The design of gable roof truss system

Device types and installation of the roof gable roof system

Among the wide variety of the most popular types of roofs for centuries enjoyed gable roof. The relative simplicity of the design, excellent stability, adaptability to different climatic conditions - good arguments, proven long-term construction practice. Gable roof truss system has some peculiarities and nuances when it is installed, which are discussed in this article.

Gable roof, gable and it is called, consists of two rectangular inclined plane - roof slopes, which are installed at a certain angle to the outer walls of the building. Due to the inclination of skates provided natural flow of natural rainfall (rain, melt water).

Roofs with irregular angles of inclination of rays (ie the location of the ridge through the center of the building is not) and different length of eaves are used in the desire of the customer to express architectural feature of his property. This roof, looks quite original in terms of design, but has the disadvantage of irrational use of the attic.

Loma gable roof is applicable in cases where there is a need to use the attic space under the attic. In such roof loft increased volume makes it easy to arrange the loft which is protected from moisture and insulated.

Symmetrical gable roof has at its base an isosceles triangle. Orthodox form and simplicity in the construction of made her a favorite not only of professional builders, but also beginners.

The first thing you should pay attention to the organization of the construction of a gable roof - the angle of inclination. To a lesser extent, it depends on the architectural features, but largely on the climatic characteristics of the region in which the roof is erected, and the type, installed roof. Roof with a steep angle of inclination is set in regions that are subject to frequent precipitation. Areas with strong winds, areas require installation sloping ramps to unload the structure from wind loads.

rays inclination angle may range from 5 to 90 °. A common one is a roof having a tilt angle 35-45 °. This option is the most economical in terms of consumption of building materials and distribute the load evenly across the perimeter of the building. With this inclination of the attic space is cold type in the future it is not fit to live in it.

If you need a loft conversion living room, then you need to use the broken gable roof. In this case, the upper part of the roof becomes flatter, and the bottom will have a steep slope. Attic space will increase and will be able to use it under the attic housing. For this type of skates complicated design truss system compared with a simple embodiment.

Types of roof system gable roof

Apparatus gable roof truss system has differences in the use of support bases for the trusses. Distinguish pendant and naslonnuyu rafter system. Accordingly, the truss system used in its construction hanging or naslonnye rafters. There is a third embodiment - Hybrid, when the truss system are set as padlocks and naslonnye rafters.

Hanging rafters are used in plants with a distance between supports no more than 6-6.5 meters.

Naslonnye rafters installed in buildings with a wall or the carrier medium with the pole inside.

Bearing elements in the structure are gable roof truss system and mauerlat.

Rafter system includes elements such as rafters, uprights, inclined struts, beams, struts, ridge run. All these elements are connected into a unitary structure and form a truss system as such.

The material of which are made rafters and other structural members, may be made of wood, iron and concrete.

Before using the material it is necessary to pay attention to hitting bitches do not exceed in length one third of the thickness of the material!

Mauerlat - a timber with a cross section of 100 × 100 × 200 mm to 200 mm, which is placed under the rafter foot or structures laid around the perimeter. His mission - uniformly distributed load on the exterior walls.

Installation mauerlat occurs on the upper walls of edge. Installation is either wall axis or offset to the outer or inner edge of the wall (but not more than 50 mm from the outer face). Before installing mauerlat, under it enclose a waterproofing material, for which, most often serves roofing material. Compound mauerlatov units must be firm and occurs via direct locks.

Installation of rafters gable roof

Before installing trusses occurs mauerlatov fastening to the longitudinal walls by means of anchor bolts. Further it is necessary to determine the optimal cross section rafters, which depends on their length and the distance between them. You can use the table below, which allows you to choose the section of rafters, depending on their length. If necessary, the timber to have a different width and length of rafters, the required resolution is achieved by splices (capacity) using fasteners.

If the heater is used, it is necessary to choose a rational distance between the rafters in such a way that as little as possible had to cut the heat-insulating material.

