The construction concept of "slope" is associated with the slope of the roof. This is the angle of the slope to the horizontal surface. A smaller degree of angle makes the roof slope steeper. The calculation of the angle is based on the principle: the height of the ridge board is divided by 0.5 of the width of the room, as a percentage - multiply by 100. Visually: we divide the width of 20 m and the height of 5 m and get 0.5, multiply by 100 and get 50%.
The minimum angle of inclination is affected by the climatic conditions of the area. A slope of 30 degrees is used in regions with heavy precipitation. In arid areas, roofs are built with a slope of 10-25 degrees.
Building material - metal tile - is used in the construction of buildings of various complexity. Exception - the minimum angle of inclination for a metal tile is from 14 degrees, no less. Such a slope is able to withstand strong gusts of wind, unlike snow, which cannot roll down such a small slope.
Minimum slope allows you to save on building materials. Reliability and a solid foundation of the roof will create a wooden crate, a small distance between its boards will make the fastening of the metal tile strong.
A few tips for setting and coordinating the minimum roof pitch
- Layers of metal tiles should be laid on a perfectly flat surface, the height of the row cannot be more than one meter
- Take layers should be in construction gloves that protect hands from damage
- You need to hold the layer by the edges
- Securely fasten the metal tile to the crate with construction screws
- Walk on the roof of metal tiles in special soft shoes that do not damage the surface of the roof, do not step on the waves of tiles
- Cutting metal tiles should be carried out according to a preliminary scheme, measuring the right dimensions sheets
Preliminary Processes:
- The truss system must be completely ready. We measure slopes
- We eliminate the existing errors of the triangular shape with additional details
- It is recommended to get rid of moisture between the metal tile and the insulation layer thanks to the crate (height 0.4 cm)
- We leave gaps of 0.5 centimeters in the cornice sheathing
- We lay waterproofing on the rafter boards. From the edge of the cornice board, the waterproofing should have a sag of 0.2 centimeters. We lay the waterproofing joints with an overlap of 15 cm.
- We insulate the roofs with special plates. We lay them between the rafters
- We apply the next layer - vapor barrier
Detailed introduction to the video in the next tab.
Lathing installation
Sheathing is an important element of the roof. It is installed on the truss system. Consists of identical boards. They are pre-treated with an antiseptic solution. The distance between the boards lying on the edge of the cornice is 30-35 centimeters, the next - 35-40 centimeters. The metal tile is attached to the crate on the troughs of the waves.
A drainpipe is screwed to the cornice board, providing a uniform flow of rainwater. The cornice is installed on the edge of the metal tile roof with flat-head self-tapping screws. The coincidence is built with an overlap of an average of 7 centimeters. A solid crate is used near the chimney. The valley is installed in the internal joints of the roof (overlap - 10-15 centimeters).
Additions for the installation of the roof and the arrangement of its minimum slope
Roof installation involves a complex process, and it is simply impossible to avoid important nuances:
- It is impossible to mount a metal tile in the upper bend of the wave
- Self-tapping screws are not tight
- Don't use a hammer
- Screw in self-tapping screws with a special lining
- When cutting metal tiles, you need to use electric scissors or other special tools (do not use a grinder)
- Do not use construction foam
The slope of the roof is formed due to the structure of the rafters, it is they who create the angle. For details on installing the roof and setting its minimum angle, see the video in the next tab.
Tiles - roofing material made of fired clay, plastic or metal.
The metal tile is considered one of the most reliable and durable materials, due to its characteristics, such as wear resistance, practicality and decent appearance. Thanks to her, it is possible to update the old roof. To do this, you do not need to remove the used materials - on the contrary, they will serve as additional waterproofing. For proper installation, the minimum slope of the roof from the metal tile is calculated.
Metal roofing is one of the most durable and strong materials.
What is a slope?
Many people have a question, what is a bias. Slope - the angle of inclination of the slope to the horizon. The larger the angles, the steeper the roofs. To calculate the slope, you need to divide the height of the ridge by 1/2 of the width of the building, and to express this value as a percentage, multiply it by 100. For example, with a building width of 10 m and a ridge height of 4 m, the slope will be: 4: 5 = 4 / 5 = 0.8. To express as a percentage, multiply by 100: 0.8*100=80%.
