Wooden structures roof nodes. The device of the roof of a private house - the main elements and features of various types of roofing

The pitched roof of the house consists of a large number of parts, each of which is connected to others in a special way. Such a connection is called a roof node. In this article, we will talk specifically about the connection nodes, how it is carried out, what technologies are used, what fasteners are used.

The main parts of the roof structure

Before proceeding directly to the analysis of the topic of the article, it is necessary to indicate what elements (details) the roof structure consists of. We list all the main details and indicate their purpose.

Mauerlat. This is a beam that is laid on the walls of the house, located along the perimeter of the building. The purpose of the Mauerlat is to evenly distribute the loads emanating from the truss system. After all, if there is no Mauerlat, then each rafter will put pressure on the wall pointwise. And it is in this place that the destruction of the wall structure will occur.

rafter legs. They are made either from boards with a thickness of at least 50 mm, or from timber. Rafters are the basis of the roof, it is they who form the slopes and bear all the loads acting on the roof structure.

Skate run. This is the uppermost beam, installed horizontally. Its purpose is to support the upper ends of the rafter legs. It is he who forms the ridge of the roof.

These are the three main elements of the roof, which will be discussed further. Of course, these are not all the details of the roof, and it cannot be said that others are less important. It's just that these three elements form the structure itself. The only thing to add is that in some roof structures there is no ridge run. It's just that the upper ends of the rafters rest against each other. This type of rafters is called hanging, and with a ridge run layered.

In order for the roof structure to be the most reliable, it is necessary that the roof nodes are correctly connected. In this case, the force of the acting loads and their direction must be taken into account.

How to connect the elements of the roof structure

More recently joining timber roofing carried out with the help of notches. That is, they cut the elements of the roof structure in order to connect them along one fairly wide plane. Therefore, so that the roof details do not reduce their strength characteristics, as well as their bearing capacity, they were selected with a sufficiently large cross section. And it's not economical. That is, the larger the cross-section of lumber, the more expensive it is.

Today, the technology of fastening nodes and parts of the roof structure has changed dramatically. To do this, use bolts, dowels or metal perforated profiles. The latter are made of galvanized steel, which makes it possible to operate fasteners for a long time without losing their quality. At the same time, manufacturers offer a fairly wide range of them for each type of node. The photo below shows some of these fasteners.

It should be noted that perforated profiles gradually replaced all other types of fasteners due to the strength, reliability and ease of fastening operations. After all, for this you just need to install the profile at the required place and fix it to various parts with wood screws or ruff nails.

Let's now look at how fasten parts roof structure to each other. In principle, there are two types of connection: Mauerlat-rafter, rafter-ridge run. The remaining parts are connected parallel to these joints. They will also be talked about.

Mauerlat and rafters connection

There are actually a huge number of fastening options, from ordinary nails to perforated profiles. For example, the photo below shows an option where ordinary wire is used as fasteners. That is, a through hole is made in the rafter itself, where a wire with a diameter of 6 mm is inserted. They also make a hole in the Mauerlat or in the floor beam.

Then the ends of the wire are pushed into this hole and twisted, pressing the rafter leg against the Mauerlat. The connection is actually strong and reliable, but the process is laborious.

Can be used instead of wire metal tape 3 mm thick. She simply wraps two connected elements and through the strip is attached to them with self-tapping screws, more often with nails. In the latter case, there is no need to drill through holes in the metal. note that in the lower photo, the fastening is carried out to the reinforced belt with an anchor, which increases the strength and reliability of the connection.

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The next type of fastening is a perforated corner made of galvanized steel. The most convenient option, but the most reliable. To do this, the corner is simply installed so that it is tightly pressed against the plane of the Mauerlat and the rafter leg with its mounting shelves. Fastening is carried out with screws or nails.

Fasten the corners it is possible not only with self-tapping screws or ruff nails. There is another more reliable option where bolts are used. True, holes will have to be made under them, which increases the costly time for carrying out this type of work. But in this case, the quality is above all. The photo below shows just such a mounting option. Please note that the corner is attached to the Mauerlat with self-tapping screws, and to the rafter leg with a bolt. In this case, one bolt is used to connect two corners located at opposite ends of the rafter.

And another mounting option - on the slider. This is a special type of fastener, consisting of two parts. One is attached to the Mauerlat, the second to the rafter leg. In this case, both parts are not tightly connected to each other. This is done specifically so that the rafters can move relative to the Mauerlat during the thermal expansion of the lumber. This means that there will be no loads that act on the junction of two roof parts. The photo below shows this connection option.