Installing rafters gable roof in the following order:

  1. At first it made a template on which will be assembled trusses. For this taken two boards (board length equal to the length of the rafter) and connected with one end interconnected with one nail.
  2. The resulting construction (shears), the free edges of planks laid on the support, in places where they will build rafters. The resulting, final angle - the angle of inclination of the roof, must be secured with a few nails, and for better fixation of the angle between the boards to fix the transverse bar.
  3. Next is another template, by which will be carried out by mounting gash on the rafters. The easiest way to make plywood.
  4. Mounting on rafters are cut using a template gashes and are interconnected at an angle of inclination of the ramp. The resulting triangle called roof truss, which is lifted to the roof by means of auxiliary structures (staircase, logs, etc.) and attached to mauerlat.
  5. At the beginning of set two extreme gable truss. For their proper horizontal and vertical installation use temporary struts that secure them.
  6. Between the extreme vertices farms stretch cord that serves to indicate the future skate, and also for the rest level between rafters.
  7. Further rise and set the remaining trusses to previously calculate a distance (not less than 0.6 m) apart.
  8. Bulky design, depending on the need, strengthening crossbars, dams, braces, etc.
  9. Ridge beam (run) mounted on special supports. Next to it are attached intermediate, and short diagonal rafters.

Calculation of loads and the tilt angle

Correct and accurate calculation of the gable roof truss system - the key to the future strength and durability of your home. When designing a complex roof structure of its calculation must be performed by a professional. Calculation of a gable roof with a small area can be calculated independently by means of simple instructions and the use of simple formulas. Ultimately, in self-counting, it is still best to seek expert advice in order to be completely confident in the reliability and durability of the roof of the future.

In the beginning, determined with a slope roofing rays. The inclination angle in the 5-15 °; suitable for a small number of roofing. In view of this, we first selected roofing material, and only then calculated truss system. With an angle of inclination greater than 45 ° fits any roofing, but at the same time growing and material costs.

It is also necessary to accurately calculate the live loads - wind and snow. Snow load limits are in the range 80-320 kg / m 2, and depend on the climatic region. On the roof with an inclination angle of not more than 25 ° from the transition coefficient of the snow cover on the roof equal to 1. For roofs with a slope of 25-60 ° is assumed to be 0.7.

For example, when the load of the snow cover on the ground 120 kg / m 2 load on the roof with an inclination of 25-60 ° is 120 × 0.7 = 84 kg / m 2.

The wind load is calculated using the change ratio of wind pressure and aerodynamic effect.

Calculated weight roofing pie - constant load, which includes weight lathing, kontrobreshetki, insulation, roofing material, and, in the case of a loft, interior trim weight ceiling. The average value of the constant load ranges 40-50 kg / m 2.

Thus, the total load is calculated, which consists of permanent and temporary loads. On the basis of the total load per square meter of roof rafters selected section.

In any case, in the calculation of roof system gable roof, the work should be entrusted to professionals, you can also use directories in the network and specialized Internet resources.

Gable roof truss system with their own hands - on instruction device

Gable roof or gable - is the roof on two slope, ie, having two inclined surfaces (slopes) of rectangular shape.

Frame gable roof because of design features perfectly combines the simplicity of the device and services with reliability and durability. These and many other features make the construction of a gable roof practical and rational solution for private and commercial construction.

As part of this article will look at how to make a truss system gable roof with his hands. For the effective perception of the material presented in a step by step guide from A to Z, from the selection and calculations, before mounting mauerlat and crates under the roof. Each stage is accompanied by tables, diagrams, drawings, paintings and photos.

Popularity roof house due to a number of advantages:

  • variation design;
  • simplicity in calculations;
  • natural flow of water;
  • the integrity of the design reduces the likelihood of leaks;
  • efficiency;
  • preservation of the useful area of ​​the attic or the possibility of arrangement of the attic;
  • High maintainability;
  • strength and durability.

Installation of frame of roof gable roof depends mainly on its design.

Identify several options gable roofs (types of species):

1. A simple gable roof - symmetric

Simple gable roof - symmetric most common due to the simplicity and reliability of the device roof option. Due to the symmetry is achieved by uniform distribution of load on the load-bearing walls and mauerlat. The type and thickness of insulation does not affect the choice of material.

The cross section of the beam makes it possible to ensure the supply of the bearing capacity. There is no likelihood prigibaniya rafters. Struts and spacers can be placed almost anywhere.

A clear disadvantage - impossibility of full arrangement of the attic floor. Because of the sharp edges appear "gluhie9raquo; areas that are unsuitable for use.

