How to calculate the optimal roof height. How to calculate the height of the ridge for a gable roof
No house can be imagined without a roof. Such a design is necessary, because thanks to it the protection of the entire building from environmental influences is ensured, as well as the correct arrangement of the roof makes it possible to build an attic or attic.
The roof is exposed to various weather conditions.. If you choose the wrong angle of inclination of the slope, and, accordingly, the height, then there is a risk that gusty winds or heavy rainfall can violate the integrity of the structure. In the best case, you will have to carry out minor repairs, in the worst case, to rebuild the structure.
When designing the construction of any object, one cannot neglect any parameter, including the value of the roof height. The following series of arguments will confirm the importance of correctly defining such a parameter:
- Longevity and reliability. The most important characteristic that interests every home owner. Optimally selected roof height will allow the structure to be resistant to the existing loads exerted by roofing materials and other structures, seasonal loads, such as snow masses.
- Appearance aesthetics. It is important when building a house to take care of its appearance. Wrong parameters used in the design will not allow the house to look complete and aesthetically pleasing.
- Convenience. Due to the height of the roof, it is possible to build an attic space in the house and adapt it for living or storage, which provides certain amenities and increases the living space of the house.
The top point of the roof is called the ridge. In other words, this is the junction of the inclined planes of the roof, located in the horizontal plane.
If the height of the roof level is calculated incorrectly and is lower than necessary or higher, then this promises not only an imbalance in the architecture, but also problems during the period of use. The height parameter must correspond to the technological processes.
Atmospheric loads
What does it depend on
A very important parameter, which will have to be taken into account in the calculations and on which the reliability of the structure depends, is the angle of inclination.
There are a number of factors on which this parameter depends, as well as the value of the height of the structure.
atmospheric phenomena
It is necessary to adapt to such a factor, because it is pointless to resist such phenomena.
Of the atmospheric factors that affect the roof, there are the following:
- Wind. The slope angle is selected depending on the weather conditions that are inherent in the area in which the house is located. If gusty winds prevail in the region, then the angle is chosen no more than 10-20 degrees. In other cases, the wind does not affect the angle of the roof slope.
- Precipitation. A region that experiences heavy rainfall the slope angle is recommended to choose more than 45 degrees. This roof structure allows precipitation to drain quickly.
- Snow mass. Similarly to the previous factor, the choice of height depends on the abundance of snowfall in winter. It is advisable to choose a slope angle of 45 degrees or more if snow in the region falls frequently and in large quantities.
All information about the characteristics of the above parameters can be found from SNiP 2301-99.
The need for an attic
Non-residential buildings are usually erected without an attic. and light enough, such as garages and sheds. For a residential building, it is always necessary to provide for the presence of an attic space. To use it or not is already a personal matter for everyone.
The need to build an attic space is a factor that affects the height of the roof based on the comfort of movement around the future room. Namely, there is a need to move around the attic and operate it as a residential or storage space.
If the premises are provided for non-residential, then There are a number of rules for such a design:
- fire requirements for the house are taken into account in the calculation of the height of the roof;
- the size of the room should not interfere with maintenance;
- a through passage is required, 1.6 m high and 1.2 m long.
roof type
There are special rules, based on which the roof height parameter is determined. regarding the material for its coating:
- If in roofing material many piece elements, then the angle of inclination is chosen as large as possible.
- If the roof is selected low, then joints in the roofing material should be kept to a minimum.
- For material of large mass is selected maximum angle so that the total weight of the material is evenly distributed over the surface.
NOTE!
These parameters should be taken into account in the aggregate to ensure a reliable and long service life of the roof.
Roof height in relation to the width of the house
From this angle, the determination of the height of the roof is determined based 
pythagorean theorems. To do this, the cross section of the structure is represented as an equilateral triangle.
The parameters that are needed for calculations are roof pitch. The height of the structure is leg of a right triangle.
The calculation is carried out as follows:
- Necessary determine the tangent selected value for the slope angle.
- Knowing the width of the house, one side adjacent to the corner can be calculated by dividing the value by 2.
- Next, the existing values should be substituted under the well-known formula a = b * tg a.
- According to this principle, one can understand the dependence of the height of the ridge on the width of the house. The greater the width of the house, the greater the slope angle.
The ratio of the width of the house to the height of the ridge
Gable roof ridge height
How to calculate the height of the ridge of a gable roof and not make mistakes? The above is the easiest way to determine the height of the roof for its gable variety. A mathematical formula is used for this. But there is another way to calculate - graphic. Initially, a drawing is made on paper, after which the obtained values \u200b\u200bare measured.
The principle of this method is to transfer the real parameters of the roof structure in an exact proportional ratio on a smaller scale.
Despite the fact that the method is considered not as accurate as the mathematical one, it is convenient for many and also allows you to find out the necessary results.
The algorithm of actions is as follows:
- An isosceles triangle is drawn and is carried out to the meridian - this will be the height of the ridge.
- It is necessary to draw a triangle starting from the previously selected angle of inclination depending on the individual parameters of the house and its location.
- In order to draw the exact angle of the roof, you should use a protractor.
- After the triangle is drawn, measure the resulting meridian, i.e. skate height.
This method is especially convenient for those who are going to equip the attic for a residential type room. In this situation, it is possible to visually determine and designate all the necessary parameters.
Gable roof height
Calculation of the height of a hipped roof
Despite the fact that the four-pitched type of roof is much more complicated in design, you can use the parameters and formulas in the calculations according to the principle of calculating the height of the two-pitched type.
The hipped roof has two varieties:
- Shatrovaya. In this design, all roof slopes have the same length, area and are identical in shape. This variety is used in regions with strong winds.. It is able to withstand strong gusty winds and a high degree of load.
- Hip. The slopes are represented by two triangles and trapezoids. This variety requires significant costs for materials for its construction, however, this Ideal for attic floor. However, this design is not suitable for regions where there are strong gusty winds in the ground. Under such conditions, the structure needs additional reinforcement.
In any of the listed types of roofs for calculations, it is necessary to find in the design the figure of a right triangle. This will determine the desired values.
For a roof of a four-slope variety, the method by which the value of the height of a gable roof is calculated is suitable:
- In the design you can find a right triangle.
- In the found figure, designate the hypotenuse, which will be the rafters, the second side is the width of the house, divided by 2.
- Based on the slope angle parameter (tg angle), the third side of the figure is calculated, which represents the height.
hip roof height
Useful video
You can learn how to determine the height and angle of the roof from the video lesson:
Conclusion
Determining the height yourself for the future home is a simple, but responsible task. Considering that this is a rather important parameter on which the reliability of the entire structure depends, it is better to entrust such work to specialists. Especially if there are doubts about determining the angle of inclination of the slope. Special programs for design will also help in this matter.
In contact with
One of the main building elements is the roof. The viability 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:
- truss system;
- crate;
- 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. Two-slope, as well as four-slope (hip) species are widespread.
In addition to them, there are hipped roofs, and domed, and broken (attic) and complex multi-pitched.
Among the most widely used roofs are gable roofs, which are a simple structure consisting of two inclined slopes and two gables - vertical walls of a triangular shape.
Gable roofs are usually mounted on,. The gable roof with an attic also looks original.
The truss 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 was called the ridge. This is the uppermost part of the entire building on which many owners of private houses install a decorative one.
To determine the area of \u200b\u200bthe roof and calculate the number of boards for the crate, roofing material and the length of the logs themselves, you need 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 all the loads that fall on it. In winter, this is an accumulation of snow on the roof; during the year, it is a wind effect, which is the greater, the larger the area of \u200b\u200bthe 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 board or metal tiles, you can significantly reduce the amount of snow that will accumulate. With 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 smaller 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
The first way is mathematical
To calculate the height of the ridge of a gable roof, it is necessary to present its design in a cross section. It will be an isosceles triangle. Therefore, the height of the skate 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 comply with the optimal operating conditions of the 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. Calculate the height of the ridge of a gable roof, based on the specified parameters, will help the Pythagorean theorem and the Bradis table.
According to the theorem known to everyone since school years, the length of one leg (ridge height) 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 (roof slope angle).
We give the value of the tangent of the angles from 20o to 45o with a step of 5o.
For example, we calculate the height of the ridge for a standard wooden house 6x8 meters, located in the middle zone of our country, with a roof slope 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 the angle 40o is determined from the table. It is equal to 0.839. We 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 the use of mathematical formulas and tables, you can determine the height of the ridge by making an image of the roof section on a small scale. To do this, draw an isosceles triangle and draw the median, which will also be the height.
The angle at the base of the triangle must be accurately drawn using a protractor. When correcting for the accuracy of mathematical tools, you can get an approximate value of the quantities you are looking for. 
Important! After completing the process of mounting the ridge on the roof, it is necessary to cover the ridge run with lightweight side tiles. This is required by the installation of a pitched roof ridge.
Thus, the height of the gable roof ridge is calculated. When planning to use the attic, 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 on building a gable roof ridge and installing rafters:
Russian hut - gable. The rafter system for it is quite simple, and this has ensured great popularity for this type of roof. A hip roof (four-pitched), for example, is geometrically more complex. It is more difficult to calculate and build, so let's take up the calculation of a symmetrical roof with two slopes.
Its calculation consists in determining the length of the rafters that form pairs. Each of these pairs is attached to the adjacent roof trusses with the help of a crate. The ends of the roof are triangular gables. The length of the rafters, like the height of the roof, will be determined by its angle. How to choose it correctly? This will tell the weather prevailing in the area.
Skate height selection
Whoever has been to the Baltic countries or Scandinavia, could notice that the roofs of the villages there are pointed. This is due to the high amount of precipitation, which, in turn, is explained by the predominance of the maritime and temperate climate. Water immediately flows from such a roof, and snow does not linger at all. However, the neighborhood with forested hills reliably protects these settlements from strong winds, so the large windage of such roofs is not of great importance.
Arab houses had flat roofs because the rainfall in the desert was minimal. But strong dry winds in such parts happen.
In the same place where the winds rage in the middle lane, you can find houses with completely different roofs - almost flat or arched, because the lack of windage or good streamlining plays a big role.
And if earlier such houses were built intuitively, based on the experience of generations, today sets of rules have been created for different regions of Russia that describe wind and snow loads on the roof. In particular, this is SP20.13330.2011, developed on the basis of SNiP 2.01.07-85* "Loads and Impacts". In the central region of the country, for example, it is recommended to choose the height of the ridge so that the angle of inclination of the slopes is approximately 30–45 °. It is this angle that will make it possible to calculate both the height of the roof ridge and the length of the rafters.
Let's turn to school geometry. Our roof must be presented in the form of a triangle, in fact, which is each of its gables. Such a triangle will be obtuse. We divide it along the axis of symmetry into two right-angled triangles. We received two legs, one of which (a) is known to us - this is half the width of the house. The second leg (b), which is not yet known, is the height of our roof.
b = a * tan α, where:
α is the angle of the roof, taken from the set of rules.
The tangent of this angle can be calculated on an engineering calculator or use mathematical tables. The resulting leg b is the height of the roof.
Knowing both legs, we can calculate the value of the hypotenuse. This is the approximate length of the rafters. However, since the roof often extends beyond the walls of the house, hanging over them, the length of the rafters can be increased. It all depends on the architecture of a particular building.
Knowing the length of the rafters and the length of the roof itself, which in this dimension can also protrude beyond the edges of the house, hanging like a visor over the gables, we can already calculate its area, and therefore the amount of roofing material.
Calculation example
Let's say the house has a width of 6 m. Divide it in half and get 3 m. This is our leg a. The slope angle recommended for building a house in this area is 45 °.
b = 3 * tan 45° = 3 * 1
But even without using this formula, one can guess that with an inclination angle of 45 °, our right triangle will turn out to be equilateral. That is, even without tables and a calculator, it will become clear that the height of the roof will be 3 m, that is, half the width of the house.
When constructing any building, one of the most significant moments is the correct calculation of the height of the roof ridge, as well as its area. With a low ridge height, a large amount of snow can collect on the roof, which will create an additional load on the entire structure. On the other hand, with a sufficiently high ridge and a large coverage area, the windage of the roof increases, which can become a problem in strong winds. Therefore, it is important to know how to calculate the height of the roof ridge, preventing its premature destruction.
Roof design features
When designing any building, it is important to correctly calculate the parameters of the roof. Here, all possible loads, as well as the required amount of roofing materials, should be taken into account. In this case, one of the main parameters will be the correct slope of the slopes of the structure. In typical gable roofs, the slopes usually have a slope of 12–45 degrees. The direct dependence of this angle of inclination on the loads created by the weight of the roof on the entire roof structure of the building is known.
Note! It is necessary to make additional strengthening of the truss system, which will entail additional construction costs. If you reduce the slope of the slopes, then there will be an increase in the load on all structural elements due to precipitation.
It is equally important to correctly calculate the rafter system. This is due to the transfer of the total load from the rafter legs to the load-bearing walls of the building. In turn, the rafter legs are determined by the size of their section and length. Such structural elements are selected based on what acting loads are on the roof, taking into account the angle of the slopes. To ensure the necessary margin of safety, experts recommend slightly increasing the results of calculating the thickness of the rafter legs.
Since the roof configuration may be different, the calculation of the necessary parameters will be made depending on some features. To correctly calculate the height of the roof, you should always take into account the number of slopes and its shape. Neglecting these characteristics will lead to errors in the calculations. Without such data, it will be impossible to determine the roof area, as well as calculate the required amount of materials for roofing. The height of the ridge affects the length and configuration of the rafters.
Main settings
When constructing their own house, each owner will definitely be faced with the calculation of the height of the roof level. Before determining such a parameter, it is necessary to take into account the following nuances:
- the number of slopes;
- the presence of a residential attic or attic;
- the angle of inclination of the slopes, taking into account possible precipitation;
- selected roofing material.
In this case, one should take into account the simple dependence of the amount of precipitation and the angle of inclination of the slopes. The amount of material needed for roofing can be determined by first calculating the height of the roof. In practice, a slope of 45 degrees implies an increase in the cost of the roof by 1.5 times compared to the design of a flat slope.
It is believed that the regulatory requirements for the building determine the proportions and height of the roof ridge. Meanwhile, such a parameter can be calculated, knowing the actual dimensions of the walls of the structure. In this case, the calculation of the height of the ridge can be determined using the simplest geometric formulas. To do this, you need to know the width of the structure, as well as the angle that determines the slope of the roof slopes.
Calculations
Parameters such as the height of the roof ridge and the angle of inclination of its slope are directly related. In addition, the selected roofing material also affects the angle of the roof. For example, soft tiles can be laid on a roof that has a slope of 11–90 degrees. Ceramic tiles require a slope limit of 60 degrees.
It is also necessary to take into account the aesthetic component, therefore, it is necessary to provide for the correspondence of the height of the roof ridge to the height of the building. The fact is that an excessively flat or too high roof can adversely affect the appearance of the structure. Considering the existing climatic conditions, the best option is considered to be the angle of inclination of the roof, which is 35-45 degrees. A roof that has a flatter design will be subject to increased loads due to precipitation.
If we take the height of the ridge as one of the legs of a right triangle, then the other leg will be half the width of the building. Accordingly, the length of the slope will be considered the hypotenuse. In accordance with the trigonometric formula, the length of the leg in such a triangle will be equal to the length of the second leg, multiplied by the value of the tangent of the angle at the base. For example, let's take a building width of 6 m with a roof slope angle of 40 degrees. Referring to the Bradis trigonometric table, we determine the tangent of an angle of 40 degrees. It will be equal to 0.83. It turns out that half the width of the house - 3 meters must be multiplied by 0.83. As a result, we obtain the height of the roof ridge of such a building, which will be 2.49 m.
How to calculate roof height
What is important to know for calculations and what are the dangers of errors
- Types and forms of modern roofs
- Ridge run and slope angles
- Calculations of the height of roofs of various shapes
- Roof calculation using online resources
- What to consider when starting roof calculations
The final stage in the construction of any house (be it a spacious main dwelling or a small country house) is the arrangement of the roof. It is she who gives the exterior a presentable and complete look. But at the same time, it performs a very important function - it retains heat, creates a cozy, most comfortable and pleasant atmosphere inside. It is this element of any structure, without exaggeration, that is called one of the most important.
What determines the height of the structure and what is taken into account when performing pre-assembly calculations
It is especially important to know how to calculate the height of the roof for a house, and to understand exactly how to do it correctly. That is why you need to take some time to study this issue. Inaccuracies made in pre-wiring calculations lead to serious problems that are too difficult to deal with later. Often, to eliminate errors, you have to start work on arranging the roof again.
For example, if the slopes are made with a small angle of inclination, then winter snowfalls will cause serious harm to such a design (due to the accumulation of snow, there is a risk that the roof will break). It is logical to assume that you can just make a high skate and all problems will be solved. But this is not so, because too high a roof is most vulnerable to gusts of wind.
- the general square of the structure;
- climatic conditions (as you may have guessed, in regions with snowy winters, sloping roofs are not recommended, which are optimal for warm continents);
- material for arranging the roof, as well as battens;
- selected form;
- height of the main building;
- personal preferences and tastes of the owner.
A number of other factors also largely affect the design parameters, for example, there is a direct dependence on the layer of insulation laid or the installation of snow retainers. The dimensions of the ridge are related to the features of the truss system, but at the same time they can increase the total area of \u200b\u200bthe roof and the amount of materials required for its arrangement.
All of the above confirms the fact that the strength of the structure, the durability of its operation, the aesthetics and harmony of the external appearance of the building depend on the size of the roof.
What are the common types of modern roof structures
The type of roof has the most direct influence on the calculation and the formulas used for it, as well as on the amount and, therefore, on the consumption of the material that needs to be purchased for the arrangement of the roof.
Today, the following structures are most often erected:
- shed (it is preferable to use it for outbuildings);
- gable (the most popular for residential buildings);
- four-slope. Also a great choice for residential buildings. Various options are provided here: spectacular tented ones (a characteristic feature of which is the same size and shape of all slopes) or complex hip ones (their feature is the participation of two triangular hips and two slopes with a break (trapezoid shape));
- attic (consists of two slopes, but always with a break). This fracture allows you to increase the area of the attic.
Skate and determination of rational slope angles
For calculations of different forms of roofing, such a value as the size of the ridge is used. This name refers to the upper, horizontally located rib of the structure, which was formed at the intersection of two roof slopes (inclined planes).
There is a ridge on all types of roofs, except for hipped and domed ones.
If the design is simple gable, then it is one, but if it is complex, then the skates are formed from two or more. During the construction of the roof, the rafter legs rest on the ridge runs, and based on which roofing material is chosen for the final coating, the base of the ridge is also selected.
Knowing how to calculate the height of the roof correctly is necessary both for the construction of a reliable and durable structure, as well as in order to predict the preliminary construction costs and plan the budget. In calculating the rational angle of inclination, the material from which it was decided to lay out the roof is taken into account: some roof coverings can be laid at an angle of up to 90 degrees, while others can only be laid from 15 to 60 degrees.
When choosing which slope of the planes to choose a roof for your house, you need to take into account the functionality, the overall appearance of the resulting structure (after all, you want to get an aesthetic structure) and climatic conditions. As practice shows, for European countries, an angle of 35-40 degrees can be called an ideal solution.
Examples of calculations that are easy to do on your own
In principle, if we are talking about simple roof structures, then it will take quite a bit to calculate the height of the roof: a calculator and a few well-known principles from the basics of geometry, which are still taught in the school curriculum.
We take the basic principle of calculation from the rule that the length of one leg in a right triangle will be equal to the length of the other, if it is multiplied by the tangent of the angle formed with the base.
we measure the width of the building (let's say we have a four-meter house);
we accept the angle value equal to 35 degrees (as the recommended optimal option for European latitudes);
we calculate the tangent, it is obtained for a given angle of 0.7002;
4 meters * 0.7002 = 2.8 meters.
If a gable design is chosen, then in this case it is also very easy to calculate the height of the ridge: the width of the house can be divided by “two”, and then multiplied by the tangent of the angle formed by the slope of the slopes. Consider for clarity the above described how to calculate the height of a gable roof using the example of a house whose width will be 10 meters . So, for calculations:
take an angle equal to 35 degrees;
we calculate the tangent, it turns out 0.7002;
10 meters / 2 * 0.7002 = 3.5 meters.
The most used today are four-pitched structures, and for their calculation you can use the same principle (formula) as for how to calculate the height of the ridge of a gable roof, but only the width of the house is divided not by two, but by four. Plus, doing calculations for a hipped roof, it is important to take into account the length of the ridge run directly, as well as the truss system.
The most complex calculations are accompanied by the arrangement of a mansard-type roof, a characteristic feature of which can be called the presence of two slopes with a break, which from the side makes its general appearance as if “broken”. Arrangement of a sloping roof will increase the functional area of the attic. The calculation of the hip roof is based on the example of calculating the height of a gable roof already discussed above, but do not forget that the roof has more than one angle of inclination, but several. Before moving on to settlement operations, you need to decide on them. Practice shows that it is best to choose the following angles:
for the lower - over 40 degrees;
for the rest - less than 40 degrees, but always more than 15.
To simplify calculations, but at the same time to get the most accurate result quickly, experts prefer to use the " golden section ”, for this, in the drawing, the outline of the roof is inscribed in a circle. By resorting to this successful rule, you can easily solve the question of how to correctly calculate the height of the roof, and most importantly, avoid inaccuracies in the calculation, which in practice will lead to the fact that the general appearance of the structure will be unaesthetic, inharmonious and simply ugly.
Where to go for help: online resource and consultants
If the roof being erected is of a complex shape, then it also requires more voluminous, lengthy calculations. For calculations, data on the cross section of the rafters, the step between them, the size of the spans of the truss structure are used. In addition, the dimensions of the roof windows, chimneys, the presence of parapets and overhangs are taken into account; it will definitely be necessary to analyze the possibility of supports and the endurance of the foundation.
Today, anyone who does not know how to calculate the height of a roof can do this by contacting assistants who can be found on the Internet. These can be specialists who are ready to provide you with such services online, or a special Internet resource called a "calculator", in which case the site visitor enters the requested data and the system makes calculations based on them.
When choosing who to turn to for help, remember that the hip roof is an expensive construction, so it does not tolerate mistakes and inaccuracies. The correctness of the calculations performed must be guaranteed. For beginners, the calculations of hipped, hipped and hipped roofs turn out to be quite complicated, so it is better to entrust them to a designer with experience in this field. On your own, you can only deal with calculations relating to single-slope structures for outbuildings and garages, or simple gable structures built to cover a small country house.
Calculations of the parameters of the roof is the most important stage,
concerning the construction of the roof. It is its result and accuracy that affects how reliable the structure will be, how long it will last, whether it will have an attractive and harmonious appearance. No need to spare time and effort to double-check the results and make sure they are accurate. This is a guarantee that you will have the most durable home, designed for many years of operation and providing comfort, coziness and warmth.
Accurate and correctly calculated data will help to avoid unnecessary costs for the purchase of materials, and this is a reasonable savings in construction.