Installation of a gable roof with hanging rafters. Construction and installation of a gable roof rafter system with your own hands. Chainsaw prices

Properly designed and assembled according to technology, the roof serves as a barrier preventing cold air and moisture from entering the house. From the outside, with the naked eye we see only a small part of the structure - the roofing. But the roof frame, which is the most important component, performs the main supporting functions and takes on the effects of wind and snow loads.

To prevent it from deforming as a result of operation, it is necessary to correctly calculate the cross-sectional size of its elements and determine the distance between them, taking into account the weight of the roofing material, slope and climatic conditions. In this article we will tell you what a rafter system is gable roof at home, what it consists of, how it is designed and assembled with your own hands.

Rafter system for a gable roof of a house - a system of interconnected supporting elements that together make up the frame of the structure.

It is made of wood or metal in accordance with the calculation of the loads that will affect them during operation. The roof rafter frame performs the following functions:

1. Gives the roof slopes the necessary slope. Traditional form It is the rafter frame that gives the gable roof the shape of an equilateral rectangle, forming a slope between the base of the roof and its ridge. The angled surface allows snow and water to slide freely off the slope.
2. Distributes the load from weight roofing pie . The weight of the roofing pie, taking into account the snow load, can reach up to 500 kg/m2, so the gable roof is subject to intense loads, especially in winter period. The rafters of a gable roof evenly distribute the weight that rests on them, and then transfer the load to load-bearing walls and the foundation of the house.
3. Serves as a basis for attaching thermal insulation and roofing material. The rafter frame of the roof serves as a kind of skeleton of the structure around which its “body” is built. Between rafter legs Thermal insulation must be installed, and a roofing covering must be fixed to the sheathing, which protects against moisture penetration.

Please note that the design of a gable roof truss system is quite complex to design and assemble, especially if the craftsman lacks experience. After all, in order for it to be able to withstand intense loads, you need to correctly calculate the cross-section of the rafters and the pitch of the rafters, taking into account the slope and length of the slopes, the roofing material used, and also draw up a drawing according to which the assembly will be carried out.

Types of rafter systems

Rafter systems differ in many factors; their composition depends on the layout of the wooden or brick house, the total weight of the roofing pie, the material from which the frame is made, as well as the type roofing covering.

An important characteristic of a structure is their load-bearing capacity, which determines how much weight they can withstand without deformation. By characteristic features The following types of rafter systems are distinguished:

Layered

A layered rafter frame is a frame whose rafters have 2 support points. The upper end of the leg rests on a ridge girder mounted on vertical posts fixed to interior wall. And with the lower end it is installed on the Mauerlat.

Assembly of a layered rafter system on a gable roof is possible only if there is at least 1 load-bearing partition or main column located inside the house. This design is often called non-thrust, because the second support point of the rafters compensates for the thrusting load on the walls of the house, which is assumed by the hanging installation of the frame.

Rafter legs of the layered type experience load only in bending, which can be eliminated by various struts. The layered rafter system allows you to cover houses up to 14 meters wide.

Hanging

The hanging rafter system is distinguished by the fact that its rafters rest only with their lower end on a mauerlat beam installed on the external load-bearing walls. The upper end of the rafter legs of this design does not rest on anything, but seems to hang in the air, which is why 2 types of load arise: bending and expansion.

The thrust load of such a layout of elements on the external walls is so great that it has to be compensated with the help of numerous crossbars and ties, due to which the rafter pairs are tied together.

The structure of a gable roof with hanging rafters consists of triangular trusses, the rigid shape of which is not subject to loads. The complexity of the dangling circuit is believed to be much higher.

The rafter system of a gable roof can be easily installed with your own hands if you correctly calculate the pitch of the rafters, that is, the distance between the rafters and the size of their cross-section.

Combined

Combining the best of both systems, it is recognized as the most reliable. It is used in cases where columns, rather than walls, are used indoors as support inside the house. Then hanging and layered rafters can be alternated to strengthen the structure with additional elements without increasing the consumption of building materials.

Important! A sliding rafter roof is another type of frame, which differs in that the rafter legs are installed on the Mauerlat not using a rigid fastening, but using a movable support. The sliding fastening allows the roof to change dimensions within the range of movement during the shrinkage of the wooden house.

Design

The construction of a gable roof truss system of any of the listed types is a set of auxiliary and supporting elements. They distribute the weight of the roofing pie evenly, and also compensate for the bursting and bending loads that arise between them.

The cross-section, length and pitch of the rafters are determined using an engineering calculation that takes into account the weight of the roofing pie, climatic conditions in the construction region, as well as the slope of the structure. Part rafter frame gable roof usually includes the following elements:

1. Mauerlat. Install the Mauerlat beam on the external walls of the house on which they rest roofing slopes. It serves to soften the pressure on the supports and evenly distribute the load from the weight of the roofing pie. It is made of durable timber with a cross-section of 150x150 mm or 200x200 mm and is attached to the upper chord of the walls using anchor bolts or long metal studs.
2. Sill. This is an analogue of a Mauerlat, only it is installed on internal load-bearing walls, and vertical posts need to be placed on it for installation ridge girder.
3. Rafter legs. This term refers to frame elements that are made from boards with a cross-section of 150-40 mm and are installed at an angle to the base of the roof, forming an angle of inclination of the slope. The distance between the rafters, their length and thickness are determined using calculations that take into account the total loads to which they are subjected during operation.
4. Puff. A tie is called a beam that is placed horizontally and connects the legs of one pair of rafters to reduce the bursting load on the outer walls of the structure. The crossbar is a tie installed under the very ridge of the structure.
5. Racks. It's called a stand vertical beam, placed on a bed to support the ridge girder. It is easy to determine what distance should be between the racks, because it follows the pitch of the rafters.
6. Struts. Diagonally located supports that support the rafter legs in the middle or at the bottom, preventing them from bending, are called struts.

Please note that determining how to correctly position the elements of the rafter system can only be done by calculating the temporary and permanent loads to which they will be subjected during operation. Calculating the total weight of the roofing pie helps determine the correct distance between the rafters, calculate their length and required thickness.

The calculation of the rafter system of a gable roof is based on the fact that in the frontal dimension it has the shape of an equilateral triangle, the sides of which can be easily calculated using simple trigonometric formulas.

These simple calculations help determine the optimal distance between the rafters, their thickness and length. The design calculations are performed in the following sequence:

• Determine the structure and slope of the roof. Exist various ways choice of type and inclination roofing structure. This parameter depends on climatic conditions and performance characteristics selected roofing material.
• Determine the total load on the structure. To do this, sum up permanent loads (the weight of the roofing, the weight of the frame, thermal insulation and ceilings) with temporary loads (snow load, wind load), multiplied by correction factor, taking into account the slope of the slopes, and then add 10-15% to this figure so that the frame has some margin of safety.
• Calculate the length of the rafter legs. To do this, they use the Pythagorean theorem, because the truss is an equilateral triangle. It turns out that the square of the length of the rafter leg is equal to the sum of the squares of the height of the blood and half the length of the laying. Knowing how to calculate the length of the rafters, you can calculate the height of the ridge.
• Determine the cross section of elements. The optimal cross-section of elements is selected from tables in accordance with the length of the rafter legs and the distance between them. The higher these indicators are, the thicker the rafters should be.

Remember that before you calculate the rafters for the roof, you need to decide on the basic design parameters. In particular, it is necessary to know exactly the height of the ridge and the slope of the roof, as well as the dimensions of the room being covered. The result of the calculation of roof elements should be detailed diagram rafter system, reflecting their sizes and angles between them.

Calculating the angle of inclination

The angle of inclination of the slopes is selected not depending on aesthetic preferences, but based on weather conditions, taking into account the roofing material. More steep slopes 40-45 degrees are built in areas with big amount snow cover, and flatter 10-20 degrees in places with strong gusty winds.

Keep in mind that the steeper the slope, the higher the consumption of materials, the higher the final cost of the roof. Be sure to take into account the requirements of the material:

1. Tiles and slate require a slope of at least 22 degrees, otherwise precipitation will seep through the joints between the elements.
2. Metal tiles are laid at an angle of at least 14 degrees, since they suffer greatly from gusts of wind, they can become deformed or even fly off.
3. The soft roof allows an inclination angle of up to 5-10 degrees, making it possible to cover slopes of any geometry.
4. Ondulin is considered one of the most reliable materials and can be used even for roofs with a slope of less than 6 degrees.
5. Corrugated sheets cannot be laid at an angle of less than 15 degrees, however, it is advisable to treat slopes even with an acceptable slope with sealant for better waterproofing.

Assembly technology

Before installing the roof frame, it is necessary to calculate the parameters of its elements, based on calculating the total load on the structure, and also create detailed drawing, reflecting its results.

Having a frame diagram in front of you, it is much easier to carry out high-quality installation of the rafter system of a gable roof. The technology for assembling the structure implies the following sequence:

1. First, a mauerlat is laid on the upper belt of the external walls, on which the slopes will rest, and a bench is mounted on the internal partitions, if the system is layered. These elements must be firmly fixed using anchor bolts or studs.
2. Then the rafters are fastened. They are fixed with nails to the Mauerlat, and are also connected to each other using a metal plate. It is worth remembering that the rafters are cut to fit the mauerlat timber, and not vice versa. First, the rafters located on the edge are installed in order to set the level along which the remaining pairs will be aligned.
3. After installing the rafters, auxiliary supporting elements, which I will support them - struts, tightening, contractions. To fix the crossbar more reliably, its end is made with a protrusion half the thickness of the beam and it is cut to the rafters, fixing it with nails in several places.
4. A sheathing is nailed on top of the rafter legs, onto which the roofing material is fixed. The material and pitch of the sheathing are selected in accordance with the characteristics of the roofing material and the slope of the roof.

Remember that a well-designed and high-quality rafter system is the key to the strength, reliability and durability of a gable roof. Therefore, do not neglect the help of professional roofers and designers when creating a roofing design for your home.

Video instruction

Variations of execution truss structure gable roof mass. Its appearance will largely depend on what it will be attic space heated or cold, depending on availability load-bearing partitions, the choice of roofing material and, of course, the taste preferences of the developer. Despite the variety of roof structures (rafter system and roofing pie), the basic installation rules remain unchanged.

The main stages of installing a gable roof

Gable roof projects

Before you begin roof installation, you must draw external forms future frame, indicating its configuration and height, so that in total the gable roof looks proportional in relation to general structure, in a word, clearly imagine the structure of the rafters of a gable roof. This can be done in any way convenient for you, the main thing is to maintain the scale for a real vision of the prospects. From experience we can say that optimal height The roof is considered to be 1/3 of the length of the house. Here we implement our ideas regarding a straight or broken slope, branching in the main lines (Fig. 1), residential or non-residential attic space and the type of roof itself, it can be hanging or layered. Last option It is more often used in the construction of gable roofs, since it is more practical and economical in terms of lumber consumption.

After you have decided on appearance And functional purpose structure, it is necessary to draw a diagram of the rafter system and make its layout in projection. This is necessary in order to calculate required amount material for roof construction.

The expenditure item of the total budget for roof installation will largely depend on how complete and rational the calculations are made. For example, if you know in advance that you will need N amount linear meters timber, then when cutting you need to take into account standard length lumber and rafter leg size. As a rule, long structural elements have to be made into joints, so without proper cutting, you can get an inflated percentage of waste.

Despite the fact that gable roofs are considered the most convenient and economical in terms of laying roofing, it is not superfluous to calculate the amount of sheet or piece material. Since the installation of each of them has its own characteristics, the need for overlap, the number of ridges or waves, technical features (one-sided capillary groove), etc., when calculating total area surface, all these subtleties must be taken into account.

The height of the slate wave and the thickness of the sheet also matter if slate is chosen as a roofing material.

According to GOST 30340-95, 8 wave and 7 wave slates are produced with the following parameters: wave height h - 40 mm, wave pitch (distance between adjacent ridges) - 150 mm, and sheet thickness - 5.2 or 5.8 mm.

Example of consumables calculations

IN ideal, when the installation of a gable roof is carried out according to the project, a selection of all structural elements is made, indicating the length and quantity of each position. Using a rational cutting system, the volumes are summed up by:

• Lumber (m.p.)
• Insulation (m2)
• Vapor barrier membrane (m2)
• Roofing covering (quantity in pieces, m2)

For clarity of calculations, we will take as a basis a house with specific dimensions

• Width(s) – 5 m
• Length (h) – 8 m
• Apex angle () – 1200
• Slope angle (A, C) – 300

We start by calculating the height of the roof, it is calculated as follows

h = ½ x a/ tg /2 = 0.5 x 5/ 1.73 = 1.44 mm

the length of the rafter (AB) according to the right triangle theorem will be equal to the product of ½ the width of the house divided

by sine of ½ vertex angle

L(AB) = 1/2 x a / sin /2 = 1/2 x 5 / 0.87 + 0.5 = 2.87 m

To the resulting length, do not forget to add the length of the eaves overhang; it is determined in the range of 0.5 ÷ 0.8 m. Therefore, the final size of the rafter leg will be equal to 2.87 + 0.5 ÷ 0.8 = 3.37 ÷ 3.87 m (let's stick to the 3.5m option)

S over. roof = a x L(AB) x 2 = 5 x 3.5 x 2 = 35 m2

This is not a total figure for the amount of roofing material that will be needed to cover the roof. To it you will need to add the percentage of waste based on the cutting according to the roof configuration. For each option it will be individual, so the final result will be known after specific calculations.

Lumber for sheathing is also easy to calculate. The pitch between the battens (m) is taken to be 300 mm. Total

M = L(AB) / m x b = 3.5 / 0.3 x 8 x2 = 187 l.m.