2. Simple asymmetrical gable roof

Simple asymmetrical gable roof apparatus one angle greater than 45 ° leads to a drop of unused space. There is an opportunity to make a living room under the roof. At the same time increase the calculation requirements, as the load on the walls and the foundation will be distributed unevenly.

3. The broken gable roof, with external and / or internal fracture

Polyline gable roof, with external and / or internal roof fracture Such design allows to arrange a full second floor under the roof.

Of course, a simple gable roof truss is characterized by sloping, not only visually. The main difficulty lurk in the calculation complexity.

The design of gable roof truss system

The construction of the roof of any complexity with their hands implies knowledge of the destination of the basic design elements.

elements location shown in the photo.

Elements of the roof gable roof system Elements of the roof gable roof system - circuit 2 Elements of the roof gable roof system - Scheme 3

  • mauerlat. It is designed to distribute the load on the truss system on the supporting walls of the building. Everything for mauerlat selected timber from solid wood. Preferably, larch, pine, oak. The cross section of the beam depends on its type - solid or glued as well as the intended century design. The most popular sizes 100x100, 150x150 mm.

Silhouette of a truss structure defines the external appearance. Examples of farms in the photo.

Options farm truss roof system

Are important parameters of the rafters. On them will be discussed below.

  • toke - It connects the rafters and gives them rigidity.
  • Run:
    • ridge run, mounted in the junction of the rafters to another. In the future, it will be installed roof ridge.
    • side runs, they provide additional rigidity to the farm. Their number and size depend on the load on the system.
  • Stand for rafters - vertically disposed beams. Also taken over some of the load from the weight of the roof. In a simple gable roof is usually located in the center. When a large span width - in the middle and on the sides. In asymmetrical gable roof - the installation location is dependent on the length of the rafters. When the polygonal roof and in one room in the attic loft - stands are located on the sides, leaving a free space for movement. If it is assumed the two rooms - racks are in the middle and on the sides.

Location rack depending on the length of the roof shown.

Rack location, depending on the length of the roof

The regions with significant wind and snow load set not only the longitudinal struts (located in the same plane with the truss pair), but also diagonal.

  • Sill. His appointment supports the rack and place the strut mount.
  • lathing. Designed for movement during construction and fixing roofing mater. It is set perpendicular to the rafters.

The presence of drawings and diagrams showing the location of all of these structural elements will help in the work.

When calculating the material on a gable roof is necessary to choose high-quality wood without damage and wormholes. The presence of knots for beams and rafters mauerlat not allowed.

For boards lathing knots should be a minimum, they must not fall. The wood must be strong and handle the necessary preparations that will enhance its properties.

Calculation of the roof gable roof system

Calculation of the parameters of the material is an important step, so give the calculation algorithm steps.

The calculation of roof system is important to know: the entire truss system consists of a set of triangles, the most rigid element. In turn, if the rays have different shapes, ie, is an irregular rectangle, it is necessary to divide it into separate components and to calculate the load and the number of materials for each. After calculations to summarize the data.

1. Calculation of the load on the truss system

The load on the rafters can be of three types:

  • permanent loads. Their effect will always be felt truss system. Such loads include the weight of the roof, battens, insulation, film, additional elements of roofing, finishing materials for an attic floor. The weight of the roof is the sum of the weights of all its constituent elements, such loading is easier to consider. The average value of the constant load on the rafters equal to 40-45 kg / m.

For reference: the weight of some roofing materials on 1 m is shown in Table

  • live load. They operate in different periods and with different force. Such loads include: wind load and its power, snow load, the intensity of precipitation.

In fact, the slope of the roof is similar to the sail and, taking into account the wind load, the entire roof structure can be destroyed.

The wind load on the roof

The calculation is carried out according to the formula: wind load indicator equal to the region multiplied by the correction coefficient. These figures are contained in SNIP "Loads and effects" and are determined not only the region, but also a place of location of the house. For example, in a private house, surrounded by high-rise buildings, there are fewer loads. Detached country house or cottage experience higher wind loads.

2. The calculation of the snow load on the roof

Roof calculation of the snow load is carried out according to the formula:

Full snow load equal to the weight of snow, multiplied by the correction coefficient. Factor takes into account wind pressure and the aerodynamic effect.

weight of snow, which falls on 1 sq.m. Roof area (according to the SNP 2.01.07-85) is in the range 80-320 kg / m.

