Knots of the hip roof rafter system. Scheme of the hip roof rafter system. Types of hip roof rafters

The hip roof copes well with the tasks assigned to it. But its strength and reliability largely depend on the quality of installation, which cannot be done without a good circuit. How is a drawing of a hip roof rafter system drawn up? What nuances and parameters should be taken into account? This will be discussed in the article.

What is a hip

Before you start talking about how a drawing of a hip roof truss system is drawn up, it’s worth getting acquainted with the structure itself. What is a hip and why is this roofing option so popular?

Any design has its own “specific” elements. The same applies to the roof option discussed in the article. The special detail here is the hip. And what is it? The hip is a triangular part of the roof located at the end of the building. An ordinary hipped roof has triangular sides. In the case of the hip version, the main two slopes have a trapezoidal shape.

Basic principles of creating a hip roof for a house

This roof option is not used so often, but it still enjoys a good reputation. A hip roof has its pros and cons. Experts attribute the following to the advantages of this design:

• the hip, unlike the pediment, has low wind resistance. Such a roof can even withstand hurricanes;
• The rafter system of such a roof is durable and resistant to external influences. This is achieved by installing corner ribs, which act as stiffeners;
• the hip roof makes it possible to create wide overhangs on all sides of the house, which reliably protects the walls from precipitation;
• Don't forget about the appearance. A hip roof can significantly decorate any building.

But it also has its drawbacks. If we talk about the disadvantages, then first of all, experts remind you of the complexity of the drawings of the rafter system of a hip roof. The design has many elements that need to be installed correctly. It can be quite difficult to do this without the necessary skills. In addition, a large number of elements significantly increases the cost of the entire structure.

There are other difficulties. If you decide to make an attic room, you will definitely come across them. Firstly, the attic space under a hip roof is smaller than when using a conventional gable roof. Secondly, you will have to install special windows, which can be quite expensive.

Types of hip rafter systems

When erecting a roof, you need to carefully consider all its elements and structures. But the most important thing is to decide on the type of rafter system. It is this part of the roof that will bear all the loads. In the case of a hip roof option, the following two types of rafter systems are used:

1. Layered.
2. Hanging.

The first option is considered the most acceptable. This type of rafter system for a hip roof implies the presence of additional support under the ridge. To do this, the house must have a load-bearing wall located in the middle of the building. Support beams are installed on it, on which the ridge span is mounted. This design is more durable. In it, the rafter pairs rest not only on the Mauerlat, but also on the ridge span.

If there is no axial load-bearing wall, then a hanging system is used. Here the rafters are attached to each other on top, and rest against the Mauerlat from below. This type of system is used for small houses, when the length of one slope does not exceed six meters. But in the case of a hip roof, it is still better to use a layered rafter system. This will help to avoid problems during installation and further operation.

Creating a drawing of a hip roof rafter system

Before starting the construction of any roof, a lot of preliminary work needs to be done. And, probably, the most important task will be to create a drawing of the hip roof system. The speed and accuracy of installation will depend on the correctness of this work. To draw up a drawing, you need to additionally find out many parameters and characteristics of the future design. And how to do this will be discussed below.

We measure the dimensional data of the building

The very first parameter from which all other calculations will be based is the size of the house itself. A lot will depend on this characteristic, namely:

• ridge height;
• slope length;
• tilt angle;
• the amount of material needed.

If you have a house project, then finding out its dimensions will not be difficult. To do this, just look at the drawing. If there is no project or the house is built with slight deviations from it, then you need to take the measurements yourself. For further calculations of a hip roof, you will need to know the length and width of the building, as well as the height of the walls.

Choosing the optimal roof height

Once you know the dimensions of the house, you can proceed to the following calculations. The first of these is choosing the optimal roof height. The following must be taken into account:

• whether the attic space will be used. If yes, then the height should be higher so that the space is sufficient;
• the dimensions of the house itself. A roof that is too high can significantly worsen the appearance of the entire building;
• the desired slope angle. The higher the roof, the greater this parameter will be.

It is best to make such calculations after determining the angle of inclination of the slope. This is exactly what builders do most often. In this case, the height of the roof will be equal to half the width of the house multiplied by the tangent of the slope angle.

Selecting the slope angle of the hip roof

When designing a roof, all parameters must be calculated and verified. The same applies to the angle of inclination of the slope. Here experts recommend taking into account the following factors:

• First of all, you need to take into account the weather conditions in your region. If the angle of inclination is small, then a lot of snow will accumulate on it in winter, but the roof will not experience large wind loads. At a large angle, everything is the opposite;
• It also takes into account what roofing material will be used. Each manufacturer determines its own minimum angle of inclination at which its products will work most efficiently.

The most optimal option is considered to be a value ranging from 20 to 45 degrees. In this case, the angle of inclination of the main slopes and hips may differ. Also, the slope is selected depending on whether the attic space will be used. The steeper the roof, the less free space will remain under it.

Selecting points (steps) for installing rafters

After determining the angle of inclination of the slope and the height of the entire structure, you can proceed to the next planning stage. The most important element of any roof is the rafters. They are the ones who will withstand all the loads. In order to support the entire weight of the rafters, you need to choose the correct installation step.

But here a lot will depend on another parameter, namely the cross-section of the wooden blocks or boards used. The higher this value, the stronger the rafters themselves. This means that you can install them less often.

To select the correct rafter section, you need to take into account the following types of loads:

1. Variables. Here experts include loads from precipitation and wind pressure. All this data can be found from special maps.
2. Constant loads are loads from the weight of the roofing materials themselves, as well as all equipment installed on the roof.

It is best to take the section with a margin so that there are no unforeseen situations. Once this parameter has been sorted out, you can determine the pitch of the rafters. As a rule, this value lies in the range from 0.6 to 1.0 meters.

To accurately calculate the cross-section of rafters and the pitch of their installation, you can use special programs or online calculators. With their help, you can more accurately calculate all the parameters of the future roof, thereby avoiding mistakes.

Determining the length of the skate

To determine this parameter, it is very important to understand where exactly this element should be located. The ridge in a hip roof is located strictly in the middle. Moreover, this applies to both the longitudinal and transverse axis.

As a rule, the calculation of the length of the ridge is carried out in the following sequence:

• the width of the house is determined and this value is divided in half;
• the resulting value will be equal to the distance at which the ridge will begin and end relative to the building’s pancakes;
• from here you can calculate the desired parameter itself. The length of the ridge is equal to the length of the entire house (roof) minus its width.

This calculation is considered standard, but it can be changed. The most important thing is to maintain a strictly central position of the skate.

We calculate the amount of material needed

A very important question that needs to be resolved before construction begins is how much money will be required to invest. But it can only be solved by calculating the consumption of materials. A lot depends on the size of the house itself. The calculation itself can be carried out in the following sequence:

1. First, we calculate the roof area. Knowing the angle of inclination and height of the ridge, this will not be difficult to do.
2. Next, you can find out how much roofing material, waterproofing and insulation (if the roof is warm) you will need.
3. After this, knowing the installation step of the rafters, we calculate their number.
4. Also, do not forget about additional elements. If the roof is large, then you will definitely need supports, guy wires, crossbars, and so on.

It is very convenient to use special programs for calculations. Some of them will not only calculate how much and what material you will need, but will also help you create a sketch and drawing of the rafter system and the entire roof. But even after this, it is better to ask a professional to check all hip roof calculations, especially the diagram. The hip roof is a rather complex structure and it is easy to make mistakes when designing it. But such miscalculations can lead to serious consequences during operation.

Structures with hanging rafters are in demand when constructing a roof supported only by the outer walls of the house. This construction principle is applicable to both gable and hip roofs.

Design features of a hip roof

The calculation and construction of a hip roof is much more complicated than the construction of single-pitched and double-pitched structures. A hip roof has two trapezoidal slopes and two triangular slopes (hip). This configuration allows you to withstand high wind loads and reliably protect building structures from external influences. In addition, the resulting spacious attic space can be used as a living space (windows for natural light are mounted on the roof slopes).

A hip roof with a ridge girder can be erected in two ways: with layered or hanging rafters. The use of layered roofs makes the roof lighter and simplifies calculations and installation. But in this case, it is required that the building have a load-bearing middle wall. Hanging rafters during the construction of a hip roof can be used when the building is small in width and there are no internal walls. The operational load is transferred to the external walls of the building.

The angle of inclination of the slopes of a hipped roof with hanging rafters should be more than 40°.

The hanging rafters of a hip-type roof rest either on floor beams or on a mauerlat. Designing a rafter system requires accurate calculations and detailed drawings indicating the principles for installing fastening units. For small buildings of the correct geometric shape, calculations can be performed independently; in other cases, it is recommended to turn to professionals, since design errors will cause a significant decrease in the reliability of the roof during operation.

At the first stage of calculations, it is necessary to select the angle of inclination of the hip roof, which directly affects its height. For a system with hanging rafters, the optimal angle of inclination is 40 – 60°. The higher the ridge is located, the more material will be required to build the roof. At the same time, a high roof is the best option for regions characterized by high rainfall. A flatter roof has less windage and better withstands wind loads.

When choosing the angle of inclination of a hip roof, it is recommended to adhere to the “golden mean” rule and proceed from aesthetic considerations. You can select the angle of inclination of the slopes, and based on this, calculate the height of the ridge. Or vice versa, determine the desired height of the roof, and then calculate its angle of inclination.

When calculating a hip roof, it is necessary to ensure the correct positioning of the ridge girder. It should be located strictly parallel to the load-bearing side walls, exactly along the central axis of the building and equidistant from the end walls. Otherwise, the center of gravity of the roof will be shifted, which will lead to uneven distribution of the load on the truss structure and load-bearing walls, which can lead to deformation and destruction of the roof.

Drawings prepared as part of the project development must contain information about the location, cross-section, shape and dimensions of all elements of the rafter system. Their appearance and design features, fastening features, span width, ridge length, roof height are taken into account.

Rafter system of a hipped roof

The main elements of the hip roof truss system include::

• Mauerlat/floor beams (support for rafter legs);
• ridge girder (an element that, together with slanted rafters, determines the configuration of the roof);
• ordinary side rafters (connecting the ridge and load-bearing walls);
• diagonal (corner, slant) rafters (directed from the corners of the walls to the ridge);
• central rafter hip;
• sprigs (short rafter legs connecting the slanted rafters to the mauerlat);
• struts and racks (used as additional supports);
• crossbars (provide a rigid connection between the rafter legs in pairs);
• sprengel (serves as an additional support for the diagonal rafters).

When constructing a hip roof using hanging rafters, a ridge girder is not installed. Instead, central trusses are installed - rafter legs connected by crossbars for rigidity. The rafter system in the central part of the future hip roof is performed in exactly the same way as during the construction of a gable roof. It is recommended to make roof trusses on the ground according to a pre-prepared template in order to accurately comply with all dimensions. When installing trusses, it is necessary to check the verticality of each structure. It is important that the outermost trusses are at the same distance from the corresponding end walls of the building: this will ensure the correct geometry and symmetry of the hips.

After installing a row of trusses, bars or boards are installed in the ridge part of the resulting system (on both slopes) connecting the trusses to each other. Then, slanted rafters are attached to the outer trusses, resting on the corners of the building. At the next stage, the central hip rafter (on each triangular slope) and the flanges are installed.

Rafter trusses can rest on the mauerlat or floor beams. When developing a project, it should be taken into account that in the second case, the spacing of the beams must correspond to the spacing of the rafters. If the rafter system involves the installation of trusses on the Mauerlat, then the tie rods located in the lower part of the trusses will not only ensure the rigidity of the structure, but can also serve as floor beams.

Bottom tightening can be used if the span does not exceed 6 meters. If hanging rafters are installed in a span of 6 to 7.5 meters, it is necessary to use crossbars in the upper part. With a span length of 7.5 - 9 meters, the upper part of the rafters should be tied to the tie using a headstock (stand). If the span length is from 9 to 10 meters, the previous type of structure should be reinforced with struts.

Before proceeding with the installation of the rafter system, it is necessary to check the geometry of the walls of the building. The upper part of the walls (mauerlat, floor beams) must be positioned strictly horizontally.

Principles of manufacturing and installation of slanted rafters

Installing diagonal rafters is a key stage in the construction of a hip roof. It is important to ensure the correct geometry of the structure so that the rafter system evenly distributes the operational loads of the roof.

Diagonal rafters are longer than the side ones; they rest on the corners of the building frame, and in the upper part they are connected to the ridge element of the roof. The rafter half-legs (shortened) - the trusses, in turn, rest on the mowing ones. Increased strength requirements are imposed on slanted rafters, since they carry an increased load, acting as supporting elements of the system. The total load on diagonal rafters is twice as much as on conventional rafter legs. The lower part of the slanted rafters rests on the mauerlat or on a beam laid at the corner of the wall, or rests on them, depending on the design principle - spacer or non-spacer.

Sloping rafters can be made from durable laminated timber of the required length. But, most often, double boards are used, spliced ​​in compliance with certain requirements. Splicing the diagonal rafter leg allows:

• increase the resistance of the element to loads due to the doubled cross-section;
• make a continuous beam of the required length;
• unify the dimensions of the hip roof parts.

Unification makes it possible to use the same material for the manufacture of diagonal elements as for standard rafter legs - the use of boards of the same standard size simplifies design solutions when designing and installing rafter system components.

One or two supports are installed under the diagonal rafter. The boards are spliced ​​along their length so that the joints are located at a distance of 0.15L from the center of the support. Accordingly, the length of the boards for making slanted rafters is selected depending on the length of the span and the number of supports required. In particular, if a hip roof requires a 10 meter long diagonal rafter, it is recommended to use 7 and 3 meter long boards to position the post 1/4 of the span from the top end of the rafter. In this case, the structure will be able to withstand the design loads - it is not recommended to place supports under the middle part of the rafters.

A strut or stand made of timber or paired boards acts as a support for the diagonal rafter. The installation angle is not of fundamental importance if the strut rests on a solid reinforced concrete floor (with the installation of a waterproofing layer). If the stand rests on the bench, the installation angle is usually 35 - 45° to the horizontal plane.

Additional supports are installed according to the following principle. Span lengths up to 7.5 meters require the use of one strut. If the span is 7.5-9 meters, a support is installed at the bottom of the rafters, or a truss truss is installed. As the span length increases, additional support is installed. If the ceiling is not strong enough, it is necessary to lay an additional intermediate beam to support the racks.

Sprengel is a beam that intersects the angle formed by two walls adjacent to each other. A truss truss is a structure in which the slanted rafters are supported by supports that rest on the trusses. The entire system is strengthened by two struts. To make a truss truss, timber of 100×150 mm for beams, 100×100 for racks and 50×100 for struts is used.

Installation of the upper part of the diagonal rafters

The upper end of the hanging rafters is attached to the ridge part of the outer truss when installing a system with hanging rafters. This may require the use of a sprengel or a hammer (a short board with a thickness of 50 mm), to which the ends of the diagonal rafters, sawn at the required angle, are attached. If the ridge is positioned with an indentation from the ridge, you get a Danish half-hip hipped roof. The following types of fasteners can be used to secure sloping rafters at the top::

• perforated plates;
• nails;
• twisted wire rod;
• clamps.

The frames are attached to the slanted rafters using the cutting method or with the installation of cranial bars (the second option makes it possible to obtain a more rigid structure). The cross-section of the bars, which are sewn onto the rafters on both sides, is 50x50 mm. The frames should be supported on the rafters with a shift so that joints of the bars do not form at one point.

The hipped roof is familiar to most developers. But its second name - hip - can confuse even an experienced builder. It's all about the triangular end slopes (hips), which replaced the vertical pediments.

Why did the creators of such a roof need to complicate the design of a gable roof, you ask?

There are several reasons for this:

• The aerodynamics of a hip roof are better than those of a gable roof. Therefore, it steadfastly resists strong winds.
• Triangular slopes make the roof rigid and reliable.
• The hip design makes it possible to install wide eaves overhangs along the perimeter of the building, protecting the façade of the building from rain.
• The appearance aesthetics of such a roof are better than a gable roof.

Construction and types of hip roofs

In order to understand how a hip hip roof is structured, let’s consider its main elements.

Hip impenetrable roof design

As can be seen from the diagram, the main elements of this roof are the same as those of a gable roof. There is a ridge girder, rafters and a mauerlat for attaching them to the wall, racks that support the ridge and struts that relieve the middle part of the rafter legs.

The wind beam holds the rafters together during roof installation, and the fillets extend them, forming roof overhangs. The differences begin with the diagonal rafters that form the hip slopes. Short rafter legs adjacent to the diagonal rafters are called sprigs. To reduce the deflection of long hip beams, trusses are placed under them. This is the name for short T-shaped stands-stands, embedded with their ends into the Mauerlat.

Depending on the width of the building and the presence of internal walls on hip roofs, two types of rafter structures are used:

• hanging;
• layered.

The name of each speaks for itself. Hanging rafters rest only on the outer walls. In the upper and lower parts they are connected by horizontal tie beams, providing structural rigidity. Layered rafters at the ridge joint are supported by vertical posts, in the middle part - by struts, and with their ends placed on the outer walls.

Structural diagrams of hanging and layered rafter systems for hip roofs

In addition to the classic hip roof, there are several varieties of it, created for reasons of aesthetic appeal:

• half-hip 4-slope (Danish);
• gable half-hip (Dutch);
• tent (4 identical hip slopes);
• hip with a broken slope.

Calculation features

The process of calculating a hip roof can be divided into three stages:

• The choice of slope angle depending on the type of roofing material.
• Determination of the lengths of the structural elements of the roof, based on the drawings of the cross section of the building and the plan of the floor to be covered.
• Selection of the cross-section and pitch of the rafters along their length, taking into account the type of wood used and the standard snow load of the construction region.

The angle of inclination of the slopes depends on the roofing material. Therefore, when making a diagram of the truss structure, you need to take into account its minimum value recommended by the standards (in degrees):

• for slate - 22;
• soft tiles - 11;
• metal tiles - 14;
• corrugated sheets - 12;

For a roof made of a waterproof membrane, the angle of inclination of the slopes can be any. Based on the minimum permissible slope value, its actual value is chosen depending on the purpose of the attic space.

If a living space is to be built under a hip roof, its slopes should have an angle of inclination that allows for comfortable movement within the “living area.”

The easiest way to determine the actual length of the roof structural elements is by drawing the rafter system on a scale convenient for measurements.

Knowing the length of the rafters, their pitch and cross-section can be found in the table. The dependence of the geometric dimensions of the rafters on the type of wood and the snow load of the construction region is indicated here.

Selection of rafter cross-section and pitch depending on length, type of wood and snow load

This table can also be successfully used in reverse order. By choosing the pitch and cross-section of the rafter beams, the type of wood and the amount of snow load, you can easily find the maximum rafter length allowed by the standards.

The cross-section of the Mauerlat beam must be no less than the cross-section of the rafter leg. Most often it is 10x15 cm, 15x15 cm or 15x20 cm. The cross-section of the ridge beam is usually equal to the cross-section of the rafter legs.

For the lathing, use a 25 mm thick board, filling it at intervals recommended for the selected roofing. To install a continuous deck on the roof frame, an OSB board with a thickness of 12-15 mm is used.

Installation features

There are opinions circulating on the Internet that installing a hip roof is very complicated and time-consuming. There is some truth in this, but, at its core, the assembly of this structure is not much different from the construction of a conventional gable roof.

Hip roof for a gazebo - invaluable assembly experience

The process of installing a hip roof rafter system includes several stages:

1. A Mauerlat is laid around the perimeter of the walls. In this case, it is placed on threaded steel studs embedded in the masonry and tightened with nuts. At the joining areas (at the corners of the house and at the splice points), landing planes are selected on the Mauerlat, cutting off half of the beam.

2. The further sequence of work depends on the width of the span to be covered (roof area). This point must be taken into account at the stage of drawing up a drawing or diagram of the roof.

You can do without racks supporting the ridge beam if the width of the building (span) is less than 7.5 meters. With a house width of 6 to 7.5 meters, the hanging rafters in the upper part must be tied with a crossbar (a beam with a cross-section of 50x100 mm).

If the width of the building is small (up to 6 meters), then the bottom tie-downs (floor beams) will be sufficient to ensure the rigidity of the rafter system.

Having laid the Mauerlat, mark the central axis on the end walls. Two outer racks are placed along it and secured with temporary struts to the floor beams. If the building is covered with panels, then a central beam is laid on them (the cross-section is the same as that of the Mauerlat). The lower ends of the outer posts are fixed on it.

The initial stage of installation is the installation of vertical posts under the ridge

Intermediate racks are placed in increments of 1-2 meters. If the house is covered with beams, then the racks can be mounted on them, secured with staples or screws.

3. The ridge beam is placed on the racks, the installation locations of the rafter legs are marked on the mauerlat and they are mounted. To attach the rafters to the mauerlat, a notch is used (a cut is made on the rafter leg for a tighter contact).

Cutting the rafter leg into the mauerlat increases the reliability of the joint

4. Hip (sloping, diagonal) rafters are fixed with the lower end to the mauerlat, and with the other - to the junction of the ridge beam and the outer ordinary rafters.

After this, short rafter legs (springs) are attached to them.

Anyone who wants to make a hip roof with their own hands must remember that the main attention here is paid to the quality of assembly of the components. You need to take a very responsible approach to installing the ridge beam, joining the diagonal rafters with the ridge and with the ridges.

The junction of the spigot with the hip rafter

On large roofs, the standard length of timber (6 meters) is not enough to make a solid diagonal rafter. Therefore, it is assembled from two parts, securely fixing them together.

Hip roof overhangs are made by stuffing scraps of timber or thick boards (fillets) onto the rafters, extending 50-100 cm beyond the perimeter of the walls.

Having completed the installation of the rafter system, the sheathing is nailed to it and the roofing material is laid.

We have already talked about the hip roof on the site. There the roof structure was described with the rafters resting on the mauerlat. After publishing the article, I received many requests to show how to make a hip roof with rafters supported on floor beams, and also to answer the question whether it is possible to make a hip roof with different slope angles.

Thus, I wanted to “kill two birds with one stone” with one example. Now we will look at the design of a hip roof with the rafters supported on the floor beams and with different slope angles.

So, let's say we have a house box of 8.4x10.8 meters.

STEP 1: Install the Mauerlat (see Fig. 1):

Picture 1

STEP 2: We install long floor beams with a section of 100x200 cm in increments of 0.6 meters (see Fig. 2). I won't dwell on it any further.

Figure 2

The very first to install are the beams that run strictly in the middle of the house. We will be guided by them when installing the ridge beam. Then we put the rest with a certain step. For example, we have a step of 0.6 meters, but we see that there are 0.9 meters left to the wall, and another beam could fit, but it doesn’t. We leave this span specifically for “removals”. Its width should not be less than 80-100 cm.

STEP 3: We install the stem. Their pitch is determined when calculating the rafters, about which a little later (see Fig. 3):

Figure 3

For now we are installing only the stems corresponding to the length of the ridge, which will be equal to 5 meters. Our ridge length is greater than the difference between the length and width of the house, which is 2.4 meters. What does this lead to? This leads to the fact that the corner rafter will not be located at an angle of 45° in plan (in the top view), and the angle of inclination of the slopes and hips will be different. The slopes will have a gentler slope.

It is enough to secure the stem on the Mauerlat with nails. We attach them to a long floor beam, for example, like this (Fig. 4):

Figure 4

There is no need to make any cuts in this node. Any cut will weaken the floor beam. Here we use two LK type metal rafter fasteners on the sides and one large nail (250 mm) driven through the beam into the end of the extension. We hammer in the nail very last, when the stem is already fastened to the Mauerlat.

STEP 4: Install the ridge beam (see Fig. 5):

Figure 5

All elements of this structure except the struts are made of 100x150 mm timber. Struts made of boards 50x150 mm. The angle between them and the ceiling is at least 45°. We see that under the outer posts there are beams resting directly on five floor beams. We do this to distribute the load. Also, to reduce the load on the floor beams and transfer part of it to the load-bearing partition, struts were installed.

We determine the installation height of the ridge beam and its length for our home ourselves, making a preliminary sketch on paper.

STEP 5: We manufacture and install rafters.

First of all, we make a template for the rafters. To do this, take a board of the required cross-section that is suitable in length, apply it as shown in Figure 6 and make markings using a small level (blue line):

Figure 6

The height of the block that we placed on the stem to mark the lower cut is equal to the depth of the upper cut. We made it 5 cm.

Using the resulting template, we make all the rafters of the slopes, resting on the ridge beam, and secure them (see Fig. 7):

Figure 7

In such structures, where the rafters are supported not by long floor beams, but by short extensions, we always place small supports under the rafters above the mauerlat, forming a kind of small triangle and relieving the attachment point of the extension to the beam (see Fig. 8):

Figure 8

There is no need to bring these supports further inside the roof, much less place them at the junction of the extension with the beam. Most of the load from the roof is transmitted through them (this can be seen in the calculation program) and the floor beam may simply not withstand it.

Now a little about calculations. When choosing the section of rafters for a given roof, we calculate only one rafter - this is the slope rafter. It is the longest here and its angle of inclination is less than the angle of inclination of the hip rafters (explanation - we call a roof slope in the shape of a trapezoid a slope, a hip - a roof slope in the shape of a triangle). Calculations are made in the “Sling.3” tab. Example results in Figure 9:

Figure 9

Yes, I forgot to say. Who has already downloaded this calculation program from my website before December 1, 2013? There is no “Sling.3” tab. To download the updated version of the program, go to the article again at the link:

This article has also been slightly adjusted thanks to feedback from some readers, for which special thanks to them.

STEP 6: We add a stem and attach wind boards (see Fig. 10). We add enough stems to leave room for attaching a corner stem. For now, we simply sew the wind boards at the corners together, controlling their straightness. Check visually to see if the corners are sagging. If so, place temporary supports under them directly from the ground. After installing the corner extensions, we remove these supports.

Figure 10

STEP 7: We mark and install corner offsets.

First we need to pull the string along the top of the floor beams, as shown in Fig. 11

Figure 11

Now we take a beam of suitable length (the cross-section is the same as for all stems) and place it on top of the corner so that the lace is in the middle of it. From below on this beam we mark the cut lines with a pencil. (see Fig. 12):

Figure 12

We remove the lace and install the timber sawn along the marked lines (see Fig. 13):

Figure 13

We attach the corner extension to the Mauerlat using two roofing corners. We fasten it to the floor beam with a 135° angle and a large nail (250-300 mm). If necessary, bend the 135° corner with a hammer.

This way we install all four corner offsets.

STEP 8: We manufacture and install corner rafters.

The hip roof that I described earlier had the same angles of slope and hips. Here these angles are different and therefore the corner rafter will have its own characteristics. We also make it from two boards of the same section as the rafters. But we sew these boards together not quite usually. One will be slightly lower than the other (about 1 cm, depending on the difference in the angles of inclination of the slopes and hips).

So, first of all, we pull 3 laces on each side of the roof. Two along the corner rafters, one along the middle hip rafter (see Fig. 14):

We measure the angle between the lace and the corner stem - the bottom cut. Let's call it “α” (see Fig. 15):

Figure 15

We also mark point “B”

We calculate the angle of the upper cut β = 90°- α

In our example α = 22° and β = 68°.

Now we take a small piece of board with the cross-section of the rafters and saw one end on it at an angle β. We apply the resulting blank to the ridge, combining one edge with the lace, as shown in Fig. 16:

Figure 16

A line was drawn on the workpiece parallel to the side plane of the adjacent rafter of the slope. We will make another cut using it and get a template for the top cut of our corner rafter.

Also, when we apply the workpiece, we need to mark point “A” on the rafters of the slope (see Fig. 17):

Figure 17

Now we make the first half of the corner rafter. To do this, take a board of suitable length. If one board is missing, we sew two boards together. You can sew it temporarily by cutting an inch about a meter long onto self-tapping screws. We make the top cut according to the template. We measure the distance between points “A” and “B”. We transfer it to the rafter and make the bottom cut at an angle “α”.

We install the resulting rafter and secure it (see Fig. 18):

Figure 18

Most likely, due to its length, the first half of the corner rafter will sag. You need to place a temporary stand under it approximately in the middle. It is not shown in my drawings.

Now we make the second half of the corner rafter. To do this, measure the size between points “C” and “D” (see Fig. 19):

Figure 19

We take a board of suitable length, make the top cut at an angle β, measure the distance “S-D”, make the bottom cut at an angle α. We install the second half of the corner rafter and sew it to the first with nails (100 mm). We drive the nails at intervals of approximately 40-50 cm. The result is shown in Fig. 20:

Figure 20

The upper end of the second half of the corner rafter needs to be sawed down again. We do this with a chainsaw right on the spot (Fig. 21):

Figure 21

In the same way, we manufacture and install the three remaining corner rafters.

STEP 9: We install racks under the corner rafters. First of all, it is imperative to install a stand resting on the junction of the corner extension with the floor beam (see Fig. 22):

Figure 22

If the length of the span covered by the corner rafter (its horizontal projection) is more than 7.5 meters, we install more racks at a distance of approximately ¼ of the span from the top point of the corner rafter. If the span is more than 9 meters, add racks in the middle of the corner rafter. In our example, this span is 5.2 meters.

STEP 10: We install two central hip rafters. At the beginning of the 8th step, we already pulled the laces to measure them.

We make the rafters in this way - we measure the angle of the lower gash “γ” with a small tool, calculate the angle of the upper gash “δ”:

δ = 90° - γ

We measure the distance between the points “K-L” and make a rafter along it. We file the ends at the angles we have determined. After this, the upper end needs to be filed down (sharpened) again, taking into account the angle “φ”, which we also measure using a small tool (see Fig. 23):

Figure 23

STEP 11: Add offset to the corners. We make the outermost extensions, which do not reach the mauerlat, lightweight, from a 50x200 mm board (see Fig. 24):

Figure 24

STEP 12: We install spigots. I described in detail how to make spigots in the first article about. Here the principle is absolutely the same, so I will not repeat it (see Fig. 25):

Figure 25

We attach the corner rafters to the corner rafters using a 135° metal corner, bending it if necessary.

After installing all the frames, all we have to do is hem the cornices from below and make the sheathing. We have already talked about this many times.

The hip roof type is most often used for private houses or cottages. The complex is designed in the form of a hipped roof with two trapezoidal slopes. It is based on complex elements consisting of rafters and beams. In this article we will tell you how to install a hip roof, and also analyze the structure of the rafter complex.

Elements of the rafter system can be layered or hanging. The layered rafter system is considered the most profitable. This complex is used for supporting structures or structures with a middle load-bearing wall. The hanging system is used on walls with external openings. The disadvantage of the Viyasky complex is its complexity of installation.

For information! Due to the presence of an additional supporting structure, the span area can be significantly increased. Most often, such a device is used in a hipped roof with an inclination angle of 35 degrees.

The hip roof has the following rafter system:

• racks, struts;
• trapezoidal elements of the slope;
• connoisseurs;
• trusses;
• crossbars;
• sloping elements fastened diagonally or in the direction of the corners of the opening.

The diagonal sloping element is fixed with its edge into the lower support of the entire rafter system or into the beam. This design has large linear dimensions and can withstand high power loads. Extensions are rafter elements that are short in length. They are attached to the mowing system at one support point, and the second is fixed at the lower support point. To reduce the linear size, racks and struts are used. This connection allows the installation of a hip roof without additional spacers. It is worth noting that in the ridge element of a hip roof it is possible to use spacers to support the entire structure. Installing a horizontal level, which is used together with the lower support, will help prevent the formation of thrust:

• fixation onto a beam, which is cut into an additional beam and placed on the lower support;
• fixation on the lower beam with mandatory tying of the top crowns.

Experts do not recommend performing fixation in the lower support, because such an action significantly reduces the strength and reliability of the structure. Regardless of the chosen roof structure and rafter system, due attention should be paid to waterproofing. For example, when laying the sheet on a brick layer, the section of the roll waterproofing should be 100x150 mm, but when laying the sheet on wall openings or ceilings, its height can be 10 cm less.

For information! The rafters of a hip roof may have no ribs only if there are no struts on the roof.

Purlins serve as additional reinforcement of the entire structure. They are placed as a support at a distance of 4.5 m. The installation of the trusses is carried out taking into account the linear size of the spans, and its manufacture is made from timber or logs. Sloping rafters increase the load and turn into a truss.

The installation process of the rafter complex

The design of a rafter system for a hip roof consists of the following steps:

• Construction of a mauerlat along the entire perimeter of the walls. It is fixed using threaded rods, which are installed in the masonry and tightened firmly with nuts. At the junction points of the Mauerlat, a landing plane is found and half of the beam is cut;
• The next stage requires strict adherence to the house design drawings. If the width of the house is up to 7.5 meters, the hanging rafters are connected with a crossbar at the top. If the width of the house is less than 6 meters, the bottom tightening is performed;
• After laying the Mauerlat, the central axis is marked on the end wall, the two outer posts are fixed and placed on the floor beams, secured with temporary struts;

For information! If the roof structure is covered with panels, a central beam should be installed on top, with the lower ends of the outer posts secured. If the structure is covered with beams, the racks are mounted on them and secured with self-tapping screws.

• The ridge beam is laid on the racks, the rafter legs are marked on the Mauerlat itself and their installation is carried out. The rafters are fastened to the mauerlat using the cutting method. To do this, a special cutout is made on the rafter leg, due to which the supporting elements become dense and provide high strength;
• Sloping and diagonal hip rafters are fixed to the Mauerlat, and the other end to the joining point of the ridge beam. The photo clearly shows the element of supported rafters on a hip roof.

Methods of fastening the sprig

Narozhniki are made from solid material. To ensure rigid fastening, the upper edge of this element is filed in the same area as the slanted rafters. The installation of the rafters is further reinforced with metal parts. The frames are mounted on the roof's load-bearing frame, due to which the rafters are supported, which significantly increases the reliability and safety of the roof. To increase the load-bearing capacity of the rafter system, the following method is used:

• All sides of the lower plane of the rafter element are reinforced with bars with a cross-section of 50x50 mm. The rafters should be installed from well-dried wood, pre-treated with special antiseptics.
• If the rafters are installed on the mauerlat, they are lengthened by additional elements - fillies, which serve as a canopy over the wall.

Strengthening the rafter system

When constructing rafter elements, you should take the docking joints seriously. The load-bearing capacity of the hip can be increased by installing a special rack, the task of which is to connect the slings and the floors. Another important point is the installation of the sheathing, which is made of boards or timber. Any pitch of the sheathing can be used, however, when using soft tiles, experts recommend installing a continuous sheathing, and in other types the pitch is 20-50 cm. Comfortable living in the house will be ensured by proper installation of vapor barrier, waterproofing, ventilation and sound insulation. All building materials are laid in the form of a roofing pie.

For information! The installation of a roofing pie will ensure normal ventilation of the room and will also preserve the elements of the rafter system.

Installation of a hip rafter system is a rather complex and lengthy process that requires strict adherence to rules and regulations. Each action in its design affects not only the appearance of the roof, but is also responsible for the technical and operational characteristics. Proper calculation of all indicators and the correct structure of the roof will create comfortable living conditions in the house.