Roof slope drawing. How to choose the optimal roof angle for snow melting? What are the advantages of pitched roofs

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:

1. 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 °.

1. 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.

1. 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.
2. 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 applied 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.

Roofs made of metal tiles are a practical and popular solution for the construction of private low-rise buildings. This roofing material is characterized by high bearing capacity, resistance to mechanical damage, external environmental factors and heavy loads. The durability and reliability of the finish coating depend not only on quality, these characteristics are influenced by the design of the roof, including the correctly selected minimum slope. In this article, we will tell you how to choose the right slope angle and check it for compliance with SNiP.

The slope of the roof is an important design parameter, which indicates the angle formed by the plane of the floors and the roof slope. This indicator is expressed as a percentage or degrees. It is calculated as the result of dividing the height of the ridge by half the width of the building. The angle of inclination of the slope depends on the technical and operational properties of the material and is regulated by SNiP and the manufacturer's instructions. Depends on it:

1. The possibility of using one or another type of roofing.
2. The design, composition and section of the elements of the truss frame.
3. The ability of the roof to effectively remove rainfall.
4. Roofing cost.
5. Roofing cake weight.

Note! If the slope of the metal tile roof is increased from 22 degrees to 45 degrees, the slope area will increase by 20%, which will affect the cost of materials (finishing, waterproofing, insulation, wood), as well as the weight of the structure. It is necessary to decide on the optimal angle of inclination during the preparation of the project in order to correctly determine the load on the foundation.

Optimal values

Roofs made of metal tiles are a relatively new constructive solution, therefore the technology of its installation and operation is not clearly regulated by SNiP. Information about what the minimum roof slope should be is provided by the manufacturer, since this indicator directly depends on the technical characteristics of the material itself. This indicator is calculated in accordance with the thickness, bearing capacity and method of laying the roofing.

• According to SNiP, the minimum angle of inclination of a metal roof, if the slope is 6 meters long, must be at least 14 degrees.
• The permissible slope for a metal roof is in the range of 14-45 degrees.
• The optimal angle of inclination, which ensures the effective removal of precipitation with less mercy on the slopes, should be 22 degrees.

Important! The minimum slope of a metal roof, which manufacturers allow, is 11 degrees. Some grades of material can be laid even if the slope is 10 degrees. The reduction in this indicator has made it possible to achieve the use of new, smoother polymers and stronger steel for the production of roofing.

Slope selection

It can be difficult for a non-professional builder to correctly choose the minimum angle of inclination of a metal roof. This indicator, in addition to the requirements of SNiP and manufacturer's recommendations, is influenced by other factors that must also be taken into account. When choosing the steepness of the slope, the following is taken into account:

Please note that the choice of the steepness of the slopes depends on the design of the roof. The optimal angle of inclination of the slopes of a shed roof made of metal is 20-30 degrees, and a gable roof is 20-45 degrees.

Features of roofs with a small slope

The minimum recommended slope angle of a metal roof is 14 degrees, however, experienced craftsmen can lay this type of roofing material with high quality, even if the slope of the slopes is in the range of 10-14 degrees. To increase the reliability of this design and reduce the risk of leaks, the following measures must be taken:

1. Increase the frequency of the battens and reduce the pitch between the rafters. To minimize the risk of roof collapse due to intense snow load, it is necessary to strengthen the truss frame of the structure and mount a frequent or continuous crate.
2. Increase overlaps. Manufacturers recommend that when installing metal tiles, make a horizontal overlap of 8 cm, and a vertical one of 10-15. To eliminate the possibility of leakage in structures with gentle slopes, you can increase the overlap at the joints of the sheets.
3. Isolate joints. To prevent the penetration of melt and rainwater between the joints of the sheets, it is possible to treat the seams with silicone sealant, although this measure has a limited duration.

Experienced craftsmen say that the easiest way to make a reliable metal roof is to follow the manufacturer's recommendations and strictly observe the recommended angle of inclination.

Video instruction

In modern private construction, gable roofs are very popular because they are easy to install and economical in cost, and they can also be built independently. The angle of inclination of gable roofs is one of the indicators of both reliability and aesthetic appeal of the future home, so it is of paramount importance.

gable roof

The correct choice of the slope of the slopes, chosen in compliance with building codes and technological features, will maximize the protection of the building from adverse weather conditions, as well as optimize financial costs.

The angle of a gable roof in construction is usually understood as the slope between the line of the rafter leg and the horizontal level coinciding with the wall of the building. It is measured in degrees. Less common is the percentage measurement of the slope of the slope, which is calculated by formulas based on the ratio of the sides of the triangle in percentage terms.

According to the slope of the slope, all roofs can be divided:

It is believed that the standard or has a slope of 45 degrees, however, this design requires more reliable fastening, since it has an increased windage and is not suitable for every terrain.

In construction practice, flat roofs with angles ranging from 0 to 45 degrees are more common. The only exceptions are the lower parts of a broken gable roof, in which the slope is 60 more degrees.

Often, during construction, the owners set the slope of the roof, as they say, “by eye”, guided solely by aesthetic considerations. This is a risky decision, as it not only increases the likelihood of premature wear, but also eliminates the possibility of optimizing both usable roof space and material costs.

Factors to Consider When Calculating Roof Pitch

When designing the overall design of a gable roofing at home, the choice of the optimal slope of the slopes must be given special attention, since both the functionality of the roof and its reliability will depend on this.

In doing so, the following factors must be taken into account:

1. .
   Different types of roofing material

   
   Each type of roofing differs not only in installation technology and weight, but also in recommended minimum installation angles, including:

   
   An example of a metal roofing material for a roof

   
   
   

   Coating type	Minimum angle value in degrees	Peculiarities
   Ruberoid and other roll materials	4	This slope is acceptable when laying in three layers. For a single layer coating, the minimum value is 25 degrees.
   Soft bitumen roof	4	The upper limit is 15 degrees, since in hot weather there is a possibility of slipping of the roofing.
   Folded steel sheets	5	It is not recommended to make such a coating on slopes with a slope of more than 30 degrees.
   Ondulin	6	For laying on flat roofs, continuous purlins are required.
   profiled sheet	12	At a minimum, additional sealing of joints is required
   metal tile	14	It is better to lay on less sloping slopes to prevent wind blowing off the coating.
   Slate	20	Smaller slopes may cause water leakage.
   natural tile	22	It is recommended to lay on steeper slopes in order to reduce the load on the truss system, since the tiles are of considerable weight.

   
   
   
   
   

2. The functional purpose of the roof space.
   With a natural desire is to make the most of the under-roof space and, as a rule, they equip living quarters there. With a different slope of the slopes, the usable area may vary in height and width.
   It is believed that the best solution for a dwelling will be a slope in the range of 30 to 45 degrees.
   It should be noted that even with such a slope, the attic area will be small. An alternative option would be to make a gable roof of a broken type, which allows you to make the most of the under-roof space.

   Broken roof drawing

3. Average snow load.
   This factor is also of no small importance, since snow lying on the roof after a snowfall significantly increases the pressure on both the coating and the truss system and increases the likelihood of roof collapse.
   For areas with heavy snowfalls, it is recommended to install roofs with a slope of 35-40 degrees. The current angle will also be a slope of 45 degrees, since with this arrangement the snow cover is blown away by the wind, such roofs are called self-cleaning.
   The relationship between the angle of a sloping roof and the amount of snow on it

   

4. wind weather conditions.
   in open areas with strong winds, it requires a decrease in the angle indicator in order to reduce the windage of the roof and prevent the roofing from being torn off.
   On the other hand, too little slope increases the risk of tearing the entire truss system from the building.
   Therefore, the recommended slope of the corners for houses built in areas of high winds and hurricanes is 30-42 degrees.

   Wind load on the roof

It should be noted that a roof with steep slopes will cost more than a flat one. However, technical characteristics should be decisive when choosing a slope, since they affect the safety and durability of the structure.

Calculation of the angle of a gable roof

In order to calculate the optimal angle of inclination of a gable roof, you must perform the following steps:

After analyzing all the data received, you can decide what will be the optimal angle for the gable roof of a particular house. Video tutorial on finding the height and slope of the roof.

Calculating the Angle of a Custom Gable Roof

The types of gable roofs are not limited to the classic type or the one that forms an isosceles triangle from the pediment and the slopes have the same slope.
Other types that have a more complex design, but for which the calculation of the angle of inclination of the sides is also relevant, are:

To design a complex roof online, the calculator will be the best way to calculate the slope angle of each of the slopes, since it allows you to quickly calculate and optimize this indicator based on input data, such as:

Depending on the type of roof and the program, the data required to enter may differ in the presence of additional parameters.

The advantage of using online calculators is that by changing the input parameters, you can choose the best option for a particular building.

If you do the calculation of a complex roof manually, then you need to take into account the following main points:

1. Broken roof.
   The main purpose of this type of roof is to increase the useful area of ​​​​the under-roof space, which is provided by steeper lower slopes and a sloping upper part.
   
   
   The optimal angles for the top are 30 degrees and the bottom 60 degrees. This combination of slopes makes a gable sloping roof aesthetically attractive and functionally convenient.
   Examples of a gable sloping roof

   
   
   

2. Roof with different lengths of slopes.
   Often, this option is resorted to when it is necessary to place premises of different functional purposes under one roof, for example, in this case, the slope of a longer slope will be much less than a short one.
   In this case, it is advisable to calculate a short slope according to the standard method, and calculate the angle of the second side mathematically based on the height of the ridge and the length from the point corresponding to the projection of the ridge to the end of the slope.
   
   
   A multi-angle roof requires careful selection of the roofing material to ensure that both roof pitch angles are within the allowable range of the particular material. If this is not possible, then it is necessary to position the building on the ground so that the longer slope is on the leeward side, while it is recommended to focus on the weather service data on the wind rose in the area.
   Examples of roofs with different lengths of slopes

   

3. Various levels. Such a structure of a gable roof has recently become more and more popular, since it expands the possibilities of organizing internal space, and also allows you to use energy-saving technologies to the maximum.
   An example of roofs with a multi-level slope

   
   Two types of different levels of coverage can be distinguished:

   • with the same slope slopes;
   • with different angles of inclination.

   The principle of calculation for any of the types is the same as in the previous versions.
   

The variety of design options for gable complex roofs suggests a flexible approach when calculating the slopes of the slopes in each individual case, but the principles of calculation should remain unchanged.

Thus, the angle of a gable roof is an important indicator when designing a roof, since the durability and safety of the building will depend on it.

A correctly calculated roof with your own hands will be a guarantee of future comfort, as well as optimal financial costs for construction.

In order for the roof of a building to be able to fully perform all the functions assigned to it, it is necessary to take into account a number of parameters when creating it. One of the most important parameters of the roof is its slope, which ensures the removal of atmospheric precipitation from its surface and affects the ability to withstand external loads. How to calculate the slope of the roof, and will be discussed in this article.

Determining the slope of the roof - what it depends on

In order to correctly calculate the roof slope, several factors must be taken into account, among which the following stand out the most:

1. Wind loads. The slope of the slopes is very strongly influenced by the wind. In order for the roof to be able to normally resist its effects, you need to choose its angle correctly. At too large angles, the load on them will be high, but an excessive decrease in the angle can also be dangerous - a sloping roof can simply be torn off by a strong gust of wind.
2. Snow and rain loads. With snow, everything is quite simple - increasing the angle of inclination simplifies its convergence from the roof surface. With a roof slope of more than 45 degrees, snow will hardly linger on it. With a small angle of inclination of the roof, a snow bag may appear, which increases the load on the roof. With rainfall, the situation is the same - if the angle of inclination of the roof is too low, then water can flow into the joints or even stagnate on the roof surface.

Based on these factors, you can calculate the angle of inclination of the slopes. In addition, before calculating the angle of a gable roof, you should pay attention to the recommended indicators: for areas with strong winds, a slope of 15-20 degrees is suitable, and in other cases, the optimal slope is 35-40 degrees. Of course, you need to understand that the calculation of a gable roof is individual, and it is simply undesirable to choose average indicators.

Calculation methodology

When designing a roof, it is imperative to carry out a number of calculations, among which there should always be a calculation of the angle of inclination of the slopes. This parameter directly affects the roof structure: with an increase in the slope, the snow load decreases, but the effect of the wind increases, so the truss system has to be further strengthened. For the arrangement of slopes at a large angle, more materials are also required, which negatively affects the cost of construction.

Before you know the degree of roof slope, you need to calculate the operational load on the roof, which requires two parameters:

• The total mass of the roof structure;
• Peak levels of snowfall typical of the region where the construction is taking place.

A simplified calculation algorithm is reduced to the following steps:

• First you need to determine the weight of one square meter of roofing cake;
• The resulting value is multiplied by the total area of ​​​​the roof;
• The mass of the roof is multiplied by a factor of 1.1.

An example of calculating the roof slope in degrees

To understand how to calculate the angle of the roof, it is worth considering the calculation process using a specific example. For example, the following data will be taken: the crate has a thickness of 2.5 cm, one square meter of the roof weighs 15 kg, a 10 cm thick insulation is used as a heat-insulating material, a square meter of which has a weight of 10 kg, and ondulin with a weight of 3 kg is used for coating per square meter.

The calculation of the roof slope is carried out in accordance with the method described above. Substitution of the available data leads to the following expression: (15+10+3)x1.1 = 30.8 kg/sq.m. The resulting value is quite acceptable - the average load on the roof of residential buildings is slightly less than 50 kg / sq.m. In addition, the formula contains a coefficient of 1.1, which slightly increases the actual weight of the roof structure and allows you to replace the roofing with a heavier one in the future.

How to find out the angle of the roof

There is a direct relationship between the slope of the roof slopes and the snow load. If the angle of the roof is less than 25 degrees, then the snow load factor is 1, and at angles ranging from 25 to 60 degrees, then this factor increases to 1.25. A roof with a large angle of inclination will not be subject to snow loads at all, so they are not taken into account in the calculations.

To determine the angle of the roof, you need to use the Bradis table and a simple technique: the height of the roof structure is divided by the length of the gable, divided by two, after which it remains to find the angle in the table that corresponds to the result obtained.

The height of the roof in the ridge is determined as follows:

• The first step is to calculate the width of the span;
• The resulting value is divided by 2;
• To make a calculation of the height of the ridge, the result of the previous calculation is multiplied by a factor corresponding to a certain angle of inclination.

For example, the implementation of such a calculation technique looks like this: with a building width of 8 meters and a 25-degree roof slope, the calculation coefficient is 0.47. As a result of substituting the values, an expression of the following form is obtained: 4x0.47 \u003d 1.88 m. The resulting value is the roof height corresponding to the available initial data.

The choice of roofing depending on the slope of the roof

On the market, roofing materials are present in a large assortment, so there will be no particular problems with choosing the right option. Roof coverings differ in characteristics and application possibilities, and all their parameters must be studied before measuring the roof angle - only in this case it will be possible to create a reliable and effective design.

When choosing a material for a roof, it is worth starting from the following recommendations:

1. If the angle of inclination of the rafters is from 2.5 to 10 degrees, then stone chips or gravel coatings are best suited. In the first case, the top layer of the coating has a thickness of 3-5 mm, and in the second - 10-15 mm.
2. With a slope of more than 10 degrees, the best option would be coarse-grained or rolled materials, supplemented with bituminous waterproofing.
3. For the arrangement of pitched roofs with an angle of inclination of not more than 20 degrees, corrugated board or sheet asbestos cement is usually used. All seams and joints between roofing materials must be treated with sealant.
4. If the angle of inclination of the roof is in the range of 20-60 degrees, then it is most often covered with metal sheets. Joints of materials in this case must be sealed without fail.

Conclusion

Knowing how to find out the angle of the roof in degrees will greatly simplify the design process and allow you to create the most reliable structure that can well protect the building box from precipitation, wind and cold.

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 the document SP 17.13330 SNiP II-26-76, which is called the "Code of Roof 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.

As for 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.