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Connection of rafters with a ridge run

The second main node of the wooden roof - joint between rafter leg and ridge beam. In fact, the ridge roof truss assembly is very complicated, because two rafter legs and a beam are joined on it. In this case, all the elements are located in different planes, meaning the rafters and timber. This means that more than one fastener will have to be used to connect them.

To connect the rafters to each other, they use perforated plate. There are two of them, installed on different sides of the rafter legs to increase strength and reliability.

Perforated corners connecting the rafters to the Mauerlat. There are four of them, two for each rafter leg, installed from different sides.

It should be noted that fastenings can be carried out not only with self-tapping screws or nails. Often masters use bolts for connection paired fasteners.

Pay attention to a different type of fastening. Only corners are used here. This option is used if a board with a thickness of 50 mm is installed as a ridge beam.

Another interesting option for attaching rafter legs to a ridge span, for which special perforated complex shape profiles. In fact, these are brackets into which the rafter leg is inserted. The bracket not only fastens the parts together, it supports the rafters, reducing the load on its end.

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Pay attention to all of the above options for connecting rafters to each other. They clearly show that the ends of the rafter legs are joined tightly to each other, for which they have to be filed at a certain angle. You can do without filing if you use a complex mounting lock, consisting of several plates that are bolted together. In the photo below, this connection option is clearly visible.

Connection of hanging rafters

The rafter system of this type differs from the layered one in that it does not have ridge run. That is, the rafter legs in the upper part (ridge) rest against each other. In order for them not to disperse in different directions, the rafters are connected to each other by a horizontal tightening. The latter is a board located at any distance in height: from above, below or in the middle.

It should be noted that hanging rafters not assembled separately on the roof. Farms are assembled from them on the ground, which are installed ready-made on the roof of the house. In this case, all elements of the farm are interconnected by perforated plates.

Video description

In the video, the master tells how to assemble a roof truss using perforated plates and nails:

Other types of knots

As mentioned above, there are many details in the roof structure. Therefore, we will tell and show a few more important connection nodes.

If the span of the house is more than 6 m, then a rack is installed under each rafter, which itself must rest either on a concrete base or on a floor beam. In this case, the connection of the rack with the rafter leg is carried out with ordinary boards, as shown in the photo below. Although you can use perforated metal plates.

Under the ridge beam is also installed vertical support posts, which are attached to each other by perforated plates. But in some roof structures, a completely different approach is used to solve the installation of a ridge run. Under the beam, jibs are mounted from the bars, which are fixed to the ridge with special fasteners made of metal. The photo below shows one of the options for this type of fastener.

Very often, when constructing a rafter system, it becomes necessary to lengthen the rafters themselves. It is not difficult to do this, while the masters use several technologies, where they use various additional fasteners.

Video description

The video shows one of the options for lengthening the rafters:

Roof structures are several varieties of their forms. Almost all models have a large number of identical elements. But among them there is one design that differs significantly from the others. This is hipped roof. Its distinctive feature is that the rafters are connected by their upper edges to one point, which is called the ridge knot.

So, in order to connect the rafter legs to each other, you need a support to which they are attached. There are several ways to ensure high node reliability. The photo below shows one of them, which uses U-shaped perforated metal mounting profiles.

Conclusion on the topic

In fact, we have considered only a small part of the connecting nodes for attaching the roof truss system. But even on their example, the variety of parts and assemblies becomes clear. That is, the roof structure is a complex system, consisting of a large number of different elements and parts that are interconnected in different ways.

When designing any residential building, architects pay special attention to the roof, as it performs not one, but several functions at once, depending on its design features. It must be said that not all future homeowners are satisfied with the usual gable roof, although it can be called the most reliable, since it has only two pitched planes and one joint between them. Many are attracted to more complex designs that add a special appeal and originality to the structure. Other, more practical homeowners prefer attic structures that can simultaneously serve as a roof and a second floor.

The basis of any roof is an individual truss system, which has its own design features. Making the choice of the desired roof frame will be much easier if you figure out in advance which ones types and schemes of truss systems used in building practice. After receiving such information, it will become more clear how complex such structures are in installation. This is especially important to know if the roof frame is supposed to be built independently.

The main functional tasks of truss systems

When arranging pitched roof structures, the truss system is a frame for covering and for holding materials of the "roofing pie". With proper installation of the frame structure, the necessary conditions will be created for the correct and non-insulated types of roofs that protect the walls and the interior of the house from various atmospheric influences.

The roof structure is also always the final architectural element of the exterior design of the building, supporting its stylistic direction with its appearance. Nevertheless, the design features of the truss systems must first of all meet the requirements of strength and reliability that the roof must meet, and only then - aesthetic criteria.

The frame of the truss system forms the configuration and angle of inclination of the roof. These parameters largely depend on the natural factors characteristic of a particular region, as well as on the desire and capabilities of the homeowner:

• The amount of precipitation in different periods of the year.
• Direction and average wind speed in the area where the building will be erected.
• Plans for the use of space under the roof - the arrangement of residential or non-residential premises in it, or using it only as an air gap for thermal insulation of the premises below.
• Variety of planned roofing material.
• Financial capacity of the homeowner.

Atmospheric precipitation and the strength of wind currents give a very sensitive load on the structure of the roof. For example, in regions with heavy snowfalls, you should not choose a truss system with a small angle of inclination of the slopes, as snow masses will linger on their surface, which can lead to deformation of the frame or roofing or leaks.

If the area where the construction will be carried out is famous for its winds, then it is better to choose a structure with a slight slope of the slope so that the sharp gusts that occur do not rip off individual elements of the roof and roof.

The main elements of the roof structure

Details and nodes of truss systems

Depending on the type of truss system chosen, the structural elements used can vary significantly, however, there are details that are present in both simple and complex roof systems.

The main elements of the pitched roof truss system include:

• Rafter legs forming roof slopes.
• - a wooden bar fixed on the walls of the house and serving to fix the lower part of the rafter legs on it.

• The ridge is the junction of the frames of two slopes. It is usually the highest horizontal roof line and serves as a support on which the rafters are fixed. The ridge can be formed by rafters fastened together at a certain angle or fixed on a ridge board (run).
• Sheathing is slats or beams mounted on rafters with a certain pitch and serving as the basis for laying the selected roofing material.
• Retaining elements, where you can take beds, girders, racks, struts, ties and other parts, serve to increase the rigidity of the rafter legs, support the ridge, link individual parts into a common structure.

In addition to the above structural details, other elements can be included in it, the functions of which are aimed at strengthening the system and optimal distribution of roof loads on the walls of the building.

The truss system is divided into several categories depending on the different features of its design.

attic space

Before proceeding to the consideration of different types of roofs, it is worthwhile to figure out what an attic space can be, since many owners successfully use it as utility and full-fledged living quarters.

The design of pitched roofs can be divided into non-attic and attic. The first option is called just that because the space under the roof has a small height and is used only as an air layer that insulates the building from above. Such systems usually include or have several slopes, but located at a very slight angle.

The attic structure, which has a sufficiently large ridge height, can be used in different ways, be insulated and not insulated. These options include attic or gable option. If a roof with a high ridge is chosen, then it is imperative to take into account wind loads in the region where the house is built.

Slope slope

To determine the optimal slope of the roof slopes of the future residential building, first of all, you need to look at the already built low-rise neighboring houses. If they have been standing for more than one year and steadfastly withstand wind loads, then their design can be safely taken as a basis. In the same case, when the owners set the goal of creating an exclusive original project, unlike the buildings standing nearby, it is necessary to familiarize yourself with the design and operational features of various truss systems and make appropriate calculations.

It should be borne in mind that the change in the tangent and normal values ​​​​of the wind force depends on how large the slope of the roof slopes is - the steeper the angle of inclination, the greater the importance of the normal forces and the smaller the tangents. If the roof is sloping, then the structure is more affected by the tangential wind load, since the lifting force increases on the leeward side and decreases on the windward side.

Winter snow load should also be taken into account when designing the roof. Usually this factor is considered in conjunction with the wind load, since the snow load on the windward side will be much lower than on the leeward slope. In addition, there are places on the slopes where snow will definitely collect, giving a big load on this area, so it should be strengthened with additional rafters.

Roof slopes can vary from 10 to 60 degrees and must be selected not only with regard to the consolidated external load, but also depending on the roofing that is planned to be used. This factor is taken into account because roofing materials differ in their mass, their fixing requires a different number of elements of the truss system, which means that the load on the walls of the house will also vary, and how large it will be, also depends on the angle of the roof slope. Equally important are the features of each coating in terms of resistance to moisture penetration - in any case, many roofing materials need one or another slope to ensure the free flow of storm water or melting snow. In addition, when choosing a roof slope, you need to think in advance how the process of cleaning and repair work on the roof will be carried out.

When planning this or that angle of the roof slopes, you need to know that the fewer joints between the sheets of the coating, and the tighter they are, the less you can make the slope of the slope, of course, if it is not supposed to arrange a residential or utility room in the attic space.

If, however, a material consisting of small elements is used to cover the roof, for example, ceramic tiles, then the slope of the slopes must be made steep enough so that water never lingers on the surface.

Given the weight of the roofing material, you need to know - the heavier the coating, the greater the angle of the slopes should be, since in this case the load will be correctly distributed to the rafter system and load-bearing walls.

The following materials can be used to cover the roof: either a profile sheet, galvanized steel, corrugated asbestos-concrete and bitumen-fiber sheets, cement and ceramic tiles, roofing felt, soft roofing and other roofing materials. The illustration below shows the allowable slope angles for various types of roofing.

Basic structures of truss systems

First of all, it is worth considering the basic types of truss systems regarding the location of the walls of the house, which are used in all roof structures. The basic options are divided into layered, hanging, and also combined, that is, including elements of both the first and second types of systems in their design.

fasteners for rafters

Layered system

In buildings where internal load-bearing walls are provided, a layered truss system is often installed. It is much easier to install than a hanging one, since the internal load-bearing walls provide reliable support for its elements, and in addition, fewer materials will be required for this design.

For rafters in this system, the defining reference point is the ridge board, on which they are fixed. The non-thrust type of the layered system can be equipped in three versions:

• In the first version, the upper side of the rafters is fixed on a ridge support, called a sliding one, and their lower side is fixed by cutting to the Mauerlat. Additionally, the rafters in the lower part are fixed to the wall with wire or staples.

• In the second case, the rafters in the upper part are cut at a certain angle and interconnected using special metal plates.

The lower edge of the rafter legs is attached to the Mauerlat with movable fasteners.

• In the third version, the rafters are rigidly fastened in the upper part with bars or processed boards located horizontally, parallel to each other on both sides of the rafters connected at an angle, and a ridge run is pinched between them.

In the lower part, sliding fasteners are used to fix the rafters, just as in the previous case.

It is necessary to explain why sliding fasteners are often used to fix the rafters on the Mauerlat. The fact is that they are able to save the load-bearing walls from excessive stress, since the rafters are not rigidly fixed, and when the structure shrinks, they have the ability to move without deforming the overall structure of the roofing system.

This type of fastening is used only in layered systems, which also distinguishes them from the hanging version.

However, in some cases, a spacer system is used for layered rafters, in which the lower end of the rafters is rigidly fixed to the Mauerlat, and in order to remove the load from the walls, puffs and struts are built into the structure. This option is called complex, as it includes elements of a layered and hanging system.

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Gable truss system

Gable truss systems are the most popular for one-story private houses. They look neat, fit well into any style of construction, are reliable and can be used, depending on the angle of their slope, to equip the attic for living rooms, utility rooms, or simply to create an air gap that retains heat in the building.

wood screws

For a durable and reliable roof, it is important to make all the nodes of the truss system with high quality. What this means, we will analyze right now.

The rafter is the skeleton of the roof, on which the inner and outer skin, insulation, waterproofing and other elements are held. Also, very often they are used as the basis for communication. Huge loads fall on the roof and, accordingly, the rafters, which can reach 200 kg / m 2. This is the weight of building materials, snow with foliage and other debris. And what about gusts of wind?

Roof rafters as a basis for communications

When carrying out repair work, this system must withstand not only the weight of a person, but also the necessary equipment. Moreover, all these parameters are strictly individual and depend on a number of factors, ranging from the configuration to the climatic zone. However, in any case, the roof and all its elements must be sufficiently reliable, and only then can we feel truly protected.

First you need to familiarize yourself with the terminology. The Mauerlat can rightly be called the foundation of the entire system. It is a beam on which the structure is attached. Its main function is to evenly distribute the loads on the walls. But the beam on which the crate is fixed is called the rafter leg. This is the most important element that determines the angle of inclination of the slope and the general appearance of the roof. Between themselves, the rafter legs fasten the run. It is located both on top and on the side. Depending on this, there are ridge and side runs. At the bottom of the leg are fixed with a puff.

Mauerlat for fastening the truss structure

Thanks to the struts and racks, the rafter beams are located as stable as possible. Edged boards are stuffed perpendicular to the legs - crate. It serves as the basis for the roofing material. And the junction of the roof slopes is usually called the ridge. A continuous crate is stuffed on it to make this part of the roof as reliable as possible. Continuation of the rafter legs - filly. They are located under an overhang that protects the walls from precipitation. Very often, it is these structural elements that begin to rot first, since they are most susceptible to the negative effects of the weather, while the legs themselves can serve for a very long time. The reliability of the entire structure depends on how high quality absolutely each attachment point will be. We will talk about them in more detail.

This concept combines a number of structural elements, as they consist of crates, racks and braces. In fact, this rigid structure is the skeleton of the roof. Depending on the size and personal wishes, there are four types of farms. If the width of the house is from 12 to 24 m, then the most suitable would be a segmented or trapezoidal shape. For larger structures, up to 36 m wide, a polygonal one is suitable. But the classic triangular one will be an excellent solution for the construction of houses with a width of 9–18 m.

Roof trusses of different sizes

The material also plays a huge role. The most commonly used wood. In this case, the beams are mounted by cutting and subsequent fixing with nails, self-tapping screws and other fasteners. However, the use of a tree is not relevant in all cases. So, if the span length exceeds 16 m, then trusses with stretched metal racks will be more suitable, since it will be difficult to ensure reliable fastening of wooden elements in this case. The combined type is also popular, in which both wooden and metal parts are used at the same time.

The ridge is a horizontal rib at the junction of two slopes. There is a layered and truss system of a hanging type. In the first case, the skate is mounted on racks parallel to long walls. It is very important to ensure the maximum adjoining of the rafters to the ridge; for this, appropriate cuts are made. Fixation is done with nails.

Skate at the junction of two slopes

If we are talking about a hanging structure, then the ends of the rafter legs are connected in pairs. To ensure such a pairing, the end of each beam is cut at an angle equal to the slope of the roof. Next, the rafters are connected by cut planes and fixed with nails hammered at an angle. It is imperative to close the junction with a metal plate or a wooden lining.

Pair connection of rafter legs

When connected with a notch in half a tree, maximum strength is achieved. To do this, at the junction, the rafter legs are connected to the ledge. Then a hole for a 14 mm bolt is drilled. Further fixation is achieved by bolting. When it comes to a sliding system, in this case the ends of the legs are connected by means of metal plate hinges.

This is the next attachment point for truss systems, which you need to dwell on in more detail. There are two technologies for fixing beams to the Mauerlat. Rigid fastenings exclude any shifts, vibrations, turns, torsion and other manipulations. To achieve a similar effect, a drink is made on the leg. Further, the connection is additionally fixed with nails, wire, self-tapping screws and other auxiliary elements. Usually, several nails are hammered at an angle so that they cross inside the Mauerlat. And then another nail is driven vertically.

Washed down on the legs for attachment to the Mauerlat

Sliding mounts are obtained thanks to special fasteners. There is one, two or three degrees of freedom of this conjugation. Such a connection is great for wooden houses, as a rigid fixation during shrinkage can be severely damaged. Such a mobile connection can be provided in several ways. The leg rests against the Mauerlat with a hemmed bar or sawn tooth and is rigidly fixed with a metal corner. Thus, the rigidity of the fastening in the horizontal plane is achieved. At the top, the legs are connected by notches, while a bevel is made on a horizontal platform to provide a sliding connection.

Sliding fastening elements

If only one nail is driven in at the place of fixation to the Mauerlat or special flexible plates are used, then the pairing will turn out to be sliding in this part of the truss system.

Now let's focus on the typical nodes of the wooden truss system. The peculiarity of such a roof is the presence of hips. This type has a number of advantages. They are more durable, since the load is distributed evenly over the entire surface, they are not afraid of strong winds and precipitation, and they are economical. However, they are more technologically complex.

Typical hip roof nodes

This roof consists of two long trapezoidal slopes, while they do not cover the entire area, triangular hips are installed at an angle from the ends of the building. In this case, typical elements appear - additional sloping rafter legs, from which end slopes are formed. The connection of diagonal beams can be different. Both hanging trusses and a layered structure fixed to the Mauerlat are popular.

Roofing from trapezoidal slopes and triangular hips

If the rafters of the slopes rest on the ridge, then the sloping legs should be adjacent to the console of the ridge run. It is very important that the console outlet is not less than 100 mm, but not more than 150 mm. The lower part of the diagonal rafters is fixed to the Mauerlat or a special beam on the wall of the house. Sometimes a wooden bar is used to make rafter legs, in which case the slanting elements are fixed to a special board (surfboard) fixed on the farm. But the installation to the extreme hanging farm is done by means of a sprengel. At the same time, cuts are made on the beams of the legs at an angle corresponding to the slope of the hip slope.

The roof system is the outside part of the roof structure that is supported by the load-bearing structure. It includes a crate and a truss system. The triangle underlying this system should be a rigid and most economical structural element that contains the attachment points for the roof rafters.

The main characteristics of the nodes of the truss system

The main attachment points of the roof truss system are shown in fig. 1. They imply the presence of a rafter leg (Mauerlat - 1), a rafter leg (ridge run - 2), a rack (puffs - 3). The design of the truss system is the main load-bearing element of the roof.

All roof fasteners must be of sufficient strength to eliminate a significant degree of risk associated with roof collapse. The consequences of a mistake made when connecting elements can be the most unpredictable.

Figure 1. The main attachment points of the roof truss system: 1 - mauerlat, 2 - ridge run, 3 - puffs.

First, the rafters are installed on the Mauerlat if the building has brick walls. Similar nodes are provided for concrete blocks, then it is necessary to create a reinforced concrete stiffening belt, and it is necessary to insert studs into its design. Their location should be at a distance of 1 to 1.5 m from each other, and their diameter should be more than 14 mm. The top of the studs must be equipped with a special thread.

Mauerlat is drilled, making holes that are necessary for attaching elements to it. Each of the holes should be the same size as the diameter of the stud, and its pitch should correspond to the distance between the studs. A nut is put on each protruding end of the stud and tightened, which ensures the strength of the connection between the Mauerlat and the wall. The rafters should be connected to the Mauerlat in such a way that their bearing capacity is not weakened.

Description of the main fasteners for mounting the truss system

If during the construction of the house a rounded log or timber was used, then it is not necessary to create an armored belt. produced on the upper beam or on the log of the wall. For this purpose, connecting the Mauerlat with the rafters uses different methods of cutting (tie-ins).

What fasteners fasten metal rafters:

1. Plates.
2. Fasteners LK.
3. corners.
4. Brackets WW.
5. Self-tapping screws.
6. Varieties of the corner of the KR.
7. Wire ties.
8. Mounting tape perforated TM.
9. Bolts with nuts.
10. Brackets WW.

If brackets are used when connecting the rafters to the Mauerlat, then they are not cut into the rafters, which helps to strengthen the bearing capacity. Metal brackets are usually produced, and the metal is galvanized and has a thickness of 0.2 cm. The brackets are strengthened with nails, anchor bolts or screws.

You can use the LK fastener by creating attachment points not only for rafters with a Mauerlat, but also for various other elements that make up the roof structure. The LK fastener is fixed to the wood, as are the brackets, with the exception of the use of anchor types of bolts.

Mounting perforated tape allows you to strengthen the connecting nodes in the construction of roofing systems. It is used not only to create stronger nodes, but also to strengthen elements for additional use in order to give rigidity or strength to the system as a whole. They fix the perforated mounting tape with screws or nails, so it is used to strengthen the structure of the rafter system of any roof, the integrity of which will not be violated.

With the use of KR corners and their various modifications, the attachment points are reinforced so that they can effectively participate in the connection of the Mauerlat and rafters. Ensuring appropriate strength to the roof units is permissible when using corners, which improves the load-bearing characteristics of the roof structure.

The use of connecting elements made of metal is not associated with inserting corners into the roof system. This will not cause a decrease in the bearing capacity of the roofing system. You can use corners for connection using screws or nails, the protrusions of which resemble a ruff.

How are the knots connected in the ridge part?

There are three main types of fastening in the ridge parts of the roofing system:

1. Butt connection.
2. Mounting on the basis of a ridge run.
3. Ridge joint overlap.

For the purpose of fastening, in the first way, the ridge part is cut off from the upper edge at an angle that is the same as the angle of the roof slope. Then it rests on the necessary rafter, which should also be cut at an angle, but on the opposite side of the roof. A special template is sometimes used to trim corners.

Nails for connecting the rafters under the ridge should be 150 mm or more in size, two of them will be needed. Each nail is driven into the rafters at the top of the rafters at the appropriate angle. The sharp end of the nail usually enters the cut of the rafter from opposite sides. Strengthening the ridge joint can be achieved by applying a metal plate to it on the side or a wooden lining so that it is enough to pull it with bolts or nails.

The connection in the second way, that is, through the ridge run, is associated with the strengthening of the rafters on the ridge beam. The run is one of the additional support beams or beams, which is a support for the rafters. It is located parallel to the ridge or Mauerlat. The method differs from the previous one in that a ridge beam is laid between the rafters, which are sawn at an angle, which is a laborious process, so this method is used less frequently.

A more common method is similar to the first, but it differs in that the fastening is overlapped, and the joint method is not used. The rafters should be in contact with the ends, and not the side surfaces. The rafters should be pulled together with a bolt or hairpin, nails. This connection is used by many masters in practice.

In general, it is possible to install rafters on a Mauerlat by creating structures for roof truss systems that are expansion or non-expansion. This determines the choice of the appropriate method of connecting the power plate and rafters, which can be similarly strengthened to the ridge.

The main shortcomings in the installation of attachment points for the truss system

The problem of choosing the method of attaching the truss system to the structure of the building is very important when creating attachment points. Often, when creating nodes, the Mauerlat serves as a support for the rafters. The fastening of the Mauerlat beam is carried out “tightly” with the help of anchor bolts to the reinforced stiffening belt.

A possible drawback is an unanchored stiffening belt, which can lead to the overturning of the Mauerlat beam and the stability of the roof truss system. There is a loosening of the roof, and the roof is sliding down. Due to erroneous placement of anchor bolts or incorrectly made holes, the fastening is no longer effective.

If the nuts are screwed onto the bolts with an overtightening, then the fastening assembly becomes fragile and is subject to rapid destruction. In this case, wire twisting is sometimes used to create an attachment point.

During the construction of the truss system, the safety of the joints should be observed.

For example, if the truss structure is combined with the floor without taking into account the bearing capacity of the attic floor, then this is the most dangerous moment that can lead to the destruction of the building.

If the tightening is changed to a precast concrete floor beam intended for bending, then the use of precast concrete beams should be effective due to their rigid fixation in the reinforced floor stiffener, which is arranged using a reinforcing cage. Its axis must go in the same direction as the acting forces.

At the same time, the presence of shortcomings in the process of creating a truss system, which is a load-bearing wooden floor structure, often arises due to a misunderstanding of the functions performed by the puff and crossbar in the entire roofing system. The puff differs from the crossbar in that it is a longitudinal, and the crossbar is a transverse beam.

The construction of the truss system is associated with the creation of a spacer system that works on the principle of divergence at the bottom of the planes, which occurs under the influence of not only their own weight, but also the load that falls on the line of intersection of the planes, which should be prevented by the transverse beam, that is, tightening.

Getting to the roof device, you should find out all the points associated with the assumption of certain errors that occur when performing work on the installation of the truss system. The device of the roof of the house is associated with possible difficulties and shortcomings that do not allow achieving the goal.

Private construction is unique in that most developers try to build a building with an individual touch. All possible design tricks, advice from friends and acquaintances can be used here, but whatever the house, it is very important to mount the main components. If it is built of wood, then the log house can be purchased ready-made, and as for the roof, everything is more complicated here. The nodes of wooden roof structures are the most important part of the construction. They must be executed perfectly correctly so that the building will serve you as long as possible.

Knots of a wooden roof

If you have ever been present at the construction of the roof of a house, then you probably know that the rafter system is a kind of skeleton of the roof. A roofing cake is laid on them, a coating, on the reverse side it is possible to be sheathed with a facing material. Over the entire period of operation, the rafter legs hold colossal weights, which under certain conditions can reach the level of 200 kilograms per 1 square meter. This value can be achieved if the owners do not maintain the roof and a sufficiently large amount of debris, foliage and snow has accumulated on it.

At the time of construction of the roof, it must support the weight of several workers and their equipment. Such a load is purely individual, because it is difficult to predict the exact figures if you do not know how much the workers will weigh or what equipment they will take with them. Therefore, very often roofs are built in such a way that no matter how high the load, it can withstand it. Only in this case, work and further operation will take place in a calm and safe mode.

The next most important element is called Mauerlat or, in other words, the support beam. It is a kind of foundation for the entire roof. This element must be durable, therefore, in most cases, coniferous wood is used for its harvesting. Mauerlat can be attached to the wall in many ways, but the most popular and simple are: fastening using embedded parts or anchors. For the first method, special metal parts are laid in the process of building walls, and are released at the end.

The support beam holds the rafters, which means that it bears their weight and the load that they can withstand. The calculation for the selection of truss elements is quite simple and at the same time complex. It is very easy to calculate one equation, but it is not always possible to find all the nuances and insert them into the formula, so many developers simply take products with a large cross section and do not bother. This is partly true, but what if this is not enough. This problem can be solved with the help of all kinds of struts and props.

If you are faced with a volumetric roof, then the matter will not do without struts and racks. Thanks to these elements, the rafter legs feel as stable as possible. An important part of the entire system is the crate. It can be arranged by a discharged method or a continuous one. If the roofing material is hard, then you can use the first, and if soft, then only the second. As a rule, the discharged crate is stuffed over the eaves overhangs in a continuous way, thereby increasing the stability of the entire overhang and making it stronger.

The ridge knot is a very important part of any roof. It not only protects the two planes from dust and moisture, but also allows moist air to leave the attic. This is especially important when the coating or something in the roofing cake is completely insulating materials from moisture. Humid air has no choice but to begin to condense and destroy all elements of the truss system.

IMPORTANT: Before installing wooden elements, it is very important to treat them with protective compounds. Antiseptics protect the lumber structure from rotting and the growth of harmful microbes, and flame retardants increase fire resistance.

roof truss

On large slopes, trusses are indispensable. This design differs from an ordinary roof in that there are racks and braces here, which increase the maximum load on the wood several times. Often a farm is arranged all over the roof, but sometimes it can also be found locally.

It is advisable to arrange a truss truss if the width of your house is in the range from 12 to 24 meters. As a rule, trapezoidal or segmental trusses are arranged on buildings with large volumes. When the width of the building is even greater and this value does not exceed 36 meters, then a polygonal one will do. Standard designs with a width of 9 to 18 meters are content with a triangular one.

In addition to the shape of the roof truss, the material from which it is made plays a very important role. In most cases, this is wood, but metal can also be used. Self-tapping screws or nails are used to fasten lumber together. In cases where the span is more than 16 meters, a combined truss is best suited. It includes elements of wood and metal.

The nuances of fastening rafter legs

As you already know, the nodes of wooden roofs are the most important component of the construction of a building, and what could be more important than fixing the roof frame. Rafter legs can be attached to the support beam in two ways.

• hard
• sliding

In the first case, you will get the most stable connection, which deprives the structure of all kinds of shifts, vibrations, turns, and similar manipulations. This can be achieved with a gash or a cut. After the leg is inserted into the created slot, it is fixed with nails, wire, anchors or any other fasteners.

Sliding docking looks very different. It has three degrees of freedom of conjugation. It should be noted right away that this method of fastening is most rationally used in wooden houses, since they are characterized by large shrinkage, as a result of which rigid knots can be seriously damaged. To create such an attachment, you will need to rest the rafter leg against the Mauerlat, where a tooth connection was previously arranged or an additional beam was nailed. Such parts are connected using a metal corner. As for the upper part, here the connection takes place with the same cut, and the edge is cut along the oblique so that a sliding connection is provided.

IMPORTANT: If you are not comfortable with rigid or semi-rigid freedom, you can install special flexible plates, thereby achieving a fully sliding docking.

ridge knot

As I said earlier, the skate is one of the important components of any truss system where two slopes are joined. As a rule, it is located in the uppermost part of the roof, but there are also such structures where there is more than one skate, for example, a mansard roof, here there are 3 of them at once.

Rafter legs are almost always created so that they are as close as possible to the ridge element. This will provide better protection against dust and precipitation.

In roofing, there are two types of truss systems. The first is layered, and the second is hanging. If we consider the first, then here the connection occurs by cutting into half a tree. Thanks to this technique, maximum strength is ensured. As for the hanging rafters, here their lower part is joined in pairs. This can be achieved by cutting each beam at a certain angle, which is equal to the roof pitch. After that, they are applied to each other with saw cuts and matched with nails so that each fastener penetrates through the cut into another beam.

Often you can find ridge elements with a perforated body. Small holes do not allow small rodents and birds to enter the attic, and the quality of natural ventilation increases several times.

Complex parts of the hip roof

The hip roof is suitable for almost all types of buildings, so it is best to sort out all the difficulties on it. A distinctive feature of the hip design is obviously the presence of hips. This truss system boasts the following advantages:

• Durability. Due to the correct distribution of the load, the truss elements are subject to less pressure, therefore, they are in relative rest.
• Low windage. The material on such a roof is very difficult to pry even the strongest winds.
• Resistant to all types of precipitation.
• Cost-effective option for large structures.
• The optimal angle of inclination allows the use of almost any roofing material.
• The hip roof is quite voluminous, so you can equip a living room in the attic. To create additional lighting, skylights can be inserted into the slopes, which will also be auditory at the same time.

A rather difficult device can be attributed to the weak side.

The appearance of the roof includes only a few paired figures: a trapezium and a triangle. They are opposite each other, so that the truss system can be considered symmetrical. At the points of contact of these slopes, rafters are arranged. You can attach them to the rest of the system using trusses and a layered structure.

The sloping beams in the lower part are attached to the mauerlat, or timber, which is arranged on the inner wall. From above, the support goes to the ridge, so the legs must be adjacent to the ridge run.

Any roof must be laid according to the norms and rules of the construction business. This is the only way to achieve a high-quality and safe design. When working at height, remember safety precautions.