Asymmetrical gable mansard roof. Gable roof with different slopes: conquering asymmetry geometry

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The roof is one of the main elements of the house, along with the walls and foundation. Without her correct device the house will not be durable and comfortable enough to live in. The result of a bad roof will be dampness, wet walls, all kinds of diseases and additional heating costs.

The preferred type of roof depends on the climate of the area and prevailing weather conditions. The most common in our conditions are gable ones, which are quite simple to construct and maintain, and reduce the load from snow or other heavenly moisture. Aesthetics play an important role in choosing them.

Types of gable roofs

Gable roof is quite simple design, consisting of two slopes connected to each other at an angle. They form something like a triangle. But despite the simplicity of this figure, triangles are different. Gable roofs also differ from each other.

The main difference between their designs is the angle of inclination. Depending on the type of building and other necessary conditions it may vary. In addition, the angles at which the slopes are installed may differ from each other. As a result, one of the following types is built:

Simple symmetrical;
Simple asymmetrical;
Broken (the break can be either internal or external).

Each type has its own positive and negative sides, forcing you to choose one or the other builder, depending on the circumstances.

Simple symmetrical roof

This type of construction is undoubtedly the most common. It is the easiest option to make yourself. His appearance always looks good. In the end, it is also good because under such a roof there remains a lot of useful attic space.

From the name of the design it is clear that it is distinctive feature: the slopes form an isosceles triangle. The symmetry of this figure allows it to look proportional on any home.

Simple asymmetrical roof

The main difference from the previous version is also directly reflected in the name. The ridge of this type of roof is shifted to the side and, as a result, the triangle formed by it turns from isosceles to scalene. This design It looks modern, so it is well suited for modern style homes.

An asymmetrical roof has two important features:

Reducing the size of attic spaces;
Unequal load distribution.

As a result, this type of design is good for those who need extra space for rooms that can go right up to the roof. But it requires correct calculations.

broken roof

This type of construction is the most complex, so not everyone decides to do it with their own hands. Although, in fact, this is quite possible. It’s just important to carry out the correct calculations from the beginning. After all, the main feature is its irregular shape, where the loads are distributed extremely unevenly.

The main advantage of a sloping roof, in addition to its varied appearance, is that it provides maximum free space underneath. As a result, it is possible to equip a full-fledged residential second floor, an attic. Thanks to this feature, it is also called attic.

Rafter system design

The rafter system is the basis of the roof. There are two main constructive solutions for gable roof rafters:

Hanging.

Design rafter system gable roof

The first of them is used when the house has internal supports, for example, load-bearing walls. In case of their absence, the hanging type is preferable.

But, regardless of what type of rafter system it is decided to build, everyone who wants to know how to build a roof with their own hands must understand the main elements of the structure. Namely:

Rafter leg or simply rafters. Rafter legs are the basis of the design of the entire system. They are placed on top, along the building, and connected to each other to form a truss. Since they are the ones that support the roof covering, it is important to use durable wood here too. It is desirable that it be a log or timber. Installation is carried out based on pre-made calculations, since it will be very difficult to change something later;
Rafter post. This structural element helps distribute the load from the rafters. It is a vertically located beam. Its location depends on the type of structure the roof has and its size. If we are talking about a simple symmetrical roof with a small span, then the rack is installed in the center. If the width is large, then two additional ones are placed on the sides. The asymmetrical version involves the location of this element depending on the length of the rafters, and the broken one - two on the sides. True, if there are more than one rooms, then in the latter case an additional rack in the center is needed;
Run. The main task of the purlins is to connect the rafters, while simultaneously giving them rigidity. The purlins can be ridge or side. The first is located at the very top of the roof, in the area of its ridge. They make purlins from timber. Sometimes boards are used. The most common section is 50 by 150 mm. If the run is made not only with a ridge, but from several beams or boards on the sides with long length roofs, then they are supported by a stand coming from the ridge and resting on the footing. The side purlins are connected to it by means of struts;
Strut. They are a structure made of beams located at a certain angle and resting on a bench. Their main task is to serve as supports for racks. Can be diagonal or longitudinal. The latter are used most often; they are on the same plane as the rafters. At the same time, the former are necessary if there is an increased snow or wind load in the area. With it, it is also advisable to choose a brace angle of 45 degrees;
Sill. Located at the very bottom of the structure. If possible, it is placed on an internal load-bearing wall. Its main purpose is to serve as a support for racks. Slopes are attached to it;
Puff. This element connects the rafter legs, located perpendicularly under them. At the same time, it provides greater structural rigidity;
Rigel. It also connects the rafter legs, but unlike the tightening, not from below, but from above. Installed with overlap. They make a crossbar from a board of the same cross-section as the rafters themselves;
Lathing. This element is installed at the final stage of mounting truss structure, since it is the basis for the coating. It consists of beams and boards that parallelly connect the rafters from top to bottom. In addition to the fact that it serves to secure the roof, the sheathing helps to redistribute the load from it. Therefore, the distance between the elements depends on the material that will be used for coating.

A general understanding of the meaning of each structural element will greatly facilitate the task of building a gable roof with your own hands.

Calculations

Calculation of the load on various roof elements is the most important stage, since the strength and safety of the structure depends on it. It must be remembered that the triangle is its toughest part.

Loads on rafters can be of three types:

Permanent. These are the loads that the rafters feel constantly. For example, the weight of finishing and roofing materials, sheathing, etc. In order to recognize it, it is enough to add up all these weights. Typically the constant load is about 40 kg/m2;
Variables. They operate in different time With different strengths. These include, for example, wind. In order to calculate the wind load or the load from precipitation, you need to look at the SNiP;
Special. We are talking about loads associated with increased seismic activity.

