How to make a four-slope equilateral hipped roof for a cottage. Recommendations, description, drawings and photos of rafter systems for a classic hipped roof

The hipped roof is symmetrical and in shape resembles a pyramid with a rectangular base. This design allows you to save on wall material, since it does not have gables.

A significant drawback of a hipped roof is the rafter system, which is more complex than its construction for other types of roofs. The rafter structure must be properly installed, since the slightest error in the calculation can even provoke its collapse. For this reason, it is quite difficult to carry out construction work on your own; it is wiser to resort to the services of professionals.

There are two types of rafters:

- inclined, which are installed, as a rule, on a hipped roof with an angle of inclination of no more than 40 degrees, such rafters are quite easy to install and are beneficial from the point of view of economy;
- hanging, for which the outer walls serve as a support, such rafters are quite difficult to manufacture and also to repair.

The structure of the hipped roof is made as follows. A support bar, the so-called Mauerlat, is placed under the rafter legs or along the entire length of the structure. In the case of a brick house, the timber is installed on the inside of the wall, while a moisture-proof material must be placed between the wall and the Mauerlat. If the house is wooden, the top of the frame will act as a Mauerlat.

In the upper part of the rafter structure, parallel to the support beam, it is necessary to lay the support beam (girder). It is needed in order to support the rafters. Above will be the ridge of the roof. During the construction process, it is necessary to take into account the fact that the gap between the girders and the Mauerlat should not be more than 4.5 meters. To withstand wind loads from the side of the pediment, diagonal braces, braces and struts are made. To insulate the roof, it is recommended to lay a layer of steam and waterproofing material. After completing all these works, you can start installing the roofing.

With a square type, the ramp consists of four triangles. But, the hipped roof also has its drawback. Its frame is quite complex and requires precision and considerable effort during installation.

The biggest difficulty in creating such a roof is the correct calculation of the structure diagram. By making inaccurate measurements and calculations, the builder risks exposing himself to additional costs for the purchase of additional materials and restructuring of the structure. Such an incident will inevitably lead to a significant increase in the cost of work and materials.

Nevertheless, it is possible to make the correct calculations and mount the roof without resorting to the services of professionals.

After carrying out preliminary calculations, you can proceed to the actual installation of the roof frame.

There are basic principles for arranging a hipped roof:

· For the ridge and the rafter system, you must use the same wood;

Intermediate boards require a steeper slope, and their size cannot be less than 5 centimeters by 15 centimeters;

· Short elements are attached to corner rafters;

· The central rafters are fixed on the ridge board;

· The rafter emphasis is made into the ridge board and into the upper strapping end;

· The ridge plays the role of a bearing axle;

· The rafters with one end are fixed on the ridge, and with the other they protrude beyond the boundary of the house;

· Central rafters are displayed on all walls;

· Forking of intermediate rafters is made from the ridge.

It is easy to learn more about the schemes and procedures by contacting us: a hipped roof - a hipped roof structure or another - will be made to the highest standard. Experts will clarify all incomprehensible questions, recommend the necessary materials and tools.

Of the tools for the construction of the frame you will need:

1. Grinder, electric and hand saws.

2. Nails, hammer and dowels.

3. Axes and a plane.

4. Electric drill.

5. Planks and beams of the same wood.

6. Roof material.

7. Steel staples.

The area of the attic or attic floor is much smaller than in the case of a gable roof. This problem can be partially solved by using a mansard type of special hip roof. Let's consider the sequence of steps that must be followed in order to build a hipped roof. Carrying out calculations Carrying out calculations in the construction of a hipped roof To complete the difficult task of making a hipped roof with your own hands, you need to have certain knowledge and skills. First, you need to perform calculations, for which hands.

The technology for making the roofing cake and other roof elements should also be described. Based on the detailed design, it will be easy to calculate the required amount of materials. The development of such a project is a rather difficult task, and if you have any difficulties in its independent development, it is better to involve specialists who will make the necessary calculations taking into account your requirements. Features by the hands of the rafter system In the manufacture of a hipped roof, slant rafters are used, directed to the corners of the house (sometimes they are called diagonal)

It is more difficult to build it than a gable or pitched roof, but, despite this, it is preferred most often. The reason for this is the best water drainage, provided by the device of slopes with a slope, as a result - a long service life of roofing materials, hydro and thermal insulation used for roof installation. In addition, the hipped roof looks more presentable and original in comparison with other types of structures. The hipped roof is characterized as one of the most reliable and practical. Main details of the original structure The structure of the hipped roof must be strictly symmetrical. It can be mounted on any building, but much easier if it has the shape of a square or rectangle. The basis of the roof under consideration is the rafter system, which is complex and intricate. To build it correctly, you must first make a careful calculation. Any mistake in its course can lead to irreversible consequences. If you plan to erect a hipped roof on a square base, then the structure will have four absolutely identical slopes.

To calculate the roof area in this case, it is recommended to determine the area of the slopes and multiply the resulting figure by 4. The result obtained during the calculations must be increased by the area of the eaves. Important! To determine the area of the eaves overhang, you must use the following form: Skarn. = (BC + EF) / 2 * DG. The roof area is determined as follows: Sroofs = (Sskat + Scarn) * 4. Before proceeding with the construction of a hipped roof, it is necessary to take into account important details. Calculation of a hipped roof type A hipped roof with your own hands will be arranged flawlessly if the calculation of the rafter system is done correctly. If the design is based on a square, then first of all it is necessary to determine the angle of inclination of the slopes, the width and length of the base, then, using the obtained data, determine the area of all four slopes. If the roof is based on a rectangle, then the calculation should start by determining the height of the trapezoid and triangle, of which the structure consists. This indicator is equal to the length of the hip rafters. After the height is determined, you can start calculating the areas of these figures. Their total indicator will allow you to get the area of the roof slopes. It is also important to very accurately calculate the area of the eaves overhang. To do this, you need to increase the height of the figure by ½ the sum of the length of the base. It's important to know! Calculations of the latter indicator can be carried out using the length of the roof and the height of the ridge or taking into account the length of the rafter legs and the length of the roof.

After the area of the roof and slopes is calculated, you can calculate the main elements of the rafter system. The calculation of the hipped roof should be as accurate as possible. It is advisable to entrust this period of work to specialists. They will draw up the most competent and accurate drawing, according to which it will be elementary to simply determine the amount of materials required for the construction of a hipped roof with their own hands, the length of the rafters and the sequence of work. Types of rafter systems The rafter system of a hipped roof is a supporting structure consisting of bars, racks, supports and other structural elements. It is considered not only the basis for fastening the roofing material and other elements of the roof, but also the reinforcing element of the entire building. Distinguish between hanging and layered systems. With a heavy span, when there is no possibility of supporting the rafters with internal supports, a hanging system is used. It involves the installation of structural elements of the roof on the outer walls and provides for the installation of metal or wooden ties.

Hanging rafters from the bottom rest on the outer walls, and from above they are connected to each other. There are two types of hip roof truss systems. The rafter system involves the installation of rafters both on the outer walls and on the inner load-bearing wall or additional supports. The maximum allowable span between the supports is 4.5 meters. If it reaches six meters, then it is necessary to install struts under the rafters. The advantages of this type of rafter system include efficiency, lightness and practicality. Constituent elements of the structure of the rafter system The rafter system of the hipped roof includes the following elements: rafter rafters - structural elements, the installation of which is carried out directly on the roof frame at the corners; rafters - structural elements that are fixed to the rafters; Mauerlat - massive beams that support the lower ends of the rafters; girders, beams and crossbars and a number of other additional supports necessary for the reliability and rigidity of the structure of the roof under consideration; struts that play the role of leg holders.

The hipped roof includes several important elements. Important to know! All of these elements of the rafter system create a reliable and stable structure that can withstand heavy loads. The absence of one of them can cause the sudden destruction of the roof. Roofing installation technology Installation of a hipped roof is not an easy task. It begins by collecting the main nodes and rafters on the ground, focusing on a pre-prepared template. Important! The beams, logs and boards necessary for organizing the roof rafter system are selected depending on the pitch of the rafters, the expected loads and the slope angle of the roof. Planks and Mauerlat are mounted on the walls of the building, scaffolds are attached to them, rafters are erected from two opposite corners. They are connected at the top points. Then the rest of the rafters are raised, the cut is adjusted and fastened in the ridge with special puffs. The installation of the hipped roof is carried out in a clear sequence. It is important to know! The hipped roof, unlike other roofs, does not imply fittings. To strengthen it, an additional stand is used, which is mounted as a support in the center of the building. When the rafters are erected and secured, the installation of the rafters with struts is performed. Springs are mined under them, strengthening the rafter legs several times. An important requirement for the installation of a hipped roof: the rafters are mounted at an angle of ninety degrees. Overhangs will allow the walls of the building to be protected from water; they are arranged at a distance of fifty centimeters from the outer walls.

Non-protruding rafters are lengthened by fillets. On top of them, a lathing, steam and waterproofing layers are arranged, on top of which the roofing is mounted. A small country house with a hipped roof Undoubtedly, it is possible to install a hipped roof on your own, but in view of the complex design features and rigid framework of its device, it is better to entrust the work to professionals. They will make a competent drawing, calculate the most important parameters of the roof with extreme accuracy and install all the elements of the rafter system correctly and quickly. If, nevertheless, a decision is made to build a roof of such a plan independently, then due attention should be paid to the calculation of the most important indicators and drawing up a project plan. Any errors can lead to the fact that the roof structure cannot withstand even small loads and collapse from the slightest serious impact. Hip roof on a country estate When selecting a team of craftsmen who will erect the roof, you should pay attention to their experience in construction. It is advisable to trust the device of a hipped roof only to professionals in order to avoid unnecessary nerves and material costs associated with resolving controversial issues.

Of course, for self-construction it is better to choose a simpler option, and in order for the result of the work to be as beautiful and high-quality as possible, you must definitely follow the detailed instructions that are offered by professionals in this field.

Initially, you need to calculate the area for the future hipped roof (consider a hipped roof or pyramidal roof). This is necessary in order to as accurately as possible determine the amount of required materials.

In this case, the school geometry course will be very useful. After all, you need knowledge of how to find the area of the pyramid and calculate the area of one slope. If, for some reason, you have forgotten this most important information, then here is a reminder:

Important! The area of the side surface of the pyramid is the sum of the areas of the side faces. The area of the pyramid is the area of one slope multiplied by 4.

On the Internet, you can easily find online calculators, in which, by setting your parameters, you will quickly find out the calculation of the necessary materials. Usually measured:

· Length of the roof base;

· The width of the base;

· The angle of inclination in degrees;

· Material for roofing.

Important! Be sure to check all the calculations several times. After all, it’s one thing when too many materials are bought - it’s offensive, but not fatal, and it’s much worse when they are not enough, because a situation may happen when you come to your senses, there will be no identical ones in the warehouse.

And remember these important points:

· Almost all roofing materials are overlapped, therefore it is necessary to purchase them with a certain margin;

· The area of the slope must be calculated from the overhangs;

· From 7 to 10 percent of the material goes to waste, this should not be forgotten either.

In order to avoid mistakes as much as possible, at the same time, without contacting a construction company, you can acquire a special program for carrying out such calculations.

In addition, it is imperative to create a clear action plan:

· It is necessary to take into account all additional elements such as roof windows, chimneys, air ducts, etc .;

· It is very important to measure the length of the slope as accurately as possible, and this should be done from the ridge to the cornice;

· In the calculations, it is necessary to add the length of some elements, for example, overhangs, firewall walls, parapets, etc.;

· Take into account the features of the material that is planned to be used for the roof. After all, each of them has its own characteristics;

· An important point - the length of the slopes is reduced by about 70 centimeters if tiles or roll material are used.

Be sure to consider all of the following parameters:

· Weight of roofing;

· Weight of steam and waterproofing;

· Weight of insulation;

· Snow, wind, rain load;

· The weight of the people who will serve the roof;

· The weight of the equipment that you intend to put on the roof (windows, antennas, lanterns, aerators, ladders, etc.).

Taking into account the angle of inclination of the slopes, calculate the length and width of the rafter section.

Calculation of the area for different materials:

By and large, a hip roof (see photo) is the same hip roof, in which the ridge length is zero, i.e. there is no ridge, and all corner rafters converge at one point. Most often it is erected on houses, the box of which is a square.

Let's take a look at one example of such a roof. Our rafters will rest on the floor beams. Let's say we have a box of a house measuring 10x10 meters with a load-bearing partition in the middle.

STEP 1: Install Mauerlats, floor beams and outriggers (see Fig. 1). We put the floor and extension beams, starting from the middle, i.e. first the central ones, and then from them to the left and to the right the rest with the calculated step.

Picture 1

We see that the extreme floor beams and the extreme outreach are at the same distance from the corner of the house. As we have already said in the article "Hip roof construction with the support of the rafters on the floor beams", it is advisable to take this distance not less than 0.8-1 meters.

STEP 2: In the middle of the future roof, we install a central pillar made of 150x150 mm timber. We determine its height from a preliminary sketch of the roof, made on paper. We fix the rack strictly vertically using two temporary jibs (see Fig. 2). After we install the center rafters in the next step, the jibs can be removed. They are not shown in the following figures.

Picture 2

STEP 3: We make and install the four center rafters of the ramps.

How the rafters are marked is shown in Fig. 3

Figure 3

Thus, we make all four central rafters of the slopes and install them (see Fig. 4):

At the top, they can be sewn together either with nails or using metal corners, as shown in the figure.

STEP 4: Sew on the wind boards and install the corner stems (see Fig. 5). How to make corner stems is also described in detail in the article on the hip roof (link above):

STEP 5: We make and install the corner rafters.

To do this, first of all we pull the lace (see fig. 6):

Now I want to show the method that we always use when installing corner rafters over 6 meters long (when they have to be extended). First of all, we take two boards of 6 meters. For one we do only the lower one, for the other, only the upper one. Then we put these two boards, stitching them together with nails right in place. We also immediately put a rack under them (see Fig. 7):

Now we measure the lengths of the two pieces that we are missing with a tape measure - one with the upper cut, the other with the lower one. We make them and sew them onto already standing boards.

This way we make all four corner rafters (see fig. 8):

STEP 6: Add the missing corners to the projection angles, and, if necessary, place the racks under the rafters (see Fig. 9):

Figure 9

The need to install racks is determined by calculation, depending on the size of the roof and snow loads. It is more desirable to rest the racks on the load-bearing partitions, or to put struts. The possibility of installing racks on floor beams is also checked by calculation. We talked about this in the article “Rafter system. Calculation of rafters and floor beams ". In doing so, always try to move the struts closer to the load-bearing walls as much as possible in order to reduce the load on the beams.

STEP 7: We make and install all wipers (see fig. 10).

We put small props above the Mauerlat under the arms, based on the stem.
After that, it remains for us to hem the cornices from the bottom and make the crate.

During the construction of a gazebo or a house, the question of choosing a roof structure inevitably arises. If the structure under construction has a quadrangular or, even better, a square shape, architects and designers often give their preference to a hipped roof. Such a complex structure fully pays off due to its original appearance, aerodynamic qualities and remarkable thermal insulation properties.

This type of roof is considered the most difficult for an independent device, but, nevertheless, many people choose it because of its originality and attractive appearance. Next, we will consider the technique of making a hipped roof on our own.

The hipped roof is a special hipped roof structure with a square base, where the roof slopes appear as isosceles triangles that converge towards this base. Such a roof can have a variety of slopes, or it can be generally round. The main thing is to observe symmetry when arranging it. In appearance, such a roof looks like a tent, which is where its name comes from.

It should be noted that the absence of gables in the tent structure makes it possible to save on materials during its construction.

A roof with a hipped structure, if desired, can be erected on almost any building, but it will be much more convenient if the house has a square base. The basis of the structure of the hipped roof consists of a rather complex rafter system, which can be arranged independently if you have certain skills in building a roof.

Types of roof rafter systems

The roof rafter system of a tent-shaped roof is a supporting structure of supports, posts, bars and other structural elements. It serves as a base for fastening the roofing material and other elements of the roof, as well as a reinforcing part of the entire building.

There are two types of rafter systems for hipped roofs:

1. layered systems;

2. hanging systems.

If the span is weighty and there is no possibility of supporting the rafters with internal supports, then a hanging system is used, which implies the installation of roof structural elements on the external walls and involves the installation of wooden or metal ties. Hanging rafters rest on the bottom of the outer walls and are connected to each other from above.

Under the layered system, it is assumed that the rafters are to be installed on both the outer walls and the load-bearing inner wall or additional supports. The maximum distance between the supports is 4.5 meters. If the span reaches six meters, then struts must be installed under the rafters. The advantages of this type of rafter system are practicality, lightness and economy.
The main elements of the structure of the hipped roof

A hipped roof should have a strictly symmetrical structure that can be mounted on any structure, but it will be much easier if it has a rectangular or square shape. The basis for the type of roof under consideration is the rafter system, intricate and complex.

For its correct construction, a careful preliminary calculation should be made. The slightest mistake of any kind can lead to negative consequences. If it is planned to erect a hipped roof on a square base, then the structure will have four completely identical slopes. To calculate the roof area, in this case, the area of the slopes should be determined, and the resulting indicator should be multiplied by 4. The value obtained as a result of the calculations should be increased by the area of the eaves overhangs.

It should be noted that to determine the area of the overhang of the eaves, it is necessary to apply the formula S eaves = (BC + EF) / 2 * DG. To determine the area of the roof, use the formula S roof = (S slope + S eaves) * 4.
Calculation of the parameters of the roof of the tent type

A self-erected hipped roof will be flawless if you make the correct calculation of the rafter system. If the structure is basically a square, first of all, you should determine the length and width of the base, the angle of inclination of the slopes, and then, using the obtained indicators, determine the area for all four slopes.

If the roof has a rectangular base, then the calculation should begin by determining the height of the triangle and trapezoid that make up the structure. This indicator is equal to the length of the hip rafters. Having determined the height, they begin to determine the areas of these figures. Thanks to their total indicator, you can get the value of the area of \ u200b \ u200bthe roof slopes.

It is very important to calculate as accurately as possible the area of the eaves overhang, for which the height of the figure increases by ½ the sum of the length of the base. It is important to note that the calculation of this indicator can be made using the height of the ridge and the length of the roof, or taking into account the length of the roof and the length of the rafter legs.

After calculating the area of \ u200b \ u200bthe slopes and roofs, you can calculate the main elements of the rafter systems. It is recommended to entrust the calculation stage to professional specialists who will draw up the most accurate and competent drawing, thanks to which it will be possible to easily determine the length of the rafters, the amount of materials that are required for the construction of a hipped roof with their own hands and the further sequence of work.
Tent roof structure

A hipped roof is usually considered in construction as a kind of hip roof, in which the ridge connection is transformed into a ridge knot, and more specifically from a line it has changed into a point. The hip roof is a pyramid, in which the sides are formed by four slopes in the form of isosceles triangles. In this case, the square shape of the base of the roof will give the opportunity to obtain perfect symmetry, which will give the best result.

The hipped roof structure includes the following main structural elements:
The ridge knot, that is, the peak of the roof, its highest point, which is formed as a result of the connection of the rafter slant legs.

Slopes - four inclined planes of slopes, which have a triangular shape, which make up a hipped roof. They have an angle of inclination, the range of which lies in the range of 20-50 degrees. Experienced roofing professionals prefer an optimal angle of 40 degrees.
The rafter system, that is, the frame that serves to support the roof structure. The rafter system carries the weight of the roofing cake and distributes it to define the geometry of the ramps. It is built on the basis of triangles - the most stable and rigid shapes, guaranteeing the reliability and stability of the hipped roof.
Roof covering is a material in the form of sheets, rolls, individual elements or modules, which has a high degree of wear resistance and good waterproofing properties. For these purposes, slate, roofing material, ondulin, corrugated board or metal tile are used.
A roof overhang that extends beyond the perimeter of the roof base and protects the walls from wind and water during rain. The overhang of the roof, which has a length of 40-50 centimeters, is considered sufficient to effectively perform its functions.
Stages of construction of a hipped roof

Project creation

It is allowed to build a hipped roof with your own hands strictly on the basis of a competent project that will guarantee its reliability. Before making drawings, you need to know at least the minimum school course in geometry in order to calculate the angle of inclination of the slopes, the area of the slopes and the height of the ridge. In order to perform these calculations, there is a simple instruction, which is as follows:

First you need to find out the angle of inclination of the slopes using the recommendations from the manufacturer of the roofing material, as well as indicators of construction climatology, dividing the territory of the Russian Federation into 8 zones in accordance with the wind and snow load. Optimally accepted slope is 30-40 degrees. This angle is suitable for almost any kind of roof.

The next step is to calculate the height at which the ridge knot is located. For such a calculation, you need to find out the size of the roof base, as well as the angle of inclination of the roof slopes. If you depict a hipped roof in the form of a pyramid, then its height will be a straight line connecting the ridge and its base. Its length can be calculated using the Pythagorean theorem.

Having learned the height, angle of inclination and dimensions of the base, you can calculate the area of the slopes and the length of the rafter legs. These calculations are necessary in order to calculate the amount of building material consumed, and more specifically for covering the roof and wood for the rafter system.

We must not forget that a hipped roof with a rectangular base, in contrast to a similar structure with a square base, will have slopes with different slopes and different lengths of rafter legs. It is important to take this into account when calculating and installing a hipped roof.

The project is created using a computer program or manually. The program not only performs all the necessary calculations of the length of the rafter system parts, but also selects the thickness for them. As a result, a diagram is obtained with the presence of dimensions and the relative position of the roofing parts, which will serve as a support for the ongoing installation work.
The structure of the rafter system of the hipped roof

The roof rafter system of a tent-roofed type is made from wood of various conifers. It consists of the following main and additional elements:
Lezhen and Mauerlat are timber supports, which are necessary to distribute the load along the entire perimeter of the bearing walls. The Mauerlat is laid on the outer partitions, and the bed is placed on the inner ones. The role of the support bar in a wooden house is played by the upper crown, made of a log or bar. For structures made of blocks and bricks, a concrete reinforced belt is required, in which metal studs are embedded. Mauerlat is laid on them through a layer of waterproofing.
Uprights, which are vertical supports that support rafter legs or a ridge knot.
Roof rafter legs that extend to the corners of the structure from the ridge knot, forming the edges of the hip-type roof slopes. The length of the knuckle legs is longer than usual and they are subject to increased stress. For this reason, they should be respectively twice as thick.

Narodniks are rafters of various lengths, which are attached to the Mauerlat and oblique legs. They form the surface of the slopes.
The struts are an element of the rafter system, located to the rafters at an angle of 45 degrees.
Crossbar, tightening - a lintel located horizontally between two rafters. Its function is to damp the expanding action that the rafters exert on the walls.
Roof lathing - the base on which the roof covering is laid. Depending on the type of roofing, a solid or lattice type of lathing is used.

During the construction of a hipped roof, a layered or hanging rafter system is used, depending on what the layout of the structure has. Although roofing masters with experience do not recommend using the layered type of rafter system if the slopes have a slope of more than 40 degrees.
The process of installation work of the truss system

Having approved the project and purchasing the necessary materials, you can proceed with the independent installation of the hipped roof. In this case, the following sequence of actions is performed:

1. The first step is to install the Mauerlat, floor beams and a bed. If the project provides for the outrigger beams, then they are also mounted at this stage. Laying begins with the central beam, and a step distance retreats from it in both directions, moving towards the edges.

2. The central post is installed exactly in the middle of the hipped roof being erected. For it, a bar is used that has a thickness of 15 × 15 centimeters or more. In order for it to keep its upright position, it is temporarily fixed with two jibs.

3. Next, the central rafters are installed, which in the upper part are fixed to the rack using metal plates, and in the lower part to the Mauerlat. Pulling a cord for a reference point from the corners of the Mauerlat to the ridge knot, the rafter slant legs are mounted. To install them, a double cut is made on the top. The overhangs of the rafters are connected by means of a wind board. If necessary, beams and struts are installed.

4. Then all the women are filed and nailed. Those women who rely on the stem beams are additionally reinforced with racks to unload them. Eaves are hemmed with moisture-resistant plywood or board.

5. On the rafters, a waterproofing film is laid in strips, which overlaps at the joints by 15-20 centimeters. The film is attached using a construction stapler, and along the rafter legs it is fixed by means of counter-lattice rails. The crate is mounted. If a solid sheathing is planned, then plywood sheets will be required, and if lattice, then an unedged board measuring 15 × 4 centimeters.

6. After the roofing is laid. For this purpose, cutting is first performed, given that the strips and sheets are not fastened in a joint, but with some overlap. It is necessary to use special galvanized self-tapping screws as fasteners, which are supplied with the roofing material or nails with a rubber hat, which deforms after screwing in, thereby closing the hole.

7. The final stage is the installation of a drainage system, which consists of a drain pipe, a gutter, a water intake funnel, as well as snow retainers.

Some parts of the roof truss system of a hipped roof have a size that exceeds 6 meters, that is, the standard length of lumber. Therefore, it is required to make type-setting rafters, which consist of several elements, or glued.
Conclusion

Of course, it is quite possible to build a hipped roof with your own hands, but given the complex design features and severe limitations of its device, you can entrust this work to the appropriate professionals. They will make a competent drawing, calculating all the most important parameters of the roof with the utmost precision and will carry out the installation work of all parts of the rafter system correctly and in the shortest possible time.

In the event that it is nevertheless decided to build a tent-roofed roof on your own, then it is required to pay due attention to the calculations of the most important indicators and drawing up a planned project. Due to any small errors, it may happen that the roof structure will not be able to withstand even weak loads, and as a result, it will collapse from a small serious impact. When selecting a working team of craftsmen who erect a roof, attention should be paid to their experience in the field of construction. It is recommended to entrust the device of the hipped roof only to experienced professionals in order to avoid unnecessary material costs associated with solving the controversial problems that have arisen, and to save your nerves.

The process of self-construction of a hipped roof is a hard and time-consuming work, however, the result obtained will be worth all the effort and effort spent, making the gazebo or house stand out from other neighboring structures.

Hip roofs have all the advantages of four pitched roof structures. They resist all environmental attacks well and are very economical. However, hipped roof truss systems are equipped with special requirements and construction techniques. They need to be known to novice builders who want to build such a roof on their own.

Features of the rafter systems of hipped roofs

Hip roofs are also called "envelope roofing", which displays their configuration in the drawings. For the construction of a hipped-roof frame, technologies are used for arranging roofs with four pitched surfaces, but in compliance with certain own specifics. Such roofs completely lack the ridge top beam and gables. Functionally, the ridge bar is replaced by a central post (support), in the upper part of which all the main supporting parts of the rafter system converge.

Geometrically, a hipped roof consists of 4 or more isosceles triangular planes. The lower parts of these planes rest on the walls through the bars / logs of the Mauerlat. The vertices either abut against the central pillar (support), or against each other.

Types of structures of rafter systems of hipped roofs - diagrams

As for conventional roofs with one / two pitched planes, 2 types of rafters are used for the erection of a tent frame:

layered - which use 2 reliable supports in their upper and lower parts. The use of such rafters is possible if the constructed house-building has an inner wall on which the central support bar is installed. Instead of a wall, a support pillar can be installed in any buildings, which rests with its lower part on the attic / basement slabs made of reinforced concrete;
hanging - using only the support in their lower part. Such rafters are installed when the structure does not have an internal support wall, and it is impossible to center the support post.

Important: the choice of the type of rafters - layered or hanging, is determined by the subsequent technology of installation of other elements of the rafter system.

The overhead technology for installing rafters in the rafter systems of hipped roofs is used more often. A hanging structure is more difficult to equip and is inconvenient to repair, since some of its parts are interdependent, and when replacing damaged parts, undamaged elements must be dismantled.

Hip roof rafters: shortened and diagonal

The corner parts of housing construction and the upper part of the hipped roof type are connected by slant / diagonal rafters - an obligatory part of roofs with four pitched planes. They are the longest and most loaded parts of such a rafter structure. Then they are supported by shortened rafters, called - wives. These elements form the triangular surfaces of the slopes at such a roof - hips. When the length of the diagonal rafters exceeds 4.5 m, it is made from 2 boards, sewn with 1 m piece of the same wooden building material as the rafters themselves. The board from which the rafter frame of the insulated roof will be built must have a sufficient width, taking into account the future ventilation gap of 3 cm. It is formed by the upper sloping surface of the rafter system and heat insulating elements. When the commercially available building materials do not provide the required ventilation gap, then a bar counter-lattice structure is attached to the outer parts of the rafters.

Additional support parts of the attachment parts

To increase the strength of the frame of the hipped roof and prevent sagging of very extended rafters, additional support parts are placed under them. The type and number of such additional supports directly depends on the length of the span covered by the diagonal rafter:

for a length of 7.5 m and less, the rigidity of the diagonal rafter will provide a brace located at the top of the span;
with a length of 7.5-9 m, a brace is placed, and an additional support is placed at the bottom of the rafters;
for a length of more than 9 m, a third support is placed in the central part of the rafter. According to the standards, it can only be resting against reinforced concrete floor slabs.

The braces are placed at an angle with an arbitrary value in the range of 45-53 degrees.

Important: sprengels (and trusses) of the racks are placed only in a vertical position.

Fastening the top of the rafters

Tent roof rafter systems do not use ridge or ridge girders. More often, the central rafters or diagonal ones are supported with the help of cuttings on the supporting central pillar. The only supporting element of such a tent, located at the top of the structure, has 3 installation methods:

With this type of fastener, the load on the spacer is transferred to the Mauerlat bars. Therefore, all hips are equipped with a crossbar.

Features of the installation of handcuffs

The lower attachment point for shortened rafters (called rafters) is formed similarly to the attachment points for central hip rafters. Top attachment to diagonal elements is carried out in several ways:

with the help of a cut into a bar, which is used to create an oblique rafter.
by resting on an additional block fixed along the lowermost edge of the diagonal.
by nailing 8.2 cm with nails, when there are no additional strength requirements for the shortened rafters.

Methods for attaching the rafters to the hinged roof rafters

And the most successful is the fastening through a support bar, which is attached flush with the underside of the oblique. With such a fastening, the strength indicators of the diagonal rafters do not suffer, and the installation of the rafters will be performed faster. In addition, during this installation option, there is no need to observe the gap for the shortened rafters when marking and securing them. And when fastened with the help of cuts, the tops of the wedges cannot converge at one point.

The pitch for installation on standard and short rafters for insulated roofs must match the width of the insulator. When the tops of the rafters are attached with cuts / nails, it is possible to change the pitch between the rafters in order to displace the tops of adjacent pitched planes in relation to each other.

Stages of erection of a hipped roof

At the initial stage of construction of the construction of the rafter system of the hipped roof, the base is being prepared - the Mauerlat. For these purposes, Mauerlat parts are mounted, floor beams are placed.

Step-by-step construction of the hipped roof truss system

The latter elements then form the roof overhangs directed towards the beams. Beams that function as a projection and overlap are placed from the center - they start with the installation of the central one, and then the rest of the beams are placed from it with a set step.

For concrete walls, an armored belt is formed on top, to which the Mauerlat itself is attached. At the next stage, the supporting support of the rafter structure, central rafters and corner rafters are installed:

In the center of the overlap, a stand is installed made of a bar with a cross section of at least 15 cm, with a mandatory check of the correctness of its installation using a plumb bob;

The central rafters are located, at the top to the rack and at the bottom to the Mauerlat bar - they are attached with metal corners;

Cords are stretched from the rack assembly to the corners of the base, and then slants are installed along them. After the installation of the diagonal rafters is completed, the installation of the support posts begins.

At the end of the installation and fastening of the support racks, the wipers are made and installed.

These elements fill the space located between the central rafters and the diagonal, which provides a rigid base for the pitched planes of the hipped roof. Narodniks are placed parallel to the central rafters.

The top of the rafters is attached to the slant rafters, and the lower part is fixed to the stems / beams. As you move to the corners of the rafter structure, the length of the rafters decreases.

Supports are placed under the cuffs.

When the rafter systems of hipped roofs are mounted in their place, the sheathing structure is placed on them, heat-insulating work is carried out and the roof covering is laid.

Tent roof rafter systems - video

Sometimes a gable roof looks boring and destroys the harmony of the architectural style, so designers have to invent something more original. One of these options with a "twist" is a hipped roof. The graceful symmetrical design on one side seems simple, but at the same time strikes with its exoticism, referring to the aesthetics of the East or northern yurts.

Roofing experts advise you to abandon the self-construction of a hipped roof if you are not sure of a high level of construction skills and experience.

The easiest option is to entrust the design work and installation to professionals. However, nothing will prevent you from understanding how the hipped roof and its rafter system are arranged in order to assess the possibility of building on your own.

Design features

A hipped roof, the design of which can consist of four or more slopes, is considered in the classical version as a kind of hipped roof. The number of slopes depends on the geometric shape of the roof base.

If the building is covered in the form of a square, then there will be four of them, and if it is round, then there may be five or six or even more, the main condition is that they are the same in shape and size.

The hipped roof structure consists of the following parts:

The hipped roof is designed based on the principle of symmetry. Therefore, maximum harmony can be achieved when a round or square structure is used as the basis for it. You can also build a hipped roof for a rectangular house, but this is much more difficult than building a hip roof.

Advantages

The hipped roof is quite difficult to design and laborious to install, but looking at the surrounding houses, you can see that it is very popular. Designers explain the use of hipped roof structures in projects by its advantages:

Excellent aerodynamic properties that allow the hipped roof to withstand squally and even hurricane gusts of wind, without fear of ripping off the roofing material and collapsing the attic.
The design of the hipped roof with its steep slopes allows you to forget about such an unpleasant, routine event as cleaning the roof from snow.
The hipped roof leaves the possibility of arranging a spacious, residential attic room. However, due to the lack of gables, you will have to install expensive roof windows, which are mounted directly on the slope.
The original design distinguishes houses with a hipped hipped roof from the rows of similar projects with a gable triangular roof.

The device of the rafter system

The rafter system of the hipped roof is the frame on which it is held, its basis. Depending on, the hanging and layered varieties are distinguished.

Hanging rafters rest on two points - the mauerlat and the ridge knot, and the layered rafters have additional support on a vertical rack, which is installed on the internal load-bearing wall. The choice of the type of hip roof truss system depends on the layout and area of the house.

It consists of the following elements:

The rafter system can be made of metal or wood. Wood is a cheaper, easy-to-process material, but it needs pre-treatment with an antiseptic, fire retardant to protect it from decay and fire.

Nuances of design

The device of the hipped roof begins with the calculation and creation of a working project. Not only architects can help with this, but also special computer programs. They calculate the angle of inclination of the slopes, the height of the ridge knot, the section of the frame elements.

The hipped roof contributes to the rational distribution of heat in the house, protects from rain, prevents the formation of a snow cap, and is also suitable for an openwork gazebo, a monumental respectable cottage!

Video instruction

A hip roof is a type of hipped roof, in which two slopes have a trapezoidal shape, and the other two (end) are triangular (having the same name as "hips"). If the end slopes occupy the entire area from the ridge to the cornice, this is a hip roof, if they do not reach the cornice, it is a half-hip roof.

The roof of the house performs a double function - on the one hand, it is entrusted with protecting the building from external influences, and on the other, it is designed to decorate the structure and give it individuality.

Historically, in Russia, preference was given to simpler single, gable roofs, while Europeans prefer a hipped or hipped roof, which has advantages and disadvantages under certain conditions.

Hip roof - advantages and disadvantages

Pros:

high rigidity of the structure. It is achieved due to the corner ribs connected near the ridge support beam;

the possibility of arranging more protruding overhangs, which provides additional protection for the walls of the house;

aesthetic appeal.

Minuses:

the complexity of the calculation and installation;
higher cost of project implementation;
reducing the area of the attic (in particular at the place where the diagonal supports are installed);
the impossibility of arranging an attic;
natural light is possible only by installing windows in the roofing cake.

Since the shortcomings are not critical, the hip-type hipped roof is actively practiced in the modern construction of private houses.

Varieties (types and types) of hip roof

Studying the device of the rafter system of the hip roof, it should be borne in mind that within this type, there are several types of structures. In turn, this makes adjustments to the general process of erecting the frame of the truss system.

Classic hip roof

It differs in the support of the diagonal ribs on the ridge support beam and the location of the overhangs at the same height. The individual elements of the hip roof correspond to a triangle (gables) and a trapezoid (slopes).

Hip roof

Differs in the absence of a ridge support beam. This leads to the fact that all diagonal edges converge at a single point, and ordinary short rafters are already adjacent to them. Such a roof is preferred if there is a square box at home. But the formation of a reliable ridge knot is quite difficult.

Half hip roof

Differs in the presence of vertical gables in which windows can be installed. The picture shows the difference between two types of semi-hip roofs (Dutch and Danish).

Sloped hip roof or mansard hipped roof

The most difficult construction of the rafter system of the hip roof in terms of construction, since in this case, all the roof slopes have a different area and diverge at different angles. The sloping (mansard) roof allows you to more rationally organize the internal under-roof space and, in addition to additional living space, give the house a spectacular appearance.

Hip roof structure

Regardless of the type of roof, all types have the same elements of the rafter system of the hip roof:

ridge support beam or ridge beam - used for a classic hip roof, serves as a supporting element to which diagonal rafters are attached;

a diagonal rafter (side, edge, oblique or corner rafter) - a longer rafter leg, which joins the end of the ridge bar at an acute angle, forming one of the sides of the triangle;

central rafter - boards, of the same length, which adjoin the ridge beam and form the edges of the trapezoidal roof slope. Intermediate rafters are located between them;

intermediate or ordinary rafter - forms the plane of the trapezoidal slope, the distance between them determines the run of the rafter system;

a rafter or short rafter is a structural element that is attached to a diagonal rafter, forming a triangular overhang and corner parts of the trapezoid.

Calculation of the hip roof

The calculation of the rafter system of the hip roof is carried out taking into account the following prerequisites:

wind load in the region. The higher it is, the more shallow the slope should be, and the stronger the whole structure. To level the strong wind, the central and diagonal rafters are made thicker;

the amount of precipitation. An inverse relationship is observed. The higher the amount of precipitation, the steeper the slope should be, so that snow and rain do not create pressure on the rafter system;

type of roofing material. Each type of roofing material puts forward its own requirements for the lathing, and also has a certain weight. These factors must be taken into account even at the design stage;

the need for roof insulation. In this case, the pitch of the rafters is calculated taking into account the width of the insulating material. In addition, the distance between the rafters depends on the type and section of the wood.

The calculation of the roofing material is carried out according to the formulas, taking into account the angle of inclination of the roof. The optimal roof slope for different types of roofing materials is shown in the table:

The slope of the rafter angle determines the placement of the rafters. In turn, the laying of the intermediate rafter is calculated as follows:

first, an axial line is applied to the upper trim of the end wall;
then half the thickness of the ridge beam is calculated, and a line is drawn for the placement of the first of the number of central intermediate rafters;
then the end of the measuring rod and the line for placing the central intermediate rafter marked above are combined;
the line of the inner contour of the side wall is applied to the opposite end of the measuring rod;
the resulting point is the laying of the intermediate rafter.

The ratio between the length of the rafters and their placement is calculated using a correction factor, the value of which depends on the angle of inclination of the roof slope. The length of the rafter leg is determined by multiplying the laying by a factor.

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Hip roof formulas

Ridge height
Ridge bar length	The length of the house minus its width
Center length rafters (trapeze)		Pythagorean theorem
Length of ordinary rafters	Calculated similar to the length of the center rafters
Rafter extension to form frame overhang
Tilt angle ordinary rafters
Diagonal length hip rafters
Narodniks (short rafters)	First short rafter
	Second short rafter
Square hip roof

How to calculate the area of a hip roof?

To know how much roofing material to buy, you need to know the total roof area.

To do this, you need to break the entire roof into simple geometric shapes and make a calculation for each of them.

Calculation of the area of the hip roof allows you to determine in advance not only the cost of purchasing roofing materials and installation, but also to determine the requirements for materials, as well as the need for arrangement and the exact configuration of the lathing.

Hip roof truss system drawing

The result of the development of the project and calculations will be a schematic drawing of the rafter system of the hip roof. There are no similar drawings ready for use without taking into account the characteristics of a particular structure and the place of its construction.

The development of the preliminary scheme can be done independently (a simple sketch will allow you to determine the direction of the project). But, it is better to entrust the drawing to specialists or use special programs for calculation. It should be remembered that the more complex the roof structure, the more accurately you need to calculate the rafter system: configuration and materials. This will also affect the cost and duration of the installation work.

The drawing of the hip roof should include an indication of the purpose of the material, the place of its installation and the method of fastening. The key components of the rafter system of the hip roof, for example, the adjoining of the diagonal supports to the ridge beam or the installation of rafter legs on the Mauerlat, is advisable to be taken out in a separate drawing and described in more detail.

Hip roof drawing (layered rafters with emphasis on two runs)

Drawing of the rafter system of a hip roof with a bay window

The presence of a schematic drawing will be a good help in the manufacture of blanks and the subsequent installation of the roof.

Hip Roof Construction Tools

The structure of the roof and the methods of arranging the nodes determine the set of tools that should be prepared before starting work.

For working with wood, it is useful: a level, a hacksaw, a hammer, a tape measure, a marking string, a stapler.

To work with metal structures, you will need an electric drill, a riveter, cut-through scissors.

The tool and consumables must be prepared in advance. the complex installation of the rafter system of the hip roof involves a large number of cuts and the installation of nails.

To simplify measurements and be able to make all parts of the same size, the masters advise replacing the tape measure with a measuring rod. The measuring rod is made of plywood 50 mm wide, on which the main dimensions are applied.

Hip roof material

The species and type of wood have a direct impact on the durability and reliability of the roof structure. Craftsmen are advised to give preference to larch or pine lumber. All workpieces require preliminary treatment with fire retardants and antiseptics.

In addition to wood, you will need metal fasteners, nails, screws, anchor bolts.

Note. When forming a hip rafter system on a wooden house, which can shrink, the craftsmen advise using floating fasteners to connect the rafters to the Mauerlat. This method compensates for the movement of the crowns during natural shrinkage of the house from a bar or log.

Hip roof rafter system - installation technology

Diy rafter system devices step by step:

1. Preparation of blanks (rafters)

This is the most difficult and time-consuming part of construction, because connected with:

the need to ensure a given angle of inclination of the rafter legs;
different lengths of rafters (short rafters);
the presence of diagonal rafters (oblique), which are given special attention. Due to the length, the slant rafters carry a greater load than the main rafters, and therefore require the use of higher-quality sawn timber with a large cross-section. In addition, diagonal rafters are often longer than standard plank lengths.

In order not to buy different lumber, in practice, the method of splicing (pairing) edged boards is used to obtain a given length.

Advantages of the rafter splicing technology:

obtaining continuous beams of a given length;
increasing the strength of the diagonal rafters of the hip roof due to the doubled section;
simplification of the calculation and purchase of material (unification of dimensions: length and section);
the possibility of using boards intended for the formation of ordinary rafters.

2. Mounting the Mauerlat

Mauerlat for a hip roof is a large section of wood (100x100 or 100x150 mm) mounted along the perimeter of the walls. For Mauerlat wood of the first grade is used.

The peculiarity of laying the Mauerlat is that the timber is connected along the length only with an overlap, but not end-to-end, using many points of connection with the base of the wall. The connecting nodes are additionally reinforced with metal brackets.

Since the purpose of the Mauerlat is to serve as a support for the rafter legs, it needs protection from moisture. For this purpose, a hydro-barrier is placed between the wall and the timber (for example, roofing material is used).

Note. Under the Mauerlat in brick houses (or from aerated concrete, foam concrete, arbolite), a belt of reinforced concrete with pre-installed studs for the installation of a bar is poured. The hairpin has a diameter of 10 mm or more and should protrude 20-30 mm beyond the Mauerlat plane. The stud installation step is 1000-1200 mm.

3. Installation of the purlin

A purlin is a beam that is installed parallel to the sides of the Mauerlat. The run serves as the basis for the installation of additional supports under the rafter legs. The device of the girder is not an obligatory stage of work and is performed only for hip roofs of a large area or having a configuration of increased complexity. The location of the purlin is shown in the diagram.

It should be borne in mind that the point of maximum load will differ depending on the location - on the ridge of the hip or on the edge of the valley.

Note. The hip hip roof is mounted without support, and a complex knot is formed at the junction of the diagonal rafters.

4. Installation of support legs

The uprights act as a support when installing the ridge bar (orange in the picture).

5. Installation of the ridge beam

Installation of the hip roof ridge is accompanied by accurate measurements. Since the entire roof structure will rest on the ridge, the correctness of its installation is checked in height and level.

6. Fastening the rafter legs

The opinions of the masters differ regarding the sequence of work at this stage. This makes it possible to distinguish two areas for performing work:

central rafters are mounted, and then diagonal. This work order is simpler;
diagonal rafters are mounted, and then the rest.

During installation, the lower part of the rafter leg rests on the Mauerlat.

The support of the rafters on the hip roof is shown in the diagram. The first option (with a cut) is simpler, but the second (with a support bar) is preferable, because in this case, the fastening does not weaken the rafter.

The formation of a knot on a ridge beam is possible in different ways.

The options for the upper fastening of the diagonal rafters are shown in the diagram.

Advice. For rigidity, it is advisable to reinforce all nodes with metal elements (brackets, plates, corners).

Since the diagonal rafters bear a significant load, they can be strengthened using such means as:

installation of the rack. It is mounted vertically on the floor;
installation of a brace. Mounted at an angle. The angle of inclination is not critical. The ability of the brace to strengthen the diagonal rafter is important;
sprengel. In fact, it is a T-shaped short beam, turned 180 °. It is used on long spans and is installed so that its base is oriented perpendicular to the diagonal rafter.

7. Installation of ordinary rafters

Privates are installed in the same way as the central rafters, which form the edges of the trapezoid. Their lower part rests and is attached to the Mauerlat, and the upper one rests on the ridge beam. It is important to keep the same distance between ordinary rafters.

8. Installation of rafters (short rafters)

Narodniks are made only from solid lumber. In the place where the man joins the long rafter, cuts are made or support beams are installed. The installation site is additionally reinforced with metal elements.

Note. Installation of hip roof brackets is possible in a staggered manner to simplify installation.

In any case, the people are installed after the formation of the power frame of the roof. Their installation ends with the construction of the rafter system of the hip roof.

Do-it-yourself hip roof step by step - video

The program shows the process of installing the rafter system of a gable hip roof with a central bay window along a short wall.

After the rafter system is ready, you can proceed with the installation of the roof covering, the specifics of the fastening of which determines the need to install the lathing on the rafter legs.

Installation of the rafter system of the hip roof is a long process that requires attention to every stage of the work - from the calculation and selection of material, to the installation of parts and reinforcement of the attachment points. But, with the correct implementation of all stages, the result will be a beautiful and reliable roof for a private house.

The hipped roof can be one- and two-level, have four or more slopes. For the correct selection of sections of its elements, it is necessary to perform a sketch and correct calculation, which boils down to several formulas. In the article we will talk about the structure of the hipped roof and the method for calculating its rafter system.

A hipped roof is one of the most common options in the construction of a house or a gazebo, which are circular, square or rectangular in plan with a slight difference in the lengths of the sides. This design is a good solution for houses of a relatively small area or two-storey cottages with a small base. The roof got its name from the pyramidal shape of the traditional eastern tent, formed by one top and triangular slopes.

Hip roof options

Under the name "hipped roof" several roofing options are combined that have structural differences.

A single-level four-pitched roof is geometrically a four-sided pyramid. A two-level roof is a more complex structure: the upper part is a pyramid, the middle is a cube or parallelogram, and the lower is a truncated pyramid. It was as if the top of the roof had been cut off from the base and raised. The middle part is sometimes made in the form of a glass lantern or finished in the color of the walls.

A hipped roof can have not only four slopes, but also six and eight slopes. This shape looks more like a cone than a pyramid, and is most common in the construction of gazebos with a round base. The most difficult thing in the implementation of such a structure is the connection of the rafters in the center.

The rafter systems differ not so much aesthetically as structurally:

hanging;
layered.

The hanging truss system rests exclusively on the walls of the house, the layered one has a support located in the center of the building and rests on a load-bearing wall or on a pillar specially erected inside the house.

a - the structure of the hanging rafters; b - the structure of the layered rafters; 1 - rafter; 2 - crossbar; 3 - tightening; 4 - rack; 5 - brace; 6 - run; 7 - bed

The choice of design depends on the dimensions of the span (8 m - a hanging system is suitable, 12 m - a layered system is required) and the maximum length of the timber for construction (when connecting the rafter leg in length, the installation of a vertical support is required).

In practice, the layered system is often used, as it is more reliable and maintainable. If the house does not have a suitable load-bearing wall or pillar for support, the base can be created from a bar by dressing at the Mauerlat level.

Basic diagrams and elements of the rafter system

As we wrote, the hipped roof is geometrically a pyramid, so all calculations are carried out based on the rules that apply to the pyramids and triangles that make up it.

Main elements

In order not to be confused in the future with terms, let us name the main elements of the hipped roof rafter system, schematically shown in the figure below, and link them to the geometric image of the hipped roof in the form of a pyramid.

Hanging rafter structure

Mauerlat. Roof base and support, especially with hanging rafters. It is located around the perimeter of the building (ABCD), rests on the walls or is mounted on their outside. For the Mauerlat device, a large section bar is used.
Slant rafters. Roof corners converging at a central point to form a pyramid. On the pyramid diagram (excluding overhangs): AK = DK = CK = BK = Lн. Longest rafter legs in construction.
Ridge knot (K). The most difficult knot in a carpenter's design. If the base of the house is not square, but the ridge forms an edge, the hipped roof transforms into its "sister" - the vald roof. In a structure with layered rafters, the KF (H) section is the central support.
Central rafters. They converge in a ridge knot with nipple rafters. They are the height of each slope, which is an isosceles triangle. On the pyramid diagram (excluding overhangs) - a segment KE, length Lц.
Narodniks. These are shortened rafters running parallel to the central one in both directions.

Now consider constructions with layered rafters.

Tie-free construction with layered rafters

Along with the already indicated elements: the oblique (1) and central (2) rafters, as well as the ridge (3), new elements appear. The central support (rack) or headstock (4), which is supported by the puffs (5), connecting the Mauerlat diagonally. This is an embodiment of a rack that is not based on the masonry, but on an element of the rafter system.

In the absence of central rafters and to strengthen the ridge knot with the headstock (2), it is complemented by the crossbars (3) connecting the oppositely placed slant rafters (1) in pairs (see the figure above).

Reinforcement elements

For greater strength and rigidity of the structure, especially in a climate prone to strong winds, or with a large building area, and therefore a large length of rafter legs, the main structural elements are supplemented with reinforcement elements.

Option to strengthen the rafter structure

Along the axis of the building, an additional bar is cut into the opposite beams of the Mauerlat (1) - a bed (2). The basis of the design, as before, is made up of central (4), shortened (rafters) (5) and slant (3) rafters. Slanting rafters reinforce the cranial bars (6), anchored at the bottom. This is a reinforcement for both the slant legs and the wives who lean on them. The tie rods (7) hold the opposite rafters together and serve as a base for the installation of the uprights (8). They are fixed on top of the Mauerlat and on top of the bed and rest on them.

With especially large lengths of rafter legs, struts are used - supports located not vertically, but at an angle of 45-60 °. In practice, struts are installed with a wall length of more than 9 m (for a gable or four-slope).

The system of strengthening the main elements also contributes to saving lumber. The cross-section of the main elements in such a structure can be taken as reduced. Another way of saving is the formation of overhangs by growing rafters ending in a Mauerlat, filly - bars or boards of a smaller section.

Calculation of the rafter system of the hipped roof

The calculation is based on the following initial data:

the length of the house;
width of the house
ridge height.

Consider the order and formulas of calculations on a conditional example, using the geometric image of a hipped roof (see above):

house length: AB = DC = 9 m;
house width: AD = BC = 8 m;
the height of the ridge located in the geometric center of the roof: KF = 2 m.

Calculation of the lengths of rafter elements

1. Length of beams mauerlata.

AB + DC + AD + BC = 9 + 8 + 9 + 8 = 34 m

2. Central rafters(excluding overhangs). They are the hypotenuse of a right-angled triangle, in which one leg is the height of the ridge, and the other is half the width (8/2 = 4 m) or the length (9/2 = 4.5 m) of the house.

Remember the Pythagorean theorem:

3. Slant rafters(excluding overhangs). They are the hypotenuse of a right-angled triangle, in which one leg is half the width or length of the house, and the other is the corresponding central rafter. For a roof with a ridge in the geometric center of the roof, the lengths of the overhead rafters are the same.

4. Narodniks. The shortened rafters are located parallel to the central one, with a pitch depending on the length of the rafters. Consider a table compiled taking into account weather loads for the Moscow region.

Table 1. Data correspond to atmospheric loads in the Moscow region

Rafters step, cm	Rafters length, m
Rafters step, cm	3,0	3,5	4,0	4,5	5,0	5,5	6,0
215	100x150	100x175	100x200	100x200	100x250	100x250	—
175	75x150	75x200	75x200	100x200	100x200	100x200	100x250
140	75x125	75x125	75x200	75x200	75x200	100x200	100x200
110	75x150	75x150	75x175	75x175	75x200	75x200	100x200
90	50x150	50x175	50x200	75x175	75x175	75x200	75x200
60	40x150	40x175	50x150	50x150	50x175	50x200	50x200

Our center rafters are 4.472 m and 4.924 m long. The rafters will be shorter so you can look at the 3.5 m column.

To calculate the lengths of the beads, let's recall the school and use the properties of such triangles.

If in the figure AB is the central rafter, then MN is the rafter, AC is half the length of the wall (4.0 and 4.5 m, respectively), AM is the step depending on the number of the rafters. MC for each spouse is calculated separately.

MN = (AB MC) / AC

We will calculate the options for choosing the most economical arrangement of shortened rafters, the results of which will be summarized in a table.

Table 2. Calculation of sawn timber for women

Step of the wives, cm	Bar section, mm	Long side mongrels: AC = 4.5 m, AB = 4.472 m				Short side mongrels: AC = 4.0 m, AB = 4.9242 m
Step of the wives, cm	Bar section, mm	number in half slope	AM, m	length in half slope, m		number in half slope	AM, m	length in half slope, m	volume of lumber for two slopes, m 3
215	100x175	1	2,25	2,356	0,165	1	2,0	2,461	0,172
175	75x200	2	1,5	2,981 + 1,491	0,268	1	2,0	2,461	0,148
140	75x175	2	1,5	2,981 + 1,491	0,235	2	1,333	3,282 + 1,641	0,258
110	75x150	3	1,125	3,354 + 2,236 + 1,118	0,302	3	1,0	3,693 + 2,462 + 1,231	0,332
90	50x175	4	0,9	3,578 + 2,683 + 1,789 + 0,894	0,313	3	1,0	3,693 + 2,462 + 1,231	0,259
60	40x175	6	0,643	3,834 + 3,195 + 2,556 + 1,917 + 1,278 + 0,639	0,376	6	0,571	4,218 + 3,515 + 2,812 + 2,109 + 1,406 + 0,703	0,413

Obviously, the less costly options for our example are options with long strides. However, the requirements for fastening the roofing material and the costs of the lathing should also be taken into account. From this point of view, the answer will not be so obvious.

Calculation of the roof area taking into account the overhangs

Since the previous calculation was carried out without taking into account the eaves overhang, which in our example is performed using fillies, we will consider this part of the roof again as a simple geometric figure.

Let us take the length of the overhang (DC) equal to 0.5 m.To determine the area of the slope, we again use the knowledge about the properties of such triangles:

EF / BC = AG / AD

BC - 8 and 9 m for short and long walls, respectively.

AD - 4.924 and 4.472 m for short and long walls, respectively.

AG - 4.924 + 0.5 = 5.424 m and 4.472 + 0.5 = 4.972 m for short and long walls, respectively.

EF = (AG ∙ BC) / AD
EF = (5.424 ∙ 8) / 4.924 = 8.812 m - for the short side
EF = (4.972 ∙ 9) / 4.472 = 10.006 m - for the long side

The area of the slope is calculated by the formula:

S = (EF ∙ AG) / 2
S = (8.812 ∙ 5.424) / 2 = 23.9 m 2 - for the short side
S = (10.006 ∙ 4.972) / 2 = 24.88 m 2 - for the long side

Total area of roofing material:

2 (23.9 + 24.88) = 97.56 m 2.

Advice! When calculating the material, take into account the cutting, especially if it is sheet material, such as slate or corrugated board.

Attention! The article considers the calculation of only the basic elements of the rafter system, which can help in drawing up a preliminary budget for the construction.