December 28, 2016

What slope should the pitched roof?

Recently, pitched roofs have become very popular. First of all, it is easy to build, and it will take much less money. Most often, such a roof is built in country houses or non-residential household buildings. A pitched roof will reliably protect your home from environmental influences. It will also cope remarkably well with wind loads, provided that it is in relation to the windy side.

Many experts claim that you can install such a roof yourself without having any special skills. You just need to invite a few friends to help you. The main thing is to follow the order in which all work is performed and monitor safety. Why do many people choose to build housing with a lean-to structure? A minimum of material, easy installation, relatively low cost - these are the main factors that influence the choice of our compatriots.

Structures with a pitched roof have some special features. First of all, they allow you to rationally use all the space in the room. Often in such houses there is no attic or attics.

This type of roof is often used for the construction of non-residential premises. In a residential building, such a roof in a residential building creates a unique design.

Varieties

All pitched roofs, depending on the availability of ventilation, are divided into three types:

• With ventilation;
• No ventilation;
• Modern option.

Shed roofs with ventilation are constructed for closed buildings with an inclination angle of 5-20 degrees. The voids in the roofing pie act as ventilation. Air circulates through them. The voids are located between the insulation and waterproofing. The construction of such a roof requires the presence of holes at the roof level on all sides. This is how air circulates, regardless of the direction of the wind. Thanks to such factors, the service life is significantly increased.

Non-ventilated roofs are often built for terraces. The minimum slope of a pitched roof is the main feature of such a structure. It ranges from 3 to 6 degrees. Remember, an open type of room requires constant maintenance, especially in winter.

Modern builders use a modern combined version. It has the characteristics of ventilated and non-ventilated roofing. It provides a slight roof slope thermal insulation material. This way you can save a significant amount on materials. But on the other hand, there are inconveniences associated with the operation of the roof. For example, in winter you need to clear snow often.

Advantages of pitched roofs

Some advantages one pitched roofs we have already mentioned. This is a simple and easy installation. Now let's look at the other advantages of such a roof:

• The construction of such a roof can significantly save the developer money on wood. This is especially true in regions where wood is a scarce material. After all, to install a pitched roof it is necessary to use a minimum amount of wood.
• reduces windage. Thanks to this, the space under the roof is used rationally. In such a building there is no functional and uncomfortable attic.
• This type of roof is used for the construction of non-residential utility premises. In this case, the walls should be of different heights.
• If there is a roadway near the house, then everything can be arranged in such a way that snow and rainwater are not dumped onto the roadway.

Rafter system

The foundation of any roof is the rafters and sheathing. They distribute the load evenly roofing material and precipitation (snow). Before you start construction rafter system, it is necessary to take into account the weather conditions of the area (wind force, rain). In this case, all calculations must be carried out with a reserve.

Calculation of the rafter system must be carried out at the design stage of the structure. Here they take into account the plan of walls and partitions, the area of ​​the structure, and the length of the large span.

What should the roof angle be? This depends on the attachment to the supports of the rafter system. Today there are three types of fastening:

• Inclined;
• Hanging;
• Sliding.

When constructing inclined rafters, they are placed at an angle. The load occurs on external walls. The other end of the rafters rests on the beam. The fastening is carried out using struts and resistant ones. The support can be a partition or external load-bearing walls. The pitch between the rafters can be from 60 to 140 cm. This distance depends on the type of roof covering and the thickness of the wood. Remember that the construction of such a roof requires different wall heights. This type of rafters is often used for the construction of non-residential buildings.

If it is impossible to build a support for the rafter system between the side supports, use the hanging type. In this case, trusses are built on the ground. Afterwards they are carefully transferred to the outer supports. This is the most labor-intensive process, and the difficulty of the work lies in the large spans of the roof. Load-bearing elements are made of metal, reinforced concrete or wood.

The support in the sliding rafters is the ridge beam. “Slippers” are used to connect rafters and walls. This type of rafters is used to construct a roof in a house made of timber. In this way, the large shrinkage of the log house is compensated, preventing damage to the building in the places where its main elements are connected.

Necessary materials for construction

If you do not know how to calculate the angle of the roof, you need to study the instructions. After all, there are some features of this process. First of all, you need to pay attention to the roofing material. After all, each of them has its own permissible slope standards.

