dry wooden elements so that they do not deform and warp over the next time.
- During construction, the truss structure should include 2 rafter legs and screeds to connect the first in their lower part. Ties are fixed to the rafter legs with anchor parts and bolts. Roof trusses in the required quantity are attached to the Mauerlat and fixed using simple technologies. They consist in making the required number of cuts of the correct shape in the support bar. Rafters are installed in these grooves using simple manipulations. The distance between truss structures depends on the exact dimensions of the roof, which are repelled by the dimensions of the house. In practice, the rafters should be at a distance of up to 1 m from each other. It should be taken into account that in some roof frames, rafters with a vertical direction are used. Such structural elements are used for the construction of high roofs with a vertical size of 3 m and more.
- The lathing wooden system perfectly connects the structural elements of the frame. But before it is not yet installed, it is necessary to ensure the stability of the trusses. For this purpose, a ridge-type bar is foreseen at the top of the structure. On the lower side, a temporary strapping is organized, which is removed after the installation of the slats or battens. As you can see, the lathing plays an important role not only for the construction of the roofing material, but also for the reliable connection of all structural elements, when the roof frame is made with your own hands.
- The lathing system can be divided according to its type into intermediate and solid. The choice of the type of lathing depends on what kind of roofing material the roof will be covered with. An intermediate batten is used if the roof is covered with dense sheet materials. In this case, there must be a certain distance between the planks.
- If the roof of the roof is expected to be soft or it is rolled into rolls, then a solid lathing is used. Only on such a surface can this type of roofing material be laid with high quality, and only in this way can the long operation of the roof be ensured. Soft shingles will feel good on solid sheathing. If this material is laid on an intermediate system, then it will hang down and poorly operated.
For example, for a galvanized sheet, metal tile or slate, an intermediate type crate is well suited. But since these materials require fastening in certain places, the battens of the battens must be mounted at a certain pitch. Therefore, for the correct construction of the roof frame, preliminary calculations must be made.
Note! Any wood materials are susceptible to fungus and insects, and they also burn. To protect wood material from pests, beams and boards must be protected with antiseptic impregnations. In order for the tree to lose its ability to burn, it must be treated with fire retardants. Processing of all wooden elements must be carried out even before the start of installation work. This will increase the durability of the timber roof frame.
In industrial construction, as well as in the construction of multi-apartment high-rise buildings, roof frames are not made of wooden elements. The rafter systems are made of shaped metal in them. The lightweight metal roof frame, which consists of steel of various profiles with thin walls, is distinguished by its reliability and long service life. If we compare metal rafters and wood, then the former have a number of advantages.
- Metal elements, unlike wooden ones, are not subject to combustion. In the event of a roof fire, metal structures are able to withstand high temperatures for a long time and prevent the roof from collapsing.
- When using metal rafters, there is no need to treat structural elements with antiseptics and fire retardants.
- Since the structure is not subject to infection by insects and fungi, and the surface of the elements is coated with zinc, which prevents corrosion, such a roof can be used for about 100 years.
- Metal rafters can be installed in all weather conditions.
- It should be noted that the rafters are easy to install. For installation, you need a minimum of tools.
- Since the structure is lightweight, it does not exert heavy loads on the load-bearing walls of the structure.
Since metal rafters are not afraid of heavy loads, any roofing material can be used as roof overlap.
Photo
Video
In this video we are talking about the installation of the roof truss system.
There are many options for material for building a private house on the modern market. The most common are brick, block and logs. But lately frame houses are gaining more and more popularity. They are characterized by simple and quick installation. It can be done independently without the help of professionals. Below you will find recommendations on how to build the roof of a frame house with your own hands.
The roof structure is heavy and supports it on the load-bearing walls of the house... In the case of a frame house, the roof is installed on vertical pillars sheathed with OSB plates to the middle of the upper strapping beam. Decorative wall cladding is done after the installation of the roof. And after that, the gable and cornice overhangs are hemmed.
Erected and sheathed prior to roof assembly. Therefore, before starting work, you need to prepare a project where the appearance of the roof and its slope will be determined. The pediment can also be attached in parallel with the installation of the roof, but first you still have to install the extreme rafter trusses, securely fastened with braces.
The roof height of a frame house is usually more than 6 meters... Before starting work, you need to decide on the type of rafter system. Depending on the width of the span to be overlapped, the rafters can have a ridge board, a support screed or sloped braces if there is a central load-bearing wall. If the span is small, then rafter puffs are usually installed. Attic walls can act as a support screed.
The rafters are fastened with nails, screws, metal plates or corners. The step of the rafters is determined within 40 - 100 centimeters. This figure depends on the size of the cross-section of the wooden beams from which the posts are made. They can be within 2.5 - 5 meters.
Wooden blocks with a cross section of 10x10 centimeters, called Mauerlat, are laid on the external load-bearing vertical posts of the wall to support the rafter legs. A prerequisite for its installation is hard fixation. It is best to connect the rafter legs using toothed pads. If the span to be covered is more than five meters, it is necessary to install a special support under the rafters. After installation for laying the roofing, the sheathing is mounted. It can be made of OSB-boards, plywood, edged, semi-edged or unedged boards. It depends on the type of roofing you choose.
Subject to the presence of an attic floor, the roof must be made insulated... Insulation is placed between the rafters. Provided that its thickness is 10-15 cm, the cross-section of the rafters will be 15x5-15x7 cm. The cross-section of the rafters is chosen according to the thickness of the insulation and the amount of snow load. For this, calculations are made. If it is not possible to carry it out, then take a larger cross-section of the rafters. With a thickness of insulation more than 15 cm, rafters with a section of 20x7 cm are suitable.
When installing the rafters on the Mauerlat, a triangle is cut out in the support bar, equal to 1/3 of the rafter height.
The roof can have one or more slopes. At the same time, a complex roof looks more interesting. But the most optimal option, both in terms of the amount spent and the work carried out, will be a gable roof. It has no valleys and has only one strong point, which will be an undoubted advantage when erecting a roof with your own hands, since these places in the structure are the most vulnerable.
When choosing the slope value, it should be borne in mind that with an indicator of less than 28 degrees, the load on the rafter system increases. This will lead to the need for strict calculation and control of the load-bearing elements. And with a slope exceeding 50 degrees, wind loads increase. The best choice would be a slope within 35-45 degrees. Such a roof will look better, and the snow will not linger on it.
Roof installation
We will consider the installation of the roof using the example of a house with overall dimensions of 6x8 meters, a gable roof with a slope of 45 degrees, where bituminous slate is used as a roof covering. The construction provides an attic floor with a wall height of 1.1-1.6 meters.
The height of the walls of the attic floor should not be made less than 1.1 meters. This will cause inconvenience in the operation of the roof space. In a cold attic, the walls do not need to be lifted, and the roof structure will not change.
As a rafter system, we will use two inclined rafter legs connected by a crossbar to ensure rigidity. It is also called a puff, a jumper, a crossbar, etc.
The presence of an attic floor assumes... Therefore, we will choose the parameters of 15x5 cm as the section of the rafters. And we will take the thickness of the insulation 15 cm (according to the calculation for Moscow - 138 mm).
Next, you need to decide on the length of the rafters. This can be done by performing calculations. First of all, you need to decide on the angle of inclination. If you still do not know which slope to choose, follow the instructions below.
Two slats 6 meters long must be knocked down with nails in the shape of the letter "L". This will clearly show how the truss truss will look like. The works are carried out on the ground. After that, it is worth preparing a test crossbar. It is a long strip that is applied to the rafters to measure its length.
After that, we raise the resulting truss to the roof and rest it on the top harness bar. Further, by the selection method, we determine the angle of inclination and, accordingly, with the length of the rafters. When determining this parameter, it must be borne in mind that the overhang of the rafters relative to the wall should be 30-55 cm.
The overhang of the roof is made to protect the walls of the house from precipitation. In the absence of a drain, the overhang is made at least 50 cm.
With this method of selecting the length of the rafters, it is necessary to take into account that the total height will be 5 cm lower due to the installation on the Mauerlat. To make such an installation, a 5x5-5x6 cm rectangle is cut out in the Mauerlat bar. For rafters with a section of 15x5 cm.And when trying on rafters, it is necessary to mark where the support will take place and draw a vertical. Thus, we will mark one side of the triangle, and mark the other on the ground at an angle of 90 degrees.
The pitch of the rafters is determined depending on the cross-section of the rafters and the roof slope... For the example under consideration, a step of 70-80 cm is best suited.
The next step is to prepare the required number of rafter legs. To do this, we use the already marked truss. These works should be carried out on the ground. We mark each next rafter leg according to the first pattern in order to prevent the accumulation of errors.
Then we proceed to the fastening of the crossbars. The best place to place them is as low as possible. The crossbar is necessary to perceive the thrust, while the lower it is, the better it works.
In the presence of an attic floor, the best height of the crossbars is 2.25 - 2.35 meters... This will allow for the placement of doorways 2.1 meters high. With a decrease in the height of the openings, the crossbars can be placed lower. But at the same time, the height of the premises will be, respectively, lower. To make the height of the premises equal to 2.5 meters, which is considered the most convenient parameter, the crossbars are made at an identical height of 2.5 meters.
The presence of a counter-lattice will provide a ventilation gap in the roof. There should be two of them - a lower and an upper ventilation gap, 2-4 cm high each. This is done regardless of whether the roof is insulated.
The lower ventilation gap is made under the waterproofing layer, and the upper one is made above. They allow for the weathering of condensate and prevent the accumulation of water. The presence of both ventilation gaps will be a condition that the wooden elements are not covered with mold or mildew.
The counter lattice is attached to the rafters along the length. The step for them is chosen in accordance with the step of the rafters. The section of the boards for these purposes is suitable 2x5 cm.
Next, we make the fastening of the crate. The size of the section and step will depend on the selected material for the roof. By the condition of our example, this is. Therefore, we choose unedged boards for the crate with a section of 4x5 cm.And we will mount them with a step of 35 cm.
We choose the length of the lathing taking into account the presence of an overhang for the extreme rafter leg of 20-50 cm. It can be equated to the overhang of the rafters.
Material selection
Undried wood is suitable for roofing work (sometimes it is called wet)... You can buy it at the sawmill. When choosing, pay attention to the appearance. If the wood is gray, then this may indicate the presence of a fungus. Undried wood will require less financial investment than dried wood, since its price depends on a cubic meter, and not on a square meter.
After the purchase, the bark must be removed from the wood - this will prevent the formation of bark beetles.
After calculating the roof elements, you should order the material. It should be borne in mind that the standard length of sawn timber will be cheaper. And you can trim them yourself, spending the leftovers on something else.