Installation instructions will be incomplete without some rules. It is strictly forbidden:
- fasten the metal tile to the upper deflection of the wave;
- excessively tighten the screws;
- use hammer;
- use nails and self-tapping screws without gaskets;
- use mounting foam as ridge and valley seals;
- use an angle grinder such as a grinder.
Electric cutting is used for sheet cutting. nibblers or metal shears. Steel shavings and other debris are removed only with a soft brush. To protect the sheet from corrosion, it is necessary to immediately paint over all scratches found during installation with special paint. Three months after the start of operation, it is necessary to tighten all mounting screws.
Our vast country is located in different climatic zones. If in the Far North and the Far East there is a strong wind and snow, then in the South of Russia there may be rain and wind. You need a very responsible approach to the choice of roofing material and the calculation of the slope of the roof of your house. The most practical is the choice of metal tiles because they are inexpensive, durable and beautiful. But it depends on the expected wind load and, typical for your region, precipitation. So what should be the minimum angles of inclination of your metal roof? This question must be answered.
In modern construction, a wide variety of roofing materials are used, but metal tiles are deservedly considered one of the most popular materials. In many countries, such material as tiles has long been manufactured. Therefore, the use of metal not only reduces the cost of the final cost of the product, but also serves as a harmonious continuation of ancient traditions. The high technical characteristics of metal tiles include:
- the use of galvanizing the sheet and its coating with durable polymer paints in order to impart anti-corrosion properties;
- wide choice of color architectural solutions;
- manufacturability and ease of installation of the roof, which does not require the use of special tools and devices;
- the lightness of the material, which allows it to be mounted at high altitudes and in conditions of complex truss structures;
- no heavy load on the rafters due to the light weight of the sheet;
- with a relatively thin sheet, it can withstand fairly large loads, since it has stiffeners.
All of these properties make it possible to use this coating in difficult climatic conditions. To calculate the amount of material, you need to know the minimum angle of inclination of the metal roof.
How to determine the angle of the roof in your area
To calculate the strength of the roof structure and the amount of material needed, you need to know the optimal one. A number of factors must be taken into account, including:
- projected number of slopes;
- used roof space;
- Economy indicators;
- structure weight.
It would seem that the steeper the slope, the better, but this leads to an increase in material consumption and increased weight, as well as to a large wind load on the structure. Therefore, there is such a thing as the optimal angle of inclination of a roof made of metal.
A slight slope, about 10-12 degrees, has its drawbacks, which require an increase in the rows of the crate and reinforcement of the rafters, due to the increased snow load. In addition, you should take care of improved waterproofing and the need to increase the overlap of sheets. This is done to prevent leaks at the joints with gentle slopes. Roofs of this design are best suited for the southern regions, where the snow cover does not have much weight, and the average annual temperature is not too low. In the summer, sloping roofs warm up less, which creates comfortable living conditions in the home.
Steep slopes, ranging from 30 to 45 degrees, are more suitable for regions with lower temperatures and frequent snowfalls, but one must take into account the increasing wind load on the roof and the building as a whole. It is also important to take into account the strength characteristics of metal tiles, which are laid down by the manufacturer of the material. It is necessary to fasten the sheets, in the case of steep slopes, more often than usual, because they are prone to slipping under the influence of gravity. The greater the angle of inclination of the roof, the more time-consuming during installation and less economical it will turn out.
What is the optimal angle of inclination of the roof recommended by the manufacturers of this building material? After the tests, enterprises producing metal tiles recommend using it when the slope is from 11 to 45 degrees. In this case, the most acceptable is the angle of inclination from 12 to 22 degrees. Building codes and regulations do not give clearly expressed recommendations on this matter, but the preferred, with a slope length of about 6 meters, is an angle of inclination equal to 14 degrees. We have come to the choice of the most economical way to cover the roof, which is determined by such a concept as the minimum slope of a metal roof.
What is the minimum slope and how to determine it
Depending on the climatic zone, architectural design and aesthetic preferences of the owners of the dwelling, the following types of roofs are erected:
- a multi-gable roof with a complex and slender design;
- vaulted roof as an element of national culture in architecture;
- hip roof, complex four-pitched structure;
- hipped roof, a combination of isosceles triangles;
- gable roof, widespread and time-tested;
- the roof is shed, used mainly for technical and utility rooms or as an element of a more complex structure.
Multi-gable and vaulted roofs are not suitable for the use of metal tiles, which are used only in the elements of these structures. Whereas hip roofs are quite widely used in and are characterized by the choice of minimum slope angles ranging from 22 to 45 degrees. The hipped roof is used as a decorative element, and the angle of inclination of the isosceles triangles is in direct proportion to the area covered by the hipped roof. This structural element is very economical to manufacture, and the angle of inclination ranges from 35 to 45 degrees.
One of the most popular roofs, gable. The manufacturer recommends observing the minimum angles of inclination of the roof in the range of 12 to 14 degrees. Given the harsh climate, it can be recommended to expand these limits from 14 to 22 degrees of slope. It is with such characteristics that the roof resists well to possible strong winds, and also represents an almost monolithic structure that prevents the penetration of moisture into the under-roof space of the building.
For shed roofs, the minimum angles of inclination range from 11 to 14 degrees, since large angles of inclination create the risk of the roof falling off during multidirectional wind gusts. In the climatic conditions of Russia, it is necessary to adhere to the minimum slope of the slopes from 14 to 22 degrees. When building in a flat or mountainous area, it is necessary to take into account the landscape and the wind rose, depending on the season.
In choosing the type of roof, the taste preferences of each person play a decisive role. Everyone wants to build a house so that it is beautiful, comfortable and serves for many years. The roof crowns the building and it receives special attention because it not only decorates, but also protects from the effects of an aggressive environment. In order for it to serve for many years, you need to properly design it and build it correctly. And to save money, you need to choose the right slope of this roof for metal tiles, taking into account the climatic conditions of your region.
- Why the roof should not be too flat
- The minimum allowable and optimal slope for metal tiles
- Design features truss system
- Installation of metal roofing
- What materials and tools will be needed
- Assembling a warming cake
- Installation of metal tiles
The minimum angle of inclination of roofs made of metal tiles is one of the most important parameters, which must be taken into account when developing a project for a truss system at home. A reliable and durable roof will be obtained only if the standards recommended by the manufacturer are observed.
Why the roof should not be too flat
There is a direct relationship between the final cost of the roof and its angle of inclination. The position of the slopes, the less material is spent on the installation of the truss system and the assembly of the roofing pie. However, the angle of inclination of the rafters cannot be made very small. Otherwise, too much snow will accumulate on the roof in winter. If the load exceeds the maximum allowable values, the roofing may simply not withstand. In addition, very sloping roofs made of metal tiles on private houses in most cases do not look very harmonious. It is impossible to arrange a comfortable attic or attic under them.
Today, in private housing construction, a roof made of metal tiles is popular. In order for it to serve for a long time and successfully withstand various loads during operation, the size of the slope of the roof made of metal tiles must have optimal values.
Characteristics of metal tiles
This roofing material has the following features:
- Insignificant weight within 5-7 kilograms per "square". With the help of metal tiles, you can equip roofs that differ complex shapes designs. At the same time, there is no need to additionally strengthen the truss system in case of replacement of the coating material. Such tiles do not exert a significant load on the foundation of the building and load-bearing structures.
- Ease of installation allows home craftsmen to lay roofing on their own, because this does not require the use of special equipment.
- Thanks to the widest selection color design metal tiles, it is possible to choose a shade of material that will not violate the integrity general view Houses.
- The coating, made of steel sheets with a thickness of 0.4 to 0.7 millimeters, has the ability to withstand severe loads due to the presence of a profile.
- The metal tile is qualitatively protected from corrosion processes due to galvanization and an additional polymer layer applied on top of the sheet.
- This modern roof covering combines durability, affordable cost and aesthetics.
Features of the choice of material
When choosing products and when drafting a roof structure, it is necessary to take into account some nuances, including the minimum allowable angle of the roof slope from a metal tile.
This indicator depends on:
- choice of roofing;
- structural device of the truss system;
- the ability to withstand the weight of snow, depending on the climatic features of the region;
- the ability to quickly and completely remove precipitation from the surface of the roofing.
The small value of the minimum slope of the metal roofing is due to the rigidity inherent in profiled steel sheets and the slight surface roughness that has a protective polymer layer. Such a coating can easily withstand the effects of precipitation.
Factors affecting the determination of the slope angle
There is no unified size for the angle of inclination of a metal roof.
The value of the minimum slope is influenced by a number of factors that should be considered when drawing up a project, namely:
- The amount of rainfall. The best solution is to install the slopes at a slope of at least 22 degrees. If the angle of the roof for the metal tile is made smaller, then sealant cannot be dispensed with, since it is necessary to prevent moisture from entering the roofing cake at the junction of the sheets of material.
- roof shape. The recommended slope for a single-slope version is 20 - 30 degrees, and for a dual-slope 20-45 degrees.
- Wind loads. To calculate this indicator, you will need to know the surface area of \u200b\u200bthe roof, and in addition, the wind strength characteristic of a particular region. We should not forget about the possibility of natural disasters. Information about this can be found in reference books.
- Snow loads. In winter, snowdrifts often accumulate on the roofs of houses, which, under the force of their weight, slide down. Roofs with a slight slope should be cleaned regularly to prevent damage. roof structure under heavy snow loads. The steeper the slope of the roof from the metal tile, the faster the layers of snow slide off it. To find out the average annual rainfall, use reference books.
Specialists, working on a roof project, lay down a certain strength margin so that during operation there is no deformation of the tile if the amount of accumulated snow is much higher than the average.
The choice of the minimum angle of inclination of a metal roof during design is influenced by the presence of a heating pipeline, thermal insulation near the building and a roofing carpet. In cases where the roof structure is not sufficiently insulated, large losses of thermal energy occur through it. As a result, the snow lying on it melts, and the moisture under it either freezes or flows down.
When the slope of the roof for a metal tile has been determined before thermal insulation, the likelihood that the coating will not withstand significant snow loads increases significantly.
Minimum roof pitch
Based on the standards prescribed in SNiP, the length of the slope should be 6 meters, and minimum slope roofs for metal tiles - 14 degrees. These values were calculated by specialists taking into account the strength of the material of manufacture and its resistance to various loads.
When designing roofing systems, the recommendations of the company that produces this roofing product are certainly taken into account. Most often, manufacturers indicate that the minimum slope for metal tiles is 12 degrees.
Some enterprises have launched the production of material that can be mounted on roofs with an 11-degree slope. Changing this parameter in the direction of reduction became possible due to the improvement in the characteristics of some tile models. Such products are distinguished by a high degree of material rigidity and have a smoother sliding surface.
The dependence of the roof slope on the weather conditions in the region
By the way, a roof made of tiles with minimum size the angle of inclination is allowed to be used in those climatic conditions where an insignificant amount of precipitation falls during the year. In this case, a small slope allows the roof to effectively withstand wind gusts, but at the same time snow loads increase, since the mass of snow does not sink down.
A roof with a minimum slope will be best solution for areas where many sunny hot days are recorded throughout the year. Since such a roof has a smaller area, which means that it does not warm up so much, this circumstance contributes to a comfortable microclimate in the premises of the house.
The minimum angle of inclination for metal tiles allows you to save on the purchase of materials for the construction of the roof structure and the arrangement of the roofing carpet, since they are needed less than when building a roof that has a steeper shape.
A roof with slopes having a minimum angle for metal tiles will be practical and inexpensive option construction for regions with a hot climate, in which the average annual amount of precipitation is low.
If you do not adhere to the slope recommended by the manufacturer, then the roofing will not be able to provide the building with reliable protection against moisture penetration, and in regions with heavy snowfall, there is a risk that such a metal roof can collapse at any time.
The optimal size of the slope of the roof with metal tiles
The roof coverage area will be the greater, the greater the slope angle. At the same time, the roof, which has steep slopes, is not able to hold precipitation on its surface, and they quickly and almost completely roll down to the ground.
True, high roofs have an increased windage and during their arrangement it is necessary to purchase more building materials for the construction of a system of rafters and roofing. Thus, the steeper and higher the roof, the more expensive and more difficult the construction will be.
Due to windage, it is not recommended to build high roofs with a metal tile coating with a significant angle of inclination in climatic zones where strong winds are noted - this parameter affects the ability of the roof structure to resist loads.
To increase the strength of a roof with a slight slope, it is customary to make more frequent lathing, which will simultaneously strengthen the rafter system and give it additional reliability.
For gabled roofs, metal tiles are not entirely suitable. If the slope angle is greater than 45 degrees, then the sheets of material may slide down. To prevent this from happening, it is necessary to provide for additional fixing them to the crate.
Manufacturers of this roofing material taking into account the long-term practice of arranging roofs, it was determined that the optimal size of the roof angle for metal tiles is 22 degrees. Thanks to this design, moisture quickly leaves the roof without lingering on it.
The roof, which was erected with an angle of inclination of 22 degrees, is durable and copes well with serious wind loads. The arrangement of such a roof is relatively inexpensive.
The calculation of the optimal slope can be called the search for a compromise result, taking into account the strength of the roof structure. It should also be remembered that the tiled roof must match the architectural appearance of the building.
Choosing the right slope angle for a roof is not only an aesthetic task, but, to a greater extent, a practical one. Indeed, the performance of the coating, the protection of the building from atmospheric influences - first of all, precipitation, the durability of the structure and the consumption of materials will depend on this parameter. The minimum slope of a roof made of metal tiles, due to a number of features of the material, has greater value than for other materials and less flexible.
First of all, you should decide what a slope is, and why it is needed at all and how to cover the roof with a metal tile. The slope is the angle between the floor plane and the rafters.
It is calculated using a common fraction as follows:
i = h: (1/2L), where:
i - slope
h - the height of the ridge above the ceiling
L - the width of the building, or the width distance covered by this section of the roof (for broken roofs, where the slope can vary within one slope)
For example, with a building width of 8 m and a ridge height of 3 m, the slope will be: 3:4 = 3/4, or 0.75. To express as a percentage, this value is multiplied by 100: \u003d 75%
However, the angle is sometimes expressed in degrees - both systems have equal circulation.
At the same time, in degrees, the actual geometric value of the slope is displayed - the angle between the rafters and the ceiling.
These values do not match, which often causes confusion and errors - among the builders, and sometimes - among the compilers of the instructions.
Knowing the sides of the triangle, it is not a problem to translate one value into another.
However, for those who do not like to bother with calculations of metal roof tiles, there are special translation tables, such as the following:
| Degree | Percent | Degree | Percent | Degree | Percent |
| 1 | 1,8 | 16 | 28,7 | 31 | 60,0 |
| 2 | 3,4 | 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 | 8,8 | 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 | 19,4 | 26 | 48,7 | 41 | 86,0 |
| 12 | 21,2 | 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 |
Although the roof is designed in conjunction with the entire building, there is still some room for maneuver until the truss system is created, whether the roof slope is calculated from metal tiles, slate, or any other material.
If the foundation and walls have a certain margin of safety, then, at least within the same roofing material, the shape and slope of the roof can be varied.
Since the width of the building is a fixed value, and the length of the rafters is determined by the distance between the ridge and the place of support on the wall, the ability to change the angle of the roof remains only the height of the ridge.
When the owner of the building has determined which slope he considers optimal for himself, the following table will help calculate the height of the ridge
To get the result, you need to take half the width of the overlap, find the desired angle in degrees in the table, and multiply it by the coefficient in the corresponding line.
The resulting value will be the required height of the skate. All these calculations are also applicable to a shed roof - but then they need to take not half the width of the roof, but the full one, and instead of the ridge, the height of the largest of the outer walls will appear.
The same is true for hip (four-pitched) roofs, but in this case, the slope of the end slopes is measured from the middle of the wall to the point where the slope rests on the end of the ridge.
To display the desired height of the skate "in place" there is a simple way. It is necessary to put marks on each of the outer walls along which the slope will go (it is better that they are in the center of the length of the walls).
A cord is sequentially pulled between opposite marks, you can beat off a line along it with chalk. Exactly in the middle of the cord (measured with a tape measure), you need to install a bar perpendicular to the overlap (checked with a corner).
Now, by moving the twine up the plank, you can measure the angle against the wall to determine in which position the twine will achieve the required slope. At this point, a mark is placed on the bar.
If you now saw off the rail in this place, you will get a template that will allow you to cut without problems right amount ridge supports of the required size.
If the supports are not supposed, then the same operation can be carried out from each of the ends, fix the measuring rails, and pull the cord along their top. He will indicate the desired height of the joining of the rafters.
What is the slope of the roof? Two groups of factors can be distinguished - positive and negative, to which its increase leads.
Positive:
- Rain falls on the roof at a large angle, which virtually eliminates the possibility of falling between the elements of the coating, as well as under the overhang
- With large slopes, the snow load on the roof is reduced, and at angles of 45 ° it is not taken into account at all. Eliminates the need for a snow retention system
- The main power load on the roofing material goes “on a shift” in the direction of the slope, which is handled quite reliably by standard fasteners - nails and self-tapping screws
- Possibility of creating under-roof spaces, attics of a larger area and with more correct geometry
Negative:
- Increased consumption of roofing material - for example, changing the slope from 15° to 45° on a simple roof will increase the required coverage area by more than 20%
- The increasing weight of the roof - after all, both the mass of the coating and the supporting structures will increase
- Large windage, and, accordingly, wind load
- The complexity of the organization of the drainage system - on running meter the sewer pipe accounts for a large area of the roof, the flow of water through it descends from more speed. It is not a fact that for any slope it will be possible to select the appropriate section of the gutter tray - and this will require a drainage device in several tiers
Ultimately, the truth is somewhere in the middle - and here each homeowner is tied to his climate zone,financial resources and other factors.
But, if a metal roofing device is chosen, the manufacturer's instructions impose certain restrictions.
Different companies have different allowable values - from 12° (and even - 10°) to 15°.
Since the material is relatively new, there are no SNiP requirements for this parameter for it. But practice suggests that nevertheless this angle should be at least 14 °.
If the manufacturer does not stipulate special restrictions on the maximum angle, it can be accepted by anyone.
However, the "average" angles in terms of snow load are the most inefficient. It has been experimentally proven that in winter time snow accumulates most actively on roofs with a slope of 20-35°
This value is determined by the specifics of the material. The strength of the metal tile is its flexibility, which allows you to form quite complex structures with a roof made of metal tiles with your own hands.
But this is also its weakness, because with a small slope, or a large snow load, even a powerful carrier system does not save.
For example, the installation of a valley when roofing with a metal tile is carried out along a continuous crate. However, even this does not save at small laying angles.
After all, since the groove is the inner junction of the slopes, and in winter, the formation of snow pockets is possible here. The increased mass of precipitation presses on the metal and bends it, opening access to the under-roof space.
In the event of a thaw and subsequent cooling, frozen water fixes and expands the cracks, contributing to further leaks.
A small slope contributes to the same effect in heavy rain - the water does not have time to go down the slope, and exerts high pressure on the roof. Metal tiles with a large wave height are less susceptible to this - its bending strength is higher.
The entire metal tile is a directional material, that is, it can be mounted in only one position. Therefore, at the bottom of each sheet is placed a special rubber compressor, which somewhat reduces the effect of precipitation.
However, with intensive exposure, sealing should be carried out at least once every 3 years, otherwise it cannot be avoided. overhaul roofs.
But the flexibility of the metal tile also affects its resistance to wind loads - if they are directed into the plane of the sheet and fall on a reliable crate - there will be no problems.
But if gusts hit from the bottom or side end, creating a tearing effect, sooner or later the material will bend or tear off. Therefore, the protrusion beyond the edge of the crate is made so small - 40-50 mm, and the wind slats are attached both from the ends and from the eaves.
Summing up all the factors, we can say that the minimum slope required by the installation instructions for a metal roof is an ideal value, assuming that all requirements for installation technology will be impeccably met.
By setting a greater bias, you will, of course, have to spend money on an increased amount of material. But at the same angle of 45 degrees, you can save on installing expensive snow retainers, and be calm about possible excessive snow and rain loads on the roof, getting under the wind overhang and blowing rain spray there.
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, you should calculate the correct slope for the metal tile and observe technological subtleties 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 specifications products. 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 number in winter period. 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 gable roof calculated according to 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 one-, gable 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 a correction factor for projection in the horizontal direction is taken into account:
- 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 in practice complete absence 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 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 the recommendations of experienced roofers as a basis: for shed roofs is 20-30 °, for gable - 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 variants the steepness of the slopes and decide which angle to give preference to, depending on the weather, climatic conditions and the financial component: whatever one may say, on roofs with a minimum slope, material consumption is less.
The angle of inclination of any roof significantly affects its reliability and tightness. The minimum slope of a roof made of metal tiles, according to the requirements of SNiP, must be in the range of permissible values. Failure to comply with this rule may lead to a number of irreparable consequences. Roofing made of metal tiles has a number of characteristic features associated primarily with the specifics of this material.
Metal tile as a roofing material is very popular. It can be used for arranging roofs with various geometric shapes. It does not exert a large load on the structure. Installation of a metal tile is absolutely not difficult and within the power of any roofer. A diverse range of colors of this material is very convenient when creating any design. When choosing it, it is necessary to take into account the slope of the roof.
The concept of slope and its calculation
The slope is directly the angle of the roof in relation to the level of the horizon. When carrying out roofing work is a fairly significant factor. The angle of inclination of any roof is calculated as follows. The calculation can be seen on the example right triangle. For example: the width of the building is 10 meters, the height of the gable in the ridge is 3 meters.
Side c - ½ width. So a=3, c=4. From the secondary school program tg A=а/с. Total tgA=0.75. We look at the table of tangents on the Internet. The angle is 37 degrees. The SNiP directly prescribes the values \u200b\u200bof the minimum angle of inclination of the roof, taking into account the type of material and climatic conditions. Given the requirements of SNiP, the minimum roof slope, with a slope length of 6 meters, is 14 degrees.
What affects the choice of slope angle
The slope of any roof is designed to prevent the accumulation of snow or rainwater on the roof. There are no unified slope angles. Many factors influence the minimum slope. They must be taken into account when designing a structure. This is first of all:- type of truss system;
- climatic features;
- roof configuration;
- the purpose of the attic space;
- appearance building;
- financial opportunities to perform roofing work.
climatic factors
The angle of inclination of the slope is chosen, as a rule, taking into account the climatic conditions of the area where construction is underway. Namely, depending on the amount of precipitation and wind speed in the area.- The wind load is calculated taking into account the surface area of the roof. At the same time, it will be useful to foresee the strength of the wind and the possibility of cataclysms associated with it. Too steep a roof, as a rule, increases windage and may not withstand strong wind loads. Experts calculated that with a roof slope of 45 degrees, the wind force on it is 5 times higher than the wind load acting on a roof with a slope of 11 degrees. For the installation of such a roof, more material will be needed, which will undoubtedly hit the owner's pocket. If the slope is too slight, a gust of wind can demolish the roofing material.
- In winter, snow accumulates directly on the roof slopes. At a certain slope, it slides down. If it is small, then the roof will have to be cleaned to avoid damage to the truss system. Taking into account SNiP, the roof projection must be carried out with a mandatory margin of safety, in order to avoid possible deformation of the metal tile. The steeper the angle of the roof, the less opportunity for snow layers to stay on it. But at the same time, the weight of the roof will be greater due to the increase in the amount of roofing material. With a large angle, the problem of installing a multi-tiered drainage system also arises. The difficulty is that per unit length of the sewer pipe there are quite large plot roofs. Since the water drains very quickly, it is more difficult to choose a pipe with the desired cross section. The only way out is to install a drainage system in several tiers. And this is an additional financial cost.
- A significant factor influencing the choice of the minimum angle of inclination of the slope is the quality of the heating of the house and its thermal insulation. If the thermal insulation of the roof is of poor quality, then snow does not accumulate on the slopes, as it will thaw and slide down. However, with good thermal insulation, accumulations of snow cannot be avoided.
The minimum slope requires the installation of additional waterproofing to prevent moisture penetration. To do this, a layer of silicone sealant is applied to the joints.Even in advance, when purchasing a metal tile, you should pay especially close attention to the recommendations of its manufacturer. As a rule, he recommends designing a slope angle of 12 degrees. There is a more durable material with the possibility of mounting and at an angle of 11 degrees. Such a metal tile is made with a smoother surface, which contributes to good sliding. If you do not take into account the recommendations of the manufacturer and perform a roof with a lower angle of inclination of the slope, then as a result of heavy snowfall, there may be a risk of roof collapse. The minimum slope angle is typical for regions with a warmer climate, where the amount of precipitation in the form of snow and rain is minimal. At the same time, the roof perfectly resists large wind loads.
This design is especially relevant for areas in which the number of sunny days per year reaches a maximum. Since the roof area with such a slope is less, then its heating in summer time creates less discomfort for the residents of this house. Moreover, with a smaller roof area, a smaller amount of metal tiles will be consumed. And this is a pretty good option to save the budget. Since there are no strict requirements in SNiP as to what the minimum slope of a metal tile roof should actually be, then it must be chosen according to the recommendations of the manufacturer of this material. As a rule, its value varies between 11 and 15 degrees. Its increase brings additional expense metal tiles. Excessive reduction requires additional waterproofing and installation of additional structures for reinforcement. Therefore, the optimal solution to this problem is to choose the average value. We recommend watching the video
