What roof angle should I choose? Minimum slope of a roof made of corrugated sheets: what determines the roof configuration Minimum roof slope angle for corrugated sheets 3

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

What influences the choice of roof angle

One of the important aspects that determines the angle of inclination is the climate in the region where the building will be built. First of all this:

1. Height of snow mass;
2. Precipitation amount;
3. Rose of Wind;
4. Roofing material;
5. Strength of the rafter system.

It should be remembered that water will quickly drain from the roof, and snow will remain on it longer. You can imagine how much weight the roof must withstand, given that the level of snow drift in some regions can exceed 1 m. The more the corrugated sheet is inclined, the faster the snow mass will fall off it.

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

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

Calculating the angle of inclination of a roof made of corrugated sheets

When calculating the slope of a metal profile roof, be sure to take into account the following parameters:

• The weight of thermal insulation material, lathing system, counter battens and other layers of roofing materials.
• The weight of the corrugated sheet itself.
• Snow load in your region.
• Loading due to gusts of wind.

Calculations according to the schematic drawing

Let's take as an example the classic gable type roofs. As can be seen in the figure, A equal to the angle of inclination of the left slope, IN- right. Then, to carry out the calculation, you need to find out the height of the roof equal to h and the length of the horizontal section of the slopes With And d.

If the roof is symmetrical, With 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 corners A And IN- the same. Let's try to calculate the angles according to the existing example.

The corrugated sheet has excellent performance, due to which it is widely used in civil and industrial construction. Create high-quality coating roofs using it are possible, provided that the laying technology and slope of the roof made of corrugated sheets are followed.

Minimum slope angle

When constructing buildings for industrial purposes, it is allowed to use this material for roofing when the minimum slope of a corrugated roof is 8 degrees or more.

It is important to know that when installing roofs that are too low industrial buildings It is allowed to use special products - with a self-supporting profile. Such products are quite expensive, but if there are financial opportunities, they are also used in the construction of private households - then the roof slope angle can be at least 15 degrees.

Failure to comply with permissible roof slope standards and consequences

If the provisions of SNiP regarding the permissible minimum slope for corrugated sheets are violated when designing a roof, property owners will face a number of serious problems:

• leaks that occur during heavy precipitation penetrating through the holes for the screws;
• pushing through the roofing surface with snow masses;
• increased heat loss through the roof;
• deformation of the roof covering under strong and sudden gusts of wind.

Among the owners of private houses, there is an opinion that a flat roof is an economical option, since its arrangement requires less material. In reality, the construction of such a roof requires the use of an increased amount of rafter legs when the installation step is reduced to 40 centimeters. In addition, on flat roofs the covering material is installed with a large overlap, so experts recommend building steeper slopes.

The amount of overlap of corrugated sheets on the roof

This indicator most depends on the slope of the corrugated sheet roof, which was chosen when designing the facility.

The overlap, for example, should be:

• at a slope angle of 15 - 30 degrees -20 centimeters;
• at an inclination of 30 degrees or more -15 centimeters.

When in project documentation The minimum slope value is specified, the corrugated sheet is mounted with an overlap between the rows of 2 waves. At the same time, sealants and special seals are used. In addition, corrugated sheeting must be laid on a continuous sheathing.

Selection of profiled sheets

Manufacturers produce two types of profiled sheets - wall (C) and roofing (K). This material also differs in profile shape. When covering truss structure They usually use products with relief in the shape of waves or trapezoids, having a height of 25–31 millimeters.

Optimal thickness The profiled sheet for the roof is considered to be 0.8 millimeters. In some cases, 1 millimeter products are used for cladding. Roofing material of this thickness is chosen when arranging a roof with minimal inclination, ranging from 8 to 15 degrees. On slopes with a large area, profiled sheets should be laid in two or three rows.

But usually when designing a roof, it is necessary to install the roofing covering in one row, for this reason you need to pay attention to the length of the corrugated sheet. Typically, products with a length of 6 meters are available for sale.

Calculation of the amount of roofing materials

The roof project, developed by professionals, is accompanied by drawings and cost estimates. Quantity calculation procedure roofing material uncomplicated. It is necessary to divide the area of ​​the slopes by the area of ​​one profiled sheet.

At the same time, one should not forget about overlaps. Since the minimum permissible slope of a corrugated roof according to SNiP is 8 - 15 degrees, the value of this parameter will be equal to 20 centimeters. Then you need to subtract the overlap size from the sheet area.

When purchasing materials, it is necessary to make a small supply, since damage to the products may occur during the installation process. The same applies to additional elements. Especially if you choose a minimum slope for a corrugated roof. In this case, compliance with the acceptable parameters is mandatory.

In any case, laying roofing on a flat roof is more difficult than on a roof with steep slopes, because in addition installation work sealants and sealants will have to be used.

Corrugated sheet laying technology

After a decision has been made as to what the slope of a corrugated roof should be, a project has been drawn up and the necessary building materials have been purchased, they begin to install the roof covering, starting from the lower edge of the slope:

1. Before laying the sheets, install a cornice strip, a drainage system, and waterproof the chimney.
2. The corrugated sheets are fastened in blocks using self-tapping screws, to which special seals are attached. Place fasteners in the bends of the waves. To do this, first, at the ridge, the first sheet is attached to the sheathing, and then the second, which is fixed to the first. Do the same with the third sheet. Then the weight of the block is completely leveled relative to the cornice and finally secured.
3. To complete the work, install the ridge, end strips, valleys and apron of the chimney pipe and, if necessary, snow retention elements.

When working with corrugated sheets, you should adhere to several rules:

1. You need to lift the sheets up to the place of installation one at a time.
2. Metal shavings that appear during the process of screwing in the screws must be immediately removed with a brush, otherwise the polymer layer that protects against corrosion can be damaged, which significantly reduces the service life of the roofing material.
3. You should walk on the roof surface in shoes with soft soles.
4. If the polymer layer is damaged during installation, these areas must be immediately coated with a special compound.
5. The minimum slope of a roof made of self-supporting corrugated sheets is 8 degrees.
6. Sheets are attached to the sheathing special screws with gasket. Rivets or nails must not be used. The fasteners are not screwed in too tightly.
7. The steeper the angle of inclination of the corrugated sheet canopy, the more strongly the wind load affects the building. But in addition to the wind strength, its prevailing direction and average annual precipitation should be taken into account.

In the process of designing the construction of a private household, special attention is paid to the roof. When determining the angle of inclination of a corrugated roof, the ratio between the height of the roof structure and its total area is decisive. The size of the free space in the attic depends on this, whether problems with accumulation will appear snow masses and whether the wind will blow away the roof.

SNiP for corrugated roofing

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 corrugated sheeting was laid on the roof with a slope of at least 12 degrees. As for the maximum angle, in this case it 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.

Roof angle and types

Roofs, depending on the angle of inclination, are:

• flat - this parameter does not exceed 5°;
• pitched - they have a slope of 20°, such roofs are less waterproof and therefore are popular with developers;
• with a small angle not exceeding 25 degrees - attics can be equipped on them, but without window openings;
• steep - this is the name given to those roofs whose slope is more than 40° - in this case it will be quite possible to equip a residential attic;
• large - they have a slope of 45 - 60°.

Today, the best choice is considered to be a roof slope 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.

Advantages of roofs with a minimum slope

The main advantages of constructing roofs with such a slope are as follows:

• material consumption is reduced;
• roofing work becomes easier and safer;
• there is no ridge and, accordingly, problems associated with its sealing.

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.

Disadvantages of roofs with a minimum slope

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.

A wall or universal profile can be laid on a roof with a steep slope, since minimal pressure will be exerted on the roofing. 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°.

At the same time, when building a steep roof for profiled sheets, you need to build long rafters and more bars are consumed on them, but you can save on roofing material. You can also purchase inexpensive flooring with a lower wave height, since it load bearing capacity won't make that much of a difference.

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 greater the number of supports that need to be installed.

Wind and snow loads

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 particular area. Minimum value This parameter is chosen when the house is being built in a region where there are strong wind loads. In these areas, the phenomenon of “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, almost flat roofs mounted from this material can be torn off and therefore the absence of a slope 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 snow load can reach 550 kilograms per “square” of roof covering 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 of more than a meter. In this case, the worst situation is for roofs with minimal slopes.

Independent calculation of the angle of inclination

Professionals calculate the roof slope using a special device - an 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:

1. Amount of construction financing.
2. The amount of snow loads.
3. Average value of wind influence.
4. The need to equip a useful under-roof space.

Slope of pitched roofs made of corrugated sheets

If there is a need to build an outbuilding, garage or build a shed, then you can make a roof for them yourself. Ideal for these purposes pitched roof from corrugated sheets. This type The design is simple in design and execution, easy to maintain, durable and durable. 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 correct 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 properties of the corrugated sheets, a pitched type of roof, if positioned correctly, will be safe even in strong gusts of wind, and special attention is paid to waterproofing.

The size of the roof slope 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, the type of rafter structure, the length of the slope and roofing.

If there is no overflow of water between the corrugations, this slope pitched roof from corrugated sheets - minimal.

Other important aspects of construction

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 the roofing pie from moisture penetration.

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 nuances of installing corrugated sheets

The technology for constructing a roof with a minimum slope from a profiled sheet is as follows:

1. The sheets are cut and their cut edges are painted to protect them from corrosion.
2. A waterproofing material, for example, a film that does not allow steam to pass through, is laid on the rafters.
3. A sheathing is laid on top of the waterproofing layer, the frequency of installation of which should correspond to the type of corrugated board.
4. Then another layer of film is attached and another lathing is placed on top. Wood slats It is advisable to pre-treat with an antiseptic composition, which helps extend the life of the roof.
5. Then sheets of roofing material are laid and secured with self-tapping screws. Special rubber or neoprene gaskets must be placed under each bolt.
6. The places where the corrugated sheets are connected are sealed special means, which contains silicone.

Minimum slope of a corrugated sheet roof: the angle of inclination of a corrugated roof in degrees for a shed roof and a multi-pitch roof for a house

Construction of a roof from corrugated sheets with a minimum slope

One of the most painstaking tasks during the design of a corrugated roof is choosing its angle. No aesthetic considerations play a role here: the ratio of the height of the roof to its total area in the future will affect how much usable space remains in the attic, will there be problems with snow accumulation, and even whether the wind will blow your roof away in a strong storm. But this is not uncommon! Shall we figure it out? So, what is the minimum slope of a corrugated sheet roof? And how to build a roof with a minimum slope - all the pros, cons, recommendations and subtleties of construction are here!

Let's look at the official data. So, according to SNiP, building codes and regulations, any roof can be covered with corrugated sheeting, the slope of which has a slope of at least 8°. This is the only way that precipitation will not be able to penetrate through joints and screws. The sheathing step in this situation should be 40 cm.

But 8° is the minimum angle of inclination for the roofs of utility and industrial buildings, and for residential buildings this threshold is 10°. And if the roof is laid in two or more layers, then the minimum threshold will be even higher. That's why modern construction companies They give guarantees for their work only on the condition that they cover a roof with a slope of at least 12° with corrugated sheeting. But the maximum angle for a roof made of corrugated sheets can be at least 70°, or even more.

Therefore, for profiled steel sheet as a roofing material, SNiP recommends a 20° slope as the most best option. But what if you need to build an almost flat roof? For a garage, outbuilding or gazebo? Then just follow our advice - and no problems will arise!

Degrees, percentages and ratios

The roof slope is 8°, which corresponds to a value of 1:7 - this is the minimum value that can be when installing corrugated sheets. And after completing all the work, it is necessary to carefully check the roof for ventilation. But why do roofers, when determining the angle, talk not only about degrees, but also about percentages and even coefficients? All this is the same thing, the only difference is for design documents and when ordering materials. We have prepared a table for you that will help you figure out what's what:

Now let's look into construction terms. So:

• Flat roofs are those whose slope angle does not exceed 5°.
• Sloping ones are those that are usually more than 20°. Naturally, pitched roofs are more waterproof, and therefore more popular in private construction.
• Roofs with a slight angle of inclination - up to 25°. Here you can already equip attic spaces, but without windows.
• Steep - those that have a slope of more than 40°. Steep ones allow you to arrange a good residential attic, which is never superfluous.
• Large is the roof slope that falls between 45-60°.
• But today the ideal roof slope angle is 38-45°.

So, the minimum angle of inclination of a corrugated roof is 8°. Here detailed video master class on how to build such roofs:

If you need to build a roof with an even smaller slope, then the profiled sheet should already be at the bottom of the roofing cake - like a ceiling. The design principle simply changes.

Pros and cons of a roof with a minimum slope

And now about what you will have to face during the construction of a minimum slope roof and what to expect from it in the future.

Advantages

Let's list the benefits first. The main advantages of building such a roof:

1. Less material consumption.
2. Easier and safer roofing work.
3. No ridge or problems associated with its sealing.

Consider another point: the higher the ridge, i.e. The greater the angle of inclination of the roof, the heavier the roof itself will be. There will be more material available. And this is significant pressure on the house and foundation. In this case, the load will be insignificant.

Flaws

And now we move on to the annoying disadvantages. The minimum roof slope is bad because rainwater will drain much more slowly, and will quickly find small cracks and joints to seep into the roofing pie. The threshold in this regard is considered to be an angle of 12°, at which it is still possible to do without additional sealing measures. Therefore, if you are building a flatter roof, the slope angle of which is less than 12°, the overlapping areas of the corrugated sheets will have to be sealed with special roofing sealants.

The chosen angle of inclination will determine what material you can use for the roof. Yes, for flat roof and roofs with a slight slope, only durable load-bearing corrugated sheeting with high corrugation is suitable. But on roofs with a steep slope it is allowed to cover them with both a universal and a wall profile - because now the pressure on the sheets will be minimal. In other words, the same snow will easily slide off, and the water will not linger either.

Second point: material consumption will also increase, because The overlap of the sheets on each other will have to be made a little larger. So, if you are going to build a roof with an angle of 12° to 14°, you will need to increase the overlap of the sheets, but you can still do without sealant; if less, you will need both. This is why a slope of 15-30° is considered optimal for a corrugated roof. Here is a more detailed table of this data:

Although to install steep roofs from corrugated sheets you will have to build quite long rafters, and more bars will be needed, but you will save a lot on roofing material. It will be possible to use corrugated sheeting that is cheaper, with a lower wave height, because now its load-bearing capacity will play a smaller role than with flat roofs

In addition, if the angle of inclination is insufficient, it is impossible to equip a residential attic, which reduces the heat loss of the house through the roof by up to 9%.

And finally, roofs with a slight angle of inclination require the construction of a much more complex rafter system that could withstand a lot of weight. The smaller the angle of inclination, the more additional support elements there are.

And now we will disappoint you a little: even after weighing all the advantages and disadvantages of a roof with a minimum angle, and giving our preference to the value of 8° as more suitable, it may not be possible to build just such an option. Or rather, it will not even be safe! Why? Read on!

Wind and snow loads

Determining the angle of inclination of a corrugated roof is actually influenced by many initial data. First of all, this is - climatic features the area where your house is located. Therefore, find out in advance what the usual depth of snow cover is on the winter days, how often it rains, how strong the wind is and what its predominant direction is:

After all, the slope of a roof made of a material such as corrugated sheets is calculated not for aesthetic reasons, but based on weather factors. Thus, the slope of the roofs of those houses that are located in areas with strong wind loads tends to a minimum value. In these areas, the so-called “roof windage” is dangerous. Have you heard or seen how powerful polycarbonate greenhouses, torn down by the wind, sometimes “walk” through the fields? But they were also not placed on the ground without fastening. And now imagine the possible consequences if part of your roof is literally ripped off. Do you remember what the main disadvantage of corrugated sheeting is? "Sail"!

Here are the SNiP requirements in this regard. With an average wind load, the slope angle should be 35-45°, and with strong winds - 15-25°. In places where strong winds are the norm, make the roof angle made of corrugated sheets close to the minimum in order to minimize wind resistance. But almost flat roofs from this material there is a risk of being easily torn off, and therefore the complete lack of steepness in this case is also no better. Here is a rather impressive recording from a DVR, where the wind tears off a flat roof made of corrugated sheets:

Therefore, do not think that wind load is more harmless than snow load. In the Novgorod region, for example, the average value is 23 kg/m, where snow cover is about 75 kg/m.

Then shouldn't all roofs be flat? Not at all. In Russia, as everyone knows, there is snow up to the neck in winter. But snowflakes that seem so fragile at first glance actually weigh a lot. For example, in one unremarkable winter, so much snow can accumulate on a flat roof as if a whole company were standing closely on it. No rafters can withstand this, and therefore in areas with significant snow loads the roof slope has to be made up to 45° - so that the snow does not linger. Then there is no need to strengthen the rafters - precipitation on such a foundation will no longer be retained at all. After all, snow slides easily only from steep roofs.

Here's a map to help you find the parameters for your area:

Let's scare: in Yakutsk the snow load on the roof sometimes reaches 550 kg per person square meter. And this is already half a ton! This is why the roofs of houses in this region are always so high and steep. But in southern countries they can even be covered with straw in a horizontal position.

Even a small layer of snow is much heavier in weight than you can even imagine. And, unlike rain, snow lingers on the roof, and in some regions of Russia its height on roofs sometimes exceeds more than a meter. And the worst thing in this regard is precisely the minimum slope.

Therefore, you need to make a decision about whether to make the roof angle of corrugated sheets so small.

How to calculate the angle of inclination yourself?

First of all, pay attention to what kind of roofs your neighbors have. We mean the place where you are going to build. Usually they have almost the same slope, the value of which has been hard-won over centuries and tested by hurricanes. And calculate the exact angle of inclination finished roof This can be done either with the help of special graphs and matrices, or armed with a regular square.

Professional builders, for example, calculate the slope of a roof using a device such as an inclinometer, or using some geometric formulas. The result is written in degrees or ratio:

Or even simpler. As you probably remember from your school geometry course, the first thing you need to do is find out the length of the hypotenuse and leg. The hypotenuse is the straight line of the roof slope, and the distance from the ridge to the ceiling is the opposite leg. The distance from the middle of the ceiling to the eaves slope is the adjacent leg. Now let’s use the trigonometric function or arm ourselves with an engineering calculator:

The second one is no less common and is like this the right way: we determine the ratio between the height from the ridge to the ceiling and half the width of the ceiling. Divide the height by half the width of the building, and multiply by 100. Simple!

So decide what the slope of your roof will be based on four main factors:

1. Planned budget.
2. Estimated snow loads.
3. Average wind value.
4. The need for useful under-roof space.

And, if you finally come to the decision that you need a roof with a minimum angle, we will tell you how to avoid mistakes in construction and what you need to do.

Other important aspects of construction

Typically, minimum roof slopes with reinforced rafters are made in the roofs of those houses that are located in areas with frequent sunny days and little rainfall. To reduce heat interior spaces, in the roofing pie provide thermal insulation materials and a ventilated gap. Otherwise, all that remains to be taken care of is that no water gets into the house.

Leak protection

On flat roofs, when installing corrugated sheets, be sure to use sealing tapes and mastics for overlaps and joints of sheets. And such a roof is protected from leaks and damage by special membrane waterproofing materials. Here standard pie such a design: corrugated board => rafters => insulation => waterproofing => sheathing.

There is still such a moment. If you are making a roof with a slope of less than 10°, use a modern three-layer membrane as waterproofing. Only this material can protect the roofing pie from moisture inside.

And finally, no matter how minimal the roof slope is, you will still have to build a drainage system for it. Moisture, like snow, lingers on such surfaces longer than many expect. Therefore, plan the slope so that it goes towards the water intake funnels, if the collection system is internal, or towards the gutters, if external.

Rafter system and sheathing

As in conventional projects, with a minimum slope, the corrugated sheeting is also laid on the sheathing and secured with self-tapping screws with rubber gaskets. But clamp the overlap, from 10 cm to 20 cm, with steel rivets. We recommend making an overlap of two waves.

There is such a dependence: the smaller the angle of inclination of the roof, the wider it is necessary to overlap the sheets. And the smaller the effective area of ​​the material:

• Within 15-30° of inclination, make an overlap of 15-20 cm.
• But when building a steeper roof, with an angle of 30°, the overlap should be from 10 to 15 cm.
• If the angle of inclination of the roof is already less than 14°, then the sheets must be laid horizontally with an overlap of 20 cm.
• With a minimum angle of inclination of a metal profile roof of 8°, the joints between the sheets must be made double, carefully sealing them with sealant to prevent water from getting inside.

The usual rafter system is installed in increments of 60 cm to 1 meter, but with a minimum roof slope it is better to reduce this increment to 40 cm. The base will be stronger and will more easily withstand the accumulation of snow on the roof.

In addition, with minimum slopes between the rafter system and the corrugated sheeting, a ventilated gap is required - this is also a measure to reduce heat loss. More specifically: the smaller the angle of inclination, the wider you will have to make the gap for ventilation - and this is at least 50 mm.

Installation subtleties

Here is a detailed master class on how to install corrugated sheets on such a roof:

Follow the technology, follow our advice - and everything will work out!

Minimum slope of a corrugated sheet roof: we build a roof with a minimum angle

DIY pitched roof (calculation and construction instructions)

Shed roof– one of the simplest and cheapest types of roofing to install. Convenient for low-rise construction ( summer houses, cottages) and utility rooms (barn, garage, etc.). Sometimes it is also used for cottages, and a window can be built into the slope. As a rule, for permanent housing such roofs are installed in areas with strong, prolonged winds (one direction) or in areas with little snow. The wind attack area on such a roof is small, so the design turns out to be optimal.

Minimum angle pitched roof slope, ensuring good drainage of rainwater and spontaneous melting of snow in the spring - 10 degrees. However, the angle of inclination also depends on the roofing material and the size of the roof. If the distance between load-bearing walls is large, and the roofing material does not hold the weight of snow well enough (which can fall in any quantities, including very large ones), it will be necessary to increase not only the number of rafters, but also their angle of inclination. The maximum angle is 60 degrees; tilting more is simply irrational.

For a single slope made of corrugated sheets, the angle of inclination of the slope is from 8 to 20 degrees, for seam roofing from 18 to 35 degrees, for metal tiles from 25 to 35 degrees, for slate from 35 to 50 degrees. The slope is ensured by the difference in the height of the load-bearing walls, on which the rafter system actually rests (in fact, the rafters of a pitched roof are beams). Sometimes the edges of such a roof are decorated with curbs, like a flat roof, leaving only the drain edge open (the top of the curbs must be decorated with waterproofing caps, cladding, etc., otherwise water, absorbing into them, will destroy both the walls and the roof).

Having decided on required angle tilt, we adjust the height of the walls accordingly and purchase from the right quantity roofing material. The required angle of inclination can be measured using a building level and fixed with a pole and rope at the stage when the walls are still the same height. One end of the rope is attached to the “low” wall, the second - to a pole installed on the future “high” wall. Since the angle at which the rope goes coincides with the desired angle of inclination of the roof, the height of the pole at which the rope is fixed is the desired level of “superstructure” for the “high wall,” and the length of the rope is the length of the rafter beam.

To ensure that the roof has overhangs on both sides of the building and protects the walls from precipitation, the length of the manufactured rafters is increased by another meter. For those who do not trust ropes or the angle measured by a building level, we can advise using trigonometric calculations (this will, by the way, be more reliable).

Calculation of material for a pitched roof

If you look from the side, you can see that the pitched roof is a right triangle. One of its legs (ac) is the width of the house (the distance between the load-bearing walls), the second (bc) is the difference in the height of the load-bearing walls (the height of the superstructure), and the hypotenuse (ab) is the length of the rafters. Considering that we know what angle of inclination of the hypotenuse we need (usually the size of an acute angle is denoted by the letter “A”), we can calculate:

1. height of the “superstructure” wall L(bc) = L(ac)* tgA
2. rafter length using the equation L(ab) = L(bc)/sin A

The values ​​of tgA and sinA are in the table:

• Suppose the distance between the load-bearing walls is L(ac) = 6 m, and the angle of inclination A = 20 degrees.
• Then the height of the “superstructure” wall L(bc) = L(ac)* tgA = 6*0.36= 2.16 m.
• Length of the rafter leg L(аb) = L(bc)/sin A = 2.16 / 0.34 = 6.35 m.
• The length of the rafter leg with a margin to protect the walls is 6.35 + 1.0 = 7.35 m.
• The pitch between the rafters is determined depending on the roofing materials, so the specific number of rafter beams is determined based on this and the total length of the house. Usually the step is within 60-70 cm.

Roof installation

Let's consider the construction of a pitched roof and proceed to step by step instructions its buildings.

A simple pitched roof consists of rafters supported by load-bearing walls (sloping rafters), sheathing, steam-waterproofing and the roofing material itself.

1. Logs and mauerlats are made from dry straight-layer wood (preferably pine or larch); as a rule, 10x10 or 10x15 cm timber is used. In the mauerlats and the upper part of the logs, sockets and grooves are pre-selected - so that you can fasten the mauerlat and rafters not only fasteners, but also mechanically, hooking them onto each other.
2. Mauerlat beams are laid along the top of the load-bearing walls (high and low) and firmly attached to the walls ( anchor bolts, embedded wire, etc.). The beams must become part of the wall; the strength of the roof depends on this.
3. The rafters are installed with the upper end into a pre-cut nest of the upper Mauerlat, secured mechanically, the second end is placed in the same nest of the lower Mauerlat or the “heel” of the rafter is formed (usually this is just a triangular cut, which rafter beam rests on the lower beam and which does not allow her to slip off it). Then the top and bottom part rafters are nailed to the mauerlats or screwed with wire
4. If the span (distance between the load-bearing walls) is more than 5 m, then technically the pitched roof is already half of the gable roof, and needs supporting beams, racks, supports (struts) and crossbars. For this purpose, sometimes, while the walls are still the same height, transverse horizontal floor beams (beams) are laid on them, and then one of the walls is built up, forming nests around the shanks of the beams. These beams will then serve as support (beams) for the racks of the rafter system. Or they provide a protrusion (shelf) in the wall for subsequent laying of horizontal beams. Racks can be simple, vertical, or angled, and also have struts. If the span width is more than 7 meters, in mandatory Either a column (supporting wall from below) or a truss truss is required.

Lathing and vapor and waterproofing

The finished rafter system is sewn with an unplaned board across the joists. The distance between the boards can be up to 15 cm if the roof is hard. For soft roof It is better to minimize the gap. Lay on top of the sheathing vapor barrier film, securing it to the sheathing with a construction stapler or nails, laying wide plates of electrical cardboard or plastic under the staple or nails (otherwise they will break through the film), if necessary, arrange thermal insulation and waterproofing.

Rolled materials are always rolled out across the rafters, the tapes are laid from bottom to top, with a slight overlap, and the joints are sealed (for roofing felt - with bitumen mastic, for polyethylene - with glue or tape, etc.).

The only drawback of such a roof is the relatively rapid removal of snow from it in the spring, so it is advisable to either provide the ability to clear snow from it (preferably without climbing onto the roof, since it does not withstand winter walking on it well), or snow-retaining devices that hold snow on the roof, until it melts. Well-waterproofed roofs of low country houses with strong rafters and a slope of 20-35 degrees, you can cover it with geogrid, fill it with soil and sow it with grass.

Roof insulation with several types of insulation in a detailed guide to choosing insulation technology with instructions.

Advice from life: take the time and money and treat the rafters and, preferably, the sheathing boards with a fire-bioprotective compound. Especially if it's not open veranda or a gazebo. Because a small mistake (imperceptible damage) during insulation and the tree will gradually (sometimes for quite a long time, but still) rot. And the “final surprise” can be downright dangerous!

Do-it-yourself pitched roof: installation of a rafter system, calculation

Do-it-yourself pitched roof made of corrugated sheets

If you decide to build small garage, an outbuilding or a shed, then you can build the roof of such a structure yourself. Ideal option there will be a pitched roof made of corrugated sheets. This type of design is not only simple to implement, it is quite easy to maintain, strong, durable and aesthetically pleasing. Before installing such a roof, it is important to choose the correct slope, choose the thickness of the corrugated sheet and the cross-section of the load-bearing elements. We will talk about all this in our article.

Selecting a profiled sheet

In order for a corrugated roofing to be strong and durable, it is necessary to understand the types of this material. On sale you can find the following types of profiled sheets:

• Products marked “C” are wall sheets with a thickness of no more than 0.06 cm and with a wave height of no more than 1 cm. Such corrugated sheets are not subject to special requirements in terms of rigidity, since it is used for wall decoration.
• Sheets marked “NS” are more durable material, which can be used for walls and roofing. The height of the corrugation is 1-3.5 cm, and the thickness of the sheet reaches 0.85 mm.
• Profiles marked “H” are load-bearing corrugated sheets. The wave height is 4 cm and above, and the minimum sheet thickness is 3 mm.

It is better to make the roof of a pitched roof from profiled sheets marked H and NS. A profiled sheet marked C is only suitable for covering a small outbuilding, provided that a continuous sheathing is installed.

Important: because single-pitch structures They are distinguished by an impressive surface area of ​​the slope; the roof takes up a significant snow load. In this regard, for a pitched roof it is recommended to use corrugated sheets of the following brands: NS44 and NS55.

Selecting the angle of inclination

Before making a pitched roof from corrugated sheets, you need to decide on its slope. This is important for the effective removal of melt water and water during rain. Most often, for corrugated roofing, a sheet with a corrugation height of 3.5 cm and a thickness of 0.07 cm is chosen. This coating can be laid on lathing installed in increments of 1.5 m. This design of a pitched roof can withstand a load of no more than 60 kg/m² . Moreover, you can walk on this roof when carrying out repair work or clearing snow.

If you decide to make a pitched roof from a profiled sheet, then the angle of inclination largely depends on the following indicators:

• At an angle of inclination within 5-10°, the continuous lathing. The overlap along the longitudinal joint of the sheets is made into two waves, along the transverse one - at least 30 cm.
• The angle of inclination of the slopes in the region of 10-15° requires the arrangement of sparse sheathing in increments of 0.45 m. The longitudinal overlap is made by one wave, and the transverse overlap is at least 20 cm.
• A roof with a slope of more than 15° is made using lathing installed in increments of 0.6 m. The longitudinal overlap is equal to one wave, and the transverse overlap is at least 17 cm.

It is also worth considering that when covering a pitched roof with corrugated sheeting grade S-8, the angle of inclination must be at least 15°, and the sheathing must be continuous. If profiled sheets C-10 and 20 are being installed, then continuous sheathing is needed for a slope of less than 15°. In other cases, the sheathing is installed in increments of 30-50 cm. Sheets C-21 and NS-35 can be mounted along a sparse sheathing even with a slope of less than 15°. In this case, the greater the angle of inclination, the greater the pitch of the sheathing will be.

Attention: profiled sheets of grade N-60 and modification N-75 can be mounted on the sheathing installed in increments of 3-4 m, but the angle of inclination should not be less than 8°.

Installation sequence

We will consider the installation of a pitched roof made of corrugated sheets using the example of a combined roof (without an attic). We begin the installation of the structure with the manufacture of the Mauerlat. To make it, you will need a beam with a cross-section of 0.15x0.1 m. If your structure is built from timber or logs, then in this case the role of the Mauerlat will not be taken over by the final crown.

If the walls of the building are made of fragile gas or foam blocks, then under the Mauerlat it is necessary to make monolithic belt, into which steel pins will be placed at the installation stage to secure the beam. Do not forget to isolate the horizontal beam from walls made of another material using roofing felt.

Rafters and sheathing

Further installation of a pitched roof made of corrugated sheets involves marking the rafters. We carry out the work in the following sequence:

1. We lay the board on the Mauerlat beam in such a way that there are overhangs 400-500 mm long along the edges.
2. Using a level and a square, we mark the places where the lower and upper cuts will be made. The width of the gash must exactly match the width of the rafter leg, and the depth of the gash should not be more than 1/3 of the height of the rafter leg.
3. Next, using this cut, we make a template, with the help of which we transfer the markings of the cut under the rest of the rafters.

After this, you can begin laying the rafters and fixing them to the mauerlat beam. To do this, you can use two nails 150 mm long, which are driven in a cross direction, or steel staples.

Laying waterproofing

The construction of a pitched roof implies the mandatory use of waterproofing. To do this, use a special film, which is laid across the direction of the rafters from the bottom of the slope upward. The material is laid without tension with an overlap of adjacent strips of 10-15 cm.

The waterproofing is attached to the rafters using a construction stapler. After that, counter battens are placed on the rafters on top of the waterproofing. They are needed for ventilation of the under-roof space.

Advice: if you are making a non-ventilated roof, then instead waterproofing film use a special vapor-permeable membrane. This way, moisture from condensation will not accumulate under the roof.

The design of a single-pitched roof system, depending on the angle of inclination and the type of corrugated sheeting used, provides for the use of continuous or sparse sheathing. We fasten the sheathing boards from the bottom of the slope, moving upward. For fixation, use a staple or nail.

After this, we proceed to install the fillies that will form the roof overhangs. If desired, you can not install fillies, organizing overhangs due to rafter legs protruding beyond the walls. Subsequently, the roof overhang can be hemmed to protect wooden elements from dampness.

Laying corrugated sheets

To install the profiled sheet you will need the following tools and accessories:

• metal scissors;
• screwdriver;
• rope;
• roofing screws with rubber sealing gaskets and hex heads;
• staples;
• stapler;
• two stairs (longer than the length of the slope and from the ground to the roof).

To lift the corrugated sheet at the two ends of the ladder, you need to make loops from a rope, the length of which should be four times greater than the ladder itself. We put corrugated sheeting into the resulting loop and lift it to the roof using a ladder.

We lay corrugated sheeting from the bottom corner along the horizontal overhang of the roof. To fix one sheet you need to take about 9 screws. In this case, screws can be screwed into the rib if its height does not exceed 20 mm, or into the deflection if the corrugation height is greater.

Attention: when screwing in the screw, watch the sealing gasket. It should be pressed tightly against the sheet, but not too tight or too loose.

Laying out the sheets vertical stripes so that adjacent elements in a row overlap each other by the width of one wave. The overlap of adjacent rows is 150-200 mm.

Now you know how to make a roof from corrugated sheeting with your own hands. It is equally important to take care of the organization of drainage. Otherwise, unorganized drainage can lead to premature wear of the base, foundation, and damage to the facade.

Roof made of corrugated sheets: do-it-yourself pitched roof

Today, corrugated sheeting is one of the most common materials used in construction. This is a reliable and strong foundation not only for roofing, but also for fences and facades.

Use of corrugated sheets in the roof gable roofs– this is the optimal balance of functionality and appearance.

With its help, you can not only make strong and lightweight floors or cover ceilings and walls, but also perform roofing work. At the same time, even the slope of the roof does not affect the quality of the coating; the only condition is compliance with the recommendations for installation and overlap of the material.

Any instruction will confirm that the base for laying corrugated sheeting must be strong, and the presence of sheathing is also required. Well, let's look at everything in order.

In order to use corrugated sheeting as a roofing material, you must follow all the rules and recommendations of SNiP, according to which it is permissible to use profiled sheets “wall”, “universal”, “for floors” and with a wave height of twenty millimeters.

It is also best to take corrugated sheets from polymer coating, corresponding to the characteristics climate zone. The type of rafters for the roof, their pitch - everything must meet the requirements, any instruction will confirm this.

We propose to find out what is included in the roofing cake, what recommendations can be used when installing rafters and corrugated sheets.

Parameters affecting roof slope

The slope depends on many factors that must be taken into account when installing not only corrugated sheeting, but also determining what the pitch of structural elements will be, what are the conditions for fastening rafters and sheathing.

A slight, minimal roof slope can be done in areas where fairly strong wind loads are observed. In such places of residence, there is a windage of the roof due to powerful winds, and this can cause its breakdown or damage.

Even the most durable and expensive corrugated sheeting will not help if the base is unreliable. This can be avoided by strengthening the rafters of the structure and using additional fasteners. It is also worth reducing the installation step of the main frame elements and sheathing.

But for areas where significant snow loads are expected, the roof slope can be up to forty-five degrees so that the snow does not linger on the surface. In this case, there is no need to reinforce the rafters; with such a slope, the load from snow can be ignored altogether.

Minimum slope diagram for various types roofs.

Minimum slopes and reinforcement of rafters are taken into account when installing roofs in areas with little precipitation and plenty of sunny days. The roof of such a roof must include additional thermal insulation materials in order to reduce excessive heating of the interior; a ventilated gap is required. It is also recommended to use special membrane waterproofing materials so that the entire roof pie can be protected from leaks and damage.

Technology of laying corrugated sheets on the roof

The technology for a prepared roof has its own specifics. A pie of this design is the following combination: corrugated sheeting – rafter system – insulation – waterproofing layer – interior lining. In this case, the pitch of the rafters will depend on the size of the roof, the expected loads, and the type of material used to make the rafters themselves.

The roof sheathing under corrugated sheeting can be made of wood or metal.

The thickness of the thermal insulation layer is selected based on climatic conditions, it is necessary to have waterproofing and vapor barrier. In addition, for small slopes, there must be a ventilated gap between the corrugated sheet and the rafter system, which will not only ensure correct operating conditions, but also reduce heat loss. Don't forget about correct device battens.

When installing a rafter system, it is important to observe the pitch, which can range from sixty centimeters to one meter. In rare cases when reinforcement is required, the step can be reduced to forty centimeters - then the base will be stronger.

The corrugated sheeting is laid directly on the sheathing, fastening is done with self-tapping screws with rubber gaskets. The fastening step of the corrugated sheet can be different; each self-tapping screw is screwed into the recess of the wave adjacent to the sheathing.

The overlap, which can range from one hundred to two hundred millimeters, is fastened with steel rivets, the pitch of which can be different. When overlapping for a slight slope, it is best to overlap in two waves.

How to measure the slope angle?

Roof slope is usually calculated using special device called an inclinometer or using geometric formulas. The angle is measured in degrees, percentages, or their ratio.

In geometric calculus, you first need to find out the length of the hypotenuse or legs. The hypotenuse in this case is a straight line, which is represented by the slope of the roof. The distance from the ridge to the ceiling will then be the opposite leg, the adjacent leg will be the distance from the eaves slope to the middle of the ceiling.

Knowing these values, you can use trigonometric function quickly calculate the minimum slope angle for the roof. The angle of inclination is usually calculated using an engineering calculator, which can give a percentage.

There is another fairly simple way, which is to determine the ratio between the height from the ridge to the ceiling and half the width of the ceiling itself. Here the height is simply divided by half the width of the building, and then multiplied by 100.

Any roof slope requires a device drainage system, which will properly remove precipitation and excess moisture from the roof surface. When organizing a slope, it must be planned in such a way that it goes towards the water intake funnels if there is an internal collection system, or towards the gutters if there is an external drainage system. It is important to adhere to this system if there is a minimum angle of inclination!

When organizing a slope slope of up to ten degrees, it is necessary to use special membrane roofing coverings that provide reliable protection roofs from moisture and damage to materials. The peculiarity here is as follows: as the roof slope decreases, the gap for ventilation should increase.

Another helpful advice concerns the laying of roofing material if a minimum angle of inclination is made. As we have already seen, the corrugated sheet is mounted with an overlap on the base, which ensures protection of the under-roof space.

Therefore, during installation, the installation conditions and the recommended overlap size must not be neglected; the fastening step must be observed. If you neglect at least one of these criteria, the consequences will be very disastrous.

An important role in the construction of a reliable and durable building is the design stage. If we talk about roofing, it is important to choose the right slope of the corrugated roof. This is not just a matter of personal preference and aesthetics. The size of the attic or attic, the presence or absence of problems with snow accumulation and resistance to wind loads depend on the angle of the roof. In order to determine the slope of the roof, it is important to take into account many factors.

Some believe that the angle of inclination is related only to the desire of the customer and the architectural idea. In fact, there are two groups of factors on which the minimum slope depends:

• Climatic conditions.
• Features of roofing material.

Climatic factor

There are several climate features that can significantly affect the angle of inclination:

Dependence of the angle of inclination on the roofing material

Obviously, for areas with heavy rain and snow, it is necessary to make the roof at a large angle, and in areas with strong winds- with a minimum angle.

The choice of minimum slope is also influenced by the characteristics of the roofing material. Each of them creates its own bottom strip for the corner of the roof. Climatic factors can increase this value, but it is not worth making the roof flatter than the material suggests.

• Ondulin. The minimum slope of the slope is 6°.
• Soft tiles. Minimum 11° tilt.
• Profiled sheeting. At least 12°, otherwise you will need to start gluing the joints of the corrugated sheet.
• Metal tiles. The minimum slope value is 14°.
• Rolled materials in two layers - 15°. If a three-layer coating is used, the roof can be made completely flat (2-5°).

Various roofing materials

SNiP requirements

Slate, tiles and other piece materials. The minimum slope value is 22°.

According to the requirements of SNiP, for a roof made of corrugated board the minimum permissible threshold is 8°, but it is permissible only for outbuildings and industrial buildings. The angle of corrugated roofing for residential buildings is at least 10°. However, construction companies only provide a guarantee on structures with a slope of 12° or higher. The maximum tilt angle can be even 70° or more.

However, it is worth remembering that the lower the height of the roof and, accordingly, the angle of the slope, the smaller the distance should be between the sheathing boards. As can be seen from the table below, a roof with a slight slope requires continuous sheathing.

SNiP requirements

Advantages and disadvantages of minimum tilt angle

Why is there even a question about the minimum acceptable standard for a gable and pitched roof? What are the advantages of low structures? The following are some of their advantages:

• Reducing the consumption of roofing material. If the roof is high, it needs a more massive one rafter system. By reducing the angle of the slope, you can reduce the cost of the entire structure. However, it is worth considering that the overlap of sheets will be greater on low roofs.
• Safety when performing roofing work.
• Shed roofs are devoid of a ridge, and therefore the entire scope of work with it.

In addition to the advantages, low roofing also has a number of disadvantages:

• Slow water flow, which means a high probability of leaks and damage to the roofing pie. To do this, the sheets must be sealed in places where they overlap.
• High snow load on the roof. In some cases, during heavy snowfalls, you will need to clean the snow from the corrugated sheet roof yourself.
• Inability to equip a residential attic.

Calculation of the angle of inclination

Taking into account all the above factors, you should decide what angle of inclination will be optimal for specific situation. First of all, when planning to build a house, you need to look at the roof angle of your neighbors, because the climatic conditions in one area are the same.

It is also important to determine how the attic space will be used. If you need to create one or more living rooms, then the roof height will be greater than the minimum allowable.

There are several types of corrugated sheet roofs:

• Low slope (14° or less). The vertical overlap of the material is 20 cm, and the joint is made in three waves.
• Medium slope (15-30°). The vertical overlap is 15-20 cm and the overlap is 1 or 2 waves.
• Steeply inclined (30° and above). The minimum overlap is 10-15 cm, and the overlap is one wave.

As you can see, the slope of the roof also affects the consumption of roofing material. If you take into account all building codes and regulations, as well as correctly determine snow and wind loads, you can create the optimal roof slope angle for the building under construction.