Coefficients, showing the dependence on the angle of slope shown in the photo.

Scheme calculating snow load on the roof

  • specific load. Allowance for such loads is held in areas of high seismic activity, tornadoes, storm winds. For our latitudes enough to make a margin of safety.

Assessment of the state and the bearing capacity of the walls and foundation

It should be borne in mind that the roof has a significant weight, which is able to cause damage to other buildings.

Determination of the roof configuration:

  • simple symmetrical;
  • simple asymmetric;
  • polyline.

The more complex the shape of the roof, the greater the number of roof trusses and podstropilnyh elements needed to create the necessary margin of safety.

The angle of inclination of the gable roof determined primarily roofing material. After all, each of them makes its own demands.

It will be appreciated that increasing the angle increases the area of ​​the space under the roof, but the amount of material. What affects the overall cost of the work.

Calculation of the roof inclination,

Step trusses pentroof for homes can be from 60 to 100 cm. The choice depends on the weight of the roofing material and the roof structure. Then the number of rafters is calculated by dividing the length of the ramp to a distance between rafter pairs plus 1. This number determines the number of legs on one skate. For the second number should be multiplied by 2.

The length of the rafters for the roof of the attic is calculated according to the Pythagorean theorem.

The "a9raquo; (Roof height) is set independently. Its value determines the possibility of arrangement of residential premises under the roof, the convenience of finding the attic, consumption of material for the construction of the roof.

Parameter «b9raquo; equal to half the width of the building.

The "s9raquo; It represents the hypotenuse of a triangle.

It is worth noting that the maximum length of timber - 6 MP Therefore it is possible to splice (capacity docked compound) if necessary to timber trusses.

A method of matching the length of trusses is shown in the photo.

Methods for splicing trusses in length

The width of the roof trusses to depend on the distance between the opposite supporting walls.

The cross section of the rafters gable roof depends on several factors:

  • load, of which we have already written;
  • the type of material used. For example, the timber can withstand a load bar - another, laminated veneer lumber - third;
  • rafter length;
  • the type of wood that is used in construction;
  • the distance between the rafters (trusses step).

Determine the timber-section for trusses, knowing the distance between the rafters and rafter length by using the following data.

The dimensions of the timber (lumber and boards) to a gable roof system:

  • thickness (cross-section) mauerlat - 10x10 or 15x15 cm .;
  • . Thickness rafter and tightening - 10x15 or 10x20 cm sometimes used timber 5x15 or 5x20 cm;
  • run and brace - 5x15 or 5x20. Depending on the width of the feet;
  • Front - 10x10 or 10x15;
  • mudsill - 5x10 or 5x15 (depending on the pillar width);
  • thickness (cross-section) roof batten - 2x10, 2,5h15 (depending on the roofing material).

Types of gable roof truss system

For the present roof construction there are 2 options: naslonnye and hanging rafters.

Types of roof systems: a naslonnymi and hanging rafters

Consider each type of detail in order to make an informed choice.

Used in the roof width not greater than 6 lm Installation of hanging rafters is accomplished by mounting feet for bearing walls and ridge pole. The design of hanging rafters especially those that rafters are exposed Expander efforts. Hanging rafters with tightening mounted between the legs, can reduce its influence. Tightening a truss system may be wood or metal. Tightening often placed at the bottom, then they will play the role of supporting beams. It is important to ensure reliable fastening of the tightening in the rafters. Because it is also transmitted to bursting with the effort.

The higher the tightening, the greater strength it should have.

If the tightness does not install, load-bearing walls can be simply "razehatsya9raquo; the pressure generated by the truss system.

They are used in the regeneration of the roofs of all sizes. Design naslonnyh rafters provides for sleepers and racks. Lejeune, lying parallel mauerlat assumes some of the load. Thus, the rafters, as it were attentive unto each other and the support strut. Rafters naslonnoy systems work only on the bend. And the simplicity of installation also tips the scales in their favor. The only drawback - the presence of the counter.

Given that the modern roof of a large variety of different forms and complexity of configuration, a combined type of truss system.

Combination truss system

After selecting the type of roof system can accurately calculate the amount of materials. The calculation results are recorded. Thus professionals recommend make drawings for each roof element.

Installation of frame of roof gable roof

Once calculