a - one of most commonly used roof structures that have two inclined planes separated by an edge - a ridge.
The slopes can be either identical, creating in cross section an isosceles triangle, and different ones, having different angles of inclination and area.
In addition, it is common attic structure gable roof, when the slopes consist of two planes with different angles of inclination.
This design allows more effective use the attic space for commercial or residential purposes.
The main advantage of gable roofs is considered simplicity of construction and reliability in operation, absence or small number of valleys or grooves that facilitate the accumulation of water or snow.
The design as a whole ensures optimal distribution of the weight of the rafters and roofing on the walls, contributing to the maximum service life of the roof.
Read in detail about how to make a gable roof yourself.
During its service life, the roof is constantly experiences stress of various kinds. The problem is not their availability - this issue is easily solved strengthening. The point is the diversity and unevenness of these loads.
Constant and unchanging- the weight of the roofing pie and the roof itself, they create continuous pressure on elements due to its weight. Additional factors include wind load and the weight of precipitation.
NOTE!
These factors dangerous due to their unpredictability and a large spread of values.
If moderate winds of a certain direction prevail in the region, then a single gust of hurricane force can cause significant damage or completely tear off the roof. IN winter time If there is an abnormally large amount of snow that has fallen, the load on the roof may exceed permissible values, which is fraught with deformation or violation of the integrity of the coating and the formation of leaks.
Such natural manifestations can only be combated with preventive measures:
Choice correct angle tilting the slopes is one of the most effective methods of neutralizing harmful effects on the rafter system. It allows you to reduce snow pressure by preventing its accumulation, adjust the wind load by reducing the roof windage and ensure the drainage of rainwater, preventing it from freezing at night in the autumn.
Wind loads on rafter systems
From the point of view of saving material and reducing the roof windage, 
the angle of inclination of the slopes should be minimal.
At the same time, a roof that is too low will retain large masses of snow or prevent the effective outflow of water.
But most main criterion the choice of inclination angle is .
Its characteristics determine the optimum based on the following indicators:
Based on these parameters, for each type roofing material there are their own ramp slope limits. Simplifying somewhat, we can say that materials with a smoother and waterproof surface allow the smallest angle of inclination, while materials that are rougher and absorb water require a steeper inclination. Basically, they predominate values from 20° to 45°.
Dependence of angle on angle and roofing material
First of all, you need to decide what an angle of inclination is. This is the angle between the slope plane and the horizontal.
The slope of the slopes is usually measured in degrees or percentage. If everything is clear with degrees, then percentages are obtained from the ratio of the height of the ridge above the ceiling of the upper floor to half the width of the building.
The use of percentages is introduced for simplicity - complex trigonometric calculations fraught with errors, and dividing one quantity by another is easier and more accurate. However, they often resort to help Bradis tables, to find out the exact value in degrees.
When calculating the angle of inclination of a broken slope, values related to the areas being determined are used. This applies both to the width - the part that is covered by the roof section is taken into account - and to the height above the ceiling.
All subsequent calculations are made for each section separately; output and use some the average value is not possible.
This applies to both the determination of loads and power load-bearing elements, as well as calculating the required amount of material.
How to measure an angle gable roof
It is necessary to immediately determine the correct understanding of the term “minimal”. This refers to the smallest permissible value of the roof inclination angle, taking into account wind and snow loads.
It is at this point that many difficulties lie. : indicated values in different regions are very different from each other, so you need to know the average annual precipitation, volumes of snow and its high-quality composition(wet snow is much heavier than dry snow and may cause destruction incorrectly calculated roof).
In addition, you should be aware of the prevailing winds, their strength and direction and, most importantly, the presence of periodic hurricane-force wind gusts in the region.
CAREFULLY!
Ignore such extreme weather events for reasons of “maybe it will blow over” under no circumstances is it possible, since one single case is capable destroy the entire roof.
Considering these circumstances, the minimum angle can be defined as smallest value, declared in SNIPs, adjusted for climatic conditions. Experts definitely consider for pitched roofs at least 20°, which applies only to non-residential or unused attics.