Slope of a pitched roof depending on the material:

• Corrugated sheeting - 8 - 20 degrees;
• Slate - from 35 degrees;
• Metal tiles - from 25 degrees;
• – 18-35 degrees.

When building a roof yourself, you should not make its angle less than 8 degrees. In this case, there is a high probability that the roof will simply collapse under the weight of the snow.

The minimum slope has been determined; now it is necessary to align the length of the building walls so that the required angle is formed. In this case, it is better to calculate the angle of a pitched roof using trigonometric formulas. To avoid mistakes, many turn to specialists for help. They will calculate all the features of the roof. In other words, they will make a project for your roof, which will indicate all the necessary data for the construction of a high-quality and reliable structure.

Having spent a minimum of time, you can independently build a pitched roof for your home. This process is not labor intensive. As a result, you will get a reliable home with rationally used interior space.

Shed roof types are becoming increasingly popular. This is due to many factors. Among them low price, high practicality, original appearance. Their angle of inclination is most often different from other types. The ramp is smaller. It is about the minimum angle of inclination of a pitched roof, what the calculation involves and what is limited, that we will talk about in this article.

Types of pitched roofs

Such roofs can be classified according to the presence of ventilation. Based on this, there are the following types:

• Ventilated. Used in the construction of structures closed types. The slope level will fluctuate between 3-20⁰. The arrangement of ventilation assumes the presence of voids in the spaces between the hydro- and thermal insulation. It allows you to significantly increase the service life. Openings are installed on the sides of the structure at the same level as the roof, ensuring a constant flow of air.

• Not ventilated. Mainly used during the construction of terraces. The slope is 3-6⁰. An open-type structure requires special care, especially in winter.

A third option, combined, is also possible. In this case, the slope of the pitched roof is minimal. Material savings for construction are achieved. However, there are some drawbacks. When there is an abundance of snow, constant snow removal is required to reduce the load on the roof.

SNiP requirements

The requirements of SNiP II-26-76 and the update of SP 17.13330.2011, which determine the construction of roofs, state that the slope flat roof must be within 2-12⁰. We can conclude that a value of more than 12⁰ is expected for pitched options. But it is not so. There is no clear description of the angle of a pitched roof. Accordingly, the requirement for 12⁰ will not be mandatory. In practice, the boundaries between flat and sloped are determined by eye. There are no prescribed requirements.

You can classify a structure as a lean-to structure based on the material used. Flat ones are mainly covered with bitumen-based materials.

Determining the optimal angle

To calculate the angle of inclination of a pitched roof, you should take into account the architecture of the structure. The optimal inclination will mainly depend on this. For small buildings it will be more economical and a slope of 10 to 15 degrees will be sufficient.

It is problematic to create an attic with a pitched roof. Design features impose their own limitations. Making full use of space is problematic. However, if an attic-type room is needed, then it is not advisable to make a slope of more than 30⁰. Even with a flat roof with a slight slope of 10-20⁰, you can create several rooms with different ceiling heights. By correctly distributing the rooms, you can fully exploit the space under the rafter system.

It happens that the layout involves the presence of floors offset relative to each other. In this case, the optimal angle for using the attic space will be from 20 to 35⁰.

How to calculate the minimum slope?

The factors that will most influence the maximum and minimum angles are the requirements for roofing materials. Each of them has its own limitations. However, a pitched roof is flat, so it is worth taking a closer look at how to calculate the angle of inclination for the minimum level.

Rolled bitumen materials provide the possibility of overlapping any type. There is only a limitation regarding the maximum value - 25⁰. In practice, it is better not to work with such materials at an angle of more than 15⁰. The work becomes noticeably more difficult. The most durable coatings are those whose top layers are covered with stone chips. Most of them are laid by heating on a bitumen base.

For previously popular slate a significant angle is required. When using reinforced sheets, it is necessary to have a slope of 25⁰, when using ordinary sheets - from 35⁰. Here we note that the value of the overlap in the top row will be taken based on this value. The more, the more significant the overlap should be.

Euroslate does not require such a steep slope. Laying is allowed from 6⁰. When attaching bitumen slate, the slope will affect the amount of overlap and the design of the sheathing:

• Slope from 6 to 10 degrees – continuous;
• From 10 to 15 – along the axes the step is 45 centimeters;
• From 15 and above – step 60 centimeters.

Metal tiles can be laid at a slope of 10⁰. However, when working with angles from 10 to 20 degrees, the joints will have to be processed and sealed. It's complicated. The most optimal solution would be to use metal tiles on structures with values ​​starting from 20 degrees.

WITH corrugated sheeting You can work with an inclination of 5 degrees. In this case, the overlap surface increases, and the joints are compacted and sealed.

Seam roofing, regardless of the type of manufacture, can be used with angles from 8⁰. If the joints are fully waterproofed, the slope can be reduced to three degrees.

Bituminous flexible tiles should be installed on structures with a slope of 11⁰. When the angle is up to 18 degrees, the lining layer must be made continuous. When more than 18⁰, rolls of this layer can be rolled out only along the outer contours of each plane and, in addition, the holes can be insulated.

Cement and ceramic tiles Can be installed on roofs with a slope of 22 degrees. You can reduce it to 10, but underneath it you will have to create another layer of waterproofing. In practice, it is rarely used on pitched roofs due to its weight.

Formula for calculating the required values

Since pitched roofs have an emphasis on the walls, which are located on at different levels height, then the slope is ensured at the stage of wall construction, adjusting the height. In general, for construction in building regulations accepted values ​​are 5-60°. In areas with increased levels of snow cover, the values ​​already vary between 45-60°. When calculating the angle of inclination, loads from precipitation must be taken into account. This is especially true for single-pitch ones with their nuances of structure and strength of the materials used.

The following formula can be used in calculations:

L walls =Llength ×tgA,

L walls - the height of the pediment;
L length – value of the length of the wall;
A – angle of inclination

During the construction of a pitched roof, you need to calculate the length of the rafter legs. The following formula is used

L rafters =Lwalls ÷sinA.

To determine sinA and tgA, use data from the following table:

For example, let's do the calculation.

The wall is 6 meters long. Llength = 6 meters;

The roof slope is 25 degrees. A = 25°;

Determine the height of the wall: Lwall=6×tg25°=6×0.47= 2.82 meters;

We determine the length of the rafters: Lrafters = 2.82÷sin25° = 2.82÷0.42 = 6.7 meters.

In order to obtain the most reliable values, you need to add the overhang values ​​to the length of the stops. They will serve as additional protection.

Advantages of a pitched roof

This design has many advantages. They brought this design to a leading position in the construction of utility structures. These include:

• Simplicity of the design process;
• Fewer materials required;
• Easy installation;
• Low construction cost;
• Short construction period.

Flaws

However, naturally, there are disadvantages.

• During construction, it will not be possible to equip a full-fledged attic;
• Making complete insulation is less possible than with the other type. This is explained by the minimal amount of usable space under the roof.

Carrying out correct calculation will ultimately result in a building with the best appearance. For the most part, private developers choose more high options, which can give the building a more slender appearance. Yes, and a more spacious attic can be equipped. However, from the financial side, erecting a single-pitched, flat roof will cost much less than pointed roofs.

Roofs with one slope are becoming fashionable. There are many reasons for this, including their practicality, low cost and distinctive appearance. The slope of shed roofs in most cases differs from gable and hip roofs: it is smaller. Let us consider what the optimal depends on and what is limited by minimum slope pitched roof.

The updated version of SNiP II-26-76 “Roofs”, updated within the framework of SP 17.13330.2011, indicates that the slope of a flat roof should be from 2° to 12°. It is logical to assume that the standards assume a value for a pitched roof of over 12°. However, SNiP does not contain any information about the slope of a pitched roof. A value of 12 degrees is optional. In fact, the boundary between a flat and a pitched roof is not fixed by regulation and is more often determined “by eye”.

One of the factors indicating that the roof is pitched is the use of roofing material intended for pitched roofs (all types of tiles, sheet materials, corrugated sheets, etc.). Flat roofs on average they have a slope of 3° and are covered, with rare exceptions, with rolled bitumen materials. Roll bitumen roofing can successfully get a job pitched roofs.

Sloping pitched roof, almost flat

Determining the optimal slope angle

The optimal slope of a pitched roof is dictated by the architectural and planning features of the building. With the same gable roof slope, the ridge of a shed will be twice as high, so shed roofs are flatter. For a barn, garage, or veranda, in most cases 10-15° will be sufficient. A shed roof is economical, especially for small buildings. As a rule, a slope of 10-15° is sufficient.

A pitched roof is of little use for organizing an attic in the classic form: one part of the room will be too low, the other too high, such a volume is difficult to use rationally. Even when constructing an attic floor, it is hardly worth making a slope of more than 30°. A roofless shed roof, relatively flat, (10-20°) allows you to equip rooms with different ceiling heights on the floor. Living rooms are located in the higher part, and bathrooms, utility rooms, and staircases are located in the lower part.

If the layout provides for offset floor levels, a steep pitched roof with a slope of 20-35° would be rational.

Steep roof, approximately 35°

Calculate the minimum slope

The limiting factor for the minimum and maximum slope is the manufacturer's recommendations for specific types of roofing materials. Shed roofs are quite flat; we will be more interested in the minimum values.

Roll fused bitumen roofing allows you to cover any roof, including flat ones. Only the maximum angle is limited to 25°, although it is better not to go beyond 15° so as not to complicate installation. The most durable and reliable bitumen-polymer materials, the top layer is sprinkled with stone chips. Rolled materials are hot glued to bitumen mastic.

Shed roofs are often used in Western Europe during the construction of budget suburban housing. The house has a higher facade with living rooms and French balconies on the sunny side

Asbestos-cement corrugated sheets (slate) require a fairly large slope. For reinforced profile sheets it must be at least 25°, for regular profiles - 35°. It should be noted that the amount of overlap of the sheets of the top row is taken depending on this value. The higher it is, the greater the overlap.

The so-called “Euro slate” is less demanding on surface steepness; a minimum of 6° is allowed. When installing corrugated bitumen sheets, not only the amount of overlap, but also the design of the sheathing depends on the slope: at 6-10° it should be continuous, at 10-15° the pitch of the bars or boards is 45 cm along the axes, with a larger value 60 cm is sufficient.

Metal tiles can theoretically be laid with a slope of 10°. But with a parameter of 10-20°, you will have to seal all the joints of the sheets, and this is not an easy task. A rational solution would be to use metal tiles for roofs with a slope of over 20° without additional sealing.

Corrugated sheeting can serve as a roofing covering for roofs with a slope of 5°. At 10° the overlap is increased and sealing tape is placed at the joints.

A pitched roof does not have to have the same slope over the entire surface

Seam roofing, both from standard elements with a factory seam, and when seams are made on galvanized steel sheets directly at the construction site, is used for bases with a slope of 8°. Provided the seam joints are sealed, the value can be reduced to 3°.

Flexible bituminous tiles are used on slopes of at least 11°. At a value of up to 18°, the lining layer must be continuous; at a higher value, it is enough to roll out the rolls only along the outer contours of each of the roof planes and additionally insulate the holes.

Ceramic and concrete tiles require a slope of 22°. It can be reduced to 10° if an additional waterproofing layer is installed under the tiles. The tiles are quite heavy and are not often used for pitched roofs.

The slope of the roof in one direction allows architects to find impressive interior solutions

The data provided is not completely accurate. Each roofing material manufacturer sets its own requirements; they may differ slightly. In addition, the slope largely depends on the snow load for a particular area. The less snow, the flatter the roof can be. There are territorial standards that establish minimum requirements depending on the climatic characteristics of the area.

We found out that the angle of inclination of a pitched roof is determined by the architecture of the building and is limited technical requirements. The calculation of the rafter system to ensure the necessary strength with rational consumption of materials should be entrusted to specialists.

The roof may be various types, be it a house, a cottage, a garage. An equally popular model today is the shed roof. Thanks to its positive characteristics. The main ones are ease of construction and low price.

Advantages of a pitched roof

• Simplicity of design.
• Cost-effective due to the absence of an attic.
• Low repair costs.
• Affordability.
• Light weight.
• Durability.

Disadvantages of a pitched roof

• At large angles of inclination Reinforced hydro- and thermal insulation is required.
• Wanted correct calculations material sections, as it depends on snow loads.
• The appearance is not very attractive. Small space under the deck.
• No possibility for an attic with small width.
• No resistance from strong winds on the high part of the flooring.

Construction of a pitched roof

There are two types of shed top structures:

• Non-ventilated. Installation of these types is used above the terrace, with a slight slope (3 - 6 degrees). And it requires constant care during snowy weather.
• Ventilated. Perfect for installing bathhouses, houses, garages to create a favorable microclimate. To do this, make gaps between the layers of insulation and holes on the sides of the roof.

In buildings with one slope, the rafter system is quite simple. The rafter supports rest against the Mauerlat. The difference in wall heights is achieved by tilting. Let's say the canvases are smooth, then you should build a pediment on one of them.

The span length in the rafter structure plays a big role. The rafter is not reinforced with intermediate supports if the length is 4.5 meters.

Consider a span length of 12 meters. The span is divided in half, and the center of the rafter will rest on the purlin, which, in turn, is installed on the rack.

You also need to secure two rafter legs to the rafters and lay the beam parallel to the supporting walls. Consequently, a span of 16 meters will have two such structures as with a 12-meter run.

The racks in this version are fastened with a screed. Only two rafter legs are needed, one for each rack. They need to be directed towards the supporting fabric, which is closer.

Sloping calculation of a pitched roof

It is influenced by the selected type of material.

A structure with one slope can be covered: tiles, metal profiles, metal tiles, roofing felt, slate, ondulin.

So, with the material very clear, you can proceed to the calculation, which will help roofing materials from freeing snow and rain.

The smallest inclined angle of the top is 5 - 10 degrees for roofing material. The slate should have a slope of 20 degrees. Tiles – 30.

Basically, the garage is covered with slate. Let's look at it with an example. Let's say a garage is 3.5 meters wide and built in the yard. Then the difference between the walls will be 1.27 m. That is, the formula is used here when the tangent of the angle of inclination is multiplied by the distance between the walls.

Tools and materials

In order not to be distracted while working, you need to prepare materials and tools in advance:

• Ceiling beams(the thickness is the same as the wall).
• Bruschi, not edged boards, wood.
• Construction stapler, saw, knife, axe, hammers, carpenter's pencil.
• Tape measure, level, brush(for coating fire retardants).
• Raw materials for waterproofing: mastic or polyethylene film.
• Thermal insulation: foam plastic or foam glass, mineral wool.
• Roof covering: can be metal tiles, seam roofing, roofing felt, corrugated sheets, corrugated slate.
• For fixing waterproofing and roofing materials: screws, nails, self-tapping screws, anchor bolts.

Rules for roof installation

The initial stage of construction will be the facade wall. It can be made from the main material of the building or wooden according to the project.

There are some rules for the phased installation of the coating:

• Arrangement of the Mauerlat.
• Construction of rafter legs.
• Installation of waterproofing.
• Arrangement of sheathing.
• Creating a roofing pie.

Rafter legs are the basis of the frame and have the following features:

• Coniferous wood species are used for harvesting.
• Dry thoroughly (humidity 20%).
• Covered with antiseptic and fire-resistant impregnation.

To invest the minimum cash When building a deck, here are some tips:

• Distance between load-bearing walls guarantees the reliability of the design. Additional supports can be replaced with two beams between the posts if it is no more than 4.5 meters.
• Calculate the angle yourself roof slope.
• When constructing walls, leave them at different heights., since the coating will have one slope.
• The sheathing must be strong, smooth, solid.
• Lay the covering only with an overlap.
• The voids between the joists are filled building material, except for spaces where there will be drainage.
• Garage frame made of stone, you should put a Mauerlat on the third row to make the surface even and strengthen the lag.

Mauerlat for a pitched garage roof

Channel, metal beam, wooden beam used in the manufacture of Mauerlat. A beam is laid along the outer border of the wall; it will support the rafters.

Taking on the load, with its further distribution over all walls, is the purpose of the Mauerlat. And not only that, he also connects the structure to the roof.

When building a garage, the mauerlat is made of two beams that are laid on walls opposite each other. Moreover, at different heights, which forms the angle of inclination of the garage roof. Mauerlat is attached anchor bolts.

To make them hold more securely, construction glue is poured into the holes. Through holes are drilled in the beams to secure the anchor bolts. Next, staples are applied on both sides of the rafters to the base of the roof.

Features of creating a pitched roof

The main feature of single-pitched peaks is the absence of skates and posts. In their design, it is enough to lay beams on the walls various sizes, and you get a slope. If the width of the covered opening is 4 meters, no additional work will be required to maintain the covering.

The choice of lathing is influenced by the type of coating. The use of a soft covering entails the installation of a perpendicular beam, as well as the fastening of an OSB board to it. This will be like a flooring and will not allow the top cover to deform.

When choosing slate, you should only make the sheathing. This applies to all similar materials. When constructing a shed roof, the direction of the wind is taken into account, whereas for many other types it does not matter.

The rafter structure is responsible for uniform distribution of the load on the supports and atmospheric influences (snow, rain, wind). When designing this type, it is worth giving a margin for the endurance of the rafters.

Rafter system and its structure

The inclined transverse rafter beams are laid at intervals of 75 - 85 cm. The rafters are fastened to the mauerlat with 100 mm nails, and to the concrete with anchor bolts. For ease of use, the rafters are covered with boards on which you can move.

When covering with slate, they should be removed. The sheathing is being done. A right angle must be maintained when filling the slats. This will require bars 5 by 5 cm. Slate sheets should protrude 20 cm on both sides.

The sheathing will provide rigidity to the structure and will serve as a base for the roofing material.

Rafter installation technology

The rafter installation technology is designed to:

• Thickness of beams and walls should be the same.
• Mounting the Mauerlat must be rigid, using anchor bolts.
• Before installing the rafters waterproofing will be carried out.
• Mauerlat installation under constant control so that there is no distortion.
• Marks were made on the beams and cut holes for the rafters.
• Nests are processed will be a protective coating.
• Rafters placed in grooves, should protrude 40 cm from the beams.
• For beams longer than 4.5 meters, additional supports will be installed.
• On top waterproofing material installation of sheathing under the roof is being carried out.

Fire protection of garage rafter systems

When building a garage roof, you should think about fire safety. Rafter structures should be impregnated with fire retardants.

In the construction markets it is possible to purchase a certified product that includes two functions: bioprotection and fire prevention.

Bioprotection of the mixture preserves decorative features wood Impregnation should be applied before installation.

Installation procedure

are carried out in the following order:

• Beam, size 10 by 15 cm, is erected on top of the load-bearing walls of the garage. It will be the connection between the main structure and the roof. The entire future structure of the coating depends on how the timber is secured. It should be secured to the wall with wire or anchors, fittings, and mounting tape.
• Construction of rafter supports. The supports with the main beam are attached strictly at an angle of 90 degrees and must extend beyond the wall by 40 cm. The pitch between them is selected according to the width of the insulating element.
  An allowance is made to prevent precipitation from getting inside. Where two materials meet, nests are made in the rafters that will firmly hold the structure.
• Installation of waterproofing. A diffusion membrane is fixed with an overlap of 15 cm, from bottom to top.
• Arrangement of sheathing. It is a board that is stuffed perpendicular to the rafters. It is used both as a continuous cover and at some distance. The dependence depends on the type of cover.
• When creating a roofing pie, waterproofing is laid on top of the sheathing. The diffusion membrane principle is used. A counter-lattice is attached to the moisture-proof film. It consists of beams (3 - 4 cm in cross section) and is intended for ventilation, as it creates an air gap. Insulation is laid on the inside of the roof, between the rafters, and covered with panels.

Water vapor barrier

The water vapor barrier flooring is laid on top of the sheathing slats. Take a plastic film and attach it over them. It is very important to start the flooring from the bottom and work your way up carefully. You can fasten the film with construction staplers, making an overlap of 15 cm. Then water will not flow inside.

The bottom row is laid, the second row will also overlap on it.

It is worth paying attention to the connection of four slates at one point.

Here the fastening is done with special nails. In other areas, the fastening is evenly distributed.

Preventing damage to a pitched roof

Precipitation is the enemy of pitched roofs. In winter, snow sticks to the slate and does not slide down, which leads to various damage to the roof. Therefore, preventive inspections are carried out once a year, followed by repairs, if necessary.

It is important to understand that if the house has a pitched roof, then one wall will be significantly higher than the other.

This leads to increased consumption of building materials.

Before you begin calculating the slope of the roof, you need to understand the degree of impact on. There are two types of loads - dynamic and constant.

To permanent loads include those which will affect roofing Always, regardless of the time of year. This includes the chimney, antenna, the weight of the roof itself, etc.

Regarding dynamic loads, then these are non-constant quantities, i.e. weight that affects the roof from time to time. Such an impact can be caused by the weight of a person who periodically visits the roof to carry out any work, the weight of snow and hail, the impact of wind, etc.

If the roof slope is 30 0, then the force of snow will be 50 kilograms per square meter. If you increase the angle of a pitched roof to 45 0, then most likely the snow will not linger on the roof.

That is why, this value should be selected based on your region of residence, i.e. based on the amount of precipitation.

At the same time, if you want the snow to come off the roofing yourself (at least some part of it), then minimum value the slope should be 10 0. The maximum value is 60 0.

Be that as it may, owners of houses with pitched roofs carry out self-removal of snow from the roof to reduce the load on the roof.

Wind loads

The design of a pitched roof is such that it is always made with a low part towards the leeward side in order to reduce the load from the wind.

Combined loads

Many people ignore this fact, which often leads to unpleasant situations. This type of load represents the maximum impact, which appears on the roofing covering at any moment.

It is necessary to provide that critical load, consisting of constant and dynamic impacts that the roof can withstand.

Let's imagine a situation when there is a snow storm outside, i.e. the roof is exposed to both strong wind and snow mass at the same time. In addition, a person is forced to climb onto the roof to adjust the antenna or he has to pick up a toolbox, it doesn’t matter.

It turns out that in addition to snow and wind, the weight of the human body is added. If you do not take this fact into account, the roof may not withstand.

Dependence of slope on the choice of roofing material

In addition to various atmospheric phenomena, the slope will be influenced by the roof covering that a person uses in this particular case.

Here are the minimum values ​​for various materials:

• , or any other piece material can be used on the roof, the minimum slope value of which is 22 0.
• If you apply roll materials , then the number of layers matters. A two-layer coating will require at least 15 0, and if the material is spread in three layers, then from 2 to 5 0 will be enough.
• If used, the minimum tilt angle should be 12 0. If this value is smaller, then you will need extra work in the form of gluing joints for better sealing.
• The angle at is 14 0.
• The angle at equals 6 0.
• will require at least 11 0 tilt.

ATTENTION!

If you intend to install a pitched roof, then not every roofing material you like may be suitable for you.

This means that if the slope of your roof is less than the minimum parameter characteristic of a particular material, then you should refuse to use it.

Angle of inclination depending on roofing covering

How to measure the pitch of a pitched roof

We have already said that with pitched roofs the height of the walls will be different. That is why the slope of a pitched roof will be formed at the time of construction of the walls themselves, on which the roof will be subsequently installed.

If your area experiences a lot of snow, then the values ​​should be 45-60 0. If you are in the temperate zone, then the parameters will be as follows - 5-60 0. Of course, the minimum angle of inclination must also be taken into account, depending on the material used.

Lwalls = Llength * tgQ,

Where Lwalls — this is the height of the pediment;

Llength — this is the length of the wall;

Q - this is the angle of inclination.

It is also necessary to take into account the lengths of the rafters. It is calculated using the following formula:

Lrafters = Lwalls / sinQ.

The values ​​of sine and cotangent should be taken from this table:

Here is an approximate calculation. Let's say we use ordinary tiles, so the minimum angle of inclination is 22 0. To calculate, we take 25 0 - the value of Q.

The length of the wall is 7 meters, i.e. Llength = 7m.

Lwalls = 7 meters * tg25 = 7 * 0.47 = 3.29 meters.

Lrafters = 3.29 / sin25 = 3.29 / 0.42 = 7.83 meters.

Minimum slope angle of a pitched roof

To calculate the minimum slope of a pitched roof directly affects the level of precipitation, which may be different for each region.

If you live in a "snowy" area, then the pitched roof should be quite steep, i.e. within 45 0.

In this case, the snow will not linger on the roof, which will significantly reduce the load on the roof.

If your area doesn't get a lot of snow, then 25 0 is enough.

The opposite situation occurs in regions where strong winds are observed.. Here you need to build roofs with a slight slope so that the load from the wind is minimal.

Also, the type of roofing material, which we talked about a little earlier, plays a big role when choosing the minimum angle of inclination. You can read more about the minimum angle and its calculation.

Minimum angle

The optimal angle of inclination of a pitched roof made of corrugated sheets

Corrugated sheeting is a rather “harmful” material, because it has many layers with different sizes waves, as well as the thickness of the material itself.

According to SNiP, the minimum slope for residential premises whose roofs are covered with corrugated sheets is 12 degrees. According to the same rules, the optimal parameter for this tilt should be 20 degrees.

For a long time, pitched roofs were considered the domain of garages or various non-residential premises, but recently the situation has been changing. Many note the fact that when choosing this type of roof, the interior design of the room becomes more original, although more troublesome in terms of finishing.

But this does not stop those who value not only reliability in their home, but also an attractive appearance.

Optimal angle

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