Section of the roof of the rafter system. What is included in the roof truss system

One of the main elements in building a good and durable house is a high-quality rafter system for the roof. The rafter structure must be made of quality materials, because it bears a huge load from the weight of the finishing roof and the load of weather conditions.

Before you start installing a truss structure, you need to understand what types, principles and rules for installing trusses exist.

Factors influencing the choice of rafter structure

The rafter structure is the basis of the roof, which is supported by supporting elements and is the basis for all building materials used during installation.

The parameters and structures of the rafters are determined by a number of factors:

Purchased material
Design size
Personal choice of the customer
Roof loads in different regions.

The roof truss consists of:

Lathing
Screed
Wooden racks
Mauerlat
Rafter legs.

All of the above factors directly influence the choice of the type of rafter structure.

Types of structures

The following types of rafter structures are often used:

Hanging rafter structures. They are the simplest types of structures.

Layered rafters. When choosing this system, you should take into account the need for an additional load-bearing wall located in the center of the building.

Mixed systems. This system is more complex, since the installation uses two of the above types. Often used for attic spaces.

Rafter structures for various types of roofs

For a specific type of roof, a specific type of roof truss is used. Let's take a closer look at each of the structures:

Rafter system for gable roofs

This system consists of two rectangular inclined planes. The entire structure looks like a triangle from the end of the building. The main elements are the sling legs and the Mauerlat.

For uniform distribution loads on slings and walls use such building materials as: strut, crossbar and racks. With the help of these elements a durable, rigid, simple circuit truss structure for gable roofs.

At correct installation structure of the rafter system, the entire load is distributed evenly over the area of the building.

Hip roof rafter systems

During installation it is necessary to mount different types rafters The rafters are placed on the side, made of boards, and installation occurs in the same way as when installing traditional pitched roofs.

Beams installed diagonally must be symmetrical so that the roof does not deform from any loads in the future.

Self-installation of a roof truss

Before starting work, it is necessary to calculate the rafter system, the amount of building materials, thermal insulation and other additional consumables.

Mounting is carried out according to the following algorithm:

We make a model from which you will assemble the structure. This requires the presence of two boards that correspond to the length of the slings; they need to be connected with nails from one edge.
Get a design called “scissors”.
We are installing the second model, with the help of which the cuts on the slings will be installed. For this template you will need plywood.
We cut special-purpose cuts on the rafters. We connect them at the slope angle of the slope. We attach the resulting triangular template to the Mauerlat.
First, we install two side front slings.
We stretch the cable between these tops of the rafters. Let us denote by this the ridge, as well as the points of the remaining rafters, which will be located in the gaps.
Raise and install the remaining rafters
For bulky structures, we use additional reinforcing struts and supports.
We install ridge bars.

To install the correct and reliable design on the Internet you will find a huge number of photos of the rafter system with step by step guide actions.

Fastening of the truss structure

In order for the rafter system to be reliable, you must first determine the methods of attachment to load-bearing roof and a skate.

When using fastening to prevent distortion of the roof during shrinkage of the structure, use a hinge plate or nut with a bolt and a sliding support to strengthen the rafters.

For hanging rafters, an additional plate of wood or metal is used, they are secured using the cutting method and connected with nails.

Based on the above, you can ideally select a sling system and install a reliable and durable roof.

Photo of the rafter system

Every day new houses appear on earth, which are built using completely different technologies. By trial and error, people choose the optimal design for themselves that will serve them for a long time and with high quality. The choice of roof construction system is one of the most important issues resolved in the process of designing a house. Currently, the roof truss system is becoming in demand, which has been used for quite a long time and has many advantages.

The rafter system is called load-bearing structure roof, which is the basis for the tightness of the roof and the stability of the walls. That is, how durable the house will be depends on the quality work done in this direction. This is a roof frame, which consists of a number of interacting parts.

Elements of the roof truss system

This is a rather complex structure, and the importance of each of its component parts should not be underestimated. Here's what it's usually made from:

Rafter, or rafter leg. This is a beam that is used to form the angle of inclination of the entire roof. In addition, the rafter is also a support for the roof. The choice of material from which the rafter leg will be made must be taken seriously, because it will be affected by the wind, the weight of people, and precipitation. Therefore, these elements of the rafter system are made from boards with a large cross-sectional size, especially in the vertical direction.
Puff. This is a beam or board connecting the rafters, which are located on opposite slopes. It is located horizontally and does not allow the rafters to creep apart.
Run. This is a beam that serves as a support for the rafters at the top or in the middle.
Rack. This element is used to support the purlin or rafters. A rack is a component of the system, located vertically; walls often serve as support for it.
Mauerlat. This is a beam, most often square in shape, that supports the lower part of the rafters. Mauerlat is laid along the entire perimeter of the building on the walls.
Wind beam. This element connects the rafters to each other, forming a roof slope. We are talking about a board that is attached at an angle to the rafters from the attic. The wind beam prevents the rafters from moving in strong winds.
Strut. The roof rafter system requires the presence of timber, which should support the rafters so that they do not sag. The strut is attached at an angle to the vertical elements of the building.
Sprengel. This is a beam made of logs or timber, thanks to which the entire structure is strengthened. Its location is horizontal. The sprengel is located on adjacent walls; it would be correct to install it perpendicular to the bisector of the angle that these walls create.
Filly. This is a board that is attached to the rafters, namely to their lower part. the main role this element - to create a roof overhang.
Narozhnik. This is a rafter, but shortened, resting on one side on the mauerlat, and the other on the diagonal leg.

Features of the gable roof rafter system

A gable roof is the most common type of roof for houses up to 3 floors inclusive. Installing such a roof is not at all difficult; you can do it yourself. This installation of the rafter system assumes the presence of two rectangular planes inclined towards each other, which make the upper part of the structure triangular.

Gable roofs mainly consist of rafters and mauerlats. There are layered and hanging rafter systems of this type of roof. With a layered system, the rafter legs cover the roof and have a span of up to 7 m. If it is necessary to cover a larger span, they resort to installing intermediate supports, which increases the span length to 12-15.5 m. Layered rafters have supports on the top of the walls or on the crown log house The middle and lower parts serve as support rafter legs.

A suspended roof truss system is a structure in which the rafters rest on load-bearing walls, while there are no intermediate beams. This type of roofing is acceptable for houses in which the walls are made of lightweight material. The advantage of the hanging system is this: it is excellent for forming long spans. To make the structure strong, purlins, struts, and racks are used.

Rafter system of a hipped roof: advantages and disadvantages

The hip roof is one of the most popular for modern private houses. It has a number of advantages:

hurricane resistance;
resistance to deformation;
good protection of building facades from precipitation;
beauty of appearance.

However, there are also disadvantages of such a rafter system:

the design is more expensive than a gable one;
slopes reduce the area of the attic;
It is very difficult to install a four-slope rafter system yourself.

Main fastenings of the roof rafter frame

To know how to properly make a roof frame, you need to understand what the main components of the rafter system are. The main nodes are as follows:

Attachment point to the beam. The rafter leg must be attached to the beam using a tooth with a tenon (in the rafter) and a socket (in the beam). In this case, the nest should have a depth that will be 25-30% of the volume of the beam. If we're talking about For roofs with an angle of less than 35°, a two-tenon assembly is used. To create the structure, metal screws, nails, angles, bolts, as well as wooden scarves, tenons and beams are used.
Mounting point to the Mauerlat. For fastening, a cut or saddle is made on the rafter, then the connection is fixed using nails, staples and wire. Two nails are crossed together, and the third is forgotten between them in the center. This is how the rafters of the gable roof and the Mauerlat are fastened.
Ridge connection unit. Can be mounted end-to-end, overlapping and on a ridge beam. Most often this is done with an overlap, in this case the rafter legs touch each other not with their ends, but with their planes. Fastening occurs using a pin, nails or bolt.

Video with errors during the construction of the rafter system. You can't build like this:

An example of calculating the rafter system of a conventional gable roof

It is quite possible to build a rafter roof yourself; it is important to be able to correctly calculate the amount of materials needed for this work, as well as take into account all the essential nuances.

It is necessary to consider a specific example of calculating a roof truss system, and then everything will become completely clear. So, let's take a house 4 m wide and 6 m long. In this case, the angle of inclination of the rafters is 120°. It will be implemented that there is 1 m between the rafters. 0.5 is the allowance for the roof canopy.

Find the height of the central support: 0.5x(Width of the house)/tgY/2=0.5x4/1.73=1.2 m.
Calculate the length of the rafter leg. The size of the rafters for the roof is: 0.5x(Width of the house)/sinY/2+0.5=2.8 m.
Roof area: (House length)x(Rafter length)x2=33.6 m². This is the number of metal tile sheets you will need for the roof.
Let's calculate the length of the beam: 2x(Length of the rafter leg)+(Width of the house)+(Height of the central support)=75.5 linear meters.
Since the length of the house is 6 m and the distance between the rafters is 1 m, it will be necessary to have 7 rafters.

Installation of rafters

You should start working with beam floors. To understand how to install rafters on the roof, you need to understand the installation options. If you do not plan to use the attic as housing, you can take 50x150 mm boards. If you need to make an attic, you need a 150x150 mm beam, which will be installed on the load-bearing walls of the house.

The rafter installation process involves the following steps:

Preparation of structural elements. To do this, boards and beams of the required size are made using a circular saw.
Marking of all components of the structure according to templates.
Assembling the roof truss system according to the markings. After completing this work, all elements should be marked.
Sockets are selected in rafter legs and other elements. All fastenings are made using nails, screws, self-tapping screws, metal corners, dowels and wire.

Rafters with small spans can be assembled off-site at special enterprises and purchased in this form. Thanks to this, the roof frame is made much faster.

It is not for nothing that the rafter system is chosen for roof installation, because it is simple and reliable. Knowing the algorithm of actions, you can create a durable roof that will protect from wind, cold and precipitation.

Video on installing the rafter system:

The roof performs a row important functions to create decent living conditions coupled with ensuring external attractiveness. It is quite reasonable that it is considered a significant structural component of the building. For the formation roofing structure meets the rafter frame. It must withstand the load, determine the configuration and be combined with the exterior of the house.

Only a well-chosen roof base can cope with the tasks at hand. Do right choice it is much easier if the owner of a country estate knows everything possible types and diagrams of rafter systems, the specifics of their construction and scope of application are clear.

The list of roof responsibilities goes beyond weather protection. Although the confrontation weather events in a particular area, without a doubt, heads an impressive list of tasks.

The roof, as the final architectural touch, complements the appearance of the building, gives it a stylistic direction or completely deprives it. The rafter system as the basis of the roof structure must meet the entire range of technical and aesthetic requirements placed directly on the roof.

Factors in choosing the “backbone” of the roof

The rafter system is an indisputable accessory of pitched roofs, which:

sets the configuration and steepness;
holds topcoat and components roofing pie;
creates conditions for the flawless operation of roofing system elements.

Choosing a roof ultimately comes down to determining the ideal version of the rafter system, which, in addition to the personal preferences of the home owner, is also influenced by such compelling factors as:

The amount of winter and summer precipitation characteristic of the area in which construction is planned.
The strength and direction with the speed of the winds prevailing in the region.
The owner’s desire to use the space under the roof to organize utility or residential premises.
Type of finishing roof covering.
Financial capabilities of the owner.

Climatic data greatly influences the choice of roof and the design of the rafter system. In regions with abundant snowfall, it is not advisable to erect structures with a slight steepness, which contributes to the formation of snow deposits. In areas with gusty winds, on the contrary, streamlined and low-sloping shapes are preferred, which will be difficult to be torn off and carried away by a powerful weather phenomenon.

It is clear that the flat design is not suitable for the arrangement of useful premises in it. For those wishing to equip the space under the roof, there are rafter systems designed for construction in regions with varying degrees of wind loads.

If there is no need to use an attic, a roof of a complex or simple configuration can be built without it. There are a lot of options, including various combinations of basic versions, familiarization with which will give an idea of the essence of building a rafter system of any type.

In order not to suffer from guessing about the most rational shape and angle of inclination of a pitched roof, it is enough to take a closer look at the surrounding low-rise buildings.

The proven configuration can be safely taken as a basic option in order to adjust and modify it in accordance with the requirements of the future owner and the technical characteristics of the roofing. If you don’t want to copy your neighbors, you should familiarize yourself with the design and operational specifics of various rafter systems.

Basic options for rafter systems

A pitched roof can be simplistically represented as a set of slopes - planes along which atmospheric water “rolls”. The slopes are formed by the ribs of the rafter legs - the main elements of the rafter system. The classification of pitched roofs and their corresponding rafter systems is made depending on the number and configuration of the slopes. According to the indicated characteristics, their ranks include:

Single-pitch. Roofs with one slope are installed mainly over utility buildings, extensions, and verandas. rest on two walls or two rows of racks. One of the walls or one row of supports must be higher than the other so that water can flow along the plane formed by the rafters without obstacles.
Gable. Roofs with two rectangular slopes are most often found in domestic spaces. Rafter legs gable systems rest on two walls of a rectangular box of the house. In the classic design, the area of both slopes is equal, as is the height of the supporting walls. True, they have often become design solutions with slopes of different areas and supporting walls of different heights.
Hip. Otherwise called hipped, based on the number of pitched planes. Rafter legs hip system form a pair of trapezoidal and a pair triangular slopes. The rafters of the trapezoidal components rest on the long walls of the box, and the triangular ones rest on the short end walls. In plan, the hip roof looks like a postal envelope. Looks impressive and can be used everywhere. The hipped category includes roofs with shortened triangular slopes, which are strongly recommended for construction in areas with high wind loads.
Tent . A roof that consists of triangular slopes converging at one vertex. The minimum number of slopes is 4, the upper limit is unlimited. Rafters tent system rest on walls or supports of equal height. They prefer to erect tent structures over verandas and gazebos. Variations with steepness hip roof allow them to be installed in regions with any wind load.
Broken. They are also called attic, because it is the broken technology that allows you to create the maximum spacious premises under the roof. Rafter legs of broken structures are installed by analogy with gable systems, but are constructed in two tiers. The lower rafters rest on the walls of the box being equipped, the upper ones on the supports of the lower tier of the rafter frame.

The listed types of roofs and rafter structures have numerous variations on the pitched theme. For example, a gable roof may have a regular gable gable at one end and a hip on the opposite side, or it may be supplemented single-pitch construction above the porch in the middle of the main slope.

When two gable systems are combined crosswise, a composite roof with four wooden gables or stone gables is formed. In the arrangement of boxes with a T-shaped or L-shaped configuration, several types of rafter systems are often involved simultaneously. The upper tier of a sloping roof can be built using hip technology.

A truss structure of any complexity can be represented as a set simple shapes. To make it easier to understand the intricacies of construction, it is better to conditionally divide the object into separate blocks. They will tell you how to build each of the parts and connect the basic types listed above to each other rafter frames.

Overview of pitched rafter structures

In order to understand the abundant variety of structures and the possibilities of their layout, we will consider the main types of rafter systems and the corresponding diagrams.

Type #1 – lean-to rafter frame

Most shed roofs are classified as non-attic, because regardless of the steepness, the space they create under the roof is not large in volume. However, if you want to build a strictly horizontal ceiling, a ceiling separating the attic from the main rooms is still built.

The scheme depends on the size of the span to be covered with a single slope:

If the distance between the upper and lower supports of the rafter leg is less than or equal to 4.5 m, additional struts and racks are not used.
If the span is in the range from 4.5 m to 6 m, a bench is laid near the high wall. A strut is rested against it - a rafter leg that ensures the rigidity of the rafter closer to the top of the span.
If a span of 6m to 9m is to be covered, the beams are laid on both sides and the rafter legs rest against both beams.

If it is necessary to cover a larger span, it is divided into sectors with the distances indicated above. At the border of adjacent sectors, racks for purlins are installed, and within the sector, beds and struts are installed according to the described rules. For construction in regions with high wind activity, single-pitch rafter structures are supplemented with diagonal wind braces from the inside.

In plan, the diagram of a single-pitch rafter frame resembles a series of parallel beams. A roof with one slope is not very beautiful, but it is very economical. Optimal angle slope from 4º to 12º, a greater slope is not prohibited.

It is advisable to equip structures with low slopes with continuous sheathing and waterproofing, which is not necessary for steep roofs. As finishing coating It is better to use corrugated sheets or roofing metal for low structures for arranging steeper structures.

Type #2 – rafter systems for gable roofs

Gable rafter frames are built on reinforced concrete floors and wooden beams, mainly with attics. The most common type of roof has a huge number of low and high, insulated and cold modifications.

Depending on the architectural and technical specifications object rafter legs used in the device gable roofs, are divided into:

Layered. These are rafters that have a strong support under the upper and lower heel. They are manufactured and installed like the rafters of pitched roofs. Layered rafter systems are constructed over boxes with internal load-bearing wall. It is needed as a supporting structure for the ridge girder. The role of a wall can be played by a number of supporting posts or columns. In the simplest layered scheme with a span of up to 5 m, the tops of the rafters rest on a purlin, which rests on a beam through support posts. Rigidity is provided by struts. Schemes for more substantial spans are equipped with contractions, headstocks and additional runs.
Hanging. Hanging type rafters have only a lower support; their tops rest against each other. The elements of the hanging rafter frame are immediately made in the shape of a triangle, so you can dispense with the Mauerlat. In such cases, the function of the Mauerlat is trusted to the base of the triangle - a tightening used to compensate for the thrust on the roof from the weight of the snow, the roof and the system itself. Hanging technology is used in the arrangement of small boxes that do not have internal support for the ridge girder. If it is necessary to cover long-span structures, the hanging system is equipped with headstocks, struts, tie rods, etc.

Depending on the technical characteristics The roof sheathing is arranged continuous or sparse. Low slopes up to 12º are completely covered with a waterproof carpet, high ones - only in places of possible leaks: along the eaves, ridge, valleys, around pipes and other roofing passages.

Type #3 – hip and half-hip system

Hip, or “envelope” roofs, differ from gable structures in that the place of vertical gable gables in their structures is occupied by inclined triangular slopes - hips. The central part of the roof is occupied by a standard gable rafter system, to which the same hips adjoin at an angle.

Diversity in the family of hip structures is achieved through variations with proportions. By changing the ratio of the length of the ridge to the length of the base and the height of the slope, you can get a design that meets any taste and architectural needs.

In the construction of rafter frames the following are used:

Slab or hanging roof trusses with appropriate structural elements: beds, ridge runs, puffs, etc.
Diagonal rafters connecting the tops of the outer trusses to the corners of the frame.
Sloping shortened rafters that form inclined slopes of the hips and parts of the main slopes adjacent to the hips.

Hip structures can be attic or non-attic. I must admit, they are not very suitable for organizing rooms under the roof. Four inclined slopes seriously limit the space. However, for fans attic houses There is a Danish variety with a shortened hip. Adherents of non-standard architecture will certainly like the Dutch type, which belongs to the category called “” along with the Danish version.

Rafter systems for hip and roof types are erected with an angle of inclination from 10-12º to 60º. The absolute priority is the classic proportions with a slope of 25-30º.

In addition to walkways, skates and eaves overhangs All convex and concave corners of the hip structure need enhanced waterproofing. The complex configuration of the slopes dictates the use of piece materials in finishing. When cutting metal tiles and corrugated sheets, there will be too much waste.

View #4 – hip roof

A simple hipped hipped structure is a hip roof without a ridge. Its plan layout resembles a square with diagonals running from corner to corner. Triangular slopes are connected at one vertex, which makes the roof similar to a tent. Build over boxes of a clear rectangular or polygonal shape.

In the construction of hip rafter systems, standard layered and hanging principles are used:

A truss structure of the layered variety is erected above the box with a central support or load-bearing wall.
Above an object without interior wall or the supports erect the frame according to the hanging principle.

The steepness and number of slopes depend on the personal preferences of the future owner. The ideal roofing covering for finishing triangular slopes would be piece material, solely because when cutting large sheets An impressive amount of waste remains. Regardless of the steepness, they prefer to equip tent structures with continuous lathing and a waterproofing carpet.

View #5 – broken rafter system

Rafter frames for broken lines, i.e. are specifically focused on increasing the attic space in order to create domestic or residential premises in it.

Broken technology is mainly used in construction attic roofs, which can be cold in country houses and insulated in permanent residences.

Each slope of a classic sloping roof can be divided into two rectangular parts, creating between them outside corner. The required shape is obtained by changing the sizes of the parts of the slopes, the angles between them and the angle in the ridge zone.

Rafter system mansard type- one of the most complex species rafter systems: diagrams and drawings of a broken frame introduce the complex structure of the structure. It consists of two tiers perched on top of each other:

The lower tier of rafter legs rests through the Mauerlat on the beams wooden floor, reinforced concrete slabs or ceiling beam wooden house. To support the top of the rafters, purlins are installed, which also serve as support for the bottom of the rafters of the upper tier. The rafters of the lower part of the sloping roof are only allowed to be layered.
The upper tier of rafters rests with their lower heels on the purlins of the tier located underneath. The purlins serve as the basis for laying the attic ceiling beams. In the construction of the upper part, both layered and hanging methods can be used. The task of the top is only to form the ridge part, because the responsibilities for distributing the roofing pie are assigned to the lower part of the attic roof.

The owner chooses the angle of inclination of the lower and upper parts of the slopes according to his own preferences. The ideal shape is considered if the five corners are intersected by an imaginary circle. Solid or sparse sheathing is installed depending on the type of roofing, and there are no restrictions on its choice at all.

It is better to install continuous sheathing and waterproofing on the flatter upper part. On the steep lower part of the slopes, precipitation does not linger, but it is threatened by heavy winds.

To prevent the sloping roof from falling off in areas with frequent strong winds each rafter is attached with a wire bundle to the wall, and not through one, as is customary when fixing conventional pitched roofs.

Video review of types and shapes of roofs

Expert Tips:

Photo selection (slideshow):

Presented schemes different types rafter systems are suitable for arranging a wooden house, brick and foam concrete frame. The only difference is in the fastening of the Mauerlat on wooden and stone walls. Information about the basic types of rafters will help you correctly determine the type and configuration of the roof for a country property.

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It's hard to imagine a house without a roof. Without it, the house cannot be called complete. The roof, as you know, protects the house from precipitation, inclement weather, etc. In addition, it is used to complete the architectural image of the constructed object. In this case, it is necessary to correctly calculate and install the roofing system, only then will the roof last long years, and it will not need to be repaired every year.

The structure of the rafters can be very different. We propose to consider their most common types and types, methods of their fastening.

As you know, the roof can be flat or pitched. As for suburban construction, in this case the installation of a gable roof rafter system is especially popular. If the house is very large, then the roof will be of the appropriate size, for example, hipped (more details: ""). Thus, the developer must imagine the design of the rafter system hipped roof. The most simple option the device of the rafter system is considered pitched roof, since it is very labor-intensive and requires sufficient knowledge.

Still, it is worth noting that the installation of a gable roof rafter system is considered the most common option today. The design consists of two planes that are on the same level. They are also the load-bearing part that rests on the walls of the house. Usually there is an attic under the roof slopes. If it is heated, then it can be used as attic floor, where you can arrange a functional room.

It is worth noting that the angle of inclination will depend on the roofing material future roof. It is usually measured in degrees.

Determining the reliability of the rafter system

When installing a roof, developers Special attention given to the rafter system. It must be made reliable, because the service life of the roofing structure depends only on this system.

The reliability of the rafter system is usually affected by the following points:

Construction of a rafter roof: structural components

We can conclude that if the rafter system is calculated incorrectly and unprofessionally, it may simply not withstand the load in the future. In this case, terrible consequences cannot be avoided.

When calculating the design of the rafter system, the following points must be taken into account:

roof shape;
location of internal supports;
floor span size;
expected operating loads.

In the design of the rafter system, the triangle is the main figure. Rafter legs are also important in such a design; maximum attention must be paid to their design. They are usually laid along the roof slope. The sheathing is supported precisely by the rafter legs.

What types of rafters are there?

Today rafters can be:

hanging;
layered.

Sami optimal sections there will be the following options:

for boards – 16-18x4-5 cm;
for bars – 16-18x12-14 cm;
for round timber – 12-16 cm.

The axis distance between the bars and logs should be 150-200 centimeters. The distance of the rafters between the beams of the boards is usually 100-150 centimeters.

At the end of each rafter leg, so-called fillies must be nailed. Suitable for their implementation regular board. Along the entire cornice along the slope of the filly, you need to nail the formwork, which will serve as the base for the boardwalk. It is on this decking that the roof material is attached.

The installation of a rafter system for a gable roof or any other may encounter such a difficulty as expansion (read: ""). To avoid expansion of the rafter system, the rafters must be attached to the ridge very firmly.

At wrong device clivus displacement may also occur. If you cut the rafter legs into the wood floor, this will not happen. The strength of the joint can also be achieved with an overlay, or with reliable fastenings, which are made using bolts and dowels.

In this case, it is necessary to take especially seriously the calculation of the maximum roof load, and we must not forget about the snow cap. Price roofing works in this case, it will increase significantly, since more lumber will be required, and the tiles themselves are not cheap.

Due to such high costs, many people choose soft roof covering. In this case, you need to remember about the sheathing, which is made entirely of boards or plywood. This type of roof also requires underlay carpets. Consequently, the developer will also have to pay a considerable amount when purchasing building materials.

Roof structure

Any low-rise residential building is built in such a way as to obtain a long service life and maximum usable space with minimal costs of materials. From this point of view, of particular interest are attic spaces, allowing you to double usable area without any additional changes. On the other hand, the design of roofs, the rafter systems of which are designed to create a residential attic, will be more complex.

Today during construction country houses Several types of roofs are used:

Single-pitch. This is the simplest option, since here you can often do without a ridge beam and even without a number of other elements that are required in other cases. Typically, such solutions are used in the construction of utility rooms, extensions and garages, but they are also suitable for residential buildings with a small area.

Roofs of this type are among the most economical. They require a minimum amount of roofing material and wood, which is used for rafter structures.

Gable. This is the second most difficult type of roof to create, since only two slopes are required here, and the rafter system, as a rule, is no different. Roofs of this type are among the most popular in modern times. suburban construction, because, despite their simplicity, they cope well with wind and snow load, and are also suitable for creating an attic.
Four slopes. This category includes hip, hip and sloping roofs. In the latter case, it is worth mentioning that we are talking about a variety gable roof, which, due to a fracture, received four slopes. Such structures are more complex than the two previous options, however, the aesthetics of the building along with them are higher.
Gable and multi-slope. Complex knots rafter fastenings, special technology devices and the need for careful calculation are the reasons why such roofs are erected only by professionals. Of course, you can try to build something like this yourself, but only if you are an expert in this field.

The choice of roof type depends on the climate in the region and the wind load. The second point is the angle of inclination of the slopes, which depends on the location of the building, the presence of nearby buildings or trees and the climate.

Slope angle

Perfect option for any roof - this is a design that will require minimal attention from the owner. Self-cleaning roofs are generally attractive because they allow you to avoid having to worry about large amounts of snow accumulating.

The accumulation of snow cannot be neglected, since its mass after intense snowfall can be up to 200 kg per m2, which means that only very strong rafters will withstand such a weight.

An alternative is the device original roof like alpine houses, which have very large slope slopes, often descending almost to the ground. It should be noted that to obtain the snow removal effect, an angle of 45 degrees is required. In this case, precipitation will roll down the surface under its own weight.
On the other hand, an increase in the slope of the slopes leads to increased consumption of roofing and building materials. Moreover, if you plan to build an attic, then the insulation will be expensive, because what more height ridge, the higher the consumption of this material. In addition to the cost of a pitched roof, the choice of slope is influenced by its type. For roofs that are not in use, it is not necessary to use a large amount of insulation, however, increasing the angle of inclination does not always justify itself.

The main sign of an unused roof is a different design of the rafter system and the absence of a gap between the ceiling and the external protective structure. Usually this flat roofs or those that have a very small slope. Their main drawback The problem is that during intense snowfalls, snowdrifts can form, which will not only create a load on the ceiling, but also cause a “flood” during a thaw.

The type of roofing material will need to be determined in advance, since it must be taken into account when calculating the angle of inclination of the rafters. Typically, for multi-gable structures, flexible materials and bitumen coatings. For example, metal tiles, corrugated sheets or galvanized iron. Other options, such as slate or tiles, are better suited for roofs that have a simple configuration.

Classic tiles are rarely used today, since they require a fairly large slope angle, ranging from 30 to 60 degrees.

Bituminous materials can be used even at small angles of inclination (from 8 degrees), and the limit value for them is 18 degrees. Metal tiles and asbestos-cement sheets are used at angles from 14 to 60 degrees. Under consideration roofing materials We will not go into detail, since this issue has already been covered on our website.

Expansion and non-expansion layered rafters

These are two types of rafters, one of which is chosen taking into account the shape of the house, roof and size future design. Layered rafters are an option suitable for single-pitch or gable roofs. Their main feature is that they use two fulcrum points. On one side, the rafter leg rests on the ridge of the roof, and on the other, on the wall of the house.
Non-thrust layered rafters are mounted in such a way as to avoid bursting pressure on the wall of the house. Typically, roof trusses are created using one of the following options:

The rafter leg rests on the mauerlat. It is hemmed with a block and fixed by cutting with a tooth. In addition, additional insurance with wire is performed. The upper part of the beam is mounted on the ridge girder. Fastening is carried out using the sliding support principle.
The bottom of the rafter is secured using a movable joint. Not only the Mauerlat, but also piece bars can be used as an installation point. The upper part is fixed with a bolt, nails or another method after it is laid on the ridge girder.
The third option involves installing layered rafters with rigid attachment to the purlin. Nails, pins or other fasteners may be used here.

If the thickness of the rafters that was initially chosen turns out to be insufficient, then during the work you can use supports that are mounted under elements that are too long in those places where maximum deflection is expected.

Spacer rafters

Layered rafters are spacer. In this case, it is assumed that a structure will be created in which a bursting force will be transmitted to the walls of the house. The installation method in this case is the same as in the previous one, however, the fastening of the rafter legs is fixed, so the entire system will receive internal tension. It is worth saying that this option is a transitional scheme separating non-thrust layered rafters and hanging rafters.

Hanging rafters

This design of the rafter system will be ideal when it is necessary to cover large spans, the length of which exceeds 7 m. In such a situation, there is only one support point for the rafter leg - the wall. The upper part of the beam is connected to the counter element located on the other slope. Several joint options are used: half-timber, slotted tenon, metal plates.
In order for the rafter legs to be securely fixed, it is necessary to connect them using a tightening. Usually it is a strong beam that is attached to the bottom of these elements. Of course, it can be placed higher, but in this case the load will increase, which means that the weight of the beam will need to be increased. In such a situation, one of the following options for installing rafter legs can be used:

The rafter leg is connected to the mauerlat using an additional notch and is securely held with nails. The second option involves the use of metal corners. Then the upper parts of the rafters are butt-joined, and the lower parts are held in place by a tie. In this case, the top of the rafter legs can also be pressed against the ridge purlin, which will rest on the headstocks.
The puffs are installed so that the heels of the rafter legs rest against the cut out tooth against the edges of the puffs, which, in turn, are attached to the mauerlat. The tops of the rafters are supported with wooden planks.
Floor beams can be used as tie-downs. In this case, their ends must extend beyond the walls by at least 55 cm. The cutting of the tooth socket is carried out no closer than 25-40 cm from the edge of the wall.
In houses made of logs, the rafter leg is attached to the upper crown through a tenon-socket connection. Special ones can also be used metal fastenings, such as sliders, sleds, etc. The latter option will allow structural elements to move and avoid the occurrence of additional stress.

The ties themselves can be solid beams or constituent elements. The splicing of bars is carried out by any in a convenient way, for example, oblique tooth, overlap, etc. Installation of tightening can be done not only at the level of the heels of the rafters, but also in any other place.

If roof rafters measuring more than eight meters are used, then we recommend creating a structure from the headstock and struts, as well as using racks and crossbars, which help increase the reliability of the rafter system.

Rafters for different types of roofs

The simplest option is the design of a pitched roof, the rafters of which rest on the walls of the building. The length of these elements cannot exceed 4.5 meters, but there is also a solution for covering large areas. In this case, it is recommended to use supports or racks that will support the extended structure.
Most gable roofs are similar to each other like twins, but they internal structure may vary greatly. Today there are four options:

A ridge girder is used, on which the legs of the rafters rest. The slopes are strengthened through the use of rafter legs, and the girder is supported by racks. The racks themselves are installed on a bench. The width of this type of roof can reach 10 m.
The second option involves the use of rafter legs, the lower parts of which rest against the ridge girder post, and the upper parts in a grip (tightening) connecting the rafter legs closer to the ridge. In this case, the roof width increases to 14 m.
There is no ridge run. It is replaced by a beam located under one of the slopes. In addition, a tie, rafter legs and a stand resting on a bench are used. The angles of inclination of the rafter legs vary from 45 to 53 degrees. This option, compared to the previous one, does not provide a particular gain in roof width, but is suitable in the case when the supporting wall is not located in the center of the building, but is shifted to the side.
In cases where it is necessary to cover wide buildings, symmetrical structures can be used, using two purlins located parallel under the rafters of the slopes. Such gable roofs require the use of two ties, the upper of which connects the rafters, and the lower - the racks and rafter legs. The width of the structure in this case can reach 16 m.

The distance between the rafters is selected taking into account their length and cross-section. For example, for a section of 40x150 mm a step of 60 cm is required, for 50x150 - 90 cm, and for 100x150 - 215 cm.

Hip roof- This is another common option today that has proven itself well for country houses. It differs in that it does not have pediments, the place of which is taken by additional slopes - hips. In general, the design assumes the presence of a purlin, and ordinary rafters on the main slopes and hip rafters on the side ones. Hip rafters rest on long diagonal members where they meet upper parts ordinary rafter legs. For such roofs it is recommended to use reinforced piping.
broken roof completes the list because it has a rather complex design. Here a method is used that involves creating a frame for rafter legs, consisting of a horizontal beam and vertical racks, after which the remaining elements are installed. The top crossbar of the U-shaped frame acts as a ceiling for the attic, but the ridge post also rests on it.

In this case, the distance between the rafters of the rafter system should be selected taking into account the load acting on the roof, the thickness of the timber used and the angle of inclination of the slopes.

Above we discussed the main issues related to the design of the rafter system for various types roofs, so this material can be used as a short guide to quickly understand the issues of roof construction.