The slope of a shed roof made of corrugated board. What slope should be at the roof of the profiled sheet? The nuances of installing corrugated board

A person who is poorly versed in the intricacies of construction may decide that architects choose the angle of the roof slope from a profiled sheet only for aesthetic reasons. In fact, the slope of the corrugated roof is one of the most important features. When choosing it, be sure to take into account many initial parameters.

What affects the choice of the angle of the roof

One of important aspects, which determines the angle of inclination - a feature of the climate in the region where the building will be built. First of all it is:

The height of the snow mass;
The amount of precipitation;
Rose of Wind;
Roofing material;
The strength of the truss system.

It should be remembered that the water will quickly drain from the roof, and the snow will remain on it longer. One can imagine how much weight the roof must support, given that the level of snow drifts in some regions can exceed 1 m. The more the corrugated board is inclined, the faster the snow mass will descend from it.

When choosing the angle of the slope of the corrugated board, you should take into account the parameters of the materials used that you have chosen for the roof. Example: bearing profiled sheet with a high wave can be used even on the flat roofs of the mall. Wall or universal metal profile, suitable only for roofs with a large angle of inclination.

Important! If the slope of the roof does not exceed 12°, the horizontal seams should be treated with sealant to prevent water from entering under the joints.

The calculation of the angle of inclination of the roof from a profiled sheet

When calculating the slope of a roof from a metal profile, be sure to consider the following parameters:

Weight thermal insulation material, lathing system, counter-lattices and other layers of roofing materials.
The weight of the corrugated board itself.
The load of snow drifts in your area.
Wind load.

Calculations according to the schematic drawing

Take the classic gable type of roof as an example. As seen in the figure, BUT equal to the angle of inclination of the left slope, IN- right. Then, in order to carry out the calculation, it is required to find out the height of the roof equal to h and the length of the horizontal section of the slopes from And d.

If the roof is symmetrical, from And d will be equal and to subtract them you will need to divide the walls 50 * 50.

Example: according to the schematic drawing, the sides of the roof are symmetrical, which means the angles BUT And IN- the same. We are trying to calculate the angles according to the existing example.

Today, in the vast market for roofing materials, profiled sheet has gained great popularity. It is successfully used in both industrial and private construction. The professional flooring besides high operational characteristics has also beautiful view– possibility to order a sheet right size greatly facilitates its installation. The only thing is that you need to observe the correct slope of the roof from the profiled sheet.

Consideration of the minimum slope is necessary not only from the standpoint of seeing the image of the future home. This issue is also relevant in connection with the climatic conditions of the area of the proposed construction.

Advantages of profiled sheet as a roofing material

Let's mark it right away
- high strength,
- operational reliability,
- ease,
- aesthetics.
It can be used with a slope of at least 8 ° (1: 7) according to SNiP. The slope of the roof in this case does not allow rainwater to overflow through the waves of corrugated board. The same applies to the effect of snow load. This is a significant advantage, since it allows covering work to be carried out all year round despite the vagaries of nature. Profiled sheets are adapted for use in adverse conditions. He is not threatened with corrosion after rain, as well as burnout under the rays of the sun.

This construction material widely used to cover large pitched roofs. The increased rigidity of the ribs prevents it from deforming, it is durable and economical.

Basic rules for roof construction

The method of laying the material when installing the profiled sheet on the roof to a large extent determines the slope of the roof from the corrugated board. When working with it, you should adhere to certain features of laying and operating rules.

What should be the slope of the roof

The minimum slope of a roof from a profiled sheet for residential buildings is considered to be - 12 °, -20 ° is considered optimal, and from a corrugated board for industrial buildings it is, respectively, - 8 °.

These limits may change depending on the number of layers laid down. For example, if laying is carried out in two layers, then the slope must be increased in order to prevent various sediments from accumulating at the joints of the profile sheet. To protect them from precipitation, the joints are coated with a hermetic filler.
- In the case when the slope of the roof is less than 14 °, then when laying the overlap of adjacent sheets in the horizontal direction should not be less than 20 cm.
At the junction with the valley and the ridge, sealing is carried out using special profiled seals. Such a gasket does not allow precipitation to fall under the roof elements during severe weather, such as heavy rain. When it is installed like this, a gap is left sufficient for air movement.

It should be especially noted that in the process of roof overlapping with an angle of inclination of 12° or less, the joints of horizontal and vertical overlaps of profile sheets are sealed using silicone sealant.
- 15–30°, overlap is required in the range from 15 to 20 cm.
- More than 30° - allowed overlap from 10 to 15 cm
How the profiled sheet is attached to the roof structure

For fastening corrugated board to roof structures made of wood, special self-tapping screws for roofing are most suitable, which are made at the end with a drill and equipped with a neoprene gasket. Unlike here, the fastening is carried out only at the bottom of the wave.

The self-tapping screws used are 4.8 x 35 mm. To fix the skates in the upper part, larger self-tapping screws are used, 8 cm long. You should also take care of vapor and waterproofing, and the presence of a gap that provides ventilation for the space under the roof. These requirements are mandatory.

Which crate to choose

In industrial and industrial facilities, the roof is usually flat or shed. For flat roofs, load-bearing corrugated board is used, having a profile height starting from 4.4 cm. It is welded onto a metal frame. Then an unexploited flat roof is arranged over it.

For pitched roofs, they mainly take a profiled sheet, the profile height of which is not less than 3.5 cm, and the sheet thickness is about 0.6 / 0.7 mm.

It is important to know that the higher the profile, the more load it can withstand.

The size of the crate determines the wave height of the used sheet and the slope of the roof from the profiled sheet.
- If corrugated board of the C20 brand is used for work, then with a slope of less than 15 °, a continuous crate is performed, and the overlap of the sheets is in two corrugations.
- With an angle of less than 15 ° and the material used is C35, it is recommended to choose a step of 30 cm for the crate, with an overlap in one wave. In some individual cases, a step of 65 cm is allowed.
- Another brand of profiling sheet - C44 and more. In this case, the distance between the laths is increased to 500 mm, possibly more. If the steepness of the slope exceeds 15 °, the structure for the sheets is performed in increments ranging from 350 to 500 mm, depending on the height of the corrugation of the corrugated board.
- With any slope of the roof, it is also supposed to arrange drainage system, which will be "responsible" for the correct removal of precipitation and excess moisture from the roof surface. Its inclination must be organized so that when installed internal system catchment area, it was directed towards funnels for receiving water, or in the direction of gutters, if there is an external catchment area. It is also important that the optimal slope of the roof from the profiled sheet is ensured.
- When organizing a slope of up to 10 °, it is recommended to lay special membrane coatings that are able to reliably protect the roof from moisture and damage to materials.
It is important to know that if the slope of the roof decreases, then the ventilation gap must be increased accordingly.
- When installing profiled sheets, you must follow all the requirements for laying conditions, fastening spacing and the recommended overlap size. In particular, they are mounted with an overlap on the base to ensure that the under-roof space is protected.
Neglect of any of the required criteria can lead to disastrous consequences.

In order for the roof to reliably protect the house and last as long as possible, when erecting it, it is necessary to take into account at what angle in relation to the house itself it will be built. In this case, the climate, the wind rose, and the abundance of precipitation in the populated area where the house is being built have a great influence. But the material that will serve as the roof is also of no small importance.

First of all, it should be noted that corrugated roofing is ideal if the length of its slope is less than 12 meters. When laying corrugated board on the roof, it is important to comply with all the requirements of SNiP, in which a wall, universal profiled sheet is recommended for use, as well as a profiled sheet for ceilings and with a wave height above 20 mm. When choosing a profiled sheet, it is necessary to comply with its polymer coating climate features.

It has already become a rule to measure the angle of inclination of the roof in degrees or percentages:

One degree equals 1.7 percent, and 45 degrees equals 100 percent.

The higher the angle of inclination of the roof, the less snow will exert pressure on it in winter, and the water will drain faster in summer. However, the influence of the wind rose (in other words, the windage of the roof) increases significantly. If the slope of the roof is insignificant, then the influence of the wind will decrease, but the load on the roof from precipitation will increase accordingly, which means that you will have to think about ensuring reliable sealing and water resistance of the roofing material.

Depending on the climatic conditions in which the house is being built, the angle of inclination is taken into account. Where there is a lot of rainfall, it is best to make the roof at a 45 degree angle so that raindrops or snow do not linger on the roof. If the terrain is dominated by dry and warm days, then the angle of inclination should be made minimal (in the case of corrugated board 8 - 10 degrees). The same slope of the roof will be appropriate in areas where storm winds are possible.

For material such as profiled sheet, SNiP recommend a slope of 20 degrees (36.4 percent). This is the ideal slope for a profiled sheet. But the roofs on the houses are made different and their angle of inclination is not always 20 degrees. Therefore, there is a minimum permitted roof slope for each material chosen for the roof, including profiled sheets.

The minimum degree of roof slope angle from corrugated board for industrial or outbuildings is 8 degrees (14.1 degrees), for residential buildings - 10 degrees (17.6 percent). If the roof is laid in several layers (for example, two), then these figures will increase, that is, the angle of the roof slope must be increased in order to prevent moisture from accumulating at the joints of the corrugated board.

The smaller the slope angle, the wider the overlap of the sheets will have to be, which will reduce the effective area of \u200b\u200bthe material. So, for example, with a slope of 35 gr. the overlap should be equal to 15 cm, from 15 to 30 gr. - 20 cm, less than 15 degrees overlap are two waves of the profiling sheet, and its joints (both longitudinal and transverse) can be sealed.

Calculations for calculating the angle of inclination

To make calculations to calculate the angle at which the roof will be tilted, an inclinometer is often used - a device specially designed for this. But it is possible to make calculations on your own, armed with knowledge of trigonometry.

This is where the right triangle formula comes in handy. The legs will represent the gap between the ridge and the floor and the gap between the cornice slope and the center of the floor. The hypotenuse is the slope of the roof measured in a straight line. Having learned these distances and applying a trigonometric function to them, it is possible to easily calculate the smallest value of the angle of inclination of the roof.

By dividing the height of the ridge by the length of the bevel, we obtain the sine of the angle of the roof slope. Using calculations on the calculator, its value is determined in degrees (percentage). If it is more convenient to use the cosine or tangent functions, then the correspondence of ½ of the overlap width and the length of the roof slope or the height of the ridge and ½ of the overlap width is applied.

note

Calculating the slope angle for a corrugated roof is the most important thing in terms of its durability. The wrong slope angle and after the first strong gust of wind your house may simply lose its roof!

If you want to avoid such a fate, then you have come to the right place. In this article, we will help you determine minimum slope corrugated roofing. If it seems to you that an architect is guided only by aesthetic considerations when planning the roof of a house, then you are mistaken. Roofing system is very complex, because it takes into account a lot of nuances and a successful solution is achieved by careful selection of data and calculations.

In this article

What affects the slope of the roof from the profiled sheet?

When building a house, one of the main points to consider is the climate of the environment. These are moisture and windiness and the volume and frequency of precipitation. To determine the desired slope of the roof, you need to take into account three climatic factors:

Snowfall level;
Frequency and intensity of rains;
Wind speed and direction.

I see little point in separately describing the impact of these factors on the roof. It is much more productive to explain how this effect depends on the angle of the roof slope. For example, snow, as the heaviest precipitation, exerts great pressure on roofing material. Therefore, it is undesirable to stay there for a long time. In this case, a reasonable solution would be to erect a steep roof, from which the snow of the critical layer will slide under its own weight.

The second determining factor is the type of material. The slope will depend on how you install the profiled sheet. shed roof from corrugated board. For example, wall and universal profiles are poorly suited for sloping roofs, for such profiled sheets with a large wave height are much better suited and vice versa.

When choosing a corner, also do not forget that from roofs at a small angle, water will not drain so quickly and in heavy rain, leaks at the junctions will be possible. The angle of inclination should be at least 12 degrees, then you can not worry about this problem. If the angle is smaller, then the joints must be additionally sealed.

Last but not least, the factor is the amount consumable and complexity roof structure. The smaller the angle, the more load goes to the truss system and more material is consumed due to the overlap of the sheets. This point requires more detailed consideration.

The dependence of the amount of overlap of sheets on the angle of inclination

The minimum slope of the roof from the profiled sheet is 12 degrees. With it, there is no need for additional sealing and you should not worry about leaks. But at the same time, in the interval between 12 and 14 degrees, there remains one more binding necessity. This is an increased overlap of sheets. For corrugated board and its economical use, optimal slope 15-30 degrees is considered.

This table clearly demonstrates the dependence of the overlap size on the angle.

Yes, the material consumption is higher, but this is a quantitative indicator, but what about quality? With quality, the situation is identical: due to the fact that with a small slope of the corrugated roof, the material must be of the highest quality, because the sheet has a large load. And the sharper the angle, the less the load on each individual sheet, and the cheaper the profiled sheet is allowed.

The rafter system, with an increase in the angle, grows upward due to the rafters themselves, however, the load on them is diluted with additional structures. With a minimum roof slope, the rafters can be shorter, but technically complex additional struts become indispensable.

As you can see, set flat or close to flat roof from corrugated board can be completely unreasonable.

How to calculate the slope of the roof?

The calculation must necessarily include the following components:

The weight of the battens, counter battens, insulation and other layers of the roof;
Roofing weight;
The level of snowfall in the region;
Wind speed and direction in the region.

To give you an idea of the calculation process, let's take profiled sheet C21-1000-0.6 as an example. The mass of a square meter of this model is 5.4 kilograms. The next step is the miscalculation of the heat-insulating material. In our example, these will be basalt slabs 100 mm thick and with a density of 150 kg per cubic meter. The mass of a square meter will be 15 kg. The crate of pine timber will tighten approximately 28.3 kg per square meter and other components weigh 3 kilograms per square meter.

We add up all these components and get 5.4 + 15 + 28.3 + 3 = 51.7 kg / m².

Advice! To leave yourself room for maneuver, the resulting coefficient must be multiplied by 1.1. With this calculation, you will be able to freely change some of the materials of the roofing cake.

We will do the same, and as a result we will get a roof mass of 56.87 kg per square meter.

The next stage is the measurement of wind speed and snowfall in the region. On the Internet, it is not difficult to find a map of the snow load on the surface of the Russian Federation. Similarly, a wind load map is also available.

Our hypothetical house will be in the third snow region with a snow load of 180 kg per square meter. This figure refers to planes, for inclined surfaces there is a special coefficient µ. For angles less than 25 degrees, it is equal to 1, for angles from 25 to 60 there is a formula µ: (60-a) * (60-25), in which "a" is the desired roof slope. For roofs with an angle greater than 60 degrees, the snow load is not taken into account.

Wind load is calculated using the formula W=Wn*Kh*C. In it, Wn is the average wind load in the region, Kh is the building height coefficient and C is the aerodynamic coefficient from -1.8 to 0.8, depending on the slope of the roof. Our load is 23, C is 0.8, and Kh is found from the following table:

Total 23*1*0.8-18.4 kg/m2.

We add up the mass of the roof and the wind load and get 56.87 + 18.4 = 75.27 kg / m2. The second most important figure is the maximum allowable weight for our sheet. With a support step of 1.8 m, it is 253 kg per square meter.

If the slope is less than 25 degrees, the mass of the snow load will be equal to the average for the region, that is, 180 kg. Then 180_75.27-255.27 kg/m2 0 the mass of the roof with all possible loads is greater than the maximum bearing capacity for the sheet. Then the desired angle is between 25 and 60 degrees.

This adds the coefficient µ to our formula and the level of the slope of the roof from the profiled sheet lends itself to such a calculation:

180*(60-a)*(60-25)+75.27=253

The result of this equation is the angle a we need. It is 25.441 degrees, it can be rounded up to 26 - this will be the minimum slope of the corrugated roof. By the same calculation, by the way, you can calculate the angle of inclination of a shed roof.

Use the formulas indicated in the article and build correctly!

At the design stage of any building, whether private house, or an industrial structure, a correctly chosen angle of inclination of the roof slopes from a profiled sheet (profiled sheet) will maximize wind resistance, achieve rapid removal of snow, water, and also find a compromise between the amount of materials used and the durability of the corrugated board. In this article, you will find out what the minimum roof slope from a profiled sheet can be installed, especially when installing a roof under different angles and calculation of the allowable angle of the planned roof.

Source profiroof.com

Reason for the need for a minimum slope

Any not flexible roof has a minimum angle to the horizontal surface of 10°. On the example of corrugated board, this is understandable due to the possibility of rainwater getting between the joints of the roof, stagnation of a large amount of snow on the roof surface. There are no strict limits on the maximum angle, however, roofs with steep slopes, where the angle of inclination is more than 60°, are less wind resistant.

Source belhouse.by

The concepts of angle and slope, minimum angle according to SNiP II-26-76 *

The angle, measured in degrees, shows the slope of the slope from the horizontal surface, and the slope, measured in percent, the ratio of two legs of a right-angled triangle, vertical to horizontal, formed by one slope and the base.

Based on building codes and rules Russian Federation for the roof of SNiP II-26-76, the minimum angle of inclination of the roof from corrugated board installed on the roof of residential buildings is at least 10 °, or with a slope of at least 17.6%.

Source obustroeno.com

The minimum slope of a shed roof made of corrugated board for a canopy is 8 °, this value is also applicable to industrial and household buildings.

The dependence of the angle on the magnitude of the vertical overlap and the distance between the boards of the crate

When designing a roof and calculating necessary materials, it is important to understand that the smaller the angle of inclination of the slope, the greater will be the overrun of materials. With a roof slope of corrugated board of no more than 12 °, it is necessary to leave at least 20 cm of the profile for vertical and horizontal overlap. In this case, it is necessary to use a sealant to seal the joints between corrugated sheets, both with horizontal sheets and with vertical ones. As the angle increases above 12° no sealant is required and the distance required for overlapping decreases.

Source centr-krovlya.ru

The maximum distance between the boards of the crate increases with increasing angle. Since on roofs with steep slopes (with an angle of more than 30 degrees) it does not linger rainwater and, especially, snow, the installation of a solid crate is not required.

Source legkovmeste.ru

An important role in calculating the cost of arranging the roof is played by the thickness of the profile profile of the corrugated board. Sheets with the smallest thickness of the profile pattern up to 20 mm, with an inclination of less than 15 °, require a base in the form of a continuous crate, which entails additional costs.

Below is a table showing the dependence of the thickness of the profile picture, the angle of inclination and the pitch of the crate.

Profile drawing thickness * - this size is indicated in the name of the profiled sheet, for example, S-8, MP-20, NS-35, etc.

Source otdelka-expert.ru

Calculation of the permissible slope of the roof from corrugated board

To calculate the allowable slope, you need to know the following components.

bearing capacity selected brand of corrugated board.

Roofing cake weight(insulation, crate, rafters).

Wind and snow load.

To calculate the permissible slope of the corrugated board to the horizontal, it is necessary to know its bearing capacity. Examples of bearing capacity for several grades of corrugated board according to the second support scheme are given below:

More detailed information about the maximum load of various brands of corrugated board can be found in the description of the characteristics of this roofing material.

The weight of the roofing pie is taken based on specifications components, for example:

Source pinterest.com

In total, we get the weight of the roofing cake equal to 58 kg per 1 m².

Details that will help solve the problem of sealing roof joints

On our website you can find contacts of construction companies that offer services roof design and repair. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

Wind load, calculation

The greatest danger to roofing with profiled sheets is wind and snow. It is not uncommon for entire roof slopes to be torn off when a strong gust of wind occurs. The accumulation of snow can deform the corrugated board, weakening it by the onset of the summer season. An avalanche-like fall of snow can lead to damage to the car, or injury to the tenant under the eaves.

When designing a roof, it is important to know in general features local climate, detailed wind rose and wind pressure value, winter precipitation, snow load.

Source absolut35.ru

Paying attention to the map of wind pressure zones of the Russian Federation, you can see that the greatest wind pressure is created mainly in coastal zones, off the coast of the Black, Caspian, Barents Seas. Whereas in the continental part of Russia, with the exception of the highlands, the wind pressure reaches no more than 42 kg/m².

Source cryptopia.ru

In order to calculate the wind load acting directly on the roof, it is necessary, in addition to knowing the calculated wind pressure, to have the value of the coefficient that takes into account aerodynamics, which is often taken as a maximum of 0.8, and the altitude coefficient, depending on the height of the building and the openness of the territory.

Thus, when calculating the roof, for example, in the Tver region in an open area, for a house 9 meters high, the wind load will be: 32 * 1 * 0.8 = 25.6 kg / m²

The previously calculated weight of the roofing cake is added to this load: 25.8 + 58 = 83.8 kg / m²

Snow load, calculation

The snow load map of Russia shows the weight of the snow cover on a horizontal plane. The largest number snow cover falls on the mountainous regions and the central part of Russia.

Source dom-krovly.ru

It is not guaranteed to calculate the minimum angle of inclination of the roof from corrugated board for snow melting, however, a slope of 30 ° or more will allow the roof to remain clean even with moderate precipitation.

Taking the Tver region for calculation, the amount of snow cover will be 240 kg / m². This value must be multiplied by the correction factor µ, which takes into account the expected slope of the roof.

The coefficient µ is equal to 1 when the slope is less than 25 degrees.

The coefficient is calculated by the formula (60 - α) * 35, if the expected angle is from 25 to 60 degrees.

The roof angle is 60 degrees, the coefficient is 0, the pressure created by snow is not taken into account due to the absence of snow retention on the surface of the corrugated board.

Having decided on a roof installation angle of 30 °, the snow cover pressure will be 205 kg / m².

The final part of calculating the angle of the roof slope from corrugated board is the comparison of the maximum load of the metal sheet of corrugated board H60-845-0.8 to the total load created by wind and snow loads.

This calculation allows, subject to all the selected conditions, the possibility of installing corrugated board at an angle of 30 degrees.

In general, for most territories of the Russian Federation, the most rational may be the construction of roofs with slope angles from 25 to 40 degrees. Roof slopes located in areas of strong winds should not be built with angles of more than 25 degrees. The optimal range starts from 15 to 25 degrees. Installing roof pitches with a minimum slope of corrugated roofing in areas of strong winds can create lift and tear off metal decking.

Source zen.yandex.ru

Video description

In the video you can see the roof from a profiled sheet with a slope:

Conclusion

Building the roof of your own house is an expensive part of construction, however, understanding the basic requirements and characteristics associated with the angle of inclination of the roof slopes covered with corrugated roofing will help you accurately assess the rationality of the services offered, give confidence in the choice and, possibly, save some money while saving quality.