How to correctly calculate the angle of inclination and height of a shed roof. Roof slope angle for various roofing materials Minimum recommended roof pitch

The content of the article

Several factors influence the minimum roof slope, not the least of which is the climate of a particular region. The roof, in addition to protecting the internal space of the house from the effects of the external environment, also experiences loads from them. Snow cover, summer rains, wind - all these factors have an impact on the choice of both the shape of the roof and its slope.

What affects the slope of the roof slope?

In areas where strong wind loads prevail, it is customary to make a slight slope of the roof. In such areas, a high roof creates additional windage, which can lead to its failure. In order to minimize these risks, it is necessary to make a reinforced truss system, which leads to a significant increase in the cost of the entire construction.
In areas with heavy snow loads, roofs are erected with a slope of up to 45 degrees or more. On such a roof, snow will not linger, therefore, the rafter system does not need to be made reinforced. For roofs with such a slope, the load from the snow cover is no longer taken into account.

Low-slope roofing is performed in regions with low rainfall and an abundance of sunny days. In this case, the roofs are built more flat. For roofs with a minimum slope, it is recommended to use membrane roofing materials that reliably protect the roof from leaks.

The abundance of the sun gives a strong heating of the roofing material, which, as a rule, for flat roofs is selected from bitumen-based roll or piece materials. Often, in order to protect the roof from overheating, pebbles are sprinkled on their surfaces, sod or green coatings are made.

But even in this case, the minimum slope of a flat roof must be supported by a drainage system so that even a meager amount of precipitation does not linger on the surface of the roofing.

The drainage system on flat roofs can be both external and internal. An internal drain is arranged in areas with severe winters. In this case, the drainage system will not be exposed to the destructive effect of low negative temperatures. In any case, the slope of the roof is made towards the water intake funnels in such a way that water can drain into them by gravity.

Slope angle and roofing material

The choice of roofing material also affects the angle of the slope of the roof slopes. Materials with a smooth surface will help drain water from the roof more quickly. Conversely, materials with a rough surface will prevent the rapid outflow of water.

Roof slope angle , in turn, dictates the conditions for the selection of the truss system and all components of the roof - rafters, sheathing step, roofing material. Naturally, the steeper the roof slope, the better and faster the outflow of water. In addition, a high roof looks better and there is more choice of roofing for it.

As for roofing materials, each of them has its own recommended roof slope.

minimum roof pitch and cover

The minimum slope of the roof from corrugated board make it equal to 12 degrees, for a roof covered with metal tiles, the slope increases to 15 degrees. But with such a small angle of the roof slope, all joints between individual sheets or other elements must be treated with a water and frost-resistant sealant. In addition, if the roof slope angle is 15 degrees or more, the profiled sheet is laid with an overlap of 200 mm, with a smaller slope angle, the overlap increases by two waves. The step of the crate under the profiled sheet also depends on the angle of the roof slope. The greater the slope, the wider the crate step becomes. With a minimum slope angle, the crate can be continuous.

Roll or piece roofing materials based on bitumen, as well as membrane coatings, ondulin, can be laid on the roof with a minimum slope of only two degrees or more. When choosing rolled materials, the number of layers of soft roofing affects the angle of inclination. The more layers, the lower the angle of the roof slope, as its waterproofing ability increases. If a soft roof is made from 1 or two layers of rolled material, then the angle of the roof slope can reach up to 15 degrees.

Soft tiles(ondulin) can be laid on a roof with a slope angle of 11 degrees, but the crate in this case must be continuous.

Minimum slope of a pitched roof covered with asbestos-cement sheets or ceramic tiles, the slope of the roof slope must be at least 22 degrees. You should also not forget that the smaller the angle of slope of a pitched roof covered with slate or natural tiles, the greater the load is created on the truss system along the entire plane of the slope. Therefore, the truss system must be calculated taking into account the slope of the roof.

How and with what is the angle of the roof slope measured?

The slope angle of any roof can be calculated using geometric functions or a device called an inclinometer. The angle of the roof slope can be measured in degrees, percentages or their ratios.

The mathematical approach to the calculation is to first find out the length of the legs or hypotenuse. The hypotenuse will be a straight line represented by the roof slope. The opposite leg will be the distance from the ceiling to the ridge, the length of the adjacent leg is the distance from the middle of the ceiling to the cornice overhang of one of the roof slopes.

Knowing two of the three values using trigonometric functions, you can easily calculate the minimum slope of a soft roof. The resulting value of the sine, cosine or tangent, depending on the dimensions of which components of the right triangle were used, is used to find the percentage value of the roof slope angle using an engineering calculator.

Another way to determine the angle of the roof slope is to determine the ratio between the height from the ceiling to the ridge and half the width of the ceiling. The height is divided by ½ the width of the building and multiplied by 100. Further determination takes place according to a special table.

Roofs made with a minimum slope must be equipped with a proper gutter system. The slope of the roof is made towards the water intake funnels, if an internal drainage system is provided, and towards the gutters, if an external drainage system is arranged.

The slope of the roof slopes - what it depends on and how it is measured.

Such an important fact for the roof is its slope. Roof slope- this is the angle of inclination of the roof relative to the horizontal level. According to the angle of inclination of the roof slopes there are low-slope(sloping), medium inclination and roofs with steep(highly inclined) stingrays.

low slope roof that roof, the installation of which is carried out based on the smallest recommended angle of inclination of the slopes. So for each roofing there is a recommended minimum slope.

What determines the slope of the roof

From the ability of the roof to protect the structure from external factors and influences.
From the wind- the greater the slope of the roof, the greater the value of the attributable wind loads. With steep slopes, wind resistance decreases, and windage increases. In regions and places with strong winds, it is recommended to apply a minimum roof slope to reduce the load on the roof's load-bearing structures.
From roofing (material) - Each roofing material has its own minimum angle of inclination at which this material can be used.
From architectural ideas, solutions, local traditions- so in different regions preference is given to a particular roof structure.
From atmospheric precipitation: snow loads and rainfall in the region. On roofs with a large slope, snow, dirt and leaves will not accumulate in huge quantities.

What is the roof pitch measured in?

The designation of the roof slope in the drawings can be either in degrees or as a percentage. The slope of the roof is indicated by the Latin letter i.

In SNiP II-26-76, this value is indicated as a percentage (%). At the moment, there are no strict rules for designating the size of the roof slope.

The unit of measure for roof slope is degrees or percentages (%). Their ratio is shown in the table below.

Roof slope degree-percentage ratio

degrees	%	degrees	%	degrees	%
1°	1,75%	16°	28,68%	31°	60,09%
2°	3,50%	17°	30,58%	32°	62,48%
3°	5,24%	18°	32,50%	33°	64,93%
4°	7,00%	19°	34,43%	34°	67,45%
5°	8,75%	20°	36,39%	35°	70,01%
6°	10,51%	21°	38,38%	36°	72,65%
7°	12,28%	22°	40,40%	37°	75,35%
8°	14,05%	23°	42,45%	38°	78,13%
9°	15,84%	24°	44,52%	39°	80,98%
10°	17,64%	25°	46,64%	40°	83,90%
11°	19,44%	26°	48,78%	41°	86,92%
12°	21,25%	27°	50,95%	42°	90,04%
13°	23,09%	28°	53,18%	43°	93,25%
14°	24,94%	29°	55,42%	44°	96,58%
15°	26,80%	30°	57,73%	45°	100%

You can convert the slope from percent to degrees and vice versa from degrees to percent using the online converter:

Roof pitch measurement

The slope angle is measured using an inclinometer or mathematically.

Inclinometer- this is a rail with a frame, between the slats of which there is an axis, a division scale and to which a pendulum is fixed. When the rail is in a horizontal position, the scale shows zero degrees. To measure the slope of the roof slope, the inclinometer rail is held perpendicular to the ridge, that is, at a vertical level. On the scale of the inclinometer, the pendulum indicates the slope of a given roof slope in degrees. This method of measuring the slope has become less relevant, since now there are various geodetic instruments for measuring slopes, as well as drip and electronic levels with inclinometers.

Mathematical calculation of the slope

Vertical Height (H) from the top of the slope (usually the ridge) to the level of the bottom (cornice)
Foundation ( L ) - horizontal distance from the bottom of the slope to the top

Using a mathematical calculation, the value of the slope of the roof is found as follows:

The angle of the slope of the slope i is equal to the ratio of the height of the roof H to the laying L

i \u003d H : L

In order to express the slope value as a percentage, this ratio is multiplied by 100. Further, to find out the slope value in degrees, we translate according to the ratio table above.

To make it clearer, let's look at an example:

Let it be:

Laying length 4.5 m, roof height 2.0 m.

The slope is: i = 2.0: 4.5 = 0.44 now multiply by × 100 = 44%. We translate this value according to the table into degrees and get - 24 °.

Minimum slope for roofing materials (coverings)

Roof type	Minimum roof pitch
Roof type	in degrees	in %	in the ratio of the height of the slope to the laying
Roofs made of rolled bituminous materials: 3 and 4 layers (welded roofing)	0-3°	up to 5%	until 1:20
Roofs made of rolled bituminous materials: 2-layer (welded roofing)	from	15
seam roof	from 4°
Ondulin	5°		1:11
Wavy asbestos cement sheets (slate)	9°	16	1:6
Ceramic tiles	11°		1:6
bituminous tiles	11°		1:5
metal tile	14°
Cement-sand tiles	34°	67%
wooden roof	39°	80%	1:1.125

The reliability of the building and the comfort of living in it depend on the quality of the construction of the roof. Its design is chosen optimal for local operating conditions. Of particular importance is such a parameter as the slope of the roof, which will be discussed further.

The angle of the roof slope depends not only on its design and features of the facade of the house, on the selected roofing material, but also on other factors. First of all, it is necessary to take into account the climatic conditions of the area where the building is being built. Where the amount of precipitation in winter is high, a large roof slope (within 45-60 degrees) is preferable: this contributes to better snow melting, which means reducing the load on the roof. Also, glaciation of the floor surface becomes less likely due to the compaction of snow covers.

If the building is being built where weather with strong winds prevails, it is advisable to choose a minimum roof slope angle to reduce the windage of the structure. Otherwise, the structure is threatened with rapid destruction. Most often, the tilt range in this case is 9-20 degrees.

The greater the angle of slope of the roof slope, the easier the snow cover comes off it.

But basically, the optimal angle of the roof slope is chosen in average values, that is, from 20 to 45 degrees. It is suitable for almost any type of roofing material, for example, for corrugated board or metal tiles that are very popular today.

In areas with a warm climate, where there are much more sunny days than cloudy ones, flat roofs will be more acceptable: their area is smaller than that of other types of structures, which means that heating from sunlight will occur to a lesser extent. But even such a design should not be absolutely horizontal: the slope of a flat roof should be at least 3-5 degrees. The minimum slope of a flat roof will ensure the normal descent of rain and melt moisture.

Types of roof structures

Household and utility buildings are often built with a shed roof: it is simply mounted and does not require large expenditures. In fact, such a building has walls of different heights with a ceiling laid on them. The slope of the overlap is selected within 9-25 degrees, which is well suited for corrugated board and metal tiles. This design requires a ventilation device for the under-roof space.

But the most popular is the gable: two inclined planes are connected along the ridge line. Other (end) planes are vertical and are called gables. They may have doors leading to a balcony or an outdoor staircase.

There are many options for roofing designs

Hip ceilings, the most popular representatives of which are hipped, are aesthetically very attractive. In such cases, especially for more complex structures, the slopes can be any: it depends on the chosen design and the personal preferences of the developers. The advantage of hip roofs is that there are no restrictions on the use of roofing material.

A variant of the hip structure is an attic: the attic is used as a living space, so the requirements for insulation are very high. Free space under the ceiling is formed due to the high angle of inclination of all slopes, in which the presence of skylights should be provided.

The dependence of the roof structure on the floor material

Before choosing a roofing material, you should study its technical characteristics: this will help you optimally approach the issue and choose the most reliable one. In addition, there is a rule that determines the dependence of the angle of inclination of the slopes on the roofing material used.

We list the main ones:

When choosing the slope value, the strength characteristics of the roof structure should be taken into account: the safety margin should be enough not only to withstand its own weight and the mass of the roofing material, but also to external loads (gusts of wind, snow). The type of crate for laying most materials also depends on the slope of the slope: with small values of this parameter, either a continuous crate is mounted or with a small step (350-450 mm). When erecting any roof, and even more so flat, it is necessary to install a system of slopes and drainage. If the area is particularly large, an additional drain will be required.

Calculation of the angle of inclination

The design must meet the following requirements: be strong enough, provide reliable protection from atmospheric precipitation, and have good thermal and sound insulation. It is also important that there is access for repairs and maintenance. How to calculate the angle of inclination of the roof so that all these conditions are met? Experts recommend using simple variants of its device, which include single-slope, gable, hip (and half-hip), attic.

Roofs can have a structure of any complexity, with different slope angles

Sheds are most convenient for verandas, outbuildings and outbuildings. The principle of creating a shed is the same as other types: installation of rafters, battens, after which - laying of roofing material. The latter plays a decisive role: for corrugated board, an angle of 8-11 degrees is required (it is better to do 20), for metal tiles - at least 25, for slate and seam roofing - 35 degrees.

If climatic conditions allow, it is better to make a roof with a slope of 45 degrees: this will allow you to neglect the calculations associated with the mass of snow. This is an almost perfect shed roof: the angle of inclination will not complicate its installation and facilitate maintenance (snow will not accumulate on its surface). But in this case, it will be necessary to strengthen the rafters and the crate, since the wind pressure on the structure increases by 5 times. It should also be borne in mind that this will require large expenditures on materials - about 1.5 times.

Roofing material must be selected depending on the slope of the roof

As can be seen from the graph, each slope corresponds to a certain group of roofing waterproofing materials. There are 11 of them in total, while the inclined lines correspond to the angle of inclination of the slope. The bold line indicates how the height of the ridge relates to ½ of its inception. It can be seen that the segment h is equal to half of the horizontal segment, indicated by the fraction ½. The numbers at the tops of the semicircular scales correspond to the angle of inclination (in degrees), the vertical scale also indicates in percent. When choosing any roof configuration, you should follow these recommendations and purchase roofing materials suitable for the chosen option.

In order to make it clear how the roof slope angle is calculated, we will give an example of calculating the smallest slope angle of a slab with waterproofing from tiles. On the graph we find a semicircular curve corresponding to this coating: this will be the curve indicated by the number 2. Tracking it to the point of intersection with the vertical scale, we find that the minimum slope of such a roof is 50%.

Considering the fact that the slope of the slope is the ratio of the height of the ridge to ½ of its inception, we calculate the slope. That is, with a ridge height h = 4 m and a laying equal to L = 15 m, the slope will be determined as h: (L / 2) = 4: (15/2) = 0.53. To display as a percentage, multiply the result by 100 and get 53%. This value of this parameter guarantees good drainage of rainwater. The minimum slope in the valley is 1%.

Features of the calculation of a gable roof

A gable roof is the most successful and common design. There are several reasons for this: high reliability, relative simplicity, low cost of construction. When constructing a roof, not everyone correctly chooses the optimal angle of inclination of a gable roof.

In areas of strong winds, it is necessary to calculate the gable roof so that its slope does not cause too strong wind loads. The greater the angle of inclination of the structure, the higher its windage.

You can not reduce it to values less than 25 degrees: precipitation will be worse removed from the roof, and dampness may appear in the under-roof space. Making it large 60 degrees is also not recommended: a strong gust of faith can destroy the roof. The roof does not have to have symmetrical slopes: if the building is oriented with a more gentle slope to the south, the roof will dry better after rain.

Conditions for the use of roofing materials depending on the angle of inclination

Usable attic area and drainage system

The useful area of the attic space depends on the design of the roof: the larger the slope angle, the larger the area and vice versa (Figure 2 clearly shows this). When constructing an attic, you have to find a compromise between the area that can be easily used, the cost of building a roof and the strength of the structure.

The method of removing atmospheric precipitation can also be different. Distinguish external or internal organized and unorganized - only external. The latter involves the installation of downpipes and gutters, while wall and suspension systems are mounted on roofs with a slope greater than 15%. The gutters are mounted with a minimum slope of 3 degrees, their sides are made with a height of about 120 mm.

The useful area of the attic depends on the angle of the roof

Between the pipes there should be a distance of no more than 23 m. The cross section of the pipe must ensure normal drainage of water and is selected depending on the area of \u200b\u200bthe slope. Outdoor drains of an organized type are more suitable for areas with a warm climate. Internal gutters are used for cold climates. Such systems consist of a funnel for receiving water, a riser, an outlet and a discharge pipe. The main condition is that water drainage must be provided at any air temperature.

The installation of a roof is a very responsible business that requires the participation of highly qualified workers. Installation errors can cost homeowners dearly. To avoid trouble, work on the construction of the roof should be entrusted to specialists with sufficient experience: this will guarantee the reliability of the building and comfort in it.

Any house is crowned with a roof - one of the main structures of the building, protecting its interior from rain and snow. One of the main criteria for any roof is the steepness of the slopes. Since a flat roof is distributed mainly only in multi-storey residential and industrial construction, this issue is especially relevant for owners of private houses and cottages.

The amount of roofing material depends on the slope of the roof, so the choice of the angle of inclination and its preliminary calculations should be made before the purchase of roofing material.

Consider how to determine the angle of inclination of a pitched roof and its relationship with the design of the entire roof structure.

In this article

What determines the slope of the roof?

The angle of inclination of the roof directly affects its performance. In construction, 4 types of roof structures are distinguished:

Steep with a slope of 45-60°;
Pitched - 30-45 °;
Gentle - 10-30 °;
Flat with a slope of less than 10°.

The definition of this value depends on a number of factors:

The impact of the wind. The wind exerts the greatest pressure on steep roofs, as they have the greatest windage due to their large surface area. When arranging such a structure, it is important to pay special attention to the strength of the truss system.

In areas with a high wind load, it is also dangerous to arrange flat and sloping roofs: if the structure is weakly fastened, it may fail. Thus, in areas with strong winds, the recommended roof slope angle is in the range of 25-30°.

In areas where a significant amount of snow falls during the cold season, a steep roof, on the contrary, has advantages. Snow does not accumulate on it. With a smaller angle, the snow will lie on the roof longer, creating an additional load on the truss system.

It is not necessary to equip a steep roof: a certain amount of snow that has lingered on the roof in winter has the useful property of retaining heat. However, it is important to calculate the load exerted by the snow cap on the structure in order to prevent its collapse.

Roofing material. Each type of roof has its own restrictions on the angle of inclination of the slopes. If you plan to use a specific roofing material, then it is important at the design stage to correlate the desired slope of the roof with its technical characteristics.
Attic size. The angle of the roof directly affects the size of the room below it. The steeper the roof and the higher the ridge, the more spacious the attic and vice versa. When planning a room under a roof, one should not forget about the risks inherent in steep construction, and its high cost compared to the erection of more gentle roofs. A broken type can come to the rescue in this situation, which allows you to save the maximum volume for arranging the room, saving on the height of the ridge.

Minimum Tilt Angle

Such a concept as the minimum angle of inclination of the roof is related to the roofing material used. All roofs are supplied with technical specifications, which, among other things, clearly indicate the pitch limits for use. It is impossible to violate these rules, since in this case the roofing material will not retain its original functions and advantages.

Consider the main roofing and the minimum angles for them:

Piece roofing materials (slate, tiles) are laid on roofs with a slope of 22 °. This indicator is due to the fact that in this case water does not accumulate at the joints of the roofing elements and, accordingly, cannot seep under them;
When working with roll materials such as roofing material, it is important to determine in advance the number of layers. If it is planned to lay 2 layers, then the roof angle should be at least 15 °, when laying 3 layers, this value can be reduced to 2-5 °;
The professional flooring is mounted at a slope from 12 °. A lower value will require the treatment of all joints with sealant;
The metal tile spreads at a value of 14 °;
Ondulin - from 6 °;
Soft tiles can be laid on a roof with a slope of 11 ° in the presence of a continuous crate;
Membrane roofing materials are the only ones for which the minimum threshold is not indicated. They can be successfully used on flat roofs.

Following the above rules is extremely important, since even a slight violation of them will result in the destruction of the roof and, possibly, damage to the truss system.

Calculation of the angle of inclination

In addition to the minimum angle, there is such a thing as the optimal angle of inclination. With it, the roof is subjected to the minimum possible loads from wind, snow, etc. We give examples of such optimal values:

In areas with frequent precipitation in the form of rain and snow, it is optimal to build a roof with a slope of 45-60 °, as it quickly gets rid of precipitation, which minimizes the load on the truss system;
If the roof is being built in a windy region, then it will be good to place its angle of inclination in the range of 9-20 °. She will not play the role of a sail, catching the passing wind, but she will not capsize with its sharp gusts;
In areas where both wind and snow occur regularly, average values of 20-45° are used. This range can be called universal for pitched structures.

Independent calculation of the angle of the slopes is reduced to a simple geometric process, which is based on a triangle. Its legs are the height of the ridge and half the width of the house, the hypotenuse is one of the slopes. And the angle between the hypotenuse and the leg is the desired value of the steepness.

The angle of the roof is in direct relation to the height of the ridge. There are two options for calculating these values:

Known roof height. If there is a desire to equip a spacious living room under the roof with an acceptable ceiling height, then the height of the ridge can be determined in advance. Having known two legs, it is easy to find out the value of the desired angle.

We accept the following notation:

H is the height of the ridge;
L is the width of half of the house;
α is the required angle.

We find the tangent of the desired angle using the formula:

tg α =H/L

We learn the value of the angle from the obtained value from a specialized table of tangents.

Pre-determined angle of inclination. If you want to use a specific roofing material or due to weather conditions in the region, the roof slope can be determined in advance. By its value, you can determine the height of the ridge of the house and check whether it is possible to create a living room under this roof. For the arrangement of the premises, the height of the ridge must be at least 2.5 m.

We leave the conventions from the previous example and substitute the known values into the following equation:

H=L*tg α

Thus, the process of calculating the angle of inclination is much simpler and faster than the analysis of all populations to determine its optimal value for a particular region and building.

Due to the fact that the shed roof rests on walls of different heights, the calculation of the given angle of inclination is carried out by simply raising one of the walls of the house.

We draw a perpendicular along the wall L sd (the length of the wall of the house), originating at the point where the short wall ends and resting on the wall with the maximum length.

If the length of the wall of the house L cd is 10 meters, then in order to get an angle of inclination of 45 degrees, the length of the wall L bc must be equal to 14.08 meters.

Conclusion

In roof design, finding the optimal angle of inclination is essential. This parameter depends on the correct assessment of weather conditions, the choice of roofing material, the desire to create a living space. Its correct definition is the key to a long and successful roof service in all weather conditions.

The comfort of operation and the reliability of the building mainly depend on how well and competently the construction of the roof is carried out, and also on how correct the slope of the roof is. It will be discussed further.

The slope of the roof of the house mainly depends on the design of the facade and the roof of the building, and the material chosen for the coating is also an important feature. The slope is taken into account depending on the climatic conditions of the region in which the new building is being built. For example, in areas where there is heavy rainfall, and in winter there is very heavy snowfall, a slope of 45 to 60 degrees is chosen. Such an angle of inclination is specially designed, as it allows you to reduce the load, especially in winter, on the roofing system, since snow simply will not accumulate on the roof, but will slide down due to its own weight.

And if they are constructing a roof for a region where strong and constant winds are typical, then they choose the minimum one, since this reduces the so-called "sail" of the roofing. Basically, the angle is chosen from 9 to 20 degrees. Therefore, the most universal solution is a value chosen between the two ranges above, i.e. it is best to make an angle of 20-45 degrees. A slope of 20 to 45 degrees has another advantage - the ability to use most roofing materials purchased in today's markets.

Varieties of roofs of houses

Varieties of roofs: a - gently sloping gable, b - steep gable, c - hip four-slope, d - single-slope (in the form of a school desk), e - broken (mansard) gable, e - hipped four-slope, f, h, i - half-hip (mansard) four-slope.

The most common for utility or utility buildings is the shed roof shape of the house, which does not offer an original design, but at the same time attracts with its simplicity of construction and its low cost. The design of such a roof consists of walls and roofing material laid on them.

The slope in this case should be from 9 to 25 degrees, since most often it is these roofs that are later covered with corrugated board. Such a rather small angle of inclination is formed due to the lack of an attic area.

Another fairly common type is the gable roof of the house. Its design consists of two slopes (two planes), connected by a ridge (one line). The walls are the ends of the building and they are called gables. They often provide doors that will allow you to use the attic as an additional room, in addition, these doors play the role of air vents (vents). Making such roofs is easier than everyone else.

Modern designers and just builders often make hip roofs. They allow you to perform a unique design of the facade and roof of a broken shape. In such structures, the slope angle can be absolutely anything, depending on the imagination and taste of the person who designs the roof structure. There are practically no restrictions on the use of roofing material in the construction of such roofs. The complex design is compensated by the spectacular appearance of the roof of the house, and the more complex the general plan, the more original design of the hip roof can turn out.

A more complex type of hip roof is a mansard roof of a broken shape, the purpose of which is to use the attic space in a residential area, while making insulation and vapor barrier mandatory.

Due to the rather high angles of inclination and slopes of a broken shape, a space is formed, of which the entire attic floor consists. In addition, it would be appropriate to make the so-called "dormer" windows, which will serve as an additional decoration of the facade. And you just need to perform insolation (lighting the room with sunlight).

You should also familiarize yourself with the data on the smallest angle for various materials:

For piece materials, such as tiles and slate, an angle of 22 degrees is considered the smallest. This prevents moisture from accumulating at the joints and seeping into the building.
For roll materials, the minimum angle of inclination will be selected depending on the number of layers laid. With a three-layer coating, the angle will be from 2 to 5 degrees, with a two-layer coating - 15 degrees.
A small angle of inclination of a corrugated roof is 12 degrees. At small angles, according to the recommendations of the manufacturers, the joints should be additionally glued with sealants.
For roofs covered with metal tiles, the minimum angle is 14 degrees.
For roofs covered with onduline, the minimum angle is 6 degrees.
For soft tiles, 11 degrees is considered a small angle, while regardless of the chosen angle, there is a prerequisite - the installation of a continuous crate.
Membrane covers have a minimum angle of 2 degrees.

Roof Slope Calculation Example

The angle of inclination of the roof is calculated, as we have already said, taking into account the climate of the area and the selected coating material. The height of the ridge and the value of the rise of the rafters are determined with a square or the width of the span is calculated, divided in half and multiplied by the corresponding coefficient from the table.

For example, if the width of the house is 10 m, and equal to 25 degrees, then the height to which the rafters must rise is calculated by multiplying 5 m (half the width of the house) by the coefficient from the table (0.47) and we get 2.35. It is to a height of 2.35 that the rafters should rise.