To build a roof with pitched planes correctly, you must first determine the optimal angle of the roof slope. To perform such a calculation, you need to find out: what determines the value of this indicator for the roof.
pitched roofs
The slope angle of pitched roofs is their main difference from flat roofs. When the slope of the roof is more than 10 °, then it is already pitched.
If the slope angle is less than 2.5 °, such a roof is flat. There are roofs with a slope of more than 80 °, but they are built quite rarely.
The value of the roof angle depends on many factors that are not always associated with natural phenomena, especially on the characteristics of the building material used to cover the roof.
The greater the angle of inclination of the roof, the stronger the wind load will act on it.
An increase in roof pitch from 10° to 45° results in a fivefold increase in wind load.
However, if you build a roof with a small angle of inclination, then the wind, penetrating under the joints of roofing materials, can simply tear the roofing sheets from their places.
From roofs with a large slope of pitched surfaces, moisture leaves much faster, and snow masses come off. The maximum values of loads of snow masses are set on sloped planes of 30°.
On roofs with a 45° angle of inclination of pitched planes, the most complete convergence of snow masses is achieved, and from roofs with smaller angles, snow masses are easily blown away by a good wind.
Important: if the slope of the pitched surface is insufficient, then the blowing wind can drive rainwater under the joints of the roofing sheets. This phenomenon sets the minimum allowable angle between the roof slopes.
So, for tiles, the minimum value of the angle of inclination is 22 °, for slate coating - 30 °, for flexible coatings - 5 °.
It turns out that it is better to equip the roof in areas with heavy rainfall immediately with pitched surfaces located at an angle of 45 °.
If there is little precipitation at the location of the future roof, then a slope angle of 30 ° will suffice.
A roof with a slope of 35-40 ° will cope with average wind loads, and in areas where strong winds often blow, a slope angle of 15 ° to 20 ° is required.
How to calculate the angle of the roof slope
To ensure long-term operation and reliability of the roof under construction, it is necessary initially, even at the planning stage of roof construction, to correctly calculate its slope. Its size depends not only on the design features of the roof, but also on the type used on it to cover the building material:
- When calculating the angle of the roof slope, it is necessary to take into account the climatic characteristics of the area in which it is installed.
The drier and warmer at the place where the roof is erected, the more gently sloping it can be. Increasing the angle of slope of the pitched surfaces will lead to a reduction in the accumulation of snow masses on the roof, therefore, the snow load on the roof will be minimized.
However, this increase also has a downside. A larger roof slope leads to an increase in wind load, so a roof that is too steep cannot be used in areas with prevailing winds. Most often, the slope of pitched roof surfaces is in the range of 10 ° - 60 °.
- By increasing the angle of the roof slope, the total cost of its construction increases significantly.
For example, building a roof with a pitched slope of 60° doubles the material costs compared to building a flat roof. A roof with a slope of 45° will have 1.5 times the total cost of a similar flat roof.
- It is necessary to calculate the roofing slope as a ratio between ½ of the laying and the total height to the ridge, in this case, cleaning snow masses from the roof will not be difficult.
- It is also necessary to take into account that in the valley the slope is at least 1%. You also need to remember that if the roofing slope is planned to be less than 10 °, and the roof is covered with a layer of flexible building materials, then it is imperative to lay a layer of crumbs - gravel or stone - on its surface to protect it.
The thickness of this gravel layer is made at least 1 cm, and a similar layer of stone chips - 0.3 cm.
For a metal tile or slate coating between the floorings, the joints must be sealed.
When calculating the angle of the roof slope, it must be taken into account that the type of removal of atmospheric moisture will depend on the size of the angle of the pitched surfaces.
Water disposal in such cases is external (unorganized), and internal (organized), as well as mixed.
Important: it must be remembered: there is no such arrangement of the roof, which simultaneously satisfies all the requirements associated with the peculiarities of the climate.
Therefore, when planning the angles of the roof slopes, it is necessary to find a balance. It should also be taken into account that the cost of building materials for the construction of a roof increases in proportion to the area of \u200b\u200bthe roof, while its total cost also increases significantly.
The choice of roofing material
After calculating the size of the slope, the building material needed to cover the roof is selected. It should be noted here that piece roofing building materials, such as natural tiles and slate, are used for installation on pitched surfaces with a slope of more than 20 °. If, when using these coatings, the slope of the roof is less than the specified value, then moisture will enter the inter-element joints of the coating, which in a very short time will lead the entire roof to a state unsuitable for further operation.
Rolled flexible coatings are used more often for covering flat roofs or roofs, the angle of pitched surfaces of which is less than 30 °. This is due to the fact that at high slopes, as a result of high temperatures, such a coating can slide off the roof surface.
Such flexible building materials can be used on almost all types of roofs.
For a metal profile, the required roof slope angle must be more than 10 °.
A roof is flat if its roof pitch is less than 3°. For the construction of a roof of this design, a small amount of building materials is needed, but such a roof can be built only when there is little precipitation in the area of \u200b\u200bits construction.
Any roof slopes have several types of roofing suitable for installation on them. The most popular types of roofing building materials for coating:
All of the above types of roof coverings are placed on pitched surfaces, the angle of inclination of which must correspond to the used building material of the covering, and are based on a truss structure that transfers the mass of the roof to housing construction. The carrier system includes truss trusses and a sheathing structure.
Roof Angle Calculator used to calculate how roof pitch angle, and missing data about the roof - projection, height, length and angle of inclination of the roof slope. Visually, where and what values can be seen on the drawing of the calculator, located under the calculation form.
To calculate the angle of inclination of the roof or data, it is enough to enter only two known quantities, and the remaining values (if any) can be used for verification.
Calculation of the angle of the roof
Known parameters Fill in the data that you know. To calculate the angle of inclination of the roof and the length of the slope, it is enough to indicate 2 data out of 4. Units of measurement: Metric English systemProjection length (W): Height (H): Roof slope length (L): Tilt angle (α): Degrees Radians Calculate the angle and length of the roof
Calculation result Projection length (W): Height (H): Roof slope length (L): Pitch angle (α): degrees Pitch angle (α): radian Roof slope: % Roof pitch: : 12
Link to calculation:
In the picture: a - slope angle, S - roof slope length, H - roof height in the upper part, L - roof slope projection length
Accordingly, all quantities can be found:
- a = arctg(H/L) or a = arcsin(H/S)
- H = L * tg a
- S = H / sin a
Calculation of slope angles of roofs by types
Calculation of the angle of inclination of a pitched roof
Shed roofing is one of the most popular and, at the same time, one of the easiest to calculate. In fact, our calculator will calculate exactly it, since more complex roofs (for example, the angle of inclination of a gable roof) require the breakdown of roof elements into separate slopes and the calculation of each of them.
When calculating the slope of a shed roof and calculating the length and angle of the roof slope, be sure to take into account the overhangs! You can calculate them by specifying the data not of the slope itself, but the height and projection of the roof along with the overhangs.
Materials and angles for pitched roofs
- roofing felt - 5-10 degrees
- from corrugated board - from 8 to 20 degrees
- from metal tiles - 20-30 degrees
- from slate - 20-35 degrees
- for a folded roof, a slope of 18-30 degrees is required
Calculation of the angle of inclination of a gable roof
Calculating a gable roof is already more difficult than calculating the angle of inclination of a shed roof. In the case of two slopes, it is necessary to calculate each of the slopes individually on our calculator, and to calculate the material it is better to use the roof calculator, because. the location of the material and its dimensions can vary.
Calculation of the angle of inclination of the hip roof
In turn, the calculation of the hip roof is even more difficult than the calculation of the angle of the gable roof. You need to not only break and count the angle of each slope separately, but also take into account that the angles for the hip roof are different.
For a hip roof, it is also especially necessary to take into account the walking dimensions of the crate, therefore, when calculating your real roof, the angles of the hip roof will vary slightly, though!
Types of roof depending on the angle of the roof slope
There are 4 main types of roofs depending on the angle of inclination:
- 3-10° - flat
- 10-30° - gentle
- 30-45° - pitched
- 45-60° - high
The reliability of any building, as well as the comfort of living in it, depend mainly on how well its roof is arranged.
And one of the criteria for the quality of the roof is its slope.
Since the amount of roofing material also depends on its size, the choice of the angle of inclination and its preliminary calculations are made before the purchase of the selected roofing material begins.
What influences it
Depending on the magnitude of the slope of the roof slopes, the peculiarity of its operation depends.
It is customary to distinguish 4 types of roofs:
- high, with an angle of 45-60 degrees;
- pitched, with a slope of 30 to 45 degrees;
- gentle, the slope angle of which is 10-30 degrees;
- flat. A slope of 10 degrees or less.
The choice of the value of this parameter is influenced, first of all, by natural factors that are characteristic of the area.
Strong wind exerts the greatest pressure on high roofs.
Because such roofs, due to the large angle of inclination, have a very large area.
A large surface area has a very high windage.
Accordingly, the load on the entire structure of the truss system is very high.
And if you decide to arrange a high roof with a very large slope, then you should take care of a very solid foundation.
However, in areas where strong winds prevail, it is unsafe to arrange and flat roofs.
With this type of roof, increased pressure will be exerted on the lower part of the slope in strong winds.
And if the roof fastening is weakened, the entire structure may fail.
Therefore, in areas where strong winds are frequent, it is recommended to arrange pitched roofs with a slope of 25 - 30 degrees.
If the wind force is small, then the slope of the roof can be 30-45 degrees.
If in the area where the house is being built, during the cold season there is heavy snowfall, then a roof with a large slope angle should be built.
In this case, the high roof is out of competition.
On roofs with a large slope, snow does not linger.
It is for this reason that in all northern countries the roofs on buildings are very high (Sweden, Finland, Norway, etc.).
The smaller the angle of the roof slope, the longer the fallen snow will be on the slopes.
The more weight will affect the entire structure.
If the design of the truss system is made with a large margin of safety, then some layer of snow on the roof is not bad.
It provides a little extra insulation.
However, if the design of the truss system of the structure is not designed for a large load, then there may be big problems.
Choosing a slope depending on the roofing material used
Gone are the days when only two types of roofing materials were used for covering: tiles and slate.
There are a lot of roofing materials today!
Each material has its own individual technical characteristics and this must be taken into account when calculating the required value of the angle of inclination.
After all, it may happen that the material you like in terms of its parameters simply does not fit.
Minimum Tilt Angle
There is a concept of the minimum value of this parameter.
For each of the materials, this parameter is different.
And if the angle of inclination obtained as a result of your calculations turns out to be less than the minimum value for the roofing material you have chosen, then you cannot use it for roofing.
In the future, a lot of problems can arise if you violate this rule:
- for any piece of stacked roofing materials, such as tiles or slate, the minimum slope is 22 degrees. It is with this value that moisture does not accumulate at the joints and moisture does not seep inside the roof;
- the angle of inclination for rolled materials (roofing felt, bicrost, etc.) depends on how many layers you plan to lay. If there are three layers, then the slope can be 2-5 degrees. If there are two layers, then it needs to be increased to 15 degrees;
- corrugated board manufacturers recommend that when constructing a roof from this material, arrange a slope angle of 12 degrees. Decking can also be used at lower values, but in this case it is necessary to glue the joints of the sheets with a sealant;
- for metal tiles, the value of this parameter is 14;
- for ondulin - this is a value of 6 degrees;
- the minimum slope for soft tiles is 11 degrees. But at the same time, a prerequisite is a continuous crate;
- for membrane roofing there are no strict requirements for the minimum value of this parameter.
It's about the minimum values.
My advice is to stick to these rules.
So that in the middle of winter you do not have to re-roof the entire roof.
Now about the optimal values
If it rains and snows often in the region, then the roof will be optimal, the angle of inclination of the slopes of which will be 45 - 60 degrees. After all, it is necessary to remove the load from water and snow from the roof as soon as possible.
Because the strength of the truss system is not unlimited.
And thanks to the large slope of the roof, rain and snow will descend as quickly as possible.
If in the region where the house is built, there are constantly strong winds, then the roof is treated differently.
With a smaller slope, its windage decreases.
And there is no exorbitant load on the roofing material and rafters.
Also, the roof will not tear off during sudden gusts of wind.
In this case, the optimal angle of the roof slope is 9 - 20 degrees.
Very often in the region there is both snow and wind.
For example, the Orenburg region.
In this case, choose the average value of the angle of inclination.
As a rule, its value is in the range of 20 - 45 degrees.
If you pay attention, most pitched roofs have exactly this meaning.
We calculate its value
For lean-to
We draw a perpendicular L sd along the wall, originating at the point where the short wall ends and resting on the wall with the maximum length.
The result is a right triangle.
If the length of the wall L cd is 10 meters, then in order to obtain a slope angle of 45 degrees, the length of the wall L bc must be equal to 14.08 meters.
For gable
The calculation principle for a gable roof is similar to the previous principle.
Consider an example
Leg C is half the width of the building.
Leg a is the height from the ceiling to the ridge.
The hypotenuse is the length of the ramp.
If we know any two parameters, then the value of the angle of inclination can be easily calculated using a calculator.
If the width is 8 and the height is 10 meters, then the formula should be used: 
cos A = c+b
Width c = 8/2 = 4 meters.
As a result, the formula looks like this:
cos A = 4/10 = 0.4
According to the Bradis tables, we find the value of the angle to which the given cosine value corresponds.
It equals 66 degrees.
For a four-slope
And again, you can not do without roulette and Bradis tables.
Knowing several parameters, you can easily calculate others.
Including the angle of inclination of the hipped roof.
It should be remembered that all dimensions must be taken as accurately as possible.
And to measure the slope of an already built roof, a special tool will help - an inclinometer.
After all, if you make a mistake, then the angles of inclination, length and area may not be correct.
This means that you will make a mistake in the amount of material required or the strength of the roof will be lower than planned.
Watch a video about the slope of the ramps.
Sergey Novozhilov is an expert in roofing materials with 9 years of practical experience in the field of engineering solutions in construction.
In order for the roof to serve for a long time and be safe during the entire period of operation, it is necessary to prepare a quality project in advance. Also, do not forget about materials, which certainly should not be saved on, so that you do not have to overpay, as in one well-known saying. They should not only correspond to the climatic conditions of residence, but also favorably emphasize the architectural features of a private house. After all, the design has not been canceled! But, in addition, it is necessary to take into account the slope of flat roofs. This is the same important stage as the selection and calculation of rafters, insulation.
The efficiency of roof operation is directly dependent on its slope. And when calculating this parameter, it is necessary to take into account the region of residence, for which exactly the attic is being built and the roofing materials used.
Advantages of flat roofs
Despite the fact that during the construction of private houses, flat roofs are made in isolated cases, they have a number of advantages. And above all - the low cost of work, since a smaller amount of building material is spent in comparison with the construction. Their installation is not as complicated as it might seem. Also, a flat roof is easy to maintain and repair.
If necessary, the roof can act as an additional platform. On it you can arrange a small pool or a children's corner. In addition, a slight slope of flat roofs will allow the installation of any equipment, often air conditioners.
The invaluable advantages of a flat roof make it popular not only abroad, but also in Russia. This is contrary to the seemingly unappealing design. Currently, the inversion type of roof is gaining popularity. But that's not what we're talking about. First you need to understand whether you need to make a bias.
The need for sloped flat roofs
Many buildings are made with a flat roof. However, it is not quite like that and has a slight bias, since this is spelled out in the requirements of SNiP and is dictated by vital necessity. Indeed, in the absence of a slope on the roof, rain or melt water will certainly begin to accumulate over time.
Even if the roof surface is perfectly flat, and there should be no talk of any puddles, reality shows the opposite. Various natural factors come into play:
- wind impact;
- solar radiation;
- precipitation;
- temperature fluctuations, etc.
As a result of all this, over time, the roof begins to deform. Accordingly, places are formed in which moisture and dirt, blown by the wind, begin to accumulate. In the presence of at least some slope of flat roofs, this probability is minimal.
What are the consequences?
It would seem that something terrible can happen because of the water? Everyone knows that it is the basis of the life of all things on earth. However, this element can easily destroy almost anything in many ways.
And since we are talking about water, which usually accumulates on the roof, its chemical composition contains a variety of substances. Here they have a detrimental effect on And in winter, the liquid generally turns into a solid state - this is where a powerful crushing force is hidden! And if there is at least some minimum slope of a flat roof, the worst can be avoided.
Many have noticed how vegetation blooms on the roofs - the wind, along with the sun and water, do their job. And as you know, the root system of plants is a fairly strong organ that can destroy almost any durable material. Over time, of course, but it doesn't get any easier.
Slope designation
All parameters of a flat roof, including the slope, are regulated by document SP 17.13330 SNiP II-26-76, which is called the "Code of Roofing Rules. The roofs" (translated from English the roofs - roofs). This document applies to the design of roofs from almost any material:
- bitumen and roll;
- slate;
- from tiles;
- profiled, galvanized, steel, copper sheet;
- aluminum, zinc-titanium and other similar structures.
The slope of the slope relative to the horizon, called the slope of the roof, can be denoted in different ways. In practice, its value is usually indicated in degrees, which is more convenient.
However, in the documentation you can find the writing of the slope of a flat roof as a percentage. However, there are significant differences between these designations. 1 degree equates to 1.7%. 31 degrees will equal 60%. In this regard, it is important to know such ratios in order not to make mistakes when making calculations.
What should you know?
When making a roof slope, it is worthwhile to clearly understand the purpose of this process. Perhaps protection from the harmful effects of external natural factors is necessary. In some cases, the slope of the roof depends on the architectural features of the surrounding buildings, and there is no desire to stand out strongly against their background. The material used also matters, since each has its own indicators that are acceptable during installation.
But special attention should be paid to At the maximum slope of a flat roof, the roof will perform the function of a sail, which is not good. On the other hand, precipitation will not accumulate on such a roof. Neither a drop of rain nor snow will linger on such a surface for a long time.
The scope of the attic also matters. For the arrangement of the attic, it is better not to do steep slopes. And in any case, financial opportunities also make their own adjustments. If you need to build a roof at an angle of 45 degrees or more, you cannot avoid increasing spending on roofing materials. Depending on this, the value of the slope angle is selected.
The dependence of the roofing material on the degree of slope
In addition to the fact that the device for the slope of a flat roof is directly dependent on the type of material used, this parameter also affects the amount of thermal insulation. If, for example, the slope angle is small, then more thermal insulation will be required, since moisture from the sloping roof is not in a hurry to leave.
For the arrangement of the roof, different materials are used. This includes slate (asbestos-cement, cellulose-bitumen sheets), metal tiles, roofing material and other options. Let's consider the most common.
metal tile
This material has considerable weight when compared with other analogues. Therefore, it is important to correctly calculate the slope of the roof. This is especially critical for areas with frequent and strong winds and hurricanes. In this case, the slope angle should be as low as possible.
If you choose too high a slope of a flat roof, it will swell, which will entail an increase in the load on the supporting structure. As a result, the roof may collapse prematurely.
As a rule, for such a roof, the optimal slope angle will be 27 degrees. Then the roof will reliably protect the house from moisture. The minimum value is 14 degrees. When using soft material, the slope angle can be reduced to 11 degrees. Only the roof in this case needs additional crate.
Decking
This material is considered the most popular for the construction of the roof. It is lightweight yet strong enough to meet the many requirements of property owners. Installation is not difficult, and you can handle it on your own, with the support of your loved ones.
With regard to the requirements for the slope of a flat roof, SP 17.13330.2011 (set of rules) allows you to build a roof from an angle of at least 8 degrees and with a batten pitch of 40 cm (grade H-60, H-75). However, the material grades S-8, S-10, S-20 and S-21 allows a slope angle of not more than 15 degrees. The step of the crate in this case is from 5.0 to 6.5 cm, but sometimes a solid construction is used.
Nevertheless, an indicator of 8 ° is the minimum value that suits the roofs of utility or industrial buildings. Residential buildings have a minimum threshold of 10°. But as for the maximum slope indicator, there are no special restrictions. For this material, it is possible to build roofs even with a slope of 70 °, even with a large angle.
The optimal value of the slope of the flat roof (the norms will be observed) will be 20 °, which will allow snow and water to drain in a timely manner. Then you will not need much large investments, and the roof can be laid in two layers. Due to this, the risk of moisture seepage through the fasteners will be minimized.
Soft roof
Here, too, there are values of the angle of inclination, if we take into account (like roofing material, ondulin) or modern polymer (membrane) products. As a rule, the value of the angle of inclination is in the range of 2-15°. More accurate indicators depend on the number of stacked layers.
If it is necessary to lay a two-layer roof, the angle value is 13-15 °. The slope of the three-layer coating will already be smaller - in the range from 3 to 5 °. When using modern membrane material, the threshold is even lower - only 2-5°.
In other words, the property owner himself chooses the slope of a flat roof; and rules) are not violated. However, one should take into account the fact that the roof must withstand loads that are not only temporary, but also permanent. The first includes precipitation depending on the season and their weight, gusts of wind. To the second - this is the mass of the roofing material itself, which acts on the supporting structure.
The metal tile is considered one of the most convenient and popular roofing materials. Featuring a high bearing capacity, strength, ease of installation, metal tiles are little subject to mechanical stress. When planning the layout of the material, it is necessary to calculate the correct slope for the metal tile and observe the technological details of installation. Then the roof will serve for a long time and will not require an early renewal.
The slope of the roof is an important defining structure, formed by the angle cut off by the floor plane and the roof slope. The indicator is expressed as a percentage or degrees, calculated by dividing the height of the ridge by 1/2 of the width of the building. The angle of inclination of a roof made of metal tiles is regulated by SNiP and the supplier's instructions. The indicator depends on factors such as:
- Roof covering application.
- The ability of the roof to effectively remove natural precipitation, withstand winds and other climatic phenomena.
- Roofing price.
- The mass of the roofing cake.
A fairly new coating, metal tile, is not so strictly regulated by standards. Therefore, the manufacturer himself often advises the minimum angle indicator, based on the technical characteristics of the product. The calculation is made according to the thickness of the sheet, the bearing capacity of the base and the method of laying the roofing. However, there are optimal values that you should rely on:
- With a slope of 6 meters in length, the minimum slope according to SNiP must be at least 14 °.
- The permissible slope of the roof of metal tiles should be in the range of 14-45 °.
- The optimal value of the angle is 22°, this indicator is sufficient for the normal removal of precipitation with a slope area of less than 6 meters.
The choice of the roof slope is not always simple, therefore, based on the indicators of SNiP, one should take into account the following recommendations for the equipped slope slope:
- The level of snow load in the construction region. To determine the indicator, you need to take information from the directory and calculate the average annual amount in the winter. The thicker the snow cover, the greater the level of slope, otherwise the snow mass will linger on the roof, which will lead to deformation of the sheets.
- Wind load - the indicator also depends on the characteristics of the region. At the maximum intensity of wind flows, the angle of inclination is small, which reduces the windage of the slopes.
Advice! The number of hurricanes, tornadoes and other natural disasters is also taken into account. The information is taken from reference books.
Features of metal roofs with a small slope
The lowest slope angle is 14 °, but experienced roofers lay materials when calculating an angle of 10-14 °. And to ensure the reliability of the roofing carpet and reduce the risk of leaks, the following actions are performed:
- The frequency of the laths in the crate increases by reducing the inter-rafter step.
- The rafter system is strengthened by means of a frequent or continuous crate.
- Significantly increase the number of overlaps! Despite the recommendations of manufacturers for a horizontal overlap of 8 cm, a vertical overlap of 10-15 cm, the overlap increases by the width of the wave. Thanks to this method, the strength of the roofing carpet increases and the risk of leaks on the roof of a small slope is eliminated.
- Carefully seal the joints with a silicone-based sealant.
Advice! All measures taken are temporary, so a visual inspection of the roof once a year will not hurt.
Determination of the roof slope by geometric dimensions or in degrees
The formula for calculating the steepness of the slope for a roof made of metal by size, for example, for a gable roof, is calculated using the following formula: I = H / (1/2L), where:
- I - the desired angle for the metal tile;
- H - the distance from the border of the ceiling to the ridge, that is, an indicator of the height of the rafter structure;
- L - dimensions of the width of the building.
To find the percentage, the resulting index i is multiplied by 100. And for the expression in degrees, you should use the trigonometric function or find the value in the corresponding table:
| degrees | % | degrees | % | degrees | % |
| 1 | 1,7 | 16 | 28,7 | 31 | 60,0 |
| 2 | 3,5 | 17 | 30,5 | 32 | 62,4 |
| 3 | 5,2 | 18 | 32,5 | 33 | 64,9 |
| 4 | 7,0 | 19 | 34,4 | 34 | 67,4 |
| 5 | 8,7 | 20 | 36,4 | 35 | 70,0 |
| 6 | 10,5 | 21 | 38,4 | 36 | 72,6 |
| 7 | 12,3 | 22 | 40,4 | 37 | 75,4 |
| 8 | 14,1 | 23 | 42,4 | 38 | 78,9 |
| 9 | 15,8 | 24 | 44,5 | 39 | 80,9 |
| 10 | 17,6 | 25 | 46,6 | 40 | 83,9 |
| 11 | 19,3 | 26 | 48,7 | 41 | 86,0 |
| 12 | 21,1 | 27 | 50,9 | 42 | 90,0 |
| 13 | 23,0 | 28 | 53,1 | 43 | 93,0 |
| 14 | 24,9 | 29 | 55,4 | 44 | 96,5 |
| 15 | 26,8 | 30 | 57,7 | 45 | 100 |
Important! This type of calculation is suitable for single, double-pitched roofs. For a single-slope, the entire span length is taken into account. In the case of arranging a roofing carpet with an asymmetrical slope, the roof angle is calculated from the distance from the projection point of the ridge element to the ceiling for each slope separately.
The optimal angle for a roof with complex structural elements is taken into account by the correction factor for the projection in the horizontal direction:
- Roof angle 1: 12 (7°) - K = 1.014;
- 1:10 (8°) = 1.020;
- 1:8 (10°) = 1.031;
- 1:6 (13°) = 1.054;
- 1:5 (15°) = 1.077;
- 1:4 (18°) = 1.118;
- 1:3 (22°) = 1.202;
- 1:2 (30°) = 1.410.
Criteria for choosing the angle of inclination
When calculating the angle of inclination of a roof for a metal tile, you need to know that a small steepness has its advantages:
- economical consumption of materials;
- reduction in the weight mass of the roofing carpet, the sheet windage index, which minimizes the risk of defects during heavy winds;
- convenience and simplicity of arranging drainage systems.
But there are also disadvantages, if the slope of the roof is minimal, then:
- it is necessary to seal the joints as much as possible, since the almost complete absence of a drain increases the possibility of moisture penetration through the attachment points;
- it will be necessary to remove snow blockages on the roof more often so that the metal tile is not subjected to increased load;
- the need to equip a powerful crate will require a calculation of the bearing capacity of the base and complicate the fastening of roofing elements;
- under a flat roof, it is not always possible to equip spacious residential / non-residential premises.
But if the slope of the roof is large, for example, 45 °, then, despite the free melting of the snow cover, the mass of the coating is increased, due to which the sheets simply slide off. The way out is to strengthen the fasteners and strict adherence to the installation technology of the roofing carpet. In addition, when the angle of inclination of the metal roof is too steep, the consumption of roofing material increases, as with the arrangement of curly slopes.
In order not to calculate which angle will be better, take as a basis the recommendations of experienced roofers: for shed roofs it is 20-30 °, for gable roofs - 25-45 °. And a little advice: when arranging the lathing with frequent steps, a kind of shock-absorbing cushion is obtained that strengthens the roofing carpet. Knowing the calculation formula, it is easy to calculate different options for the steepness of the slopes and decide which angle to give preference to, depending on weather, climatic conditions and the financial component: whatever one may say, material consumption is less on roofs with a minimum slope.
Loading...