Finding the minimum angle
The angle of a regular gable roof lies within 20°-45°, which corresponds to the spread of values of material properties and average climatic parameters.
The angle of inclination of a gable roof is important indicator , affecting the durability and integrity of the entire building, and it cannot be treated as a secondary factor.
Taking into account all possible loads, both permanent and one-time extreme, will help ensure safety and comfort of your home.
More exact values are selected based on factors such as:
The optimal angle of inclination of a gable roof
In the process of designing the construction of a private household Special attention is given to the roof. When determining the angle of inclination of a corrugated roof, the ratio between the height roofing structure and its total area. The size of the free space in the attic depends on this, whether there will be problems with the accumulation of snow masses and whether the roof will be blown away by the wind.
According to the provisions prescribed in building codes and regulations, this type of roofing can be laid when the slope is inclined at least 8 degrees. Only with this angle of the roof made of corrugated sheets can precipitation not penetrate through the joints and holes for screws. In this case, the installation step of the sheathing should be equal to 40 centimeters.
But 8 degrees is the minimum angle of inclination of a corrugated roof for industrial and utility buildings, but for residential buildings this figure is 10 degrees. If you plan to install the roof in two or more layers, then given value there will be more.
For this reason construction organizations provide a guarantee for the work performed, provided that the corrugated sheeting was laid on the roof with a slope of at least 12 degrees. As for the maximum angle, it is in in this case can be up to 70 degrees or more.
Therefore, SNiP when installing corrugated steel sheets recommends choosing 20 degrees as optimal tilt for the roof slope. But in some cases it becomes necessary to make the roof almost flat, for example, on a gazebo or outbuilding.
Roofs, depending on the angle of inclination, are:
Today best choice The slope of the roof slopes is considered to be between 38 and 45 degrees.
But the minimum slope of a roof made of corrugated sheets in degrees is 8. When you need to equip a roof with an even smaller slope, then you need to change the design principle. This means that the profile decking is placed at the bottom of the roofing pie as the ceiling of the building.
The main advantages of constructing roofs with such a slope are as follows:
When arranging the roof of a house, its owner needs to know: the greater the angle of inclination, the higher the ridge and the heavier the roof structure. As a result, a significant load is placed on the walls and foundation. With a minimum angle of inclination this problem does not arise.
A slight slope of the slopes leads to the fact that water rolls off them more slowly; moisture has time to find the slightest cracks between the joints and, as a result, seeps inside the roofing pie.
The threshold in this case is considered to be an angle of 12° - at this point it is still possible not to apply additional measures regarding sealing. Therefore, when constructing flatter roofs with a slope of less than 12°, the places where overlapping profiled sheets are laid must be treated with special roofing sealants.
The type of roofing material that can be used when arranging the roof depends on the choice of slope. If the slope is small or the roof is flat, then only a supporting profile with a high corrugation is suitable.
On a roof with a steep slope, you can lay wall or universal profile, since minimal pressure will be exerted on the coating. Snow will roll off its surface easily, and water will not linger on it.
In the case when the angle is 12-14 degrees, the consumption of roofing material will increase, since the overlap of the sheets must be larger and sealant may not be used. But when the slope is less, then enhanced sealing is indispensable. Experienced roofers claim that the optimal angle of inclination of a corrugated roof is 15 - 30°.
If the roof angle is insufficient for corrugated sheeting, it is not possible to equip an attic, but it reduces the heat loss of the building through the roof by up to 9%. A slight slope of the roof requires the construction of a more complex rafter system that will be able to withstand heavy loads. The smaller this angle, the large quantity supports need to be installed.
When calculating the slope of a corrugated roof, it is necessary to take into account many important data. First of all, this is the climate in the region where it is planned to build the building. Therefore, it is necessary to find out in advance the depth of snow cover in the area in winter, how much precipitation falls, how often the wind blows and in what direction it predominantly blows.
The fact is that the slope of a roof made of corrugated sheets is determined based on weather conditions in a specific area. The minimum value of this parameter is chosen when the house is built in a region where there are strong wind loads. In these areas, a phenomenon called “roof windage” is dangerous, when its covering is torn off by a powerful gust of wind.
According to SNiP, with a moderate wind load the slope angle should be 35-45°, and with a strong wind load - from 15 to 25 degrees. In areas where strong winds are considered the norm, you need to choose a value close to the minimum slope of a corrugated sheet roof, which will reduce the wind load to the maximum. At the same time, practically flat roofs, assembled from of this material, can be disrupted and therefore the lack of steepness cannot be called the best solution.
Snow load, like wind load, has a great impact on the roof covering. In some Russian regions, huge amounts of snow fall in winter. No rafter structure can withstand this. Therefore, in such areas, so that the snow mass does not linger, the slope is made up to 45 degrees and then reinforcement of the rafters will not be required. Almost no precipitation collects on the steep surface.
For example, in Yakutsk the snow load can reach 550 kilograms per “square” roof area. For this reason, houses there are built with steep and high roofs. Even a small layer of snow weighs quite a lot and, unlike rainfall, it lingers on the roofs, reaching a height more than a meter. In this case, the worst situation is for roofs with minimal slopes.
Professionals calculate the roof slope using special device– inclinometer or using formulas.
There is an easier way - you need to find out the length of the leg and hypotenuse. In this case, the hypotenuse is the straight line of the slope, the opposite leg will be the distance from the ceiling to the ridge, and the adjacent leg will be the segment between the eaves slope and the middle of the ceiling. Then they use trigonometric functions or an engineering calculator.
When determining the slope for a future roof, a number of factors are taken into account:
If there is a need to build an outbuilding, garage or build a shed, then you can make a roof for them yourself. For these purposes, a pitched roof made of corrugated sheets is ideal. This type The design is simple in design and execution, easy to maintain, durable, durable (read: " "). The cost of constructing such a roof is low, and it can be erected in the shortest possible time.
Before installing such a roof, it is important to choose the right slope pitched roof from corrugated sheets, material thickness and load-bearing cross-section roofing elements. This is required to ensure effective removal of precipitation.
Despite the windage of the profiled sheets, single slope type If the roof is positioned correctly, it will be safe even in strong gusts of wind, and special attention is paid to waterproofing.
The size of the slope of the roof of a shed or outbuilding is not chosen arbitrarily, but taking into account the climatic characteristics of the area of residence, the amount of precipitation, the prevailing wind rose, type truss structure, length of slope and roof covering.
If there is no overflow of water between the corrugations, this slope of the pitched roof made of corrugated sheets is minimal.
As a rule, the minimum angle of inclination of a roof made of corrugated sheets with reinforced rafters is built in regions with a warm climate and little rainfall. To reduce the degree of heating of the premises from inside the house, thermal insulation and a ventilated gap are provided in the roofing pie.
On flat roofs, when laying corrugated sheets, you need to use sealing tapes and special mastics to treat joints and overlaps. Such roofs are protected from leaks and damage using waterproofing membranes.
If a roof is being built with a slope of less than 10 degrees, experts advise using a three-layer modern membrane. Only this material can protect roofing pie from penetration of dampness.
If the slope of the roof slope is minimal, it is necessary to construct a drainage system for it. Both moisture and snow are retained on such surfaces, so the slope is designed so that the water is directed towards the funnels, if the system is internal, or gutters, when the drainage structure is external.
With a minimum slope, the corrugated sheeting is laid on the grate and secured with self-tapping screws with rubber gaskets. The smaller the angle of inclination, the greater the amount of overlap of the sheets should be, as a result of which the effective area of the roofing material decreases.
Typically, the rafter system is installed in increments of 60–100 centimeters, but with a minimum slope this distance is reduced to 40 centimeters and then the base is more durable and can more easily withstand the accumulation of snow masses on the roof.
For slopes with a minimum value between the rafters and the corrugated sheeting, there must be a ventilated gap, or more precisely: the smaller the slope, the larger it should be, and this is at least 50 millimeters.
The technology for constructing a roof with a minimum slope from a profiled sheet is as follows:
A properly equipped roof is the key to the reliability and comfort of the entire building. The slope angle is of particular importance roof slopes, the calculation of which is carried out at the design stage. Let's look at how to determine the angle of a roof in degrees without resorting to complex calculations and bulky instruments.
The degree of roof slope is influenced by the design of the entire house. In addition, it also depends on the roofing material. Climatic conditions also play some role of this region. For example, if construction is carried out in an area with frequent rain and snowfall, the minimum roof slope is recommended as 45-60 degrees. In this way, a reduction in the load of snow cover on the roof structure is achieved: snow masses They simply won’t be able to accumulate there, sliding down under their own weight.
If the area is characterized by strong winds, then the best option in this case would be a low-slope roof with a low windage. Usually we're talking about about angles of 9-20 degrees. As for the universal indicator, it is somewhere between the two indicated parameters, and corresponds to 20-45 degrees. This slope angle allows for a wide selection of roofing materials.
Outbuildings and ancillary buildings are most often equipped with a pitched roof. It does not carry any special design originality, captivating with its cheapness and speed of installation. All that is required is to build two walls of different heights and cover them with a roof. The slope angle of such structures is generally in the range of 9-25 degrees, and corrugated sheeting is often used for covering. Since there is no attic here, a minimal roof slope can be selected. However, do not forget about the need for ventilation under the roof space.
The most popular gable roofs, consisting of a pair of planes (slopes) connected along one line. Pediments (ends of the structure) can be decorated with doors to enter the attic or conduct repair activities. They may also be located there ventilation holes(products). Currently, hip roofs are gaining popularity because they have significant aesthetic potential. Roof slope indicators here can be very diverse: it all depends on personal taste and the chosen project.
More often than others, they use a four-slope type of hip structure, where two slopes have triangular shape. During construction hip roofs Almost any roofing material can be used. Although you have to deal with the design high complexity, however, the effort spent is more than repaid in beauty and effectiveness.
The mansard roof is a complicated version of the hip roof: in this case, the goal is to create optimal conditions for use attic space for furnishing a living room. This involves carrying out work on reliable insulation and vapor barrier. Attic room is formed by a system of broken slopes, with quite significant angles of inclination. Most often there are dormer windows, carrying both practical and aesthetic functions. Insolation of space is mandatory.
When choosing the optimal slope angle, you need to take into account the climatic features of the area. If the region experiences frequent strong winds, then it is best to use a roof with a slight slope. If this is not done, then due to the increased windage, the structure may be damaged and even collapse. As for the possibility of strengthening a roof with steep slopes, this is usually accompanied by significant financial investments.
If the region experiences heavy snowfall, a roof with a low slope will not be effective. The slope of the slopes should be increased, which will ensure that the snow masses quickly slide down under its own weight. In this way, it is possible to avoid a significant increase in loads on the roof structure.
For areas with abundant sunny periods, a minimum slope of slate roofing is recommended, which will minimize the heated surface. Often in such cases, to protect against overheating, dark roll materials a layer of gravel is poured onto the flat slopes. It is best for such a roof to choose a slope angle of no more than 5 degrees, carefully positioning the drainage holes.
When choosing a roofing material, you should carefully read it performance characteristics and recommendations for use.
When determining what the minimum roof slope should be, you should take into account load-bearing capacity roofing structure. It is important that it can effectively withstand all external loads characteristic of a given region. There are permanent (weight of the roof and its equipment) and temporary ( weathering) loads.
The slope angle has a direct impact on the construction of the sheathing. It is recommended to equip minimally inclined slopes with continuous sheathing, or use a pitch of 350-450 mm. Besides, flat roof will require additional time to arrange water drainage from its surface. For these purposes, a slope system is used. On large rooftops, an emergency water drainage system is often installed in case water flows exceed the capacity of the main drains.
Since roofing materials are quite expensive, you need to choose them very carefully, taking into account all the advantages and disadvantages. It is important to choose the most suitable one from the variety of options available for sale. optimal coverage for your home. The process of constructing a roof should also be organized as responsibly as possible, since even minimal errors in the process of calculating the angle of inclination can have the most disastrous consequences. It’s good if you can get it done with some minor repairs or alterations. It often happens that an incorrectly designed roof undergoes significant damage and destruction during strong winds or snow. This can lead not only to serious financial losses, but also to injuries to the people living in such a house.
When starting to calculate the slope of roof slopes, you should carefully study the climatic features of the area where you plan to build a house. When collecting information, you can turn to the experience of your neighbors, taking into account their constructive research. The more precipitation there is in the region, the larger the slope angle is; the stronger the winds, the smaller. If we talk about economic considerations, the lowest material consumption is observed when constructing roofs with a slope of 10-60 degrees.
To determine the height of the roof ridge and the location of the rafters, use either a square or a special calculation formula. Here the value equal to half span width should be multiplied by a special coefficient. For example, if a house has a width of 10 m and the angle of inclination of its roof is 25 degrees, to calculate the height of the rafters, half the width (5) is multiplied by the corresponding coefficient (0.47). The result is 2.35: this is the recommended height for raising the rafters. The list of coefficients, depending on the angle of inclination, is contained in special literature.
The ancient saying “measure twice, cut once” is also quite true for roofing. Of particular importance is the correct calculation of the slope of its slopes. If the angle of the roof is calculated incorrectly, the consequences can be dire. The most common defect is roof leakage at joints. individual elements styling This usually happens during heavy rain and spring melting of snow accumulated on the roof. More serious consequences of errors in calculating the angle of inclination are damage or destruction of the roof under the influence of wind or snow loads.
If you decide to build a house on your own, but you are not confident in making calculations for organizing the roof, it is best to turn to experienced specialists who can draw up an optimal project. Further construction works can be done independently using accurate calculations.
The content of the article
The roofs of private houses, as a rule, always have slopes - this roof structure is the easiest to operate and maintain. Water and snow drain better and faster from such roofs, which guarantees excellent waterproofing. Yes and appearance a private home becomes more attractive.
In addition, an additional room appears in the attic, which can be used for living and installing an attic or for numerous household needs.
To make the roof reliable and comfortable, it is necessary to correctly calculate the angle of the roof slope, which depends on many reasons. First of all, these are the climatic conditions of living and the characteristics of the roofing material. Natural conditions affecting the size of the roof slope:
With a low slope of the roof slopes, as a result of strong gusts of wind, water can get under the joints of the covering.
In the question of what angle of the roof slope should be made, the type of roofing matters:
From the above we can conclude that making a decision on the optimal roof slope angle depends on natural conditions, type of roofing material and capabilities of the home owner.
With a large slope, the consumption of materials during roof construction increases.
In addition, the type and pitch of the sheathing depends on the slope of the roof slopes. The smaller the roof slope, the smaller the sheathing pitch should be.. For minimum angles it is approximately 35 to 45 centimeters.
When calculating the angle of inclination of the roof, it is necessary to take into account that the higher the average annual temperature and the less precipitation, the more flat the roof can be built.
It is necessary to take into account that the type and design of the drainage system of the entire house depends on the slope of the roof.
Choosing the angle of the roof, depending on various factors
When determining the roof slope there is no perfect solution, which is suitable for all climatic requirements. It is important to find here best option, on which the consumption of materials and costs of funds depends.
How larger area roof, the more expensive it costs.
The recommended roof slope angle is from 20 to 45 degrees. When increasing it, it is necessary to take into account the creation of additional structures to strengthen the entire structure. And reducing the angle will lead to additional costs of materials to ensure normal waterproofing of the roof of the house.