We calculate the board for the rafters in the same way. The pitch between the rafters is set, it can vary from 600 to 1000 mm, the cross-section of the board, the weight of the roofing pie are taken into account, and the multiplicity dictated by the width plays an important role thermal insulation mats and the size of sheets of moisture-resistant plywood or OSB boards when performing continuous sheathing.

All other elements are calculated according to the given scheme.

Set of tools for constructing a roof

Once you have completely decided on the designs of the rafter system and the roofing pie, you can adjust the classic list of tools that you will need to build the roof. It is very convenient to have a belt for tools when working at the top, so they will always be in one place and at hand. Its kit should include:

• Roulette
• Pencil or marker
• Lace (beat)
• Hammer
• Roofing shears
• Putty knife
• Roofing knife
• Construction tape
• Hacksaw
• Screwdriver with screw attachment

In some cases, mastic-based adhesives and polyurethane foam may be needed.

Some devices greatly simplify the installation process, such as templates and slats with markings.

Roofing details

It is also worth paying attention to the so-called roofing details, which the developer often does not pay attention to, but they also affect the functionality and durability of the roofing system. The use of low-quality self-tapping screws (without the manufacturer's mark and with a thickness of EPDM gaskets less than 2 mm) leads to roof leaks. Not durable paintwork on the fittings may become damaged over time and ruin appearance roofs. Another element that is important when constructing a roof is snow retainers; their absence increases the risk of an avalanche of snow falling from the roof. In turn, this may lead to damage to the drainage system, buildings or cars under the roof. The next problem that worries developers is the problem of condensation, which is associated with insufficient ventilation of the under-roof space. To improve air exchange, it is necessary to provide for the installation of ventilation outlet elements in the roof surface; they allow you to ventilate the under-roof space more intensively, and therefore avoid the problem of condensation.

They also forget to prescribe antiseptic compounds as an item in the expense item, without which it is impossible to imagine modern construction made of wood.

Gable roof rafter system. Installation and its features.

The installation begins with the installation of a support beam - Mauerlat. It is installed on load-bearing walls and secured using pre-built anchor bolts or metal studs. The accuracy of installation of the entire rafter structure depends on how smoothly the Mauerlat is mounted. His straightforwardness

checked using a level; if necessary, leveling is done using linings or trimming off protruding parts. The flatness of the support beam allows you to use one template to make all the table legs on the ground, rather than having to adjust each one in place. It is recommended to carry out the support of the rafters on the mauerlat using one of the methods indicated in Figure 3.

It is highly undesirable to cut on a mauerlat or on a ridge run; this can reduce bearing capacity supporting elements.

If the project provides for a ridge run, and this is more reliable option, the next step is to install the beam at the top point of the gables. Fastening units A and B in Fig. 1 are made according to the diagrams shown in Fig. 4

The ridge girder is made from 50x200-250 mm boards, the ends of the beams are treated with an antiseptic compound and wrapped with waterproofing material, the end part is left open for air access. Assembling a rafter structure with a ridge girder is much easier than without it. The fact is that the presence of a longitudinal beam allows you to install a pair of rafters separately, which saves time and labor costs.

Roofing pie device

Upon completion of the installation of the rafter system, they proceed to laying the vapor barrier layer. Roll material roll out parallel to the ridge girder and fasten with inside roofs to rafters. Butt joints are made overlapping and sealed with tape.

From above, the space between the rafters is filled with insulation. To ensure protection of thermal insulation from moisture due to possible leaks roof or condensate forming on inner surface roof covering, under-roof waterproofing is installed. It is nailed to the outside of the rafters with nails or staples and secured with counter battens.

Next, the sheathing is installed; its design is selected depending on the roofing material. With the help of counter battens and sheathing, a ventilated gap is created, this ensures the air-dry condition of all roof materials.

Laying roofing is the final stage in the roof structure. It is applied according to the manufacturer's instructions. At the end of the main work, they begin to assemble and install drainage systems, ventilation, snow guards and ladders for Maintenance roofs.

For a long time, a gable roof has been the most common type of roof in the construction of a low-rise building.
Simple design, excellent stability and adaptability to various climatic conditions along with standard approach in construction and the speed of construction of the rafter system are powerful arguments, proven by many years of construction practice.

Features and types of gable roofs

A gable (aka gable) roof consists of two inclined rectangular planes - slopes, installed at an angle to the outer walls of the building.
Due to the slope of the slopes, natural drainage occurs natural waters(rain, melted snow).
There are three main types of gable roofs:

1. Symmetrical- performed in the form isosceles triangle. Classic design and ease of construction have made this type of roof the most popular among builders and private developers;
2. With uneven angles of inclination– has asymmetrical slopes, a ridge that does not go through the center of the house and different lengths eaves overhangs. Such a roof expresses the architectural feature of the building and looks very original in terms of design, but has significant drawback– irrational use of the attic space;
3. Broken– the upper part of such a roof is flatter, while the lower part has a steep slope. This roofing is recommended in cases where the attic space is planned to be used as an attic or living room.

Rafter systems

A gable roof must be strong and relatively light, so much attention is paid to the construction of the truss structure.
It is performed in such a way that the roof can withstand the loads and at the same time does not exert much pressure on the foundation of the building.
The design of the gable roof rafter system differs in the use of support bases for the rafters.
There are three types of rafter systems:

• hanging
• layered
• hybrid.

Accordingly, in the designs of rafter systems, hanging, layered, or both types of rafters are used.
used when the distance between supports is a maximum of 6.5 meters.
installed if there is a load-bearing middle wall or columnar supports inside.
In the first case, it is carried out using the wall and the roof ridge, which are supports for the edges of the rafter “legs”.
The second installation method is used in houses that have a middle load-bearing wall (intermediate support), on which the middle part of the inclined rafters rests.

The design of hanging rafters works not only for bending, but also for compression.

To reduce the bursting force created by “”, they are connected with a screed.
Beams of inclined rafters work only in bending.
At the same time, the costs are significantly lower than during the construction of any other roof.
The best option is considered to be a hybrid gable roof rafter system, which involves alternating hanging and inclined rafters.
In some cases, it may be impossible to install only hanging or only layered rafters.
Such combined system rafters strengthen the structure and reduce material costs.
On the right in the photo you can see a drawing (diagram) of the rafter system of a gable roof.
The load-bearing elements of a gable roof are:

• rafter system, including:
  • rafter legs
  • vertical racks
  • crossbars
  • spacers
  • inclined struts
  • ridge run
• Mauerlat is a beam that is laid around the perimeter of the structure or placed under the rafter leg.

Installation and assembly of rafters

Before installing the rafters, the Mauerlat is attached to the longitudinal walls using anchor bolts.
Then it is determined optimal cross section rafter legs, taking into account their length and the step between them.
If lumber is required that is not the same width and length as is available, then required sizes are achieved by splicing them using fasteners.
When using insulation, it must be selected in such a way that thermal insulation material I had to trim as little as possible.
Installation of gable roof rafters is carried out in the following order:

1. A template is made that will be used to create roof trusses. To do this, two boards (length, equal to length rafter legs) are connected to each other with a nail at one edge.
2. The free ends of the boards of this structure (scissors) are placed on supports in those places where the rafter legs will rest. Thus, you get one that is fixed with several nails. To better fix the angle, a crossbar is fixed between the boards.
3. A second template is made (preferably from plywood) for making mounting cuts on the rafters.
4. Using this template, mounting cuts are cut on the rafters. Then the rafters are connected at an angle of inclination of the slope. This results in a triangle, which is called a roof truss. He is lifted onto the roof using auxiliary structures(stairs, logs, etc.), and attached to the Mauerlat.
5. First, the two outer gable trusses are installed. To perform the correct horizontal and vertical installation, temporary struts are attached to them.
6. A cord is stretched between the tops of the outer trusses, indicating the future ridge and indicating the level for the remaining intermediate rafters.
7. After this, all the rest are lifted and installed roof trusses at an appropriate distance from each other (minimum 0.6 m).
8. Bulky structures, if necessary, are strengthened with struts, crossbars, supports, etc.
9. The ridge beam is installed on special supports. Diagonal, intermediate and short rafters are attached to it.

Calculation of loads and angle of inclination

Designing a complex roofing structure requires professional calculations.
But the calculation of the gable roof truss system small area can be done independently using simple instructions and simple formulas.
Having completed this calculation, it is advisable to consult a specialist to finally make sure of the reliability of the future roof.
First of all, you should decide on the angle of inclination of the slopes.
A slight (5°-15°) slope is only suitable for some types of roofing, so you should first select the roofing material and then calculate the rafter system.
It is very important to correctly calculate temporary (wind and snow) loads.
The snow load limits depend on the climatic region and range from 80-320 kg/m2.
For roofs with a slope of up to 25°, a transition coefficient from snow cover to roof equal to 1 is applied.
For roofs with a large slope, the coefficient is 0.7.
For example, if the load of snow cover on the ground is 130 kg/m2, then the load on a roof with a slope of 25°-60° is 130×0.7=91 kg/m2.
To calculate the wind load, the coefficient of changes in wind pressure and aerodynamic influences is used.
In addition to temporary loads, the permanent load created by the weight of the roofing pie must be calculated.
It includes the weight of the lathing and counter-lattice, the thermal insulation layer, roofing material, and in the case of an attic, the weight of the interior finishing of the ceilings.
On average, the constant load is 40-50 kg/m2.
Great importance in the construction of a gable roof has its angle of inclination.
It should be determined not so much architectural features buildings, how many climatic features region and type of roof being installed.
A steep roof angle is necessary in regions characterized by frequent precipitation.
Gentle slopes are suitable for areas with strong winds, where it is necessary to relieve the roof from wind loads.
The angle of inclination of the gable roof slopes ranges from 5° to 90°.
The most common roofs have a slope angle of 35°-45°.

The attic space at this angle of inclination is of a cold type and is not suitable for living.
The rafter system of a gable roof can be calculated independently using reference books and specialized Internet resources.
But in any case, you need to consult a specialist.
After all, the roof of the building is the most important element its design, which must be durable and reliable.
In conclusion I present to you visual video lesson on the design and installation of gable roof rafters:

Gable roof - the best option for an inexperienced builder, which can be done with your own hands. It is simple to implement, but at the same time reliable and can withstand significant loads from both wind and precipitation. She, of course, is not very beautiful, but she looks quite organic in the baths.

To do everything consciously, you need to understand the structure of a gable roof and the purpose of all its elements. Let's start in order.

Mauerlat

This is a large block fixed to the load-bearing walls around the perimeter of the building. It is this element that accounts for most of the load from the roof. And it is the Mauerlat that transfers it to the load-bearing walls.

For this element, square bars measuring 100*100 mm or 150*150 mm are used. They are connected to the walls using embedded studs. If the bathhouse is wooden, then the upper crown usually serves as the Mauerlat. For all other types of walls, a belt is made of reinforced concrete into which studs are embedded. Then the beam of the selected section is “put on” the studs and tightened with nuts. Sometimes it is additionally secured with long pins.

Since the thickness of the walls is often greater than the width of the mauerlat, its outer side can be covered with bricks. This will make the system more reliable. Only the wood needs to be wrapped in two layers of roofing felt to protect it from moisture and rot.

Rafter legs and ridge

The ridge is horizontal wooden block, located at the top point of the roof and connecting two slopes. The rafters or rafters rest on it and on the mauerlat. Since the ridge bears quite a large load, it needs to be made of a large cross-section and choose durable wood.

The height of the roof ridge is determined based on the roof slope and the width of the building. The slope angle of the roof is a value that depends on climatic factors: if there is a lot of snow in winter, then you need to make the slopes steeper. The snow will come off well from them. If in the region strong winds, a high roof will experience heavy loads and may be damaged.

For average conditions optimal angle The roof slope is about 35°-45°. They will not be heavily loaded by the wind, and the snow will not accumulate heavily. In addition, with this angle, you can choose any type of roofing: any of the tiles, soft roof, slate, metal tiles.

Also remember, the higher the ridge is raised (steeper the slopes), the larger the roof area will be. And this will lead to the fact that the purchase costs roofing materials and the volume of work will be large.

Knowing the slope angle and width of your bathhouse, you can calculate the height of the roof ridge. To do this, the width of the building must be divided by two (if the ridge is in the middle and not shifted to one side or the other) and multiplied by the tangent of the slope angle (the first formula in the figure). In order not to look for the required coefficient in mathematical tables, it is written out and summarized in a simple table.

Roof pitch angle	5	10	15	20	25	30	35	40	45	50	55	60
Tg A (ridge height calculation)	0,08	0,17	0,26	0,36	0,47	0,59	0,76	0,86	1	1,22	1,45	1,78
Sin A (rafter length calculation)	0,09	0,17	0,26	0,34	0,42	0,5	0,57	0,64	0,71	0,77	0,82	0,87

Multiply half the width of the house by this coefficient. Get the height of the ridge for your bathhouse. For example, the width of the bathhouse is 4 meters, the angle chosen is 35°. We calculate: 4 m / 2 * 0.76 = 1.52 m - the height of the ridge from the ceiling.

Now about the rafter legs. They are made from pine or spruce bars, or better yet, larch. Section 50*150 mm or 50*100 mm. The choice of thickness of the bars depends on:

The length of the rafter leg is also calculated according to mathematical formula: the height of the ridge is divided by the sine of the angle of inclination (second formula in the figure). The sines of the angles of inclination are also in the table. Find desired value and you think. For example, for the 1.52 m ridge we found and the rafter angle of 35°, 1.52 m / 0.57 = 2.67 m will be needed.

Roof overhang and filly

But the roof does not end exactly above load-bearing wall. It continues beyond the walls for about 40 cm. This protrusion is called the roof overhang. This is done so that the water flows further from the foundation and does not wash it away. That’s why the rafter legs are longer. If their length is not enough, they are extended with boards called “fillies”.

To organize the roof overhang, boards are added to the rafters - fillies

Types of rafter systems

Rafter systems come with hanging or layered rafter legs. Those hanging rest only on the outer walls of the building (on the mauerlat or upper crown). In order to increase the reliability of the system, so as not to collapse the walls, they are connected with ties (also called a lintel or crossbar). This type of rafter system is suitable for buildings of small width (less than 10 m) and in cases where there is no load-bearing wall running in the middle.

Two types of rafter systems - with hanging and layered rafters

The second type of system is with layered rafters. They rest on a ridge beam and a mauerlat, but the load from the roof is also distributed onto the middle load-bearing wall, through vertical bars - purlins, which are installed at the same pitch as the rafters and rest on the bottom tie.

Do-it-yourself installation of gable roof rafters

For most baths, the system is made with hanging rafter legs - the dimensions allow this to be done. In this case, there is less consumption of lumber and less time is required for its arrangement. Most of the work can be transferred to the ground.

They make one triangle from the rafters according to all the rules and dimensions. They try it on and then make the right amount of it. exact copies. The finished rafters with ties and crossbars, fastened and measured, are lifted onto the roof. There they are placed strictly vertically in designated places and secured to the Mauerlat and the ridge.

For an example of how you can make a gable roof with hanging rafters, see the video.

When the length of the roof slope is more than 4.5 meters, to increase the reliability of the system, vertical posts are installed, which support the rafter leg with one end and rest against the floor beam with the other. This is done regardless of the type of rafter installation: both hanging and layered. They also install slopes that make the structure even more rigid.

In any case, the rafters will need to be attached to the ridge beam, as well as to the mauerlat. The figure below shows options for attaching to the ridge.

It will also be necessary to attach the rafters to the mauerlat. How this can be done - see the photo below.

Sheathing device

Making a gable roof with your own hands ends with the installation of sheathing for the roofing material. To do this, a waterproofing film or membrane is rolled out along the outside of the rafters. Lay it in a horizontal direction. Start from the bottom and work your way up. The second and all subsequent rows are laid with an overlap of at least 15-20 cm. They are secured with small nails or staples from a staple gun.

After installing the rafter system, a waterproofing film or membrane is attached to it, and a sheathing is placed on top

There are two ways - with or without counter-latching. The counter-lattice is stuffed along the rafters, and on top there are sheathing bars. Thus, between the waterproofing and the roofing material, a air gap. This option is better from the point of view that such a roof will dry out better and faster. And this is very important for baths.

Without a counter-lattice, the bars are packed directly on top of the waterproofing. There is a gap here too, but it is smaller, therefore, the ventilation will be worse. But this option is also acceptable: less consumption of materials and work.

After making the sheathing, all that remains is to secure the selected roofing material.

Results

Now you know how to make a gable roof with your own hands. Of all the types, this is the simplest option that can be made by a non-specialist.

IN individual construction gable roofs are much more common than other options. The explanation lies not only in practicality for our latitudes, but also in the design of the rafter system.

To arrange a gable roof, the rafters are laid along the simplest scheme, without requiring either serious calculations or complex installation works

In this case, material consumption will be minimal, and strength design - maximum.

Rafter system options

Despite all simplicity structures, rafter systems can be created under a gable roof several types.

Here the choice will depend on how you plan to use attic space and what are the design features of the house itself.

So, roof slopes can be made equal or various lengths. The latter option gives the cottage’s exterior originality and allows it to better adapt to the wind rose and climatic features.

By type of structure rafter systems, gable roofs are divided into the following main ones groups:

Layered rafters

A similar rafter system is used in houses that have in their middle part longitudinal main wall. In this case, it is transmitted from the ridge through the vertical elements to central load-bearing wall. The ridge itself takes on the weight of the rafter legs, delivering the entire system without the need for cross members.

Hanging rafters

This option is the most practical with a house width from 6 to 14 m. Small permissible width home for such a system is explained by significant load on the walls. The rafters rest with all their weight on the walls, the limit strength which is not unlimited.

To reduce the load on the walls, hanging rafters are introduced into the structure additional reinforcement elements: struts, tightening, headstock, crossbars, etc. Strengthening nodes can be located arbitrary Therefore, they are often given a double functional load. For example: Tightenings installed at the lowest point of the rafter system also successfully cope with the role of beams ceiling ceilings

Main design elements

Individual elements and nodes rafter frames can be made of both wood and reinforced concrete. In individual construction, the first option is more common.