When calculating the load exerted by snow, its weight is multiplied by a set correction factor that takes into account wind pressure. A coefficient depending on the angle of inclination of the roof is also introduced - the lower it is, the greater the load. If the angle exceeds 60 degrees, it is not taken into account.

Tilt angle

The correct calculation of the angle of inclination depends on certain features. Firstly, a lot depends on the chosen material. So, ondulin, corrugated sheets, metal tiles, slate require an angle of 20–45 degrees. A soft roof- up to 20 degrees.

Secondly, the angle of inclination depends on the climate in which the roof is being built. If there is little precipitation, then you can make it insignificant. And when large quantities- vice versa. But it is worth remembering that large angles are subject to large wind loads.

Rafter length

Calculating the length of the rafters is not particularly difficult. It is based on the Pythagorean theorem. The length of the rafter is taken as the hypotenuse of the triangle. And the role of the legs is played by the height of the roof and half the width of the house. It’s worth adding a few tens of centimeters to the resulting value.

Rafter foot step

Their choice depends on the weight of the structure used to cover the roof and the material used. Usually it varies between 60-100 cm.

Rafter section

Calculation of the correct required section rafters are one of the most important points, since this indicator greatly affects the reliability of the design. This takes into account:

Loads;
Rafter length;
Rafter pitch;
Material used;
The type of wood used in the construction of the house.

The higher the pitch of the rafter legs, the higher the cross-section.
The video provides a detailed description of the calculation of the rafter system.

Types of rafter systems

There are two main types of rafter systems from which to choose when erecting a gable roof. We are talking about hanging and layered rafters. Each type is designed for different structures.

Hanging structure

Hanging rafter system

Hanging ones are designed for small houses, whose width does not exceed 6–6.5 linear meters. They are not suitable for houses with a wide roof. They are also not used where there is a middle load-bearing wall.

Design features

A design feature of hanging rafters is that they rest on the two outer load-bearing walls. As a result, the system is subject to a strong bursting force. If necessary, it is reduced using a bolt-bolt attached at the bottom.

Attaching to the Mauerlat

The design feature of hanging rafters also dictates how they are attached to the “foundation” of the entire system - the mauerlat. The only mounting option is to use a unit with a zero degree of freedom. Hinges, for example, cannot be used.

Layered system

Layered rafter system

Layered rafters are the only option when it comes to a large roof. But they require either the presence of internal load-bearing wall, or specially installed intermediate supports. A support is laid parallel to the Mauerlat, which takes on part of the load from the structure.

Differences between hanging and layered rafters

Hanging rafters do not require intermediate supports or an internal load-bearing wall, but their bursting force greatly influences the structure. At the same time, due to the fact that they also rest on a beam in the middle, layered rafters are easier, including in assembly. They are better suited for larger roofs.

Do-it-yourself gable roof installation

As already noted, a gable roof is especially popular due to the fact that its design allows you to build it yourself. Which is naturally quite attractive for those who like to build themselves or want to save a lot.
The construction of a gable roof structure consists of several large stages, each of which is important to perform correctly. In this case, the roof will stand for a long time and will not collapse.

Installation and fastening of the Mauerlat

Formally, a gable roof can be made without a Mauerlat. In this case, the rafters will rest on the floor beams. But it is not recommended to do this for one simple but important reason - the beams will have to take on additional load from the roof.
The Mauerlat is installed along the wall on which the rafters will rest, parallel to the ridge of the house, as shown in the photo.

Mauerlat

Mauerlat connection

The ends of the beams that will be connected are sawn at an angle of 90 degrees. After the ends are applied to each other, they are fastened with bolts and only with bolts. It is important not to use any other material, such as nails or wire, instead of bolts.

Fastening

The methods for attaching the Mauerlat are based on the fact that it is installed on top of the wall. At the same time, it can be located either strictly in the center of the wall or offset to one of the edges. But it is important to maintain a distance of five centimeters to the outer edge.

A layer of waterproofing is placed between the wall and the timber. A simple roofing material is quite suitable for this.

This will protect the wood from the influence of moisture that may fall on the walls. The mount itself must be as strong as possible, because it will have to withstand wind loads. There are several ways to fix the Mauerlat to the wall.
The methods of attaching the Mauerlat to the walls largely depend on what material the house is being built from.

If the building is erected from a monolith, then the best solution are anchor bolts;
If the house is being built from timber, then the usual solution is wooden dowels. They can be strengthened with additional fastening;
A fairly common fastening option is staples. They are loved because they are quite versatile, although they are not the most durable solution;
If the building is constructed from porous materials such as foam concrete, then the right choice the Mauerlat will be attached to the reinforcement;
The hinged fastening, due to the fact that it is sliding, is suitable primarily for those houses that are built from materials that give noticeable shrinkage;
As an additional fastening, you can use strong, for example, knitting wire. How independent option it does not apply.

The correct choice of fastening will allow the roof to survive the blows of even the strongest winds.

Installation of rafters and racks

There are two options for assembling rafter legs. They can be collected either from above, on the roof, or below, on the ground. The second option is easier to do with your own hands, but it takes more time. The second will require the use of mechanisms, since it is difficult to lift the structure of the rafter system upward manually.

But, one way or another, the manufacture of rafters must be done strictly according to the markings. Special templates that are made from plywood after all the calculations have been made are well suited for this.

Rafter fastening diagram

Before attaching the rafter legs to the mauerlat, you need to make a gash in them. Only rafters can be sawed, since such procedures on the Mauerlat weaken it. Three nails are used for fastening. Two of them are driven in at the edges, and the third must be driven through the upper plane of the structure in the center. Thanks to the use of three nails driven in this way, the rafter leg is well attracted to the mauerlat and does not move.

As for the upper fastening of the rafters to each other, there are three main ways to do this.

Without support beam. Rafters can be spliced end-to-end or overlapped. In the first case, the ends are cut so that equal angles are formed. After applying the ends to each other, they are connected using metal or wooden plank. In addition, a nail is driven in at the top. When joining with an overlap, the ends are cut as required and connected with bolts;
Using a support beam. This method is necessary if we are talking about a large roof. The rafters at the ridge are also attached end-to-end or overlapping, but in addition they rest on a beam, which in turn also serves as a support for the racks;
Cutting method. It involves cutting the rafter legs into the support beam.

The ridge support is mounted after the two outer rafter legs are installed. Then the racks are attached. And then, the remaining rafters. You can see all this in the photo or video.

Insulation and protection from water

Proper insulation and waterproofing are very important in the domestic climate. Especially when it comes to a roof that is constantly and heavily exposed to the environment. And the moisture that accumulates in the house itself also rises to the attic in the form of steam.

Based on the above, it is important to choose insulation that has a vapor barrier function. Otherwise, its type does not matter. But as for waterproofing, roll types are considered the most suitable. For example, a special film. It can be easily laid directly on the rafters. You can see how this is done in the video.

Installation of sheathing

The sheathing is installed last, but it plays an important role.

Without it it is inconvenient to move on the roof, and roofing material puts unnecessary pressure on the rafters. In addition, it allows an air cushion to appear between the roofing material and the insulation.

The design of the sheathing and its pitch depend on what material will be laid on the roof.

The lattice sheathing is laid under slate, tiles or metal tiles, and corrugated sheets. In the case of metal tiles, the distance should be 350 mm, and for slate and corrugated sheets - 400 mm;
Solid sheathing is used for soft types of covering.

Installation of sheathing

They make it from timber or boards, and if we are talking about soft ones - from plywood, OSB sheets or the same board. They are laid on a beam located along the rafters, as shown in the photo and video.

Calculation of roof area

A gable roof often has simple form, so calculating its area will not be difficult. But it is extremely important to do this accurately, because the consumption of materials depends on knowledge of the area.

Calculation of roof area

When calculating the roof area, in order to avoid confusion, you should not pay attention to the parameters of various ventilation holes, skylights or chimneys. You just need to know the height from the ceiling to the ridge and the length of the ridge run. These parameters are multiplied. If you divide the roof area by the sine of the rafter angle, you can find out the area of one slope.

Typical parameters

A design feature that distinguishes a gable roof is that it can be divided into separate standard parts. By calculating the area of each such element separately and adding everything together, you can get the required amount of materials.

Since the roof is made with a slope, you need to know its angle.

The cosine of the angle is needed to determine the exact area of almost all elements.

Typical elements are the rafter legs that form the base of the trusses. In addition to them, there are braces, struts, supports, purlins.

Roofing: selection and installation

Installation of metal roofing

Installation of the roofing is the final stage of the work. But it is preceded by the selection of suitable material. Nowadays, manufacturers offer a huge selection of roofing materials, each of which has its own pros and cons. The choice is always up to the consumer and depends on his aesthetic preferences, financial capabilities and climate.

Natural tiles. This is a very beautiful, traditional, but at the same time expensive material. Its high price is compensated by a very long service life, unless, of course, it is deliberately damaged or it is exposed to extremely unfavorable weather conditions;
Metal coating. Such a roof is also quite traditional solution. Today, manufacturers offer many options for metal roof sheets, differing not only in strength, but also in appearance;
Wooden roof. A shingle or spindle roof certainly has many aesthetic benefits. But quite expensive even without special processing subject to rotting;
Self-leveling coating. It is considered quite inexpensive and reliable. Belongs to the category soft coverings. The disadvantage is that it can only be used on roofs with not very steep slopes.

Each type of material is installed in its own way and different fastenings are used for them. Information can be obtained from the video or from the manufacturer. Then the eaves overhangs are installed.

Fastening parts

The ability to correctly fasten the smallest details is the most important in making a roof with your own hands. There are several basic methods for connecting and fastening parts of a roof structure.

So, a groove connection is used to fasten diagonal parts. If we are talking about connecting perpendicular elements, then it is suitable only for those of them where strength is not so important.

Metal corners and plates are also quite popular. They are distinguished by good strength. But the disadvantage is the danger that some screws will turn out from the load. To minimize risks, a combined fastening method is used.

Cost of a gable roof

The cost varies greatly depending on whether the roof is done with your own hands or with the help of craftsmen. In the latter case, it will be significantly more expensive and the price can reach several hundred thousand. In the first case, the main costs will go to materials.

The total price of the structure includes:

Materials;
Installation of the Mauerlat;
Installation of rafter system;
Installation of waterproofing;
Installation of sheathing;
Roof installation.

Carrying out any of these elements yourself reduces the cost of construction.

Finishing the gable with siding

The gable is a prominent part of the house. Therefore, it is customary to use attractive materials for its cladding. This could be a board that matches the roof, plywood or siding. When wooden houses the pediment can be cut in advance. This is explained in more detail in the video.
The gable roof, thanks to the simplicity and accessibility of the design, which makes it possible to install it with your own hands, has become truly universal solution. Knowledge of individual features will make it easy to avoid the main problems during its construction.

A gable roof is a roof formed by two inclined surfaces. They are directed towards each other, and the intersection is connected by one ridge parallel to the long side of the house. Gable roof with different slopes - this is a type of design. It is distinguished from the traditional symmetrical design primarily by geometric parameters, and only then by specific features.

Basics of geometry

To understand how such a roof is constructed, you need to consider these properties and compare photos of the two types of structures. Since we are talking specifically about the gable variety, in a profile section this shape always forms a triangle. The upper ceiling of the building is the base of the figure and serves as the supporting surface of the structure. The roof slopes are the sides of the triangle.

Looking at the symmetrical roof (first photo), you can see that the inclined surfaces are equal in length and are at the same angle to the base of the triangle. The ridge, hiding the intersection of the slopes, is located exactly in the center of the building and passes through the axis of symmetry. A multi-slope design is characterized by different lengths of slopes and different angles at the base(second photo). This concept is the result of a geometric transformation. There is a proportional relationship between the elements of the triangle. If you change one, all the others are changed.

Photo No. 1 - gable roof with identical slopes

Based on this dependence, the roof structure under consideration has two main parameters: the length of the slopes and the slope. Using this name, the latter value would be correctly calculated as a percentage. To do this, you need to calculate the tangent of the angle at the base of the roof, multiplied by 100%. However, for convenience and quick understanding, degrees are most often used as a unit of measurement. Thus, each slope of an asymmetrical roof is characterized by a separate length and slope.

Photo No. 2 - roof structure with different slopes

Why are different slopes needed?

This is a question that a novice builder will ask. The choice of design is based on two areas: design and performance properties.

The appearance of the roof is important from the very beginning for those who want to make the building beautiful and unique from an aesthetic point of view. Symmetry in everything often gets boring, and many modern tendencies in the field of design they rely on breaking stereotypes and moving away from regular geometric shapes.

That is why in this regard, a design with different slopes stands out. The ability to play with sizes and angles even in a classic triangle allows you to build roofs that are original and interesting in design. Variability gives a chance to distinguish a building from others and make it more noticeable. This is because the roof is the main element that forms the appearance of the building.

Influence of weather conditions on design calculations

Technological features come from the same geometric parameters. How the structure will withstand weather conditions depends on the slope of the slope. It is based on climatic data that the angle value that will ensure the reliability and durability of the roof is determined. A reasonable step when planning is to study the wind rose over the last 2-3 years in the local area.

From it you can judge the strength of the wind and its most frequent direction. On the side of the roof, where gusts come from in most cases, it is recommended to install a slope with a smaller angle of inclination. This will reduce the load on the supporting structure and also reduce the noise created by vibration of the roof.

Precipitation affects the calculation of slopes. In dry and warm areas, the angles may be the smallest and the lengths the largest. Areas with heavy precipitation require steeper slopes from the structure so that all moisture and solid precipitation leave the roof as quickly as possible, do not stagnate and do not create unnecessary loads. Roof angle ranges vary widely, from 11º to 70º.

Organization of space

Increasing the roof slope allows you to profitably use the space in the attic. With this approach, you can arrange a spacious storage room, a comfortable room or a spacious attic under the roof. Often one roofing surface covers two floor spans at once. This is exactly the case when the slopes obviously differ in length. Also, it becomes possible to arrange a terrace, the canopy of which will be a continuation of one of the slopes.

Common methods of increasing the area include the use of broken structures, when one of the slopes, not reaching the base, changes the angle of inclination. Of course, such sophistications incur costs for additional building materials and complex work.

Material of construction

The roof of the roof is supported by a rafter system. From time immemorial, wood has traditionally been used as a material for construction, but metal or reinforced concrete can also be used. The first is in the lead due to the possibility of precise processing, strength and optimal weight of the frame. For the construction of the structure, certain types of wood are chosen:

Pine is universal. Coniferous durable, resinous, which reduces the risk of rotting. The tree trunk is straight and light. The low cost of pine timber is explained by its wide distribution.
Larch is durable.
Spruce is just as durable, but more susceptible to moisture.
Powerful oak is suitable for critical elements, for example, mauerlat. It is easy to handle. The material is expensive compared to other breeds.
Aspen is resilient, but often has a rotten core, which limits its scope of application
Beech is durable and lasts for many years, but is difficult to process.

When using wood in the construction of gable roofs with different slopes, it is strongly recommended to use only coniferous or only hardwood for all frame elements.

Metal, like reinforced concrete, is the basis of creation load-bearing structure benefits only for large construction projects, where pitched roofs are rare. One solid span can reach 2-3 tens of meters. In other respects, it is much inferior to wood: expensive, difficult to process, allows cold to pass through, and accumulates condensation.

Frame structure and correct calculation

When calculating a pitched structure, take into account climatic conditions, wind forces, roof weight. The latter is important: the coating layer creates a constant load on the frame supports. For example, ceramic tiles are heavy; soft roofing is much lighter. In combination, all these factors form the general requirements for the roof truss system and determine parameters such as rafter pitch, number of elements, beam thickness and frame material.

A drawing of a gable structure allows you to understand what elements the supporting structure consists of:

The rafters are fastened to the building using a mauerlat - a strong frame laid to the side load-bearing walls made of bricks and blocks. WITH outside building, it is recommended to cover this frame element with an additional brick row for reliable fixation.
The ridge run is the second support of the slopes. It is installed on the upper corners of the gables.
The side purlins are attached parallel to the roof ridge. Together with the central beam, they are brought out a little further than the pediment in order to reduce the load.
Rafters are supports for the roof. They serve as a connection between the ridge and load-bearing walls. To strengthen the opposite rafters, they are connected with special ties made of wood or metal. The roof elements are assembled in two ways: hanging and layered. The first is characterized by the fact that the opposing rafters hold each other with a strong connection, the roof load is bursting. The layered structure includes additional central supports connecting the bed and the ridge beam. This device is used when there are internal load-bearing walls. The presence of different slopes implies the installation of additional ties between the rafters and other beams to regulate the load.

A gable roof with asymmetrical surfaces is a bold step for the builder of his own home. This is an opportunity to improve your home with a solid roof with efficient use of space.

The gable roof is the best option for choice, which does not require large expenses during design and construction.

It is formed by two inclined surfaces, slopes, intersecting at an angle to each other, in the area of the ridge.

This type of roof provides reliable protection Houses from wind, heavy rainfall and snow pressure during heavy snowfalls, you just need to find the slope of the gable roof.

A gable roof is quite easy to assemble and easy to match.

Symmetrical gable represents classic version. The load is evenly distributed across the roof support and load-bearing walls. The rafters do not bend and it is possible to install supports and struts at almost any point. This design has one drawback, which is extremely significant when constructing an attic - the sharp corners “steal” the space necessary to create a full-fledged room.
Asymmetrical gable differs from symmetrical only in that the roof ridge moves in one direction or another. Designing one of the angles over 45° allows you to create a fairly spacious room on the top floor. But at the same time, calculations become more complicated due to the uneven load on the mauerlat and load-bearing walls.
A broken gable makes it possible to create a full-fledged living space under the roof thanks to the kinks on its slopes. The surface of the slopes is bent in the middle, forming edges that divide them into two rectangles. The ceiling in the attic is high, there is an opportunity to bet vertical windows. Overall, the room becomes cozier, acquiring the features of a comfortable living space. But this one the project requires a significant investment of funds due to the need to purchase quality wood, insulating, insulating and other building materials. Despite this, sloping roof It only becomes more popular over time because allows you to expand the living space without affecting the height. In addition, the advantage of installing windows in the roof slopes will protect against unnecessary expenses for electricity.

Photo of the gable roof below:

Symmetrical roof

Asymmetrical roof

broken roof

Hip or gable roof?

When choosing a roof with two slopes or four, you should pay attention to the advantages and disadvantages of both designs. Keep in mind that there are gable roofs with different slopes.

Advantages of a gable roof:

Reliability and structural strength with uniform distribution of load on supporting walls and foundation;
Possibility of location engineering systems houses in the attic;
The slopes do not allow precipitation to linger on the roof;
Restoring damaged areas does not require large expenses and repairs are easy to perform;

Disadvantages of a gable roof:

(may occur when constructing an attic)

The installation of dormer windows will require additional cash injections;
will also require additional funding;

ATTENTION!

A pair of trapezoidal slopes and a pair of triangular slopes (or hips) form a roof with four slopes.

Advantages of a hipped roof:

There is no need for gables, since the windows are installed directly on the slopes;
Reliable roof structure;
Excellent resistance to wind and precipitation;
Convection in the room is carried out over the entire area, and therefore heat is distributed evenly;

Disadvantages of a hipped roof:

Complexity of design;
Only professionals can install the roof;
Heavy weight;

You can calculate the rafter system.

Both options are good in their own way. The question of choice depends only on your individual needs and financial capabilities.

House with a gable roof

House with a hipped roof

Gable roof installation

You must first develop a plan take into account climatic featuresterrain and determine the angle of the roof slope.

For example, low-slope roofs are preferable for areas with strong winds, and high roofs resist snow stagnation on the surface during snowfalls.

Before using wood, it must be must be treated with insecticidal, antifungal agents and substances, reducing the flammability of the material, and also allow it to dry to avoid sagging of the beams.

Work begins with the construction of the Mauerlat- roof supports that bear the entire weight of the structure. It is a beam placed on load-bearing walls, on which the entire rafter structure is then laid.

On a load-bearing wall under the Mauerlat it is necessary to lay a shut-off .

The next step is laying the bed, a beam that serves as a support for the rafter posts. He takes the entire load from them and distributes it over the supporting walls. It is necessary to carry out double waterproofing underneath.

Then comes the turn of installing the racks and running. For convenience, it is advisable to erect scaffolding. During work, racks are pre-attached to them, onto which the purlins are then installed.

After mark the rafter legs and attach them to the structure;

Before the rafters are finally secured, the structure is carefully checked for any inconsistencies.

At the end, they begin to install the fillies, forming a cornice overhang.

Assembly can be carried out both on top of the house and on the ground, where a truss is erected, which is a triangle of rafter legs and tie-rods and other components, which is then lifted upward with a crane, winch or, in extreme cases, using two inclined boards and a rope and secured to the Mauerlat.

You can read more about installing a gable roof.

Gable roofs of private houses photo:

Type of house with gable roof

One-story house with a gable roof

The main components of a gable roof rafter system:

Mauerlat- a beam placed on load-bearing walls and serving as support for the entire rafter system;
Rafter leg- a component that carries the roof;
Runs- elements located transversely in the middle of the rafter legs, and under the ridge;
Puff- part that unites the structure at the base;
Rack- support element rafter leg. Also located under the roof ridge;
Struts- inclined support beams originating at the base of the rack and going to the middle of the rafter leg;
Sill- serves as a support for the racks of the rafter legs, further strengthening the structure if it is located on two spans.
- boards nailed transversely to the rafters and forming the basis for the roofing material;
- This is a triangular section formed between two slopes. Its shape depends on the design of the rafters, climate and individual preferences, and the size of its ends depends on the slopes and the height of the rafter structure itself. Main components The gables are the ridge board that runs along the very top of the roof, rafters and steel studs. The pediment protects the room from moisture penetration and adverse weather conditions, and also maintains the thermal conditions of the room. As a support for floor beams, it must have sufficient strength to give the entire structure the necessary rigidity.

At need to:

Accurately calculate the load on the supporting walls and foundation and prevent it from being exceeded;
Carry out a good one to avoid uneven heating of the room;
Ensure a good level of sound insulation by choosing suitable roofing material.
Provide reliable waterproofing;
Use light types of materials to decorate the interior of the room and ceiling;

In conclusion, it is worth noting that a gable roof is one of the simplest options. You can easily try to do it yourself, which will save you money and give you invaluable experience.

Photos of diagrams and drawings below:

Gable roof diagram

Gable roof drawing

Useful video

In this video you will learn all the advantages and disadvantages of a gable and hipped roof:

A gable roof is a roofing structure that is most often used in private housing construction. It is not only simple to construct, it is reliable and inexpensive if you correctly calculate the number of elements.. The article discusses what elements this type of roofing consists of, and how it can be assembled with your own hands. You will learn about the basics of calculations, rules and assembly stages, which will allow you to talk “on the same wavelength” with the contractors of the construction company.

Source oz90.ru

Online roofing calculator

To find out approximate cost gable roof, use the following calculator:

What elements does a double slope roof consist of?

From the name itself it becomes clear that such roofs have only two slopes, which can be the same or different in area. The former are called symmetrical, the latter asymmetrical

Not all gable roofs consist of the same elements. But among them there are basic ones that are present in all designs.

Mauerlat– beam 100x100 mm (minimum cross-section), on which the rafter system rests. The main purpose is to evenly distribute the load acting from roofing structure on the walls of the building. The Mauerlat is attached specifically to the walls (there are several options).

Rafters, otherwise they are called rafter legs. These are boards (rarely timber) with a minimum thickness of 50 mm, located with a slope towards the walls. They form the slopes. At the lower end they are attached to the mauerlat, at the upper end to the ridge beam or to each other.

Ridge beam It is not always used, but only when the roof is covered with layered rafters. More on this below. Its purpose is to support the rafter legs.

Rafters attached to the mauerlat Source krysha-expert.ru

Additional wooden elements that are not used on all gable structures.

Supports for the ridge beam. They are installed only if one is present in the roofing structure.

Rafter supports. Used if the width of the building is more than 12 m. The longer the rafters, the lower their load-bearing capacity.

Run, aka timber, laid on racks across the rafter legs. The rafters rest on it, and not on the supports.

Sill– a beam located parallel to the girder, only in the lower part. Rafter racks are mounted on it.

Puffs. These are bars that pull paired racks together (between each other).

Types of rafter systems

There are two of them: hanging and layered. The first type, in which the upper ends of the rafters rest against each other, and are fastened together. To increase the strength of the connection and the reliability of the structure, a tightening is often installed between them.

The second type is legs resting on a skate. They can also be tightened if the goal is to increase the load-bearing capacity of the entire system.

Attention! The tightening functions for the hanging variety can be performed by the floor beam on which the legs rest.

Hanging and layered rafters Source kayabaparts.ru

On our website you can find contacts construction companies who offer roof calculation, installation and repair services. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.

Rules for assembling a gable roof

A gable roof is assembled in different ways. Dependency - type of rafter system. Let's look at each one separately.

Assembling hanging rafters

There is a strict sequence of operations:

Produce installation of Mauerlat on walls. It is attached to them using pins, which are installed in the poured reinforcing belt. The upper end of the stud is the threaded part onto which a nut with a wide washer is screwed. It is with them that the Mauerlat is pressed against the wall.

Produce installation of ridge beams. To do this, support posts made of timber or boards are installed along the roof structure right in the middle (if a symmetrical roof is being constructed). They are attached to the beam or to the floor beams with special metal corners using self-tapping screws. Additionally, supports and jibs are installed to maintain the verticality of the racks.

For the latest ridge beams are laid, which is fixed to the racks with the same metal profiles(corners, plates, etc.). The main task of the workman is to align the ridge girder in a horizontal plane.

Rafters are installed in pairs, forming triangles of the roofing system.

Hanging rafters Source kayabaparts.ru

If there is a need, then under the rafter legs they are installed additional racks. They are either attached directly to each other, or laid on top of the posts with a run across the legs.

On top of the rafter system lathing is installed from wooden blocks or boards.

On top of the sheathing roofing material is stuffed.

Assembly of layered

Layered rafter system of a gable roof frame house, and not only frame, it is assembled not on the roof, but on the ground. The thing is that it is difficult to fit the elements together when they do not have support at one end. To do this, you will have to build an additional temporary support structure. This is a waste of time, effort and money that no one needs.

Therefore, paired rafters, they are in assembled form They are called farms and are assembled on the ground plane. Since the structure of the truss is a triangle, which is also isosceles in a symmetrical roof, it will not be difficult to assemble it. The main task of the work producer is to comply dimensional parameters farm elements. Because it will be more difficult to adjust roof trusses if there are sufficiently large dimensional errors between them.

Raise the rafter assembly onto the roof crane or other device.

Installation of layered rafters Source pallazzo.su

At first install two extreme trusses along the gables of the house, align them with each other in height and secure them to the floor beams with supports and jibs (temporary).

Stretch a thread between the top points of two trusses, along which the remaining rafter triangles are mounted.

The rest is the same as in the case of hanging rafter legs: the sheathing and roofing material are stuffed.

Video description

The process of erecting a gable roof in the video:

Calculation of rafter legs

Important preliminary, on which the load-bearing capacity of the system as a whole depends. It is impossible to carry out the calculation yourself if you do not understand it. Therefore, ordinary people use online calculators or tables. The calculation manipulations are based on the cross-section of the bars (in mm) or boards, depending on the length of the legs and the installation pitch.

The dependence is this: the longer the legs and the greater the distance between them, the larger the cross-section of the beams should be. Eg:

installation pitch 2.15 m, rafter length is 3 m, for this purpose a beam with a section of 100x150 mm is used;

step 1.4, length 3, section 75x125 mm;

step 2.15, length 5 m, section 100x250;

step 0.9, length 5.5, section 50x200 mm.

For each position there is a specific parameter for the bars used. The tables are freely available.

Distribution diagram of rafter legs Source: chaos-heart.ru

Slope slope

Determining the slope of a gable roof structure is not easy. Take into account the type of roofing. The dependency is:

if asbestos-cement slate is used, then the angle should be not less than 22°, reducing this parameter will lead to leaks at the junctions of adjacent sheets;

metal tiles – angle 14°;

corrugated sheet - 12°;

bitumen shingles- corner should not exceed 15°, otherwise there is a possibility of the coating sliding off the sheathing;

rolled material (roofing felt, roofing felt and others) – slope within 3-25°.

But there is one nuance here. The steeper the roof, the less stress there is on its slopes, because rainwater and snow quickly disappear from the surfaces. But at the same time the windage of the structure increases. That is, wind loads increase. At the same time, high roofs mean an increase in the cost of building materials, which increases the cost of construction.

Roof slope angle Source arhplan.ru

Sloped roofs

Gable roofs with different slopes are quite common today. This is not to say that they are better than symmetrical ones, but the originality of the design made them popular. Let us add that such roofs are more complex than traditional ones with identical slopes.

These roofs are divided into three types:

Asymmetrical. Their ridge girder is located in the middle of the house. The slopes are located to each other at the same angle of inclination. But one of them is always longer than the other.

Asymmetrical. The length of the slopes can be the same or different, but the angle of inclination of both is different.

Asymmetrical with offset. The same as the previous option, only the ridge girder is shifted relative to the middle of the house to one side.

Asymmetrical gable roof with offset ridge girder Source pinterest.ca

Rules for the construction of asymmetrical gable roofs

A gable roof with different slopes is a complex structure. The whole difficulty lies in the fact that the displacement of the ridge beam relative to the middle of the building creates completely different loads. They are no longer distributed along the ridge. Their main pressure (central) falls on the long, flatter slope. That is why at the design and calculation stage it is necessary to accurately determine the location of installation of additional racks. They are installed under the rafters of a long, gentle slope.

In this case, the entire rafter system is not installed by eye. Even the smallest deviation from the project can lead to irreparable consequences. Making changes to the design will be difficult, and sometimes simply impossible.

Asymmetrical roof truss Source builtec.info

And one moment. For an asymmetrical roof (gable) the construction of a very strong Mauerlat is required, with the help of which uneven loads will have to be redistributed. Particular attention should be paid to attaching the Mauerlat to the walls of the house.

As for the construction of a roof with different slopes, the technology itself is no different from the traditional one. The main thing is to strictly adhere to the requirements outlined above. Typically, such structures are assembled from layered rafter legs with the installation of a ridge beam. Therefore, the main task of the work contractor is to accurately align the ridge horizontally on the site strictly according to the design. The dimensions of the rafters must be precisely maintained, mainly regarding the length.

Multi-level roofs

Another type of roof with two slopes. To understand what we're talking about, see photo below.

Multi-level gable roofs Source moscow.sk-evrodom.ru

According to its configuration, the roof is gable and covers the entire house. But individually, each slope is a single-slope structure. Usually a load-bearing wall is erected between them, on which both slopes rest.

But at the same time, the larger slope rests on the upper end of the wall, where the ridge beam or mauerlat beam is installed, and the smaller one on its vertical plane, where the load-bearing beam is usually fixed. The construction of such roofs is carried out using the technology of a single-pitch structure.

Gable roofs with broken slopes

These structures are mainly used in houses where the construction of an attic is planned. Organizing a room under traditional slopes is problematic. The reason is the presence of “dead” zones at the junction of the rafter system and the wall of the house. To remove these zones, it is necessary to make part of the slope steeper in terms of inclination relative to the vertical.

The cross-section of the roof will not be triangular, but pentagonal. Assembling it is not easy, there are too many elements located under different angles. But she has serious advantages before everyone else:

holds up well snow loads;

excellent resistance wind pressure.

Minus one - high consumption building materials. But the gain is clear - an additional living room for little money.

Broken mansard roof Source nkkconsult.ru

The construction of an attic roof is the installation of racks on which the beams are laid and the lower ends of the rafter system rest. At the top, the ends of the rafters are connected at the ridge. The steep lower rafter legs rest against the mauerlat from below, and on the beds from above. The result is a fairly stable and durable structure.

Video description

In this video about the construction of a mansard roof:

Generalization on the topic

The variety of roofs with two slopes makes it possible to choose the option that fits into the architecture of the house being built. The effectiveness of the structure is just the visible part. The design is based on an accurate calculation of the elements and the loads on them. But, as practice shows, most roofs in the private housing construction category are gable.

Roof installation is a complex multi-step process. To independently assemble and install a rafter system, you need to carefully study the methods of connecting elements, calculate the length of the rafters and the slope angle, and select the appropriate materials. If you don’t have the necessary experience, you shouldn’t take on complex designs. The best option for a residential building small sizes– do-it-yourself gable roof.

A standard roof of this type consists of the following elements:

Mauerlat is a timber laid on top of the walls along the perimeter of the building. It is secured using threaded steel rods embedded in the wall or anchor bolts. The timber must be made of coniferous wood and have a square section of 100x100 mm or 150x150 mm. The Mauerlat takes on the load from the rafters and transfers it to the external walls.

Rafter legs- This long boards section 50x150 mm or 100x150 mm. They are attached to each other at an angle and give the roof a triangular shape. The structure of their two rafter legs is called a truss. The number of trusses depends on the length of the house and the type of roofing. Minimum distance between them is 60 cm, the maximum is 120 cm. When calculating the pitch of the rafter legs, you should take into account not only the weight of the covering, but also the wind load, as well as the amount of snow in winter.

It is located at the highest point of the roof and most often represents a longitudinal beam connecting both slopes. The beam is supported from below by vertical posts, and the ends of the rafters are attached to the sides. Sometimes the ridge consists of two boards that are nailed to the top of the rafters on both sides and connected at a certain angle.

Racks are vertical beams with a cross section of 100x100 mm, located inside each truss and used to transfer the load from the ridge run to the load-bearing walls inside the house.

The struts are made from scraps of timber and installed at an angle between the posts and rafters. The side edges of the truss are strengthened with struts and the load-bearing capacity of the structure is increased.

Tie - a beam connecting the lower parts of the rafters, the base of the truss triangle. Together with the struts, such a beam serves to strengthen the truss and increase its resistance to loads.

A log is a long beam with a cross-section of 100x100 mm, laid along the central load-bearing wall, on which vertical posts rest. Lezhen is used when installing layered rafters when the run between the outer walls is more than 10 m.

The sheathing consists of boards or timber placed on the rafters. The sheathing can be continuous or with gaps, depending on the type of roof. It is always attached perpendicular to the direction of the rafters, most often horizontally.

If there is no more than 10 m between the external walls and there is no load-bearing wall in the middle, arrange hanging rafter system. With this system, the upper ends of adjacent rafters are sawn at an angle and connected to each other using nails, excluding the installation of racks and ridge beams. The lower ends of the rafter legs rest on the external walls. Due to the absence of racks, the attic space can be used for arranging an attic. Very often, the function of tightening is performed by floor beams. To strengthen the structure, it is recommended to install the top tie at a distance of 50 cm from the ridge.

If there is a central supporting wall, the arrangement is more justified layered rafter system. A bench is laid on the wall, support posts are attached to it, and a ridge beam is nailed to the posts. This installation method is quite economical and easier to implement. If the ceilings are interior spaces are designed on different levels, racks are replaced brick wall, dividing the attic into two halves.

The roof installation process includes several stages: attaching the Mauerlat to the walls, assembling the trusses, installing the rafters on the floors, installing the ridge, and attaching the sheathing. Before assembly, all wooden elements are carefully treated with any antiseptic composition and dried in air.

To work you will need:

timber 100x10 mm and 150x150 mm;
boards 50x150 mm;
boards 30 mm thick for lathing;
roofing felt;
metal studs;
jigsaw and hacksaw;
hammer;
nails and screws;
square and building level.

In wooden houses The functions of the mauerlat are performed by the logs of the last row, which significantly simplifies the work process. To install the rafters, just cut inside log grooves of the appropriate size.

IN brick houses or buildings made of blocks, installation of the Mauerlat occurs as follows:

The mauerlat bars must form a regular rectangle and be in the same horizontal plane. This will facilitate further installation of the roof and provide the structure with the necessary stability. Finally, markings are made on the beams for the rafters and grooves are cut along the thickness of the beam.

When choosing a hanging rafter system, it is necessary to assemble the trusses on the ground and then install them above the floors. First you need to draw up a drawing and calculate the length of the rafter legs and the angle of their connection. Typically, the roof slope is 35-40 degrees, but in open, heavily blown areas it is reduced to 15-20 degrees. To find out at what angle to connect the rafters, you should multiply the angle of the roof by 2.

Knowing the length of the run between external walls and the angle of connection of the rafters, you can calculate the length of the rafter legs. Most often it is 4-6 m, taking into account the eaves overhang 50-60 cm wide.

The upper ends of the rafters can be fastened in several ways: overlapping, end-to-end and “into the paw”, that is, with grooves cut out. Metal plates or bolts are used for fixation. Next, the lower and upper ties are installed, and then the finished trusses are lifted up and installed above the floors.

The outer trusses are attached first: using a plumb line, the rafters are aligned vertically, the length of the overhang is adjusted and attached to the mauerlat with bolts or steel plates. To prevent the truss from moving during installation, it is reinforced with temporary beams made of timber. After installing the outer rafters, the rest are set, keeping the same distance between them. When all the trusses are secured, take a board with a cross-section of 50x150 mm, the length of which is 20-30 cm longer than the length of the cornice, and nail it along the upper edge of the slope. The same is done on the other side of the roof.

The first option: a rectangular groove is cut out on the rafter leg at the point where it touches the mauerlat, 1/3 of the width of the beam. Stepping back 15 cm from the top of the box, a steel spike is driven into the wall. The rafter is leveled, the grooves are aligned, then a wire clamp is placed on top and the beam is pulled close to the wall. The ends of the wire are securely fastened to the crutch. The lower edges of the rafters are carefully cut off circular saw, leaving an overhang of 50 cm.

Second option: the upper rows of walls are laid out with a stepped cornice of bricks, and the mauerlat is placed flush with the inner surface of the wall and a groove is cut out in it for the rafter. The edge of the rafter leg is cut to the level of the upper corner of the cornice. This method is simpler than others, but the overhang is too narrow.

Third option: ceiling beams extend beyond the edge outer wall by 40-50 cm, and the trusses are installed on the beams. The ends of the rafter legs are cut at an angle and rest against the beams, secured with metal plates and bolts. This method allows you to slightly increase the width of the attic space.

Installation of layered rafters

Figure 1 shows the cutting of rafter struts into a beam laid on intermediate supports, and Fig. 2 - resting the rafter leg on the mauerlat

The procedure for installing a layered rafter system:

When the main elements are fixed, the surface of the rafters is treated with fire retardants. Now you can start making the sheathing.

For the sheathing, timber 50x50 mm is suitable, as well as boards 3-4 cm thick and 12 cm wide. Waterproofing material is usually laid under the sheathing to protect the rafter system from getting wet. The waterproofing film is laid in horizontal strips from the eaves to the roof ridge. The material is spread with an overlap of 10-15 cm, after which the joints are secured with tape. The lower edges of the film should completely cover the ends of the rafters.

It is necessary to leave a ventilation gap between the boards and the film, so first stuff them onto the film. wooden slats 3-4 cm thick, placing them along the rafters.

The next stage is covering the rafter system with boards; they are stuffed perpendicular to the slats, starting from the roof eaves. The pitch of the sheathing is influenced not only by the type of roofing, but also by the angle of inclination of the slopes: the greater the angle, the greater the distance between the boards.

After completing the installation of the sheathing, they begin cladding the gables and overhangs. You can cover the gables with boards, plastic panels, clapboard, waterproof plywood or corrugated sheeting - it all depends on your financial capabilities and personal preferences. The sheathing is attached to the side of the rafters; nails or screws are used as fasteners. Overhangs are also hemmed various materials– from wood to siding.

Video - DIY gable roof

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