How to calculate the area of ​​a hip roof. Calculation of the hip roof of a hipped roof with a drawing

Four-pitched roof structures have not only a spectacular and attractive appearance, but also have many other advantages. However, the calculation of hipped roofs and their elements, as well as their installation, is a technically complex matter, and cannot be carried out without a thorough acquaintance with the features of this process.

Varieties of hipped roofs

Roofs with four roof slopes have quite a few varieties, the most common of which are as follows:

• hip;
• tent;
• half hip;
• broken lines.

There are other options for four-pitched roofs, but they are much less common.

Hip roofs have two triangular end and two trapezoidal slopes. The end slopes are called hips and extend from the ridge at the top to the cornice at the bottom. A similar design makes such a roof the best option for rapid descent of precipitation from it. At the same time, due to technological features buildings, the calculation of a four-pitched hip roof and installation work on its installation are the most difficult to perform.

The slopes of hipped roofs are four triangles with equal sides. The bases of these triangular slopes form a square. Area calculation hipped roof of this type is also technically quite complicated, although somewhat simpler compared to the previous version. Such roofs are often made on gazebos. Before you make a hipped roof for a gazebo, you need to perform careful calculations.

Quite widespread is also another type of four-pitched roofs - half-hipped. They are a cross between a hip and a conventional gable roof. You need to know how to calculate the half-hip roof correctly. A feature of the design of such roofs is the absence of sharp corners, and their gable is made in the form of a trapezoid. Knowing how to calculate the gable area, you can immediately order material for gable sheathing. The functional advantage of semi-hip roofs is their high resistance to strong wind loads. Design and installation work here may have some features, and if we talk about how to correctly calculate this type of hipped roof, then the weather conditions of the area should be taken into account. Where there is frequent snowfall, steeper slopes and small canopies are equipped, and in less snowy regions, the opposite is true.

Broken hipped roofs are also quite common. Their peculiarity lies in the fact that geometrically their end sections are a broken line, from where such a name came from. The advantage of broken hipped roofs is that they have an attractive appearance and make it possible to use the living space as efficiently as possible. Equally important is the fact that such roofs have a relatively simple truss system. At the same time, the question of how to calculate the area of ​​a hipped roof of a broken type is quite complicated, and is usually done by professionals in the construction business.

In general, the calculation of hipped roofs of any kind, and, accordingly, their installation is not an easy task, requiring a certain skill and experience in the field of construction work.

Design features

Due to the inclined position of the pitched surfaces, the shape of the four-pitched roof differs significantly from the rectangular one. It is the non-standard form that primarily determines the main difficulties in the calculations and during the installation process, in particular, how to calculate the area of ​​\u200b\u200ba hipped roof of a house, calculate the required number of certain elements, how to connect the structural parts of the roof together, how to calculate the volume of a hipped roof roofs, etc.

Roofs with four slopes, depending on the variety, may have a different structure and constituent elements. However general principles their devices are largely identical, and they can be considered on the example of hip roofs - as the most typical version of hipped roofs.

When considering the arrangement of the central part of the hip roof, one can notice a resemblance to a conventional gable roof. The process of arranging the central part of such roofs also has much in common. Most often, rafter systems of a layered type are used here, hanging truss structures are used somewhat less frequently. When arranging a layered variety of rafters, they are supported on a ridge run located at the top of the roof, which, in turn, is installed on a running frame. The frame for installing the ridge run consists of racks and a horizontally located bed. Highly important point is its support on a solid foundation, which can be a load-bearing wall in the center of the structure being built. Sometimes in the truss systems of complex hip roofs, not one central run is arranged, but two parallel beams.

If the location of the load-bearing walls does not allow using them as a support for the purlin frame, then for this purpose a powerful ceiling is arranged, for example, from concrete slabs. The strength of the overlap must be sufficient to withstand the weight truss system, all components of the roofing and the resulting external loads.

The strength of concrete slabs is usually strong enough to withstand the load from roofing system any type and severity. Therefore, the question of how to calculate a hipped roof in terms of weight indicators, in this case, does not of great importance. It is only important to correctly make all other measurements, and then, in accordance with them, carry out the installation process.

Sometimes, instead of concrete slabs, a floor made of wooden beams. Naturally, in terms of strength, this method is noticeably inferior to the previous version. The running frame is installed on thick timber measuring 100-150 by 200 millimeters. The ridge run itself is made of a similar material, as well as the bed, if there is a need to use it. Laying of supports under the racks of the running frame is carried out crosswise with the floor beams. Stands, struts and wind ties are made from a bar measuring 100 by 150 millimeters.

The complexity of the design of a hipped roof makes it difficult to arrange supports for pitched surfaces. To this end, the corner zones are connected to the ridge run by means of diagonal rafters (sloping rafter legs). These bars are longer than usual and should have greater strength, since the shortened rafters of pitched structures rest against them.

Installation work is even more complicated if a hip roof with additional extensions is equipped. In this case, the question of how to calculate the quadrature of a hipped roof and its other parameters is a difficult task, for which the complex roof structure is conditionally divided into several simple plots, and then for each of them the calculations are made separately.

The main stages of installation of the truss system of a four-pitched hip roof

The process of building a truss system of a four-pitched hip roof consists of the following successive stages:

1. Installation of the frame for the ridge run.
2. Installing first the layered, and then the central parts of the truss structure.
3. Marking by means of a cord or rope of the directions for mounting the diagonal bars.
4. Installation of diagonal rafter legs in accordance with the markings made.
5. Installation of shortened rafter legs - sprigs - resting against diagonal rafters.
6. Sheathing with a wind board around the perimeter of the roof.

Shortened rafter legs, called sprigs, form a plane for the location of the hip roof slopes. Diagonal rafters, which abut the sprigs, are most often made of double stitched boards, which helps to increase their bearing capacity. This is important, since the load on them exceeds the load on ordinary rafters by about one and a half times. If the diagonal rafters cover a large area, then to give them additional strength, additional supports are installed: struts, trusses or racks made of timber.

As you can see, the process of arranging the hip roof truss system has a large number of nuances that must be carefully taken into account when carrying out calculations and installation work.

Arrangement of the attic

Four-slope roofing can be arranged over the finished attic room either over outbuilding, over which it makes no sense to equip a separate attic. If such a roof is installed over a residential building without an attic, then the need for arranging an attic is usually present. Attic hipped roofs are widely used in residential construction.

At the same time, it should be noted that the attics of hipped roofs are usually not intended for active and frequent use, since the slope various surfaces roofing leads to significant inconvenience in this regard. In order for the attic to be suitable for use as a separate utility room, its height and dimensions will have to be significantly increased. In this case, the consumption of materials will also be significantly higher. All these nuances should be taken into account before calculating the height of the hipped roof so that the attic space meets the requirements and requests of the owners of the home.

A few words should also be said about how to calculate the height of the hipped roof ridge. The ridge structure, as a rule, is the central and most elevated part of the roof structure. The question at what height to install it, in general, also depends on the intended use of the under-roof space, as well as on the personal preferences of the owners of the house. A higher roof will provide more effective use attic or attic. At the same time, a low-height roof is the best option in terms of economy, minimal material consumption and labor costs.

Parameters that should be calculated when arranging a hipped roof

If we talk about the necessary calculations before carrying out installation work, first of all, we should mention how to calculate the roof area of ​​\u200b\u200ba hipped roof. The correct option here is to calculate for each of the roof slopes separately, with the subsequent addition of the results. In this case, standard mathematical formulas are used to calculate the area of ​​certain geometric shapes.

So, for example, if the slope has a triangular shape, then a perpendicular line to the base, called the height, is drawn from its top by means of a rope or cord. Further, this very height of the triangular slope is multiplied by the length of the base, and the resulting amount is divided in half. The result will be the area of ​​a triangular roof slope.

For trapezoidal slopes, the formula is somewhat different: first, the length of the upper and lower bases of the trapezoid is added, then their sum is divided in half and multiplied by the height of the slope.

Another important point in calculating a hipped roof is to determine the required distance between the rafters. The size of the gaps depends mainly on the material of the roofing. So, for example, for metal tiles and corrugated board, it is 60-90 centimeters, and for shingles- 100-120 centimeters, since in the latter case the roof is laid on a continuous crate of sheet plywood.

Calculation - what and how to calculate

Of great importance is also right choice the angle of inclination of roof slopes, where a number of factors must be taken into account:

• The weight of the roofing - the larger it is, the steeper the roof should be equipped.
• The dimensions of the elements of the coating. If they are small and there are many butt sections between them, then the probability of water penetration between them increases, and therefore the slopes should be located at a higher angle.
• The climate of the area. In areas where frequent snowfalls occur, roof slopes should be placed more steeply, which ensures rapid convergence of precipitation.
• Fire safety rules for attic roofs. In accordance with them, with large attic sizes, there should be a through passage through it 160 centimeters high and 120 centimeters wide. If the attic is small (up to 2 meters in length), then the minimum dimensions of the passage should be 120 and 90 centimeters, respectively.
• The height of the chimney for fireplace and stove structures. The total height, together with the outer part extending beyond the roof, must be at least 5 meters. Of course, this heating option is not suitable for small buildings with sloping roofs.

The size of the section of the rafter beams can also be different, and depends on the total load falling on the truss system. The total load is determined by the weight roofing cake and the pressure of external factors such as wind and snow. Accordingly, the roofing material and the climate of the area also matter here. It is clear that the greater the load on roof structure, the larger the cross section should have rafter bars.

In addition to the above nuances, there are some other features that should be considered when choosing a hipped roof for a house:

• The design of the four-pitched roof allows you to equip large overhangs on all four sides, providing protection for the facade and walls from precipitation.
• Although, in general, a four-pitched roof structure is more expensive than a two-pitched one, however, due to the lack of need for arranging gables, this difference is not so great.
• If a hipped roof is intended for an attic structure, then visually it will look lower, which should be taken into account when designing.
• Installation of any kind of hipped roof should begin with a ridge structure. Mauerlat must be securely fixed and connected at the corner sections, and the racks of the running frame must have a solid foundation.
• To fix various roofing elements, it is recommended to use modern metal fasteners.
• At the end of all work, before the hipped roof of the house is considered completely ready for operation, it is necessary to revise all structures, elements and butt joints once again.
• Since the construction of a hipped roof is difficult task, you can take it only if you have sufficient self-confidence. Otherwise, the most correct decision would be to entrust the installation work to specialists.

The program will allow you to easily get all the necessary design parameters for this type of roof. You do not need deep knowledge of how to calculate a hip roof, the algorithm developed by our designers will do it for you. It takes into account all the nuances that may arise during the design and construction of the roof.

The hip roof calculator will allow you to correctly plan the process of purchasing and spending building materials, and resolve all issues related to the reliability of the truss system and the roof structure as a whole.

The specifics of the program

Our online calculator provides for the calculation of the hip roof truss system, which has equal angles between the roof base and the side and end slopes. It is proposed to fill in certain fields with initial sizes:

• Linear characteristics of the house - length, width, walls;
• Roof parameters - the width and length of the base, the desired height, the length of the overhangs;
• Data for calculating hip roof rafters and battens - width, thickness, and pitch;
• OSB sheet parameters - only for soft type roofing;
• Roof sheets and information on vapor barrier - amount of overlap, etc.

Explanation of the hip roof calculation results

1. Calculation of the hip roof truss system with a detailed drawing of the entire structure in general (with symbols) and final data:,

• Dimensions of all hip roof rafters separately (sloping, diagonal, etc.);
• Calculation of the crate and counter-crate;
• Mauerlat calculation with a detailed final drawing;
• Calculation of the hip roof area.

The total volume of wood for rafters and lathing (the volume of lumber);

Drawings of all types of rafter legs separately;

The layout of the rafters on the future roof with a mark of each type;

Drawings of the finished roof truss system from different sides;

Of course, an interactive 3D hip roof model for clarity.

The lengths of the side and hip rafters in the results and in the drawings are indicated taking into account the overhangs.

Now you do not need to think about how to calculate the hip roof area for the purchase of the necessary building materials, all the necessary information is available in our website calculator. Save to bookmarks, share with friends to useful tool was always at hand.

The calculation of the hip roof online will save time and money on the purchase of the necessary building materials, and get a detailed list of the dimensions of the main components and elements for arranging the roof of your house.

• During the construction of a house, questions arise, such as, for example, the calculation of the material for the roof, which are directly related to its architectural form- the number of slopes, the presence of an attic, etc. When drawing up a design project, all its parameters must be carefully verified to ensure its reliability and safety.

  A four-pitched roof is characterized by two triangular slopes (hips) from the end sides. It is classified mainly as a hip, or as a tent. The hip consists of two triangles and two trapezoids (the side slopes are isosceles triangles, and the front ones are regular trapezoids). If its slopes do not reach the eaves at the lowest point, then it is called half-hip. The box of the building in this case has the shape of a rectangle. If it is presented in the form of a square, a hipped roof is made, the four triangular slopes of which converge at a single vertex.

  How to calculate a hipped roof: dimensions of the base, slope

  Knowing the linear dimensions of the base and the angle of inclination of its slopes, it is possible to calculate a hipped roof. Typically, it is carried out following principle: slopes are divided into several elements, each of which is calculated separately, after which the results are summarized. Thus, you can calculate the total area of ​​\u200b\u200ba hipped roof.
  The supporting structure of the hipped roof has a complex frame. The central rafters included in it create an extra load. In addition, the rafters must withstand the load of the roof covering, as well as snow and wind. Therefore, it is required to additionally calculate the parameters of a four-pitched structure, for example, the weight of roofing and finishing materials, climatic features of the region.

  Obviously, any inaccuracy in the calculations can have serious consequences, so they are carried out with great care and taking into account all possible options.

  In this case, the following indicators should also be taken into account:

  A competent calculation of a hipped roof requires taking into account the data of meteorological services of the area of ​​​​residence. To accurately determine the required roof height and slope angles of all four slopes, the following data are required: indicators

  • wind strength and speed in the area of ​​the house under construction;
  • rainfall intensity;
  • used roofing material.

  Design and calculations: we make a project using a drawing

  Before starting work on the arrangement of the roof, it is necessary to design, calculate and execute a drawing of the future four-pitched structure.

  The slope of the slope of the slopes, depending on the purpose of the attic, atmospheric loads and the type of material for the roof, ranges from 5º–60º.

  In regions with frequent strong winds or low rainfall, the slope of the slopes is small, and in areas with significant snow loads and frequent rains, it is much larger, 48–60º.

  In turn, based on the angle of inclination, the material for the roof is chosen:

  • 5º–18º - roll coating,
  • 14º–60º - roofing metal, asbestos-cement sheets;
  • 30º–60º - tiled.

  The height of the hipped roof ridge for a given slope of the slopes is calculated using trigonometric formulas for right triangles.

  The project of a house with a hipped roof begins with the calculation of rafters. Their cross section depends on the angle of inclination of the slopes and the total value of the expected total loads: the weight of the rafter structure, roofing cake, snow and wind loads. The minimum margin of safety for rafters should be 1.4.

  Calculations also determine:

  • rafter pitch and their bearing capacity,
  • which rafters to use - layered or hanging,
  • the need for additional elements: braces that help reduce the load on the rafters, or puffs that protect the structure from loosening,
  • the need to increase the length of the rafters or doubling the beam to strengthen them, etc.

  When designing a truss system, they calculate:

  • for strength - the rafters should not break;
  • on the degree of deformation under certain parameters, for example, the deflection of rafters for mansard roofs should not exceed 0.4% of their length.

  Features of calculating the load on the truss system

  The truss system is under the influence of permanent and temporary loads.
  The first include the mass of the roof, lathing and counter-lattices, runs and the rafters themselves, and the second - wind, snow and useful - this is the load from ceilings, hot water tanks, ventilation chambers and other things suspended from trusses.

  The parameter for calculating snow loads for the middle latitudes of the country according to the standard is 180 kg / m² per horizontal projection of the roof. Having accumulated, a snow bag can increase this value to 400-450 kg / m². For the same regions, the design parameter for wind loads is 35 kg/m².

  When the slopes are more than 60°, the snow load is not taken into account, and when the slope is less than 30°, the wind load is not taken into account. The parameters of these loads can be adjusted using the available correction factors, which take into account local climatic conditions. The total mass of the roof is calculated based on the area of ​​\u200b\u200bthe structure and the materials used.

The roof of any home is considered one of the most important components. Protecting the building, it creates comfort inside it, perfectly complementing the architectural composition. Each builder is faced with the responsible task of how to calculate the height of the roof correctly, taking into account all the moments that affect its durability and appearance. The main factors that determine the height of a roof structure are:

• slope angle;
• the number of slopes;
• roof shape;
• materials used;
• wind power;
• average annual rainfall;
• building height;
• wishes of the owner of the house.

The correct calculation of the height of the roof allows you to calculate the required amount of basic building materials. In addition, you should immediately take into account the need for insulation, the installation of snow retainers and other components of the roof. One of the elements that will require additional calculation is the ridge, the height of which determines the configuration of the truss system.

Types of roofs and features of their calculation

Roofs of houses are classified as follows:

The order of calculation for each type can be fundamentally different, which must be taken into account in order to obtain correct results. The simplest is the calculation of a single-slope structure, but mastering the methodology for calculating parameters gable roof also won't cause any problems. The slope angle of a gable roof in the conditions of the European part of the continent is taken in the range of 30-50 °. With a sharper angle, snow will accumulate on the roof, and with a wider one, the wind load will increase significantly. The calculation of the height of the structure is carried out according to the formula: the width of the house, divided in half, is multiplied by the tangent of the slope angle.

The hipped roof has the highest mechanical strength. This type of roof is divided into tent and hip. In the case of a house, perfectly symmetrical, square, they talk about installing hipped roof. It has an aesthetic appearance, and perfectly withstands wind loads. Hip roofs are characterized by the complexity of construction and the possibility of obtaining a comfortable and convenient attic. One of the disadvantages of a hip roof is the complexity of the design and the use of expensive building materials. The calculation of the hip and tent structures is carried out according to the same formulas as the gable, but, in addition, the length of the rafters and the ridge should be calculated. This is mainly due to more complex design and responsible selection of materials.

A mansard roof is a gable roof with a break on two slopes, which gives the whole structure a “broken” look. With the help of this rather simple technique, the useful area of ​​\u200b\u200bthe attic (attic) is significantly increased. The calculation in this case is also similar to the calculation of a gable roof, but taking into account the selection of the required value of the slope and ridge angles. In this case, the best option is to apply the rule of the "golden section": the roof contour must be inscribed in a circle. Thanks to this simple rule, it is possible to avoid the main drawback of attic structures - an insufficiently aesthetic appearance.

The correct calculation of the roof and the ridge in height guarantees the optimal cost of building and roofing materials, long-term and reliable operation, and the aesthetic appearance of the house. For beginners in construction, these calculations are a big problem, so it is better to entrust this matter to a professional designer with experience.

How can you calculate the height of the roof of a house?

The construction of the roof is one of the responsible construction processes, on the quality of which directly depend performance characteristics the roof itself and the entire building. Construction should begin with the calculation and design of the roof structure on paper. One of the most important data for the calculation is the height of the ridge, in connection with which the slope angles of the slopes, the type of roof and the amount of building materials are found. We will figure out how to independently calculate the height of the roof of different structural types.

Preparation for calculations

Creating a roof plan and calculating a number of its parameters is important for subsequent installation. Advance billing helps:

• Calculate in advance the amount of necessary building materials and not miscalculate when buying them up or down.
• Even at the design stage, think over and distribute various systems, such as gutter, snow-retaining, etc., and determine their place in the future project.

• the size of the house;
• plans for the use of under-roof space;
• the planned shape of the roof and the number of its slopes;
• slope angle;
• stress on roof structure: wind, snow, etc.;
• type of roofing.

In this article, we will look at how to correctly calculate the height for the three most common roof structures.

Calculating the height of a gable roof

A gable type of roof is easy to design and build. The design of this type implies the presence of two planes that stand on opposite load-bearing walls and, closing on the ridge, form a triangle with equal sides.

Skate Height Calculation gable roof is directly dependent on the angle of inclination of the slopes.

The choice of the slope of the roof slopes should not be arbitrary. Its value depends on wind and snow loads, the rules for determining which are regulated by SNiP. The recommended slope for the regions of central Russia is 30-45°. Also, the choice of the slope of the roof slopes is influenced by the selected roofing material.

Having decided on the slope of the slopes, you can calculate the height of the roof of the house. Its value is calculated by the well-known geometric formula:

where a is the desired value, b is the value of half the width of the house, tg α is the tangent of the selected angle, which can be found in a specialized table.

With a slope of 45 °, the elevation of the ridge beam will correspond to the width of the house.

Calculation of a four-slope structure

A roof with four slopes is the most resistant to wind load. There are two types of pitched roofs:

• Hipped - all slopes converge at a single point at the top of the structure.
• The hip has two triangular and two trapezoidal slopes, the latter are connected at the top with a ridge beam.

It is possible to calculate the height of the ridge for both types of roof using the formula used for the gable structure. However, in order to carry out a more thorough calculation and draw up a detailed diagram, it is also necessary to calculate the length of the rafters, and for a hip roof, the length of the ridge beam.

Mansard roof design

The mansard or broken roof also has two slopes, a feature of which is a characteristic break. It allows you to increase the space under the roof and makes the broken structure one of the most suitable for creating an attic.

The calculation of the height of a broken type roof begins with the calculation of the angles of inclination of all pitched roof surfaces. Construction experts recommend determining the angles of inclination of the attic structure by a practical method, using the golden section rule. To do this, you need to write a sketch of the future roof in a circle on paper. This method will avoid such design flaws, in which the broken structure does not look aesthetically pleasing.

Design and calculations are important and fundamental steps in creating a roof. Their competent and correct implementation is the key to the construction of a reliable and aesthetically attractive roof that will last for many years.

Calculation of the height of the roof of the house, calculate the height of the roof ridge

Calculation of a hipped roof: detailed work with numbers

During the construction of a house, questions arise, such as, for example, the calculation of the material for the roof, which are directly related to its architectural form - the number of slopes, the presence of an attic, etc. When drafting a structure, all its parameters must be carefully verified to ensure its reliability and security.

A four-pitched roof is characterized by two triangular slopes (hips) from the end sides. It is classified mainly as a hip, or as a tent. The hip consists of two triangles and two trapezoids (the side slopes are isosceles triangles, and the front ones are regular trapezoids). If its slopes do not reach the eaves at the lowest point, then it is called half-hip. The box of the building in this case has the shape of a rectangle. If it is presented in the form of a square, a hipped roof is made, the four triangular slopes of which converge at a single vertex.

How to calculate a hipped roof: dimensions of the base, slope

Knowing the linear dimensions of the base and the angle of inclination of its slopes, it is possible to calculate a hipped roof. As a rule, it is carried out according to the following principle: the slopes are divided into several elements, each of which is calculated separately, after which the results are summarized. Thus, you can calculate the total area of ​​\u200b\u200ba hipped roof.

The supporting structure of the hipped roof has a complex frame. The central rafters included in it create an extra load. In addition, the rafters must withstand the load of the roof covering, as well as snow and wind. Therefore, it is required to additionally calculate the parameters of the four-slope structure, for example, the weight of roofing and finishing materials, the climatic features of the region.

Obviously, any inaccuracy in the calculations can have serious consequences, so they are carried out with great care and taking into account all possible options.

In this case, the following indicators should also be taken into account:

• rafter pitch calculation results,
• rafter sections,
• spans of the rafter structure,
• results of the analysis of the bearing capacity of the foundation and supports.
• type of rafters (hanging or layered).

A competent calculation of a hipped roof requires taking into account the data of meteorological services of the area of ​​​​residence. To accurately determine the required roof height and slope angles of all four slopes, the following data are required: indicators

• wind strength and speed in the area of ​​the house under construction;
• rainfall intensity;
• roofing material used.

Design and calculations: we make a project using a drawing

Before starting work on the arrangement of the roof, it is necessary to design, calculate and execute a drawing of the future four-pitched structure.

The slope of the slope of the slopes, depending on the purpose of the attic, atmospheric loads and the type of material for the roof, ranges from 5º–60º.

In regions with frequent strong winds or low rainfall, the slope of the slopes is small, and in areas with significant snow loads and frequent rains, it is much larger, 48–60º.

In turn, based on the angle of inclination, the material for the roof is chosen:

• 5º–18º - roll coating,
• 14º–60º - roofing metal, asbestos-cement sheets;
• 30º–60º - tiled.

The height of the hipped roof ridge for a given slope of the slopes is calculated using trigonometric formulas for right triangles.

The project of a house with a hipped roof begins with the calculation of rafters. Their cross section depends on the angle of inclination of the slopes and the total value of the expected total loads: the weight of the rafter structure, roofing cake, snow and wind loads. The minimum margin of safety for rafters should be 1.4.

Calculations also determine:

• rafter pitch and their bearing capacity,
• which rafters to use - layered or hanging,
• the need for additional elements: braces that help reduce the load on the rafters, or puffs that protect the structure from loosening,
• the need to increase the length of the rafters or doubling the beam to strengthen them, etc.

When designing a truss system, they calculate:

• for strength - the rafters should not break;
• on the degree of deformation under certain parameters, for example, the deflection of rafters for mansard roofs should not exceed 0.4% of their length.

Features of calculating the load on the truss system

The truss system is under the influence of permanent and temporary loads.

The first include the mass of the roof, battens and counter battens, girders and the rafters themselves, and the second - wind, snow and useful - this is the load from ceilings, hot water tanks, ventilation chambers and other things suspended from trusses.

When the slopes are more than 60°, the snow load is not taken into account, and when the slope is less than 30°, the wind load is not taken into account. The parameters of these loads can be adjusted using the available correction factors, which take into account local climatic conditions. The total mass of the roof is calculated based on the area of ​​\u200b\u200bthe structure and the materials used.

Hip roof calculation: online calculator

The calculation of the materials necessary for the construction of the roof is carried out, taking as a basis the correct calculation of the area of ​​\u200b\u200bthe roof.

Regardless of the shape of the four-slope structure, the calculation of this area comes down to calculating the area of ​​\u200b\u200bthe simplest geometric figures - an isosceles triangle and a trapezoid. For example, in the case of a hipped roof, it all comes down to calculating the sum of the areas of four identical triangles.

For the calculation of roofs, special programs are also used - online calculators. With their help, almost all the parameters necessary for this are determined:

• volume of materials for roofing, thermal and waterproofing,
• the number of crates,
• truss system,
• slope slope and more.

When calculating the amount of material, in addition to the area of ​​\u200b\u200bthe slopes, the following is also taken into account:

• overlap size;
• cutting waste;
• the size of the overhangs of the cornice and gables.

Calculation of a hipped roof: load parameters, slope, material

Calculation of the roof of the house: we calculate simple and complex roofs

One of the most important components of any building is its roof.

It not only protects the wall of the house and its interior space, but also performs an important decorative function.

No matter how beautiful the walls of the house are, without a beautiful elegant roof finished appearance will not work.

It depends on the shape of the roof how whole and aesthetically your building will look as a whole.

Therefore, before proceeding with the installation of the roof, it is very important to make the correct calculations, to simulate the parameters of the roof and its appearance.

And at the same time, a very large number of parameters should be taken into account.

Roof height is influenced by several main factors:

• roof shape;
• the number of slopes;
• slope angles;
• materials that are planned to be used to create a roof;
• the strength of the winds in a particular region;
• the amount of precipitation;
• the height of the constructed building;
• developer wishes.

Roof types and calculation features

And each type has its own calculation procedure.

After all, roof structures, for all their seeming similarity, differ significantly from one another.

Naturally, the simplest is the calculation of a lean-to.

Although the calculation of a gable roof cannot be called difficult.

With the correct calculation of the roof height, the costs of roofing and building materials will be optimal, and the design will be reliable.

Calculation of the height of a gable roof

The height of the roof is directly related to the angle of the rafters.

The greater the slope, the higher the roof will be on your house.

You should also measure the length and width of the building and understand what the angle of inclination will be.

The angle can have values ​​from 11 to 30 degrees.

And it depends, first of all, on what material will be used for the installation of the roof on the house and climatic conditions.

The more snow falls during the season in the area where the house is built, the greater the angle of inclination.

There are special tables for this.

Wind loads are taken into account in the same way.

Now we perform a simple geometric calculation

The height of the skate is the leg of the triangle.

The second leg is the width of your house, divided in half.

By the way, with this calculation, you can also calculate the length of the hypotenuse.

This will be the length of your roof rafters.

To determine the height of the ridge, it is necessary to multiply the length of the leg by the tangent of our angle of inclination.

To determine the tangents and sines, there is a ready-made table:

For example, let's calculate a gable roof.

The width of the house is 6 meters.

The house has two slopes.

The angle of inclination of the slopes is the same and equals 40 degrees.

We look at the table and find out that the tangent of 40 degrees is 0.84.

6/2 x 0.84 = 2.5 meters.

The height of our roof is 2.5 meters.

The main thing is to measure everything as accurately as possible!

Until the last centimeter.

We calculate the height of the four-slope structure

After all, there are different roofs with four slopes.

The easiest way to calculate roofs that have slopes in the form of a regular trapezoid, a triangle, and there are no breaks on the slopes.

However, now most hipped roofs are hipped with large quantity slopes having the shape of a rhombus, rectangle and other geometric shapes.

Well, with the calculation of the height of a hipped roof, it is clear - it does not differ from the calculation of the height of a gable roof.

But with other calculations it is more difficult.

Calculations should begin with drawing up a roof plan.

If the roof is at different levels, then the drawing shows where what height is.

After the detailed drawing is drawn up, the roof should be decomposed into separate geometric elements.

When calculating the roof, certain rules should be observed:

• the drawing is divided into several geometric shapes. Each figure is placed on a separate drawing. All dimensions are also transferred;
• the length of one slope is determined. To do this, measure the distance from the ridge to the eaves;
• count each slope. To do this, get the area of ​​\u200b\u200bthe figure and then multiply its value by the cosine of the angle of inclination;
• if the slope is an irregular rectangle, then it, in turn, must be divided into several regular figures, and separately calculate the area of ​​\u200b\u200beach of them, and then add the data obtained.

Let's take a hipped roof as an example.

Suppose that our roof consists of two regular trapezoids and two isosceles triangles.

The angle of inclination of the slopes will be 30 degrees.

We look at the plate, and find out that the cosine of such an angle is 0.87.

Trapezoidal slopes have sides of 10 and 7 meters, and a height of 3 meters.

Triangular slopes have dimensions of two sides each of 3.34 meters, and the length of the third side is 4.8 meters.

Find the area of ​​the trapezoid.

To do this, add the lengths of the two horizontal sides, divide by 2 and multiply by the height.

It looks like this in our particular case:

S \u003d ((10 + 7) / 2) x 3 \u003d 25.5 sq. meters.

Now we multiply the resulting number by the cosine of 30 degrees:

25.5 x 0.87 = 22.185 km. meters.

And the resulting number is rounded up.

We get 22.5 sq. meters.

Now we calculate the area of ​​\u200b\u200btriangular slopes:

S = ((7 x 4.8) / 2) x cos 30 degrees =

16.8 x 0.87 \u003d 14.7 sq. meters.

Now all the areas must be summed up:

S total \u003d 22.5 x 2 + 14.7 x 2 \u003d 74.4 square meters. meters.

And round up.

Total 75 sq. meters.

We calculate the roofing material

After the roof area has become known to us, we can calculate the required amount of roofing material.

The opinion that the area of ​​​​the roof in the drawing and the area of ​​\u200b\u200bthe roofing material are equal is erroneous.

After all, it's all about the so-called "overlap".

After all, roofing material is not laid joint to joint.

More about the installation of metal tiles with your own hands.

For information on how to properly fix the metal tile with self-tapping screws, follow the link. About the size of self-tapping screws and how many are required per square meter of roofing.

About Usage flat slate for beds here. How to build high bed from slate.

An overlap is made so that the roof does not leak.

In addition, the amount of overlap for each material is different.

Therefore, the consumption of material increases.

For a simple roof, it is easy to independently calculate the amount of material required.

For example, let's calculate the amount of slate on our roof.

Let's start with the proportion:

In this proportion:

S is the area of ​​our roof,

X is our stock of 15 percent.

After calculating the X value, we add it to our resulting area.

As a result, we get the area of ​​​​our roofing material.

X \u003d 15 x 75 / 100 \u003d 11.25. Rounded up to 11.5.

The area of ​​our roofing material

11.5 + 75 = 86.25 sq. meters.

You should be aware that when directly executed roofing works material waste may increase.

In some cases, up to 20%.

That is, a proportion is again drawn up in which the value of X is an expense.

Add the result to the area.

Knowing the area of ​​​​one sheet is easy to get the right number of sheets.

We calculate steam and waterproofing

Actually, the area of ​​\u200b\u200bthese materials is equal to the area of ​​\u200b\u200bthe slopes, to which you must definitely add 15% for the overlap of the fabrics of materials.

That is, if the area of ​​\u200b\u200bthe slope is 40 square meters. meters, then the waterproofing area is 40 + 15% = 60 sq. meters.

With vapor barrier everything is exactly the same.

Online calculations and calculation programs

It is very easy to calculate the parameters of the roof and the amount of roofing material if the roof is of a simple shape.

But what if the shape of the roof is complex?

Or very difficult?

In fact, everything is a little easier than it seems.

Because in the age of computerization, special online calculators and programs for calculations have been invented.

An online calculator differs from a program in that it does not need to be downloaded to your computer.

You just need to go to the site and there, in a special shell, everything will be calculated for you.

More complex detailed calculations are done by specialized programs.

Such programs must be downloaded and installed on your computer.

They have one drawback - most of these programs are paid.

Therefore, refresh your memory of the school geometry course and start measuring and calculating.

Well, if nothing helps, use the programs.

Calculation of the roof of the house (calculator): gable, four-slope

The first thing to do before starting the construction of the roof is to make accurate calculations. Necessary detailed description all connections and nodes, an accurate drawing of the entire truss system and the approval of this by an experienced person.

It sounds complicated, although in reality everything is simpler - no more difficult than a children's designer, it is only important to do everything right. And, if you are looking for how to calculate the hip roof truss system, you will find all the information you need here!

So, what is the hip roof truss system? This is a four-slope structure, i.e. one that has four planes. Such a roof is much more complicated than a gable roof, but it is stronger and more reliable in operation. And her appearance is recognized all over the world as one of the most successful and aesthetic.

Here are the main advantages of this design:

• Due to the presence of triangular end slopes in the hip roof, ordinary skylights can be installed.
• Due to the absence of a sharp protrusion at the hip roof, higher resistance to various atmospheric phenomena.
• The hip roof is considered economical - due to the fact that it does not have gables.
• Temporary deformations of such a roof are reduced to zero - all thanks to its special design.
• Warming such a roof is much easier than a gable roof (there are not all the same problematic gables).
• Great resistance to wind loads of the terrain - due to low angles of inclination.
• The ability to easily and easily convert an attic space into a comfortable attic. And this is a valuable increase in the living space of the house.

Among the shortcomings, we highlight the main one: the hip roof truss system is more complicated than that of a conventional one, and therefore its installation will cost you more, although you will save on brickwork.

Types of hip roof construction

So, let's see what types and subtypes hip roofs are being built today:

• Hip. This is a traditional hipped roof with triangular slopes on all end sides.
• The roof, in which the hip does not reach the eaves, is called half-hip.
• A hipped roof is called a hipped roof, in which identical triangles are connected together by one upper point. By the way, once in Russia, such roofs were built without exception.
• The cruciform hip roof is a rarer view due to the high cost of execution and the high labor intensity of the work. Usually it is built on houses with a complex layout or separately only above the front doors.

Our diagram will help you understand in more detail:

As we have already said, if the hip does not reach the eaves, the roof is called half-hip. Just in these places they put dormer windows, which completely solves the problem of the need for inclined roof windows. But in terms of complexity and cost of construction, a half-hip roof is higher than others.

The simplest example of a hip roof (quite aesthetic, mind you) is a triangular roof. All slopes here are the same size, and all angles are equivalent. If this height and design suits you, then give preference to this particular option - you will avoid many pitfalls and nuances!

The only point: the hip roof in its classic version is bad because it does not have vertical planes and dormers or attic windows have to be placed on sloping walls. As a result, such elements become the most unprotected in terms of leaks during rain.

Hip roof architecture in detail

For the installation of a specifically hip roof, experienced builders recommend taking rectangular beams from coniferous species, and reinforcing the stability of the entire system with additional steel elements. Indeed, in addition to the rafters themselves, in any case, you will need the following building elements:

• Mauerlat is the lower support for the rafters.
• A run is a beam that needs to be placed parallel to the Mauerlat as another additional support.
• Racks and struts are supporting elements for a structure with the so-called multi-span.
• Crossbars are special elements that help to cope with spacers (a common occurrence with improper installation).
• Sprengel is another additional element of the rafter support.
• Lying - a special support for racks and struts.

So, construction material purchased? Now put all the parts in a stack or dry them additionally. The main thing is to think about protection from the rain.

How to avoid calculation errors?

And now let's avoid the very first and most annoying hip roof design mistake - the lack of measurements of the house itself. The problem is that even trained craftsmen manage to start work with drawing up a plan and a drawing of the roof, but they do not work with the base - the walls. But only at first glance it seems that the walls are perfectly even, everything is parallel to each other and the like, but in reality it is far from ideal, even completely new house. And then, only during the construction process, certain errors are found that prevent the first supports from being correctly installed.

Therefore, first of all, before carrying out any calculations on the hip roof, we arm ourselves with a ruler and level. We check elevations, parallelism of walls, diagonals (correctness of rectangular walls) and draw up a measured plan of the house. Let's say you will be surprised by some inaccuracies. And now we decide how we will fix it:

• We correct a slight error in parallelism with a Mauerlat.
• Slight height difference different walls fix with pads.
• We correct significant differences with additional elements of the truss system, which we must include in the calculations.

In addition, we recommend that you do not make a simple two-dimensional drawing of the roof, but create a three-dimensional model that will give you a clear idea of ​​\u200b\u200byour hip roof. At a glance, you will be able to understand whether you like what happens or not. It's pretty hard to change something. And modern computer programs will help you with this, which are quite a lot.

If you are looking for finished drawing roof that fits the desired parameters, do not take too much detailed drawings with Latin abbreviations and formulas: only the master who can read them needs them. And so that you have an idea of ​​​​what exactly awaits you, we offer you a simple master class on the construction of a hip roof, where all the elements are clearly visible:

What data is needed for construction?

Here are the parameters of the future roof you should know before you start building it:

1. The angle of the roof, on each side of the hip slopes.
2. The angle of the roof from the sides.
3. The exact area of ​​the entire roof surface
4. The weight of the future roof and the exact load of the roofing material on the roof truss system.
5. The length of the diagonal rafters.
6. The section of the rafters, taking into account regional wind and snow loads, the pitch of the rafters and the weight of the roofing material.
7. The required volume of all rafters in cubic meters.

You will need to know the area of ​​\u200b\u200bthe entire surface in order to purchase the required amount of roofing material and calculate its future weight in advance:

Next - the rafters. On hip roofs, the rafters are placed directed to the corners of the walls - to the internal and to the external, and are called oblique or diagonal. The second ones are longer than ordinary rafters, and shortened ones - sprigs - rely on them. As a result, such rafters carry a load already 1.5 times more than usual.

The length of the diagonal rafters is longer than the standard length, so they are made paired. Their advantage is that the double section is designed for increased load and, as a result, is a solid, uncut board. As a result Constructive decisions such roofs are quite simple. And in order to ensure the multi-span of the hip roof, one or two supports will need to be placed under the oblique leg.

If you have already purchased scaffolding for the construction of the roof, then calculate the pitch of the rafters based on the section of the finished boards. If you have not purchased yet, look now, before drawing up the project. After all, it is not uncommon for a project to be ready, and good wood it turns out to get completely different parameters that were planned.

We bring to your attention a special free.

What should be taken into account when calculating?

The hipped roof project is one of the most difficult. Here it is extremely important not to make mistakes in the calculations, because the hip roof is a large number of very different elements, and each of them has an important function.

So, the slope of the hip roof usually varies from 5 to 60 °. Based on this, they choose the roofing material: roll coverings for small slopes and tiles for steep planes. But count right away that the greater the angle of inclination of such a roof, the more roofing material you will end up with. And the smaller the angle, the stronger the frame will have to be built, because a considerable load will now go on it.

For the final decision, you will have to take into account all these factors:

• The total weight of the planned roofing material.
• Additional weight of waterproofing and insulation.
• Local climate features (check with neighbors).
• The type of rafters and the presence of additional elements to maintain the strength of the roof.
• All devices and equipment that you are going to hoist on the roof.

It is important to take into account the wind and snow load so that tons of snow do not break through your roof and a dashing wind does not tear it off, and the weather conditions of a particular area will indicate what deformations of the truss system are possible over the years (for example, dampness, sea air, etc. .).

Note that there are usually no problems with a hip roof with a wind load, but almost always with a snow load. The reason is that at the hip roof all planes are inclined. Bad for the wind, but good for the snow.

Have you decided on a project? Have you done all the necessary calculations? Then get started!

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