The rafter system consists of the following structural elements:

• which is a high-strength beam that is laid on load-bearing walls and takes on the weight of the rafters;
• rafter legs. These are inclined beams, which are the basis for connecting all elements and determine the shape of the roof;



• horse, formed by the junction of roof slopes;
• fillies. These are boards or pieces of timber that are used to extend rafter legs to create an overhang if the rafters are not long enough;



• eaves, performing the function of protecting walls from snow and water coming off the slopes;
• racks, removing part of the load from the rafter legs. Installed vertically under purlins;
• struts in the form of inclined beams, the upper part supporting the purlins, and the lower resting against the bench or mauerlat;



• puff, connecting the rafter legs horizontally, preventing them from diverging;



• lying down - longitudinal beam, laid in the same plane with the Mauerlat under the ridge;
• sheathing, stuffed across the rafter legs. Thanks to the lathing, the weight of the roofing material is distributed more evenly.

The elements of the rafter system are connected to each other either with nails or bolts through drilled holes. Joints converging at an angle can be reinforced with overhead metal plates or boards.

Important! When preparing material for creating a wooden rafter system, it is necessary to pay attention not only to the quality of drying and absence of damage, but also to the presence of knots. If there are any, their dimensions should not exceed a third of the thickness of the board or timber.

Installation steps

Installation sequence rafter system gable roof will be as follows:

Fastening the Mauerlat

For the device, either logs trimmed at the top and bottom are used, or

Minimum material cross-section – 100 x 150 mm.

Before the final styling Mauerlat will require preparation:

• two layers of dense material are applied to the upper part of the load-bearing wall waterproofing material;
• the timber is impregnated with solution antiseptic For
• individual parts of the Mauerlat are laid out along the walls to determine their lengths. Checked along the way density landing in a prepared place.

fasten Mauerlat can be done in any available way, however more reliable and the easiest way to use anchor fasteners:

• anchor bolts strictly vertically fixed on load-bearing walls;
• in the bars of the Mauerlat are drilled out holes;
• the Mauerlat is mounted on the bolts and finally fixed.

Since the timber has a significant cross-section, its laying over long fastening bolts are often problematic. To simplify the task, before laying the timber on the wall, stacks of thin boards are placed flush with the cut of the bolts. As these boards are removed from under the timber, it will be pushed onto the bolts evenly along its entire length.

Commit the Mauerlat beam can be either screwed on with nuts and washers, or welding piece of reinforcement.

Installation of rafters

Sequence of actions during installation rafters will be like this:

• two beams of the first pair are lifted onto the working platform rafter legs, the length of which must be calculated in advance;
• in places connections rafter legs with a mauerlat are marked and cut out on them fastening cut;
• at the upper junction(under the ridge) both rafter legs are trimmed Thus, to the point overlap they could tightly connect;
• the joint of the rafter legs is fixed with nails or bolts. Next, the work is repeated for each pair of rafter legs. Optimal step rafters at the same time - 70 cm;
• timber is installed and fixed puffs;
• installed under the upper joint of the rafter legs vertical beam (grandmother);
• a horizontal one is placed on top of the rafters sheathing.

Ridge installation

To give rigidity rafter system with central support you need to install ridge run.

It is advisable that there be under it carrier wall. In its absence, planks are laid on parallel load-bearing walls, and beams are installed on them for additional strengthening the support.

For the manufacture of ridge girders, profiled timber with a section of 100 x 150 mm or board with a cross section of 50 x 150 mm or more.

And they are calculated taking into account the wind and snow load on the roof of the house.

Check carefully using a level horizontality ridge run and its parallelism cut the wall.

Attention! Due to incorrect installation of the ridge girder, problems may arise with the installation of roofing materials, leaks will appear, which will lead to emergency roof repairs.

Ridge part rafter system must have maximum possible strength. A certain degree of rigidity of the entire structure is provided runs. However, at the highest point it will be necessary to create an additional stiffening rib.

For this sheathing in the upper part of the roof should be packed tightly. Optimal width reinforced part of the sheathing under the ridge - 40–60 cm. The durable ridge part will not only provide high level security roofing works, but also will make it easier even laying of the roof covering.

From thoughtfulness and thoroughness the execution of the rafter system largely depends efficiency the entire roof. But to build a neat, inexpensive and beautiful roof quite accessible to anyone home handyman. You just need to study diagram installation of rafters, purchase material and do not deviate from time-tested recommendations.

For more information on the construction of a gable roof truss system, see video: