Rafters without pins. Types of the rafting system of the two-tie roof: for small and large houses due to the increased length

The rafting system is a design that provides the strength of the roof and serves as the basis for laying the roofing material. It is shown in the photo.

The roof is a carrier design that performs the following functions:

• gives the structure a beautiful appearance;
• accepts external loads;
• fencing the attic from the surrounding world;
• transmits the load from the crate and material on it on the walls of the building and internal supports.

The main elements of the roof include the pebble, rafters and Maurylalat. Also in the supporting structure includes additional elements of fasteners - riglels, racks, racks of rafters, struts, and so on. The reliability and strength of the roof is most influenced by the system of rafters. The rafal is the main carrier part of the roof. On the rafting system accounts for weight not only roofing, but also snow cover, wind pressure. It must withstand all these effects, so the calculation is made taking into account the type of roofing material and the climatic characteristics of the region.

Construction of the System Stropil

The connection of the rafted with each other gives the rigidity to the roofing frame, and the result is a solid rafter design. The load on the rafter can be quite significant, for example, during a strong wind, so the frame is tightly connected to the building box.

During the construction of private houses and cottages, wooden rafter systems are usually used, which are easily manufactured and installed. If, when the walls are built, errors have been made, these products can be easily processed: to shorten, increase, pose, etc.

When installed, the fasteners of the rafter system are used: bolts, screws, clamps, nails, brackets. They are also used to enhance the carrying roofing design. The related elements of the roof create a rafter farm, which are based on triangles that are the most rigid geometric figure.

Choosing material for the manufacture of the system from the rafter, it is necessary to take into account the design and architectural nuances of the project. Do not forget about the antiseptic and fire impregnation for them, as it affects the durability of the roof.

The system is made of rafter feet. Install rafters at the angle of linker of rods. The lower sections of the rafter legs are based on the outer walls using a Mauerlate that contributes to a uniform load distribution. The upper end of the rafter is based on a ram under the skate or to intermediate fittings. With the help of the rack system, the load is transmitted by the carrier inner walls.

Types of Stropil

Rafted hanging Consist of such elements: the leg of the rafted, the overlap of the attic, the riglel. These rafters have only two extreme reference points. They rely directly on the walls of the house. Stropile feet react to compression, and bending. These rafters without pods. READ ALSO: "Opported rafted on the beam overlap".

The design of the hanging rafters transmits the walls a significant driving force horizontally. In order to reduce the load, use stretching, which connects the rafter legs. Make it either at the bottom of the rafted, or at greater height. Stretching at the base of the rafter is simultaneously and the beam of the overlap is relevant in the creation of mansard roofs. With increasing the height of the stretching, it is necessary to increase its power and make sure the reliability of attachment to the rafters.

Part slopil It includes: a rafter foot, Mauerlat, grandmother, troops, tightening. This type of rafters is installed in buildings in which there is a medium carrier wall or intermediate supports in the form of columns. Elements of such a design work only on bending, performing the function of grandmothers. The weight of the utilization system is less, the materials are also required less, so it costs cheaper than harsh system.

Installation of the sleeve system is made if the supports are removed from each other by no more than 6.5 meters. If there is an extra support, the rafters sometimes overlap the width of 12 meters, and if two supports are up to 15 meters.

The rafting legs most often rest on the walls of the building, but on a special bar - Mauerlat. This element can be located along the entire length of the house or be eclipsed only under the rafter legs. If the designs are wooden, for Mauerlata take a log or a bar, which is the top crown of the cut.

In the brickwork of the walls of Mauerlat is a mounted chamber with the inner surface of the walls of a ram, fenced outside the ledge. Between this element and brick laid a layer of waterproofing - for example, you can put in two layers of rubberoid.

If the width of the rafter is small, over time they can squeeze. So that this does not happen, use a grid, consisting of a rack, riglel and ducts. In the upper part of the design, the run is laid, which connects the rafyled or farm. This is done regardless of the type of roof. Subsequently, on this run, the roof lobes make. In places where there are no bearing walls, the heels of rafters be rest in the side runs - longitudinal beams of significant power. Dimensions of these parts depend on the expected load.

When building private houses use rafters from logs - they are lighter. Metal rafters are used to create roofs on multi-storey residential buildings and industrial buildings.

Installing rafting systems

The angles of slopes are selected based on the type of building and the assignment of the attic space. The magnitude of the inclination also affects the material selected to create roofing.

If roll-in products are stacked, the angle of inclination should be 8-18 degrees. For the tile, the necessary angle is equal to 30-60 degrees, for roofing steel or sheets of asbestos - 14-60 degrees.

The installation of the system of the rafter is beginning after the construction of the bearing walls of the house (more details: "Installing the rafting system"). The design of the rafted wooden chopped house is significantly different from the systems for houses from the foamazobetone, bricks, frame wooden or panel houses. Differences are essential and with the same form, type and view of the roof. As for the process of processing the rafter system, it is necessary to use antiseptic and fire fighting tools so that the roof serves for a long time.

The main elements of the supporting design are the rafter farms and a doom. The roof is the outer part of the roof, which is placed on the carrying structure consisting of the crate and rafters.

For the production of rafters take the material of a certain size. So, the thickness of the rafted (section) is most often 150x50 and 200x50 millimeters. For the crates usually take the bars and boards of 50x50 and 150x25 millimeters. The distance between the rapid legs on average is 90 centimeters. If the inclination of the roof is more than 45 degrees, this step is increased to 100-130 centimeters, and if a huge amount of snow falls in the region, then reduce to 60-80 centimeters.

To produce more accurate calculations relative to the gap between the construction feet, it is necessary to take into account their cross section, the step between the supports (pink, the ride of the skate, racks), the type of roofing material.

The floating rafter system is fastened with the help of special brackets, allowing the "sit down" rafters along with the shrinkage of the frontones and not hang over the skate log.

Installation of the rafter system, look at the video:

If the rigidity is provided by farms, the strengthening of the rafter is made using diagonal relationships (more: "How to make strengthening rafters - options for strengthening the rafter system"). For them, boards 3-4 centimeters thick, navalized at the base of the extreme rafter foot and in the middle part of the neighboring. Stropile legs are the main element of the system, so they account for most of the roof load. For this reason, the system must be correctly calculated and installed so that the roof is reliable (read also: "How to put rafters on the house").

Installation of the rafter system must be made, accurately observing all the requirements. If there is no experience in construction, it is better to entrust the construction of the roof to those skilled in the art, since this is a difficult occupation, and the slightest errors can lead to its collapse.

Source: kryshadoma.com.

The rafters, opened into two supports without any additional stops, is used for a single-sided roof with a span of 4.5 m or two-tie span to 9 m (Fig. 30). The rafter system can be used with the transmission of the retrace to Mauerlat (walls) and without transmitting space.

Fig. 30. Sweeping rafters without subposses

Furgent rolling rafters

The bend running raftered, which does not transmit to the walls on the walls, should have one support attached, but freely rotating, the other freely rotating and movable.

Such conditions correspond three options for fixing rafters:

1. The bottom of the rafter feet is muted by the supporting bar or a wrist (washed) to the tooth and rests on the Mauerlat, and an increased horizontal wrist is performed at the top of the rafter (rushed) with a bevel (Fig. 31). The depth of words (washed) at the top of the rafter should not exceed a \u003d 0.25h. Length of trimming (support platform) is not more than the height of the cross section of the rafter (h). The trimming is recommended to scam so that it does not prevent the bending of the rafter, otherwise the wrinkle of the side cheek will be thrown into the run and obtain a spacer rafter. The length of the beveled trimming is made at least two depths. but. If the trimming of the top of the rafter to make it impossible to make it, it is laid by the trimmer of the rafted with a double-sided mounting of the mounting plates or wooden siblies. The upper ends of the rafter feet are freely stacked for a run. In the duct roofs, they are fixed to run along the type of sliding support, and each other is not fastened. A duple roof, in this case, we consider as two single-sided, stuck to each other with a high side. Pay attention to an extremely important condition: top supporting wrist or stitching of the tops of the rafter by the siblons are made horizontally. It is only worth changing the design scheme for a run, as the rafter immediately shows the standage. This assembly scheme of the setting rafter due to the rigidity of the conditions for the manufacture of the upper node (any inaccuracy in the execution of the node immediately turns the affected scheme in the spacer) is practically not used for double roofs, so it is often used in single-sided roofs. In addition, in two-tie roofs for the lack of spaced on the Mauerlate during the deflection of the rafted under the action of the load, it is necessary to pay the roofing knot.

This scheme at first glance is generally paradoxical. We are clearly visible at the bottom of the rafter, the emphasis in Mauerlat and the system should seem to have a horizontal effort. However, it does not show space. If someone wants to know why, then proof is aware of the lectures of Professor Zalessky V. G. on pages 414-415.

Fig. 31. Rejoining Niza raftered with a word in Maurylalat, and the top of the rafter to run a horizontal wrist, with a beckful cheek, does not put pressure on the wall

2. The most common way to install rafters related to two-tie roofs. The bottom of the rapid leg is made on the slider, and the top is fixed (Fig. 32): they are binding to nailting or bolt, or rest in each other and bind with wooden siblos or metal gear plates (MZP).

Fig. 32. Opporting Niza rafters without a wrinkle in Mauerlat with the pinning of the top of the rafter, does not allow the walls on the wall

To which you need to pay special attention to this on the mounting of the rafter foot to Mauerlat, it is reduced only to the attachment of the rafted in the project position ensuring the step of their installation. To do this, it is enough to drive from two sides by one nail of the neglection in the side surface of the rafter or one long nail on top or put a flexible steel plate. If fashionable fasteners are applied, it is enough to consolidate the bottom of the rafter, one nail will be enough or it is necessary to press the rafter with the corners on both sides at all without nails. Do not twist in the corners so much screws and do not score so many nails in them as there are holes in the corner. Otherwise, you will turn the slider into an imperfect hinge and get a space on Mauerlat. From the wind tipping of the roof holds flexible wire twists, it is not necessary to shift this function to the corners or the soling system should be calculated as spacer.

3. Does not retire and rigid pinching of the skate assembly when the bottom of the rafter foot is made on the slider, and the top is firmly fixed (Fig. 33). However, in the ski node, a bending moment appears, striving to destroy it. The maximum bending moment in such a design occurs on the skate support, and the lifting legs themselves get less deflection. Calculate such a node, and then it is quite difficult to make it in the construction site, so it is better to take formulas to calculate the bending moment and deflection for ordinary single-break beams.

Fig. 33. Opporting Niza rafters without a word in Mauerlat with pinching of the skate knot, does not allow the walls on the wall

In all three options, the rule is observed: one end of the rafter foot is done on the sliding support that allows the turn, the other on the hinge that allows only a turn. Fastening rafters on the crawls and stationary hinges are made of various designs. Now they are often performed on the mounting plates. It can be mounted on the old manner: brackets, nailting or use of short bars and boards. It is only necessary to correctly pick up the look of fasteners so that it allows or preventing the sling of rafters in the support.

When calculating the solo system, an "idealized" calculation scheme is accepted. It is believed that the roof presses uniformly distributed load, i.e. The same and smooth force acting uniformly in all planes of the skates. In fact, evenly distributed load on the roof rods almost never happens. The wind, outreaching snow bags on one of the rods and blowing snow from the other, the sun melting snow on the southern rods, sliding in the spring snow - make a load on the rods uneven. Under the action of uneven load, all three above the presented variations of the rafter systems are statically stable, but only under the condition of rigid fastening of the skate run. Which in the ends are introduced into the frontones of the walls or support the hicks of the hip roofs. That is, the rafter system will be stable only if the skunk run on which the top of the rafter is reliably fixed from the horizontal displacement.

In the manufacture of forcep roofs and the running of the run only on the racks (without supporting them ends on the walls of the frontton), the situation changes for the worse (Fig. 34). In the second and third embodiment, with a significant reduction in the load on one of the rods, against the calculated on the other scap, the roof will try to "leave" in the direction of higher load. The first option in which the bottom of the rafter foot is made with a wrinkle to the tooth either with the hearing of the support bar, and the top of the horizontal word is laid on the run, it keeps the uneven load well, but only under the condition of the absolute verticality of the racks holding the skate run.

Fig. 34. Loss of stability by a rafter system

To make a rafter system of stability in it, a horizontal fight is introduced (Fig. 35). It increases the stability of the system, but slightly. Therefore, in all places where the fight intersects with racks that support the skate run, it is attached to the stands of the nailing battle. There is a steady error that the fight always works for stretching, it is not. Fighting a multifunctional element: in the faded structures of the rafter, it does not work at all in the absence of snow on the roof or works on a compression when a minor uniform load appears on the skates. It works for stretching only in a pre-emergency situation when drawdown or the deflection of the skate run from the action of maximum loads. In essence, the fight is an emergency element of the rafting system, which comes into operation when the roof is filled with the maximum possible amount of snow and the ski run will join the entire calculated value or when unforeseen and uneven foundations for the foundations and, as a result, uneven walls of the walls and the skate run will occur. The lower the bouts are set, the better. Usually they are installed at a height of at least 1.8-2 m from the surface of the overlap so that they do not interfere with the person when passing in the attic.

If in the second and third embodiment, the bottom node of the solving leg (slider) is replaced by a slider a little different design (Fig. 35, c) - with the end of the end of the rafter by the wall, then it will further strengthen the entire system, making it a statically sustainable design at any Combining loads.

Fig. 35. The fight between the rafters increases the stability of the rafter system

Another event of increasing the sustainability of the entire system is rigid (which is not always possible) fixing the bottom of the racks supporting the run. They are driving into a litter and attached to overlaps in any possible way, turning the lower node with a pillage of the hinge (in the plane of the rafted) to the rolling pin (Fig. 36).

Fig. 36. Example of fastening the support node

The cross-section of kits in view of the development in them is not calculated, they are taken constructively. In order to reduce the size of details used in the construction of a rafter system, the bout cross section uses the same dimensions as the rafters, but more subtle boards can be applied. The contractions are installed from one or two sides of the rafter and are attached to them with nailting and / or bolts (Fig. 37). When calculating the cross section of the rafter, the bouts are not considered additional supports, i.e. The solry system is calculated as like the fights in it at all. However, if the fights are screwed to rafyles with bolts, then the carrying capacity of wood due to the weakening of the bolts with holes is reduced by the use of the coefficient of 0.8. In other words, if the holes for the installation of bolts are drilled in the rafter, its calculated resistance is used equal to 0.8r. When fastening the fight to rafters, only the nice fight of the weakening of the calculated resistance of the timber of the rafter legs does not occur, but it is necessary to make a calculation on the number of clogged nails. It is calculated on the cut (bending) of nails. For the calculated power, the cut is taken by space, which may occur during the emergency state of the solo system. In general, in the calculation of the nail connection of the fight with rafters is introduced (H.), which is not, with normal operation rafters.

Fig. 37. Fastening assembly

Recall once again, the static instability of the affected sling system is manifested only in the roofs, where there is no possibility to fix the ski run from the horizontal displacement. In houses with Walm roofs and houses with front-line brick and stone, faithful rafter systems are quite stable and there is no need for sustainability events. However, the "anti-emergency" structures - contractions, it is still necessary to install.

When administered to the calculation of the rafter system of the returns (even if it is not), the calculation of the squeezing force S is changed. Now it is calculated by the division of the resultant distributed load on the sine angle of the inclination of the rafting S \u003d (QL / 2) / SINα. Without going into details the decomposition of the vectors of the forces, explain it on a small example. Suppose we have a rafter system with a steep corner of the slope. Under action on her load in disserval, for example, when drawdown, leaving the vertical or destruction of the skate run, tensile voltages will appear in the fight, neutralizing the so-called space. With unchanged external load, the smaller the angle of the slope will be, the more rapper will grow and the greater the rafting legs will be compressed. And vice versa, if the rafting legs are not associated with the fights, they work as ordinary beams laid in the inclined position. In this case, the decrease in the angle of inclination, with a constant load, reduces the compressive stresses in the rafylic and increases the normal (perpendicular) force directed to bending bending. Therefore, the compressive force in the rafter systems without battles is considered as S \u003d (Ql / 2) × sinα and with the fights S \u003d (Ql / 2) / sinα. Since the two-tie rafal systems are almost never built without contractions, and the calculation is always conducted on the worst working conditions, then further in all circuits, the compressive voltages will be recorded as S \u003d (Ql / 2) / Sinα, regardless of the dependence in these schemes not.

When installing spills or bolts for fastening, the fights pay special attention to the diameter of the hole below them. It should be equal to the diameter of studs (bolts) or even less than it for 1 mm. In an emergency, the fight will not work until it selects a gap between the stud and the wall of the hole at this time of the bottom of the rafter "erupts" to several millimeters or centimeters (depends on the height of the attachment of the fight), which can move or unscrew the Mauerlat and destroy Eaves of walls, and in spacer rafting systems, where Mauerlat is rigidly fixed - "push out" light walls.

Speed \u200b\u200bsprings

The bend running, transmitting the stretch on the walls, should have two fixed supports.

We take the same options for rafter schemes and replace the lower supports with two degrees of freedom (slid) to support with one degree of freedom (hinge). Simply, where they are not, nail the support bars to the bottom of the rafter leg. Typically, a bar length is about meter and a cross section of 50 × 50 (60) mm with a naiter is calculated. Or make support on Mauerlat in the form of a tooth. In the first version of the calculated scheme, in the skate where it rafters are horizontally operats on the run, we sew the upper ends of the rafter feet with a nailing fight or fasten the bolt and thus get a hinged support.

Fig. 38. Sroplated with both ends in Mauerlat and each other show space

The calculated schemes of the rafter systems are changed slightly (Fig. 38), all internal voltages of compression and bend remain the same, but in the lower supports, the rafter will appear H \u003d (Ql / 2) × CTG α, (kg). In the upper nodes, the space in one rafter is destroyed opposite to the directed space from the end of another rafter, therefore it does not bring special hassle. However, the ends of the rafter legs, drunk directly into each other or through the run, can be tested for crumpled wood, although in most cases it is not required.

In fact, the spacer sprinkled rafters is a transitional scheme between the faded urban and hanging rafters. They already viewed the scheme of hanging rafters, but the rudiment in the form of a skate run remains. When the bottom has faltered down into the walls, and riding each other, then the run here is like a fifth wheel in the cart. On the one hand, it seems and does not hurt, and on the other, it is possible to do without it. The charter system shows the duality of its work, which depends on the density of the top of the top of the rafted to the run and to each other. The vector of force pressure on the ski knot is distributed on the rafting legs, and on the run. When drawdown, as a result of shrinkage of walls or a deflection of its own weight, the run goes out of work and the strength vectors are fully distributed on the rafters, and the rafters themselves turn into a hanging.

In the spacer rafter systems, the appointment of a slightly different way - it works in emergency situations for compression. Entering the work, it reduces the stretch on the walls of the bottom of the rafter legs, but it does not completely remove it. It will be able to remove it completely if it is located at the very bottom attached between the ends of the rafter, but this is another constructive scheme and the fight in it is called a tight.

What changes with the inclusion in the contamination scheme? We will not load you with layout of forces, simply submit a pre-emergency situation when maximum loads act on the roof. Where under the skate run there is no racks, the run of the run and the sprinkled rafters, pulled by a fight, instantly turn into a chart of hanging rafters with a compressed riglel, and the bottom of the rafter feet is returned by the corresponding calculation scheme. Where, under the skate run, there are racks or a row rigid, the fight works on the compression and the bottom of the rafter feet also transmits the spacer, but the weaker so that the top of the rafter holds the skunk run. However, the calculation is made on the worst scenario.

The use of space-sprinkled rafting systems requires taking into account the effect of the restriction on the walls. You can reduce the retrieve the installation of hard skate runs. For these rafter schemes, it will be better if the calculated deflection of the skate run will be much less normalized by SPEP. Try to increase the rigidity of the run of the installation of racks, pods or cantilever beams (change in the height of the section) or make a construction lift on it. This is especially true for houses from light concrete, bruschers and chopped out of the log. Massive brick, concrete and panel houses are easier to carry space on the walls.

It should be noted that the horizontal force arising from the squeezing voltage rolls S. in different words, is understood. In other words, run - this is a horizontal vector of forces appearing from the action of the vertical load. No need to confuse it with a rainset from the deflection of the rafter. In the calculated scheme of the rafter are considered rod elements that are not height, so the space from the deflection is not taken into account. It is sent to the rationing of a deflection in building structures. Snip, introducing normalized deflection values, brings idealized calculated schemes to real. Other words, if the deflection of the construction structure does not exceed the normalized, then it should not be thought about the returred from the deflection, it is no matter how. Although in fact it is and in the spacer scheme, it exists more than in the faithful. It is necessary to pay attention to the space from the deflection when building walls of the house of agencies. These blocks absolutely do not hold the bending and can be destroyed with a rainer even from the deflection. Do not on these walls of spacening rafters. In other cases, the space from the deflection does not cause much harm, for example, in the brick walls it perceives the elasticity of Mauerlat and steel fasteners.

The rafter system made by the spacer is a statically stable system for any combination of loads and requires a hard fixing of Mauerlat on the wall. To hold the restraint, the walls should be sufficiently massive or equipped with an inextricable monolithic reinforced concrete belt around the perimeter, like a hoop on a wooden barrel. In emergency situations, unlike faithful systems, in the spacer system, the squeezing does not save the position, it only partially reduces the space transmitting to the walls (Fig. 38.1). In order for emergency situations, we have occurred and collecting the maximum, the loads act on the roof.

Fig. 38.1. Compressing the fight partially removes the space from the walls

The calculation of the rafter system with a compressed snap-in combat is made on two combinations of loads. The cross section of the rafter foot is selected at the maximum bending moment and the deflection without taking into account the compressed bout. Imagine that uneven loads act on the roof: on one side of the skate, the snow lies, and on the other it has become or slipped. The bending of the rafter foot will simply push the compressed fight and will work as an ordinary single-break beam. Selection of a squeezed contraction and determination of the restriction on the walls, on the contrary, we will produce for evenly distributed load on both skates. In this case, the fight will be compressed on both sides and will get the maximum voltage of compression, the bottom of the rafter foot will give a reduced space on the wall, and the lines itself will turn into a continuous beam on three supports.

At the heart of each roof lies a large number of beams, rafters, racks and runs, which are all together called the rafter system. For a centuries-old history of species and methods of its organization, a lot has accumulated, and each has its own characteristics in building knots and wrist. For more information about what a dual-tie roof is a rafter system and how rafters must be attached and other elements of the system will talk in more detail.

Design of the rafting system of the bone roof

In the context, the double roof is a triangle. It consists of two rectangular inclined planes. The two of these planes are connected at the highest point in a single skate bar system (run).

Now about the components of the system and their appointment:

• Mauerlat - a bar, which connects the roof and walls of the building, serves as a support for the rafter feet and other elements of the system.
• Stropile legs - they form the inclined planes of the roof and are support for the crate under the roofing material.
• The ski run (bead or horse) - combines two planes of the roof.
• The tightening is a transverse item that connects opposite rafting legs. It serves to increase the rigidity of the design and compensation of the suspension loads.
• Lecky - Bars located along Mauerlat. Redistinate the load from the roof.
• Sidebreaks - support rafting legs.
• Racks - transmit a load from the run to liter.

The system can still be attended by the Falinka. These are boards that lengthen the rafting legs to form a sink. The fact is that to protect the walls and the foundation of the house from precipitation, it is desirable that the roofing ending as far as possible from the walls. To do this, you can take long rafting legs. But the standard length of sawn timber 6 meters is not enough for this. Order non-standard is very expensive. Therefore, the rafters simply fuse, but the boards that they do are called "Films".

Stropile construction systems are quite a lot. First of all, they are divided into two groups - with urban and hanging rafters.

With hanging rafyles

These are systems in which rafter legs are based on the outer walls without intermediate supports (bearing walls). For bantal roofs, the maximum span is 9 meters. When installing a vertical support and sub-vessel systems, it can be increased to 14 meters.

The suspension type of the rafter system of the duplex roof is good because in most cases there is no need to put Mauerlat, and this makes the installation of rafting legs easier: no need to make anything, it is enough to throw the boards. For the connection of the walls and rafters, the lining is used - a wide board, which is fixed on studs, nails, bolts, riglel. With such a structure, most of the driving loads are compensated, the effects on the walls are directed vertically down.

Types of rafter systems with hanging rafters for different spans between carrier walls

Slinged system of two-tie roof for small houses

There is a cheap version of the solo system when it is a triangle (photo below). Such a structure is possible if the distance between the outer walls is not more than 6 meters. For such a rafter system, you can not make a calculation over the angle of inclination: the horse must be raised over the tightening to the height of at least 1/6 of the length of the span.

But with such a construction of rafters, significant bending loads are experiencing. To compensate or take the rafted larger cross section or the word of the skunk part make so that they are partially neutralized. To give greater stiffness at the top of both sides, wooden or metal linings are nourished, which reliably fasten the top of the triangle (see also not pictures).

The photo also shows how to grow rafting legs to create a saint of a roof. There is a wrist, which should go beyond the limits of a line spent from the inner wall up. It is necessary to shift the place of the outbreak and reduce the likelihood of deadlock.

The ski knot and the mounting of the rafter feet to the lining board at a simple version of the system

For mansard roofs

A variant with the installation of the riglel - used at. In this case, it is the basis for covering the ceiling located below the room. For reliable operation of the system of this type, the womb of the riglel should be awesome (tough). The best option is half-fertility (see figure below). Otherwise, the roof will become unstable to the loads.

Please note that in this scheme there is Mauerlat, and the rafting legs to increase the stability of the design should go beyond the walls of the walls. To secure and docking with Mauerlat, a word is made in the form of a triangle. In this case, with uneven load on the rods, the roof will be more stable.

With such a scheme, almost the entire load falls on the rafter, and therefore they need to take a larger cross section. Sometimes raised tightening strengthen the suspension. This is necessary to prevent its deflection if it serves as a support for the ceiling sheat materials. If the tightening is small, it can be used in the center on both sides by boards, nails. With a significant load and the length of such insurance, there may be several. In this case, too, enough boards and nails.

For large houses

At a considerable distance between the two outer walls, a grandmother and a sawmill is installed. This design has high rigidity, since the loads are compensated.

With such a long span (up to 14 meters), make a delay one-piece complex and expensive, therefore, they make it from two beams. It connects with direct or oblique bore (drawing below).

For reliable docking, the connection site is enhanced by a steel plate planted on the bolts. Its dimensions should be greater than the dimensions of the Wheel - the extreme bolts are screwed into solid wood at a distance of at least 5 cm from the edge of the wrist.

In order for the scheme to work fine, it is necessary to make a spreader right. They transmit and distribute part of the load from the rafter tightening legs and provide stiffness of the structure. Metal linings are used to enhance compounds

When assembling a two-sheet roof with hanging rafters, a lumber cross-section is always greater than in systems with spots rafters: load transmission points are less, therefore, each element accounts for a large load.

With urban rafyles

In duct roofs with sputum rafters, they rest on the walls, and the middle part is based on the bearing walls or columns. Some schemes cut the walls, some are not. In any case, the presence of Mauerlat is necessarily.

Furgent schemes and knots

Houses folded from logs or timber react poorly to spacer loads. For them, they are critical: the wall can fall apart. For wooden houses, the solid system of the two-tie roof should be faithful. We will talk about these systems in more detail.

The simplest faded diagram of the rafter system is shown in the photo below. In it, the rafter foot resumes in Mauerlat. In this option, it works on bending, without cutting the wall.

Pay attention to the mounting options for the rafter feet to Mauerlat. In the first, the platform of opira is usually mounted, its length is no more than the sections of the beam. Sword depth is no more than 0.25 of its height.

The top of the rafter feet is laid on the ski bar, without fastening it with the opposite rafter. It turns out in the structure of two single roofs, which in the upper part are adjacent (but not connected) one on the other.

It is much easier to assemble the option with a rapid foot fastened in the skunk part. They almost never give the walls on the walls.

For the operation of this scheme, the rafter legs are attached at the bottom with the help of a moving connection. To secure a rafter foot to Mauerlat, one nail is clogged or the bottom of the flexible steel plate is clogged. Options for fastening the rafter feet to the skate run, see the photo.

If the roofing material is planned to use heavy, it is necessary to increase the carrying capacity. This is achieved by an increase in the cross section of the elements of the rafter and amplification of the skate assembly. It is shown in the photo below.

Strengthening the skate assembly under heavy roofing material or with significant snow loads

All the above diagrams of the bantal roofs are stable in the presence of uniform loads. But in practice, this is practically no happening. You can prevent the roof location towards the larger load in two ways: installation at an altitude of about 2 meters of contractions or pins.

Options for rafter systems with bats

Installation kits increases the reliability of the structure. So that it worked normally, in the places of its intersection with the drains, it is necessary to fix it with nails. The bruse cross section for the fight is used as as for the rafter.

Slingetts are attached to bots or nails. Can be installed from one or two sides. The attachment assembly to the rafters and the skate run look in the figure below.

In order for the system to be rigid and not "crawled", even with emergency loads, it is enough to ensure a rigid fastening of the skate bar. In the absence of the possibility of its displacement in the horizontal, the roof will solve even significant loads.

Systems of spitting rafters

In these embodiments, subcording legs are added for greater stiffness, which are also called piping. They are installed at an angle of 45 ° in relation to the horizon. Their installation allows you to increase the length of the span (up to 14 meters) or reduce the cross section of the beams (rafted).

The pump is simply substituted under the desired angle to beams and is nailed with nails from the sides and below. An important requirement: the boolean must be cut accurately and tightly lay down to the racks and the racking leg, eliminating the possibility of its deflection.

Systems with substropic legs. From above the spacer system, the bottom - the fault. Nodes of proper cuts for each are located nearby. Downstairs - Possible Toward Fastening Schemes

But not in all homes the average carrier wall is located in the middle. In this case, it is possible to establish a pitch with an angle of nnnone relative to the horizon of 45-53 °.

Systems with pins are needed if significant uneven shrinkage of the foundation or walls are possible. The walls can be sitting in different ways on wooden houses, and the foundations are on layered or bright soils. In all these cases, consider the device of rafting systems of this type.

System for houses with two inner carrier walls

If there are two bearing walls in the house, there are two subcupile beams that are located above each of the walls. The intermediate bearing walls are stacked, the load from the substropyl beams is transmitted to the litters through the racks.

In these systems, the ski runs do not put: it gives spacer forces. The rafters in the upper part are connected one on the other (clipped and fit without gaps), the connection location is amplified by steel or wooden linings that are nailed.

In the upper factional system, the tightening is neutralized with a driving force. Please note that the tightening is placed under the run. Then it works efficiently (upper diagram in the figure). Sustainability can be provided by racks, or extends - beams installed by defective. In the spacer system (in the picture it below), the crossbar is a blower. It is installed above the run.

There is a version of the system with racks, but without inferior beams. Then the rack is nailed to each rafter foot, which rely on the intermediate bearing wall.

Fastening the rack and tightening in the rafter system without a substropsy run

For mounting racks, nails are used for 150 mm and a 12 mm bolts. The dimensions and distance in the figure are in millimeters.

The frame format is distinguished among a row of roof species. It can be made quite different ways, but in any case it will be necessary to calculate rafters and establish them in all the rules. With proper knowledge, the problem can be solved by its own forces without contacting the specialists.

Features and roofing

The frame roof can be installed only with spans no longer than 1220 cm, while the gap from one farm to the other is a maximum of 0.6 m. The sizes of fragments of the frame are determined by the distances of the spans and the calculated snow load. The rafters can be both freely installed and taking the load from the attic elements. In the case of the roof of the broken shape, it is possible to provide a ceiling height sufficient for residential attachment, and it will be best on the square structure.

Multi-line roof is considered the most difficult and hardly affordable variation for amateur builders. The balanced rafter system effectively withstands even very high loads, while having excellent "appearance". Since the skate is steep, the risk of snow delay will be minimal. But at the same time will have to very carefully count all the elements of the structure, and there will be quite a few waste during the work. In addition, Endova will have to experience the impact of a significant amount of snow.

Appointment and types of systems

Mauelalat can be used in a variety of solutions. The mass of the roof of the house varies depending on the area occupied by skates, and from the materials used. But in any case, the load created is very solid. When there are a lip on the structures, it is necessary to provide a rafter frame, the legs beyond the walls. The force is attached immediately in several vectors, and in the cold season, the accumulation of snow only aggravates the problem.

Mauerlat is designed to eliminate this deficiency and prevent the destruction of the walls.Under this word, the ram of a significant cross section is meant, which is both wooden and steel. In most cases, they take the same material that was used to form a rafter, but necessarily achieve continuity of the strapping or create durable and particularly stable joints. From the use of Maurolalat refuses only in the houses from the cut or in buildings built on the framework technology - and there are its details that perform a similar task. When it fails to make an inextant unit, all fragments should be strictly the same length.

For T-shaped roof, the insertion of two wings at a certain angle is characterized. Because of this, you have to form Undov. Outdoor rafters will rest in the supporting boards. In addition to them, there will also be the main parts directly fixed on the wall. So that in the end of it all corresponds to the solved problem, we use wooden elements with a thickness of 3.8 cm. The crate is assumed to do a monolithic, the coating attach to it by the clemmers every 50 cm. Typical Mauerlat is three times less than the bearing wall, and if it is made Of the steel, you can slightly reduce this indicator.

Under Mauerlat is often equipped with a strengthening belt. This is especially important if you plan to warm the roof and ensure reliable waterproofing. Such a belt is formed from the same mixture, which is used for the construction of the Foundaode of Men. Fully all formwork is poured with concrete from one reception, the slightest individual layers are unacceptable. In the aerated concrete wall, intermediate jumpers at the top line of blocks are cut down - and a practical chute appears immediately. The attachment of Maurolalat is made either with the help of knitting wire or reinforcing bolts (but they will not help without a hardening belt) or by building studs.

Having understood with the support for the rafters, you need to find out what they can be, and more correctly use the roof for the roof. Hanging rafters are applied if there is no capital wall inside the building, their points of the supports are located exclusively on external circuits.

Such backups turned out to be in demand during the construction:

• residential buildings with one span;
• production facilities;
• various pavilions;
• mansard.

It should not be underestimated by such an option, thanks to engineering developments, suspended rafters are capable of not flexing, overlapping the spans at 15-17 m. But it is important to understand that they only gain their capabilities in close cooperation with other details. We will have to use tightening, and grandmother, and riglels. The simplest farm is performed from two beams connected in the top position, the configuration is close to the triangle. The horizontal connection of the framework parts is provided with a tightening (beam of wood or metal profile).

Due to the tightening, the transfer of returders on the walls is excluded, the force applied in the horizontal plane is simultaneously suppressed. External walls are experiencing only those forces whose vector is vertically oriented. Not always builders put the tightening at the very bottom, often it is set at the skate itself. Preparing for the construction of the attic, this element is most often higher than the base of the rafting legs. Then it will be possible to make a floor, the ceiling of which does not have to beat your head in any careless movement.

Hanging rafters for spans longer than 6 m should be strengthened using suspensions and collections.In this case, the monolithic tightening is replaced by the bound beams collected from the pair. In the classic scheme (triangular hinged), the lower bases be rest in horizontal parts. For the normal functioning of the system, the height of the skate is at least 15% of the Ferm span. The rafters act on the bending, but the tightening does not allow them to move away to the sides. So that the beams bent less, the skate nodes are driving with the calculation of the eccentricity (the emergence of the opposite vectum of the bending force).

Dersighted attics build mostly with the help of triangular arches on three hinges, and the tightening feature of the ceiling beams is assigned. Composite parts of the tightening are associated with bolts by oblique or direct adhesive. The raised tightening can also be applied in the construction of rafters under the attic. The higher it rises, the more the ceiling can be raised. But it is important to remember that at the same time the loads on all elements grow. The transfer of effort is made on Mauerlat using a moving fastening that quenched changes from the sizes from the drops of moisture and temperature.

The rafters can be subject to uneven load, since on the one hand it is higher.This leads to a shift in the same side of the entire system. It is possible to exclude such an unpleasant effect if you make rafters behind the wall contour. The tightening with a similar solution ceases to be support, it transfers either stretching effects (if the attic is satisfied), or stretched bending (when the attic is built). The hinged arches with the turn on the riglel differ from the previous version of the replacement of the sliding support to identical according to the functions - rigid. Thanks to the change in the type of supports, the type of stress generated, the rafter system turns into a spacer.

The tightening is formed in the upper fraction of the arch. Its purpose is to transfer no longer a stretching, but a compressive effect. Additional tightening, reinforcing the beegel, is needed with a significant load. Arches with suspensions and pins complement the arches of the arches with "grandmas". Such a system is needed with significant spans (from 6 to 14 m). Slopes that correct the occurrence of the bend, you need to lean into a grandmother. Regardless of the specific type of the rafter system, all parts and their bundles are used to fully perform.

Not always hinged rafters can perform the task. Then the hosted elements come to the rescue. This type of rafter is used under the hip roofs and under roofing, equipped with end. Their length is more than in the usual case. In addition, they become supports under the shortened rafters of the skates. Because of the accident rafters accounts for a load of about 50% more than in other structures.

Due to the larger length, it is possible:

• resist significant effects;
• shape beams without cuts;
• certain parts to single size by pairing boards.

To build a hollow roof with many spans, diagonal legs are supplied with supports. Such supports are made in the form of standard subposses or racks from the bar or couples of the connected boards. The support through the wood lining and the waterproofing layer is made directly to the reinforced concrete overlap. The pumps put at an angle of at least 45 and not more than 53 degrees, downstairs such a detail rests on the church. The installation angle is less important than the possibility of fixing parts of the rafted at a point experiencing the strongest load.

Available rafters, placed in openings up to 750 cm, should be held only in the upper share.With a length of from 750 to 900 cm, the current farm or rack is additionally mounted at the bottom. And if the total span length exceeds 9 m, then for maximum reliability in the middle you need to put a rack, no other support is suitable. If the selected overlap is unable to withstand the load, it will have to be enhanced by its beam. The type of support in the skate is determined by how much intermediate supports are used, what are they, as key rows of rafters are made.

Besides the type of rafters, you need to clearly understand their material. Both wooden and metal structures can be good, but only every in its place. Even the high strength of the metal does not allow to push the familiar wood. The tree for millennia confidently proved its advantages, and now it even increases popularity due to excellent environmental characteristics. Boards and timber can be bought at an affordable price, and if something has not been taken into account, always easily directly on the construction site to spill the desired fragment or increase the item.

Sometimes there are problems related to the operation of the created structures. Wooden rafters will have to carefully process with antiseptics, as well as means blocking the development of mold colonies, eating insects. The flammability of wood is suppressed due to regular processing, and in addition, under the skates longer than 7 m too difficult to search for the necessary components. Before mounting the walls are made by Mauerlat made from a log frame or based on a block of timber. The thickness of the structures is at least 180 mm, this is the only condition for the homogeneous distribution of loads.

Metallic rafters are inevitably heavier than wooden with an identical section. Therefore, the walls need to be strengthened, work on their construction becomes more expensive and longer. It will not be possible to mount the metal blocks manually, the lifting cranes will necessarily need. It is impossible or very difficult to adjust the dimensions, a geometry of rafters, so immediately as much as possible will have to construct the walls and exclude errors during their construction. The slightest slip can make an expensive block almost useless in practice.

Metallic rafters are associated with welding, and welded joints are inevitably weakened, because corrosion develops there. The cost of work is very high, and when they are fulfilled, it is necessary to fulfill the requirements of fire and electrical safety. But there is such an indisputable advantage, as an opportunity to rest the roofing rod from 700 cm and longer. If you use a special anti-corrosion paint, the durability of metal structures is fully provided. All these advantages make it possible to quickly and comfortably build industrial buildings with a significant height and length of spans.

How to choose: What to take into account?

The rafter system must be chosen as correct and clearly as possible.

When searching for a suitable solution, you must pay attention to the following points:

• strength;
• the ability to restore the rods and the roof as a whole in a certain size and geometry;
• creating a positive aesthetic image of a building as a whole.

Technical parameters are priority. Even the most beautiful designs corresponding to the design principles do not show their positive qualities if they serve too little. Experienced builders always analyze the average annual and seasonal temperatures, the financial capabilities of developers, the maximum possible pace of the wind and the severity of the overlying roof. It also takes the future use of the undercase, the scale needed for it. It is impossible to underestimate the wind, snow and rain, since these factors can have a very strong effect on the roof, and through it on rafters.

If it is reliably known that the specific area is distinguished by powerful snowfall, the minimum angle of the skate is impracticious. Even more relevant this moment when using flat roofs. Under the pressure of accumulating precipitation, the frame may be rapidly deformed or water is poured into the same inside. Another thing is when a certain region is often subjected to the arrival of cyclones and the strong winds that are brought by them. There is already a slope to be made smaller, then the situation with the breakdown of single structural elements will be almost excluded.

You can avoid mistakes, if you look at the already built nearby and for a long time exploited at home. Accurately reproducing the design of their roofing and interrelated with a solry system, you can best take into account local specifics. But not everyone goes along this path, sometimes the task is to develop an exclusively original project. Then you have to carefully collect the source data, conduct scrupulous calculations. In the absence of special knowledge to help better attract qualified performers.

After analyzing the total load created by the wind and the snow, it can sometimes be found that certain parts of the rafter complex needed selective strengthening. When evaluating the necessary angle of inclination of the roof draws attention also to the type of coating used. Heavy metal tile or professional flooring with a very large bias can spontaneously slide down, it is necessary to additionally fix them, complicating their work and express installation. In addition, individual materials have a tendency to delay water or soak it, it is possible to struggle with it only making a slope is cooler. Creating a good roof and a rafter system that satisfies so controversial requirements is not always available for non-specialists.

What makes it?

The device of the rafter system, as it is easy to see, rather complicated and even controversial. Each part of this design has a strictly defined role. So, Mauerlat is long bars of coniferous wood, and a strictly resinous tree is used to work. Such elements are unfolded along the outer bearing walls, connecting to the base with anchors or rods of a special design (with thread). This item transmits the load from the roof on the wall.

Following such a device, like a rafter foot. Under this title appears the wooden bar used to build the circuit of the skates. The design form is always triangular, because it best helps the roof tolerate the destructive impact of winds, snow and other atmospheric processes. Stropile legs put on uniform distances along the entire roof, a step cannot exceed 120 cm.

A pretty value for the roof support has a litter - this is a wooden bar, replacing Maurylalat in some cases. Lecks are put on the inner supporting walls. They turn into a roofing triangle. Thanks to them, the skates do not sprawl under their own weight. And also it is worth saying about the racks - it is the vertical brus with a square cross section. They perceive the pressure that is down by the ski knot, and translate it mechanically to the inner bearing plane. Sometimes racks are under rare legs.

Slopes are called upon to strengthen the entire design of the roof, they are associated with one whole legs and liters. This detail on the form resembles a rhombus. The community formed by tightening and sink received the name of the farm. In addition to them, it is also needed a doom, which is a thin boards, pushed at right angles to the legs of the rafter. It helps to keep the rafting legs as a single system. Absolutely any roof coating is attached to the crate.

Under the soft materials, the lamp should be made in the inseparable, and the best tool is plywood. At the very top there is a horse, which logically and physically completes the roofing triangle. The compound of a pair of opposing legs rafters is provided by a square wooden bar, which prevents the roof destruction as a whole. And at the very bottom of the pitched roof there is a sv, which is derived approximately 0.5 m from the perimeter. Thanks to him, rain flows from the roof do not pour out the outer bearing planes and do not harm them.

Filmings are used only in the situation when the rafter legs cannot be performed along the length that would allow to organize Sve. The connection with the reduced cross secting boards effectively solves this problem. For attaching wooden elements, rafters are most often recommended to use clamps, brackets. It is undesirable to apply nails, because the tree punctured them in a few years becomes weak and fragile. Therefore, professionals if connections are made directly at the construction site, they are allowed to move the bolts.

But even the bolted bunch weakens building structures, albeit relatively a bit. Connections are fastented with the help of a clamp or metal brackets. The maximum improvement of the quality of products can only with their industrial receipt, since only in strictly standardized and fully controlled conditions, deviations from the norms are excluded, deterioration of quality. You can collect a rafter design from fully finished farms very quickly, there is no risk in its use. Another thing is that it is required to rather collect information about the necessary characteristics and without distortion to transfer it to the manufacturer.

In addition to these items, the rafter system borders with the end. So called a special compound of the geometrically complex roof at points where its trajectory changes. The difference from the skate is that in such places, roofing parts form a negative angle. The technical essence of the product is that the chute helps to fall aside the liquid. The more difficult configuration, the greater the number of such chutes should be.

The carnome bar serves to restore the struts in it, the other end of which rests on the frontal board, while the droplet is not deformed and its configuration is not distorted. Wind bonds are those elements of a rafter system that translate the load generated by the wind, with a roof for the foundation. They not only increase the total stability of the structure, but also help to avoid overturning when the unstable of single parts. The roof will retain spatial stiffness even with very strong winds.

Horizontal wind ties are elements such as:

• discolutions;
• parabolic tightening;
• complex tightening complexes;
• farms supplemented by a cross-hand grid.

Vertical Saving characteristics under strong air pressure is provided by wind supports and beams. Sometimes a monolithic hardening kernel is used. Engineers have come up with a lot and other windows typography options. It is provided by frames and semiradias, pinched backpoints. In small buildings, rigid (resisting compression) or stretched diagonals are used, some cover two spans at once. The location of each element is accurately reflected in the project documentation.

The qualitative characteristics of the rafter systems and their composition are not so difficult, if you take care and diligence. But it is equally important to calculate the quantitative parameters of these systems. If you don't do this or carry out the calculations incorrectly, you can either spend too many tools, or encounter leaks even with the destruction of individual items.

• roof bends;
• average annual snow mass;
• non-uniformity in its distribution on the skates depending on the slope of the slope and the wind roses;
• wind transfer already fallen snow;

• the gathering of snow and ice masses, the flow of liquid water down;
• aerodynamic characteristics and sail construction;
• differences in exposure to individual points.

To calculate everything you need, moreover, simulating realistic situations and having laid a reasonable margin of safety into the project - not so simple. Especially since you need to pay attention to the addition of various loads, on their cumulative action. But still any customer is quite bye forces to evaluate the quality of the work of designers. The loads attached to the rafter systems are divided into three key groups: the main, additional and extreme.

The main discharge falls:

• stable factors - the severity of the roof and rafter structures, additional elements installed on top;
• long term exposure - snow, temperature;
• periodically changing factors - complete calculations of snow and temperature effects, taking into account all subtleties.

An additional group is a pressure rendered by wind, builders and repairmen, ice and rain. The extreme category includes all natural and technogenic emergencies that may arise in a particular place. Their level is projected to ensure the exclusion of unpleasant consequences. When calculating the frame roof and under it, it takes into account the limit load, in the case of an application of which the entire structure is crumbling. Additionally, an indicator or a group of indicators is given, with which various deformations inevitably appear.

The demolition coefficient reflects how much more it will be made on the leeward side and in front of the objects (parts) that delay the flow of air. In problem places, it will be possible to maximize the rainbill and thoroughly calculate the necessary thickness of the facial material. The maximum accurate assessment to all parameters can be given only when multiplying any numbers obtained on reliability coefficients. As for the wind, the effort developed by them is directed to the dropping of steep roofs and on the rise from the leeward section of a flat roof. We must not forget that the air flow acts simultaneously on the facades and on the rods.

When you hit the facade, the air breaks down into two waves: one goes down and more interest does not represent, and the other by tangent presses the roofing sink, trying to raise it. The action on the skate occurs at right angles, this area is depressed deep into. At the same time, a twist is formed, which by the tangent affects the winding sector. This whirlwind is bypassed and begins to create lifting force already in the appendix to the subvener segment. To note: when calculating the mass of the roof, it is necessary to take into account the severity of rafters, insulation, waterproofing and steam barrier.

Standard load per 1 square meter of the roof is up to 50 kg regardless of its size and other significant circumstances. By changing the distance from some rafter feet to others, you can specify the actual distribution of loads on them. According to the majority of specialists, acceptable values \u200b\u200bwill be from 60 to 120 cm. But on a warmed roof it is worth choosing such distances that are equal to one sheet or roll of insulating materials. At the same time, it is worth considering that among several suitable options for the arrangement of rafters are preferable to the one that gives the optimal effect with minimal consumption of materials used.

When loading loads that portened with rafters always look at that they do not exceed the limit endurance of the roofing material. After all, there is no point in such an exceeding. If, with the planned effect of the roof, it will still be to fake, it is impossible to talk about a solid result. When calculating the payload from the structures connected to the rafted farms is calculated according to the same touch area, which is applied to the drawing. Such designs include ventilation chambers, attic ceilings and first floors placed on the roofs of water tanks. In addition to the pressure on the rapid system, the sharpness of the roof slope is calculated.

Tilt angle: value

In the forums, with consultations of specialists and in professional literature, you can meet the mention of three units of inclination at once. In addition to the usual and expected degrees, there will be interest, and the relationship between the parties. Often they get together even within one publication or instructions from the manufacturer of roofing materials. But in fact, nothing mysterious about it, any consumer can understand the essence. At an angle of inclination of the roof, experts understand the angle that occurs at the intersection of the horizontal with a row of roof.

Stupid angles in this case can not be in principle. Moreover, to meet the skate with a cooler 50 degrees only in decorative elements, all kinds of turrets. The exception of the general rule is only rocks on the lower rows of the rafted mansard roof. In all other cases, the angles range from 0 to 45 degrees. The relative proportions of the parties are calculated as the ratio between the height of the skate and its projection on the horizontal. This indicator is equal to a uniformly designed roof with a pair of rods half of the span.

On a single roof, the proportion is equal to one, and in more complex configurations still have to carry out all the calculations and the axes on their own, without repulse from the finished values. The angle of the slope is usually expressed in the form of a fraction, the numerator and the denominator are separated by a colon. But when the figures received cannot be rounded up to integers, it is recommended to use percentages: just divide one to another and increase a hundred times. Flat roofs are those who have a slope of no more than 5 degrees; The slope of 6-30 degrees is small recognized, and all other roofs are considered steep. The flat design radically increases the useful area and is quite resistant to the wind, but it will be necessary to clean it from the snow manually and enhance the waterproofing to the limit. The slope is necessarily construed with a specific material, and the necessary values \u200b\u200bcan be found in the instructions from the manufacturer. To calculate even the most complex and bizarre configurations of the roofs, they are broken mentally on triangles and the angle is specifically calculated in each.

Step, Length and section Scroll

When it became clear which length of the skate, which angles formed by these slopes with a horizontal plane, it is time to do the actual rafters. If the roof frame is made from a 5x15 cm timber under metal tile, the mounting step is cut from 0.6 to 0.8 m. As the steepness increases, the gap is also increasing. If the roof is tilted under 45 degrees, it is required to put rafters every 800 mm, and for 75 degrees can be added to 75 degrees.

The next important parameter is the length of the rafted.It is closely related in increments: if the blocks are made long, they are most close as possible, and when a single part is shortened - push. When counting the shade, the crates comes from the type of tiles, and from the fact that each row should be folded on each slope. If it turns out a fraction, it is better to round, reduce or increase a little indicator. The rafter legs under metal tile, the cross section of which is 15x5 cm, fluctuate from 65 to 95 cm. It is not possible to increase the step when the crate of 3x5 cm.

So that the insulation is better ventilated, the rows of holes with a diameter of 1-1.2 cm are prepared in the area of \u200b\u200bthe upper edge of the rafter. Private rafters under the professional flooring go every 0.6-0.9 m. When the distance exceeds this indicator, you will have to put a crossing of the crate with a significant cross section. The neckenet under the professional flooring is assembled from the boards with dimensions of 3x10 cm, which are set with an interval from 0.5 m. Calculate the interval is needed in accordance with the height and thickness of the materials.

With all the revealed flaws of slate, it remains widely demanded. Under the slate roofing, raftered with a cross section of 5x10-15 cm, distant from each other by 60-80 cm. Most often, the average distance is recommended, which is 0.7 m. Pauses between parts of the crates are calculated according to the steepness of the material. On comparatively gentle plots of support on 4 pieces of wood justifies yourself. If the roof is done cooler, put 3 BROs, separated by 63-65 cm.

We must not forget that due to the liability of the rafter system, it is better to leave the reserve of strength, rather than make an unnecessarily weak type of rafters. For their manufacture, a timber dried up to 15% is used. The replacement of the bruce can serve as not a cutting board of the same dryness. The ceramic tile uses a 5x5 verticle lamp. In the calculated distance, the places apply nails for slate or simple self-tapping screws.

Installation: technology

Roof construction involves the use of a standard circle of carpentry tools and electric drills. If metal structures are used, the Bulgarian will be required for precise cutting. Remember that the metal tile or professional flooring cannot be treated with it, it may damage the material. The tent roof without racks is done using tighters that enhance the structure.

In the Valm version you have to strengthen runs that are diagonally.Paired boards and a particularly strong bar are dismisted. Points of compounds always have a backup (rack), and the main support is placed at about a quarter of length separating large rafters from the skate. Under the fronts on the bartal roof, there are always rafters of a smaller length. But under the main part of the four-piece design, extremely long details may be made, even more than 7 m. So that they keep securely, apply either a rack that translates the voltage to overlap or Shprengel.

The first step in creating a rafter under the broken roof is the formation of a support complex in the form of the letter P. It relies on the beams of the ceilings and is held with rapid legs. Next, three or more runs are put, two of them are removed on the corners of the frame, and the rest are positioned in the middle of the overlap. The completion of the feet in the rafter, the legs are fastened. The rafting systems are desirable to do according to the template - to connect two boards, which in length coincide with the rafters, and pinch each other with a nail. The template put the edges into the point of attaching the rafting legs and fix it with the help of cross.

An additional template (this time plywood) will help make an assembly saw. Farm attach to Mauerlat, starting with extreme. In order not to intimidate with the point of attachment of the skate, the tops of these farms are associated with a straight rope. The massiveness of the fumes as approached the skate increases. If the rafting elements are mounted with bolts, it is worth using washers or plates. It will not give nuts to delve into the tree.

How to install rafters with your own hands, look in the video below.

The rafters perform a number of significant roofing functions. They define the configuration of the future roof, perceive atmospheric loads, hold the material. Among the rafter duties, the formation of smooth planes for laying the coating and ensuring space under the components of the roofing cake.

In order for such a valuable part of the roof perfectly coped with the objectives listed, information on the rules and principles of its device are needed. The information is also useful and those who are constructed by a rafter system of a two-tie roof with her own hands, and those who decide to resort to the services of the hired brigade of builders.

A wooden and metal beams are used in the solpted framework for pitf roofs. The source material for the first option is the board, log, bar.

The second is constructed from metal: channel, profile tube, ductavra, corner. There are combined structures with steel the most loadable parts and elements of wood in less responsible sections.

In addition to the "iron" strength from the metal there is a lot of flaws. These include heat engineering qualities, unsatisfying residential buildings. Disappointing the need to apply welded connections. Most often with steel rafters to equip industrial buildings, less often private cells collected from metal modules.

In the independent construction of rafal structures for private houses in the priority of wood. It is easy to work with it, it is easier, "warm", attractive on environmental criteria. In addition, the welding machine and the welder skills will not need to perform the nodal connections.

Rafyled - fundamental element

The main "player" of the frame for the roof structure - raftered, in the roofer environment called a rafter foot. Lecks, discolutions, grandmothers, runs, tightening, even Mauerlat can be used or not used depending on the architectural complexity and size of the roof.

The rafters used in the construction of the frame of two-tie roofs, according to technical grounds and method of laying are divided into:

• Current Stropile legs, both heels of which have reliable structural supports. The lower edge of the rolling rafter rests on Maurylalat or to the ceiling crown of the cut. The support for the upper edge can be a mirror analog of adjacent rafylic or a run, which is horizontally laid under the skate beam. In the first case, the rafter system is called spacer, in the second faithful.
• Hanging rafters, the top of which rests on each other, and the bottom is based on an extra beam - tightening. The latter connects two lower heels of adjacent rafting legs, resulting in a triangular module, called a rafter farm. The tightening is extinguished by the processes of stretching, so that only vertically directed load is valid for the walls. The design with hanging rafters is although it is spacer, but it does not transmit to the walls.

In accordance with the technological specifics of the rafter feet, the structures constructed are divided into urinary and hanging. For stability, the design is equipped with piping and additional racks.

For the device, the tops of the vertex strings are mounted or runs. In reality, the rafter design is much more complicated than the elementary patterns described.

Note that the formation of a dual-tie roof frame may generally be produced without a lifting design. In such situations, the alleged planes of the rods are formed by slopes - beams laid directly on the bearing frontones.

However, we are now interested in a specific device of the solid system of a two-tie roof, and it can be used both hanging or spree rafters and a combination of both types.

Throwing Throwing Fastening

Fastening the rafter system to brick, foam concrete, aerated concrete walls is made through Mauerlat, which in turn is fixed by anchors.

Between the Mauerlat, which is a wooden frame, and the walls of these materials, a waterproofing layer of rubberoid, waterproofing, etc. is mandatory.

The top of brick walls is sometimes specifically laid out so that something like a low parapet is obtained along the external perimeter. So it is necessary that the Mauerlat and walls placed inside the parapet and the walls did not cut the rafting legs.

The rafted frame of the roofs of wooden houses is based on the upper crown or on the ceiling beams. The connection in all cases is performed by wrinkles and is duplicated with nails, bolts, metal or wooden plates.

How to do without non-shuttle calculations?

It is extremely desirable that the section and linear dimensions of wooden beams are determined by the project. The designer will give clear estimates of the geometric parameters of the board or timber, taking into account the entire spectrum of loads and weather conditions. If there is no design development master's homemade master, it lies on the construction site of the house with a similar roofing design.

You can not pay attention to the flood of the building of the building. It is easier and more correct to find out the required sizes from the Proba than to recognize them with the owners of the shaky self-container. After all, in the hands of the Proba, documentation with a clear calculation of loads on 1mqm roofs in a particular region.

The installation step of the Stropilin determines the type and weight of the roofing coating. What it is harder, the less should be the distance between the rapid legs. For laying the clay tiles, for example, the optimal distance between the rafters will be 0.6-0.7 m, and for and the proflist is permissible 1.5-2.0 m.

However, even if the step is exceeded, which requires a roof installation, there is an output. This is a device that enhances the counterclaim. True, it will increase the weight of the roof, and the construction budget. Therefore, in a step of the rafter to figure it out better before the construction of the rafter system.

The folk craftsmen calculate the step of rafaline according to the constructive features of the construction, trite separating the length of the skate at equal distances. For insulated roofs, the step between the rafalines is selected, based on the width of the insulation plates.

On our site you can find that you may also help you very much during construction.

Stropil designs of the utility type

The rafter structures of the utility type are much easier to perform than their hanging fellows. The reasonable plus of the sound scheme is to ensure full-fledged ventilation, which is directly related to the long-term service.

Distinctive design features:

• Mandatory presence of support under the skunk heel of the rafting leg. The role of support can play a run - a wooden beam, based on the rack or on the inner wall of the structure, or the upper end of the adjacent rafylic.
• Using Maurolat for the construction of a rafter design on the walls of brick or artificial stone.
• The use of additional runs and racks where the rapid legs due to large width dimensions require additional support points.

The minus of the scheme is the presence of structural elements affecting the planning of the internal space of the attic exploited.

If the attic is cold and it does not assume the organization of useful premises, then the roller construction of the rafter system for the device of a double roof is worth a preference.

Typical sequence of work on the construction of a slump truck design:

• The first thing is precipitate the heights of the construction, the diagonal and the horizontal of the top cutting of the island. When identifying vertical deviations of brick and concrete walls, we eliminate their cement-sand tie. Exceeding the heights of the logs we put. By lining chips under Mauerlat with vertical flamns, it is possible to fight if the magnitude is insignificant.
• The surface of the ceiling under the laying of Lenzny must also be aligned. He, Mauerlat and Runs should be clearly horizontal, but the location of the listed elements in the same plane is not necessary.
• We process all the wooden design details before installing with antipirens and antiseptic preparations.
• On concrete and brick walls, we lay waterproofing for the installation of Mauerlat.
• We put the Mauerlala Bar on the walls, measure it diagonally. If you need, slightly move the bars and turn the corners, seeking to achieve perfect geometry. Align the frame horizontally, if necessary.
• Mount Mauerlat Frame. The splicing of bars in a single frame is made by means of oblique wrist, the locations of the connections are duplicated by bolts.
• Fix the position of Mauerlat. Fasteners are made either with brackets to ahead of the walls laid into the wall, or anchor bolts.
• Place the position of Lenzny. Its axis must retreat from Mauerlat's BRUSEV for equal distances on each side. If the run will be relying only on the stand without Lengne, we carry out the markup procedure only for these columns.
• We establish a layer on two-layer waterproofing. To the base of its secure anchor bolts, with the inner wall we combine with wire twists or brackets.
• Mark the installation points of the rafter feet.
• We cut the racks for single sizes, because Liezhalan is put in the horizon. The height of the racks should take into account the dimensions of the cross section of the run and Lenzny.
• Install the racks. If provided for by the project, we will relate them to the struts.
• We put a run on the racks. We again check the geometry, then set the brackets, metal lining, wooden mounting plates.
• We establish a trial slinging board, place the samples of trimming on it. If Mauerlat is set strictly to the horizon, there is no need to fit the rafalle on the roof. The first board can be used as a template for the manufacture of the rest.
• Place the installation points of Stropilin. Folk wizards for marking usually harvest a couple of rails, the length of which is equal to the lumen between the rafalines.
• On the markup, we set the rafting legs and fasten them first at the bottom to Mauerlat, then at the top of the run to each other. Each second rafaline is screwed to Mauerlate with a wire bundle. In wooden houses, the rafylans are screwed to the second from the top row.

If the trimmer is made perfectly, the sloping boards are mounted in an arbitrary order.

If there is no confidence in the perfect construction, then the extreme pairs of rafaline are installed. Between them is tensioning the control of the twine or a fishing line, according to which the position of the newly installed rafters is adjusted.

The installation of the rafter design of the installation of the koblok is completed if the length of the rafter feet does not allow to form a sample of the required length. By the way, for wooden buildings, Svet must "go out" for the contour of the building 50cm. If the visor organization is planned, separate mini rafters are installed under it.

Another useful video about the construction of a two-tie rafting base with your own hands:

Hanging rafter systems

Hanging variety of rafting systems is a triangle. The two tops of the triangle are folded by a pair of rafaline, and the base is served by connecting the lower heels of the tightening.

The use of tightening makes it possible to neutralize the action of the space, because only the weight of the crate, the roof plus, depending on the season, the floor of the precipitation is performed on the walls with hanging rapid structures.

Specificity of hanging rafter systems

Characteristic features of the rafter designs of a hanging type:

• Mandatory tightening made most often from wood, less often from metal.
• The ability to refuse to use Mauerlat. Frame from a bar with success will be replaced by a board laid on a two-layer waterproofing.
• Installation on walls of finished closed triangles - rafter farms.

The advantages of hanging schemes are the space free of the root space, allowing to organize an attic without pillars and partitions. There are flaws.

The first of these is the limitations on the ridge of the skates: the angle of their slope can be at least 1/6 of the span of a triangular farm, strongly recommended cooler roofs. The second minus lies in the need for thorough calculations for the competent device of the cornisic nodes.

Among other things, the angle of the rafter farm will have to set with jewelry accuracy, because The axis of the combined components of the suspended stage system must intersect at the point, the projection of which is obliged to fall on the central axis of the Mauerlala or the replacement of its lining board.

Threads of large-year hanging systems

The tightening is the longest element of hanging rafter designs. Over time, it, as it is characteristic of all sawn timber, is deformed and saves under the action of its own mass.

Owners of households with flights 3-5m This circumstance is not too bothering, but the owners of buildings with flights of 6 or more meters should be thought about the installation of additional parts that exclude geometric changes in tightening.

To prevent sagging in the mounting scheme of the rafting system for the Bolshnaya Double Roof there is a very significant component. This is a suspension called a grandmother.

Most often, it represents a bar attached by wooden sibods to the top of the rafter farm. Sticks with racks should not be confused, because Its lower part should not touch the tightening. And installing racks as a support in hanging systems does not apply.

The essence is that the grandmother is hanging on the skate node, and the tightening is connected to it with the help of bolts or nailed wooden linings. To adjust the saving tighten, the threaded or collet type clamps are used.

The adjustment of the tightening position can be arranged in the zone of the skate unit, and the grandmother with it to join a rigid wrist. Instead of a bar on non-residential attacks for the manufacture of the described tightening element, fittings can be used. A grandmother or suspension is recommended also to arrange there, where the tightening is going out of two bars, to support the connection site.

In an improved hanging system of this type, the grandmother complements the sub-vehicle beams. The voltage forces in the resulting rhombus are quenched spontaneously thanks to the competent arrangement of the vector loads operating on the system.

As a result, the rafter system pleases with stability with a minor and not too expensive modernization.

Hanging type for mansard

In order to increase the useful space, the tightening of the rafting triangles for the attic is transferred closer to the skate. It has additional advantages to have additional advantages: it allows the use of tightening as a base for covering the ceiling.

It is joined to the rafters. It is by heart by semi-fever with duplication bolt. From saving it is protected by installing a short grandmother.

A tangible drawback of the mansard hanging design is the need for accurate calculations. It is too difficult to calculate it yourself, it is better to use the finished project.

What kind of design is more economically profitable?

The cost is an important argument for an independent builder. Naturally, the price of the structure in both types of rafter systems cannot be the same, because:

• In the construction of a sphere design for the manufacture of rafting legs, a chalkboard or a small secting bar is used. Because Current rafylics have two reliable supports, requirements for their power lower than in a hanging version.
• In the construction of the hang bags, the rafter is performed from a thick bar. For the manufacture of tightening, the material is required in cross section. Even taking into account the refusal of Mauerlat, the flow rate will be significantly more.

Save on the types of material will not work. For the supporting elements of both systems: Stropilin, runs, Lecking, Mauerlat, grandmothers, struts needed a sawn timber.

For riggers and tensions running on stretching, 1 grader will be required. In the manufacture of less responsible wooden linings, a 3rd grade can be applied. Without counting, it can be said that in the construction of hanging systems, expensive material is used in greater volume.

Hanging farms are collected in the open area near the object, then transported to the assembled form. To lift the huge triangular arches from the bar, it will be necessary for the technique for renting which will have to pay. Yes, and the project for complex knots of the hanging option is also worth something.

Video instructions on the device of the trigger design of the hanging category:

Methods of the construction of rafting systems for the roofs with two slopes are actually much more.

We described only basic varieties that are applicable in reality for small country houses and buildings without architectural clauses. However, the information provided is enough to cope with the construction of a simple rafter design.