Simple geometry: calculating the parameters of the roof. Calculation of the height of the roof Calculation of the height of the ridge of the roof calculator

Any type of building at the end of construction is clearly emphasized by the roof. But you should know how to calculate the height of the roof correctly, because many factors depend on it. The comfort of a person from living in this room will depend on how correctly the calculations are carried out and the type of material is chosen. Also, this nuance directly affects significant savings at the time of purchasing lumber.

To determine the calculations, you need to understand what shape of the roof is necessary for the structure of the building. It should not only protect the building from the external environment, but also harmoniously complement the entire building as a whole. The most popular and widely used form of roof is gable. It is simple both in calculations and in installation.

The hip type of roof is significantly different from the classic version, since it includes not two slopes, but four. Triangular slopes, which are located on the sides, are called hips. Also one of the most popular roofs is called a hipped roof, which also contains four slopes. So that they all have straight sides, you should know how to calculate the height of the roof from the slopes to the ridge.

The main parameters of the roof

Carrying out the construction of their own house, each owner asks how to calculate the height of the roof. The answer is actually simple: it is imperative that you pay attention at the time of calculations to some of the nuances. Let's consider them:

• number of rays;
• whether there is an attic room or not;
• the size of the slopes of the slopes;
• the type of material used in roofing.

How the roof height is calculated can be influenced by the location of the house. Having decided on the direction of the wind and other climatic factors, the height of the ridge can be calculated using geometric calculations based on the size of the building frame. To do this, you need to know the width of the structure and the angles that determine the slope of the roof slopes.

Roof height with attic room

If you are planning with an attic room, then you should know how to calculate the height of the roof of the house accurately. To do this, the first step is to decide what type of roof will be built:

• roof with one or two slopes;
• to calculate the slopes of the slopes, you need to pay special attention to the strength of the wind, the rate of precipitation of various forms;
• when choosing roofing elements, it must be remembered that the slope must correspond to the characteristics of the materials.

The type of roof should be planned, since the attic space should have a spacious area. It is important that the room located on the roof is bright. For this it is necessary to install windows on the sunny side. The height of the roof should not be too high, since a lot of building material will be required for its construction. In this regard, significant financial costs will have to be incurred. In the case of a hip roof, the attic room will be spacious, light, and the ridge height will be small.

Moments to consider when calculating the height of the roof

According to experts, the roof is the most important part of a building. If its installation is done correctly, then it will also give an aesthetic look to the whole house. In order to correctly determine how to calculate the height, several factors must be taken into account, such as:

• the number of slopes, as well as the angles of inclination;
• shape;
• the level of the height of the entire structure as a whole;
• climatic conditions;
• types of building elements;
• the desire of the owner.

In addition, the size of the roof can be increased with a ridge, since the number of rafters on the roof depends on it. Therefore, the first thing in the calculation is calculated and then the size and number of rafters in the roofing system are deposited from this size. From these calculations, the total coverage area will be known. This data will help to calculate the amount of materials that will be required for construction.

Roofing materials

Many owners who have no experience in construction work want to do it with their own hands. But many do not know how to do this correctly, and what materials will be required to complete the roofing device. The list of required materials includes:

• lathing;
• nails;
• rafters;
• rafter;
• insulation;
• vapor barrier;
• roof covering;
• screws.

If all the calculations are carried out correctly, then the whole structure will not only complement the house, but also protect it from the external environment.

Guidelines for determining the height of the ridge

A ridge is a horizontally located edge on which lateral plane connections are formed. With its help, you can understand how to calculate the height of the ridge of a building. These parameters are the main value in the calculations. If the height of the roof is calculated incorrectly, then in addition to violations in aesthetics, there will be technical problems during the operation of the building. It often happens that the owner wants to implement such ideas that are prohibited for technical reasons in the construction of the roof.

To make it easier to make the roof structure uniform, it is made in the form of a triangle. This option is widely used in construction. Also, gable type roofs with asymmetrical sides of the slopes are often erected. The angle of inclination is most often the same for such roofs, because the level of the ridge height is calculated using the standard version.

Hip roof system

In order to carry out the installation, you should know how to calculate the height and what material is required. The main components of this type of roof:

• Ridge board. It is located at the top of the entire structure and is located in the very center. This element is considered an important part in the rafter system.
• The rafter guides are the basis on which the lathing is fixed.
• Slant rafters are designed to accommodate the main part of the structure.
• Hip rafters are elements in a complex roof system.

Having decided on the elements of the rafter system, you can safely start the hip type.

Calculation of a hipped roof

The four-pitched roofing device can be of two types: hip and hip. Therefore, many ask themselves the question of how to calculate the height.First of all, such a coating is used in buildings of a square type, that is, all sides of the load-bearing walls must be equal. It is also quite convenient to plan an attic space under such a roof. It will turn out to be quite large and light due to the skylights. They can be positioned on either side of the ramp, since they have almost equal sides.

The only drawback of this type of construction is the complexity of installation. The cost of materials is slightly more expensive than that of the gable version due to the volume of the area. This type of roof is not recommended for installation in climatic zones with increased windiness. Strong gusts can damage the roof by slightly sloping the ramps.

One of the main building elements is the roof. The vitality of the house and the peace of its inhabitants depend on its quality and the correctly chosen form.

Any pitched roof consists of several basic elements. These include:

• Rafter system;
• Lathing;
• Roof.

A preliminary calculation when designing a house should help determine the required amount of materials for its construction. Based on this, a budget (estimate) of expenses is drawn up. It is impossible to calculate the cost of a roof without determining its shape and height.

Roof types

In modern construction, almost all forms of roofs existing in architecture are common. Gable and hip (hip) species are also widespread.

In addition to them, there are hipped roofs, and domed, and broken (mansard) and complex multi-slope roofs.

Among the most widespread, the most common are gable roofs, which are a simple structure consisting of two inclined slopes and two gables - vertical triangular walls.

Gable roofs are usually mounted on,. The gable roof with an attic also looks original.

The rafter system of such roofs consists of paired parts located at an angle to the horizontal line. Their stability is ensured by a plank or solid crate.

The upper part of the gable roofs, the junction of the rafter legs, is called the ridge. This is the uppermost part of the entire building on which many owners of private houses install decorative.

To determine the area of ​​the roof and calculate the number of boards for the sheathing, roofing material and the length of the lags themselves, it is necessary to learn how to calculate the height of the ridge.

You can quickly and accurately calculate a gable roof, including determining the height of the ridge, using an online calculator on the Internet.

Parameters affecting the height of the roof

The roof is the upper part of the building, so it takes up all the loads that fall on it. In winter, this is the accumulation of snow on the roof, during the year - the wind effect, which is greater, the larger the area of ​​the slopes and the steeper they are located relative to the horizontal.

When designing, you can slightly reduce the influence of weather factors. So, when using smooth roofing materials such as corrugated sheet or metal tiles, you can significantly reduce the amount of snow that will accumulate. If enough, it will slide down without significantly increasing the load on the rafter system and the crate.

To reduce the wind load, it is desirable to make roofs with a lower slope. But this is fraught with the formation of large snowdrifts, which, when the snow melts, can lead to the collapse of the roof. Therefore, it is necessary to find a "golden mean" between increasing and decreasing the angle of inclination of the roof.

Determine the height of the skate

Method one - mathematical

To calculate the height of the ridge of a gable roof, it is necessary to present its structure in cross section. It will be an isosceles triangle. Therefore, the height of the ridge will be the height of this triangle.

Having built the height (perpendicular to the base of the triangle), we get two right-angled triangles, in which one of the legs will determine the parameter we need. The second leg can be determined by dividing by 2 the total width of the house.

To maintain optimal operating conditions for a house in conditions of high rainfall and sufficiently strong winds, the slope angle of the roof slopes is taken in the range of 20o - 45o. To calculate the height of the ridge of a gable roof, based on the specified parameters, the Pythagorean theorem and the Bradis table will help.

According to the theorem known to everyone from school years, the length of one leg (the height of the ridge) will be determined as the product of the second leg (half the width of the house) by the tangent of the angle opposite the desired leg (the slope of the roof).

We give the value of the tangent of the angles from 20о to 45о with a step of 5о.

For example, let's calculate the height of the ridge for a standard wooden house 6x8 meters, located in the middle lane of our country, with a roof slope angle of 40o. In accordance with the above formula, the leg at our disposal will have a length of 3 meters (6: 2 = 3).

The tangent of an angle of 40 ° is determined from the table. It is equal to 0, 839. Multiply the numbers we know and get:

Thus, with the specified parameters, the height of the ridge from the house will be 2.517 meters.

Method two - graphic

Less accurately, without using mathematical formulas and tables, you can determine the height of the ridge by making an image of a section of the roof on a small scale. To do this, draw an isosceles triangle and draw a median, which will be at the same time height.

The angle at the base of the triangle must be accurately traced using a protractor. With corrections for the accuracy of mathematical tools, you can get an approximate value of the desired quantities.

Important! After completing the process of installing the ridge on the roof, it is necessary to cover the ridge girder with lightweight side tiles. This is required by the device of the ridge of the pitched roof.

Thus, the height of the gable roof ridge is calculated. When planning to use the attic space, it is necessary to determine the optimal parameters of the internal space for the free movement of residents and guests of the house.

Watch a video about building a ridge for a gable roof and installing rafters:

The roof is one of the most important structural elements of a private house, since it prevents the penetration of atmospheric precipitation, melt water and cold air masses into the premises. If you know how to correctly calculate the height of the roof and ridge, its device will allow moisture to be removed from the roofing surface by gravity without increasing the load on the rafter system.

The need to calculate the height of the roof

The house will look harmonious, provided that the appearance of the roof complements its architectural design. To do this, you need to correctly calculate the height of the roof in relation to the width of the house. Let's look at how the roof height is calculated, what are the nuances in the calculations.

In accordance with the accepted terminology, the ridge height is the distance between the middle of the base of the roofing structure and its highest point.

The following characteristics depend on the value of this parameter:

1. The angle of inclination of the slopes. The higher the height of the ridge of the hipped roof, the steeper the slope of the roof of the house is. In regions where a large amount of snow falls in winter or heavy rains are frequent throughout the year, the slope of the slopes should be 20-50 degrees.
2. Roof surface area. The higher the roof, the larger the area of ​​the slopes, which means that the installation costs increase. This is due to the large amount of building materials required for the construction of the rafter system.
3. Load-bearing capacity of the roof frame. With increasing height, the weight of the structure increases, as does the load from the layers of the "pie". For this reason, there is a need to strengthen the frame by installing additional elements.

There are 2 methods for finding out the height of the roof:

• calculate the required value depending on the size of the desired slope;
• first decide on this parameter, and then only calculate what the slope of the slopes should be.

The choice of the height of the structure

When designing, it is necessary to know the height of the roof, since this value has a significant effect on its performance.

Possession of information on how to determine the height of the roof of a house will help to calculate and create its project, which will meet the climate of the region and the purpose of the building. As a result, the roof will last much longer and require less maintenance.

When designing a roof structure, consider the following:

1. Average annual rainfall. The higher this indicator, the higher the skate should be made.
2. Wind load. In areas with strong winds, low-rise buildings with a sloping low roof are usually built.
3. The purpose of the structure. If the project of the house provides for the arrangement of a residential attic room, then the height of the ridge must be made at least 2.5 meters.

How to correctly calculate and determine the height of the roof, in relation to the width of the house

The technique for calculating the height of the roof and ridge is simple. When carrying out calculations, it is generally accepted that the vertical cut of the roof is an isosceles triangle, in which the base is equal to the width of the pediment. In this case, mathematical formulas are used.

1. The width of the structure is divided by 2.
2. To determine the slope, you need to choose the angle between the base and the surface of the roof slope.
3. Further, according to the Bradis table, the tangent of this angle is determined.
4. The half of the width is multiplied by the tangent of the angle to get the ridge height.

Usually this parameter is chosen so that the slope of the roof is 25-45 degrees.

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How to calculate roof height - 3 influencing factors and a running formula

The basis of any construction has always been, is and will be a competent calculation. Without it, at best, the owner will pay extra money, and at worst, the structure will simply collapse. It is relatively simple to calculate the height of the ridge for any rafter system, but one formula is not enough, here you need to take into account a number of factors and then we will analyze 3 main factors, plus you will get the very formula for calculating.

Three factors affecting the height of the roof

First of all, let's understand the terminology. It is customary to call the ridge of the roof the upper line of the connection of the slopes of this very roof. Moreover, the ridge is precisely the horizontal line. If, for example, a hipped roof has no horizontal line, then the height of the upper connection point of the slopes is calculated.

The calculation of the gable roof of a building is considered the simplest, where we have a triangle. If we draw a vertical line from the ridge to the base, then we get 2 right-angled triangles, which are the main characters in the calculations.

But almost all complex types of structures, upon close examination, can be decomposed into the same right-angled triangles.

The only exceptions are vaulted structures, but building such a structure with your own hands and without preparation is unlikely, so we will leave the vaulted roof alone and deal with the factors affecting the height of triangular roofs.

Factor # 1: you can't argue with nature

In this case, we are talking only about atmospheric phenomena, that is, wind, rain and snow. Because the stability of the house during earthquakes has nothing to do with the height of the ridge.

To compete with the element is, at least, stupid, so you need to adapt to it:

All of the above data can be found in the regional meteorological service or use two profile documents. The first document is SNiP 23-01-99, and the second is a collection of synoptic maps for the regions of SP 20.13330.2011.

Factor # 2: roofing material

The angle of inclination of the slopes directly affects the choice of material with which you plan to cover the roof. Often the recommended tilt range is written on most materials, but this information still needs to be found, so it is easier to remember a few general recommendations.

• If the material is piece, for example, ceramic or bituminous shingles, then the angle of inclination should be as large as possible, because there are too many holds on such a plane, respectively, there will be something to hold on to precipitation;
• On gentle slopes, smooth and large sheets are in priority. If earlier it was slate, now, in terms of sliding characteristics, it has been significantly overtaken by metal and corrugated board. There is also a seam roof, but it is more expensive, so it is used less often;
• Heavy materials, such as ceramic tiles, love steep slopes, because on gentle slopes, a much more powerful rafter system must be installed under them.

The angle of inclination of the slope also affects the amount of roofing material and, accordingly, the cost of it. The steeper the roof, the more expensive it will cost. So a roof with a slope of 10º will be 2 times cheaper than a roof with a slope of 60º.

Factor # 3: attic

Roof structures are attic and without attic. In the first case, the attic space is separated from the lower floor, and in the second, they form a single whole. Without an attic roof, it is more convenient for windy areas, while with an attic there is the possibility of arranging additional living space.

Attic structures are available with a residential and non-residential attic. So, if the attic is not residential, then the fire minimum for the height of the inner room under the ridge is 1.6 m.

In windy areas, the height of residential attics can be increased by side “attic” walls, which is considered an excellent solution.

Aesthetically, if the house is one-story, then the optimal ratio of the height of the ridge to the height of the first floor is 1: 1. If you do more, then the house will look like a mushroom, and if less, then it will visually grow into the ground.

Formula for calculating the height of the roof

Illustrations	Recommendations
	Calculator. The first and perhaps the easiest way is to use a calculator program. Under the article (in the "basement" of the site) you will find the section "construction calculators", there are such programs. You know the width of the house, you also know the desired parameters, the rest will be prompted by the program and the site's technical support service.

The process of selecting the best parameters for a gable roof is always a search for a compromise between the desired shape of the frame, the desire to obtain a beautiful high structure and the requirements for ensuring the strength and stability of the roof. In addition, the size of the gable roof will have to be tied to the weather "tricks" of the local climate and their own financial capabilities.

What determines the height of the ridge of a gable roof

To obtain a durable and beautiful structure, first of all, it is necessary to choose the optimal angle of inclination of the gable roof. This is a basic parameter, it must be selected based on the following criteria:

• The strength of the rafter system, the higher the angle, the less load on the frame from snow, precipitation is removed faster and more efficiently;
• The presence of strong winds, the correct angle helps to reduce the pressure on the roof slope;
• The height and dimensions of the attic space. The larger the volume of the air cushion in the attic, the warmer the gable roof will turn out. If you correctly calculate and plan the height of the ridge beam, the attic can well be turned into an additional living room.

Important! In addition to the listed conditions, it is necessary to take into account the weight of the structure, the longer the rafters and overhangs of a gable roof, the greater its weight, which loads the walls of the house, and the higher the cost of construction.

What is the angle for a gable roof is the optimal ridge height

In contrast to the design process, in direct construction it is rather difficult to work with angular values. To directly determine and accurately set the slope of the slope, you need an accurate measuring technique. Instead of the angle of inclination of the rafter beams, it is easier to use linear quantities, for example, the length of the rafters, the size of the span or the height of the ridge. In this case, the desired angle of inclination can be easily calculated using trigonometric formulas by measuring the height of the ridge and the distance between the rafter supports on the Mauerlat.

Climatic and technological restrictions on the height of the ridge of a gable roof

For areas where the main factor is open space, respectively, strong wind loads, the height of the ridge is most often calculated based on the recommendations of the manufacturer of the roofing material.

In such conditions, the main factor determining the stability of a gable roof is the wind load. Rainwater and sleet do not pose a particular threat due to the sweeping effect of horizontal air currents, so there is no need to increase the angle of inclination of the roof structure. Moreover, with a considerable height of the ridge, the windage of the gable roof and the pressure on the walls of the building sharply increase.

Experts do not recommend reducing the height of the ridge beam to a minimum. Firstly, it significantly reduces the thermal insulation properties of the gable roof and reduces the amount of usable space in the attic.

Secondly, the roof with a reduced ridge height is no longer pressed by the air currents against the building box, but tend to overturn or tear it off from the supporting surface. This situation is much worse than the situation with windage, since the gable roof is not designed for excessive internal pressure. Thirdly, certain types of roofing material cannot be laid on roof slopes with an extremely low ridge height. If such a situation arises, it is better to seek advice from specialists in a specific type of roofing material, who will help to calculate the safety factor and the method of installation.

If a large amount of precipitation is recorded on the ground in the form of wet snow, the height of the ridge of the gable roof and, accordingly, the steepness of the slopes is calculated according to the following scheme:

1. The maximum amount of wet snow that has fallen in a given area over the past decades is determined;
2. Based on the future dimensions of the house box and financial capabilities, determine the maximum size of the rafters and the load-bearing capacity of the roof frame with the specified thickness of the snow cover. The number of rafters, lifting height and pitch are calculated based on the methodology outlined in SNiP 2.01.85 "Loads and Impacts";
3. If the size of the timber for the rafters turns out to be prohibitively large, it is necessary to increase the height of the ridge, but so that the angle of inclination of the gable roof does not exceed the optimal values ​​for the selected roofing material.

When calculating the load on the rafters, it is assumed that with a ridge height that provides an angle of inclination of more than 60 °, the weight of the snow mass on the surface of the gable roof can be ignored. When the ratio of the ridge height above the Mauerlat horizon to the distance between the lower supports of the rafters is less than ¼, the snow pressure on the roof is taken into account in full. In an intermediate position, with an increase in the angle of inclination of the gable roof from 20 ° to 60 °, the correction reduction factor changes monotonically from 0.7 to 0.1.

Optimal gable roof ridge height

Often, the decision to increase the height of the ridge is made not to reduce the load on the roof, but to increase the usable space of the attic. The benefits of such a modification, at first glance, are obvious. You can increase the amount of usable space and equip, for example, an attic and even a balcony. It is relatively easy to assess changes in the shape and size of the under-roof space using the diagram shown in the figure.

Before making a decision, try to calculate the geometry of the consequences of the increased skate height. Consider, as an example, the change in the characteristics of the height and dimensions of a gable roof for the smallest building measuring 6x4m and a wall height of 2.5m. A sketch of the roof structure is shown in the figure.

With the optimal height of the ridge above the floor slab of 2 m, the length of the rafter beam will be 2.9 m. In this case, the usable space under the gable roof will be only 4x1.8x0.5 m. This is enough for ventilation and roof insulation work. The width of the usable space, if desired, can be increased to 1.5 m. On this area, you can organize a bedroom or a rest room, for which, in fact, the attic is used.

An angle of inclination of 45 ° with a ridge height of 2 m ensures optimal structural strength, if you choose the right material and calculate the beam consumption for the construction of rafters, you can get a very moderate cost of the rafter system, primarily due to the absence of struts and struts.

You can try to increase the width of the attic comfort zone from 0.5 m to 1.5 m. In this case, the height of the ridge and the angle of inclination of the gable roof will increase to 3.6 m and 60 o, respectively. The space available for use has increased from 1.5 m to 2.5 m, the comfort zone, or the area within which you can walk without bending, is 1.5 m, which is quite consistent with the average parameters of the attic for a country house.

The length of the rafters has increased from 2.9 m to 4.2 m. It is assumed that the cost of the timber for the gable roof frame will increase by 30% due to the need to install additional load-bearing elements - beams and struts. If the loads and the method of fastening are correctly calculated, the structure will be as strong as in the previous version.

Alternative option

Even a cursory comparison of the two options, without trying to calculate the exact characteristics, allows us to draw certain conclusions.

The size of the usable area of ​​the attic in a broken roof version is larger than that of a two-slope scheme with an increased ridge height by 15%, the amount of timber and roofing materials was spent more by 19% and 7%, respectively. The cost of work for a broken circuit is 30-33% higher. The gable roof structure is 0.8 m higher, but at the same time the center of gravity of the frame is below the center of pressure, which allows it to be more stable in strong winds, despite the fact that the angle of inclination of the rafters is 60 o higher than the angle of the upper row of the broken roof.

In addition, large air "bags" above the ceiling and in the side walls of the duplex version of the attic insulate and soundproof the room well. For a long stay in the attic room, a broken pattern is more suitable due to the increased comfort. Whereas for a country house or a bath, it is quite realistic to use the design of a classic gable roof with an increased height of the ridge beam.

The given comparison is valid only for small-sized gable and broken circuits. As the size of the house increases, the gable version of the roof with an increased height of the ridge beam becomes much more expensive than the cost of a similar-sized broken pattern.

Conclusion

It should be noted that the calculation of the required ridge height greatly depends on the type of roofing material. The vast majority of roofing materials, from tiles to ondulin, fit perfectly on a slope with an angle of inclination of 60 °. Due to the fact that the roof slope is a single plane, the laid roof has a significantly higher resistance to any form of precipitation. Broken structures often suffer from rainwater leaks during heavy rain and wind precisely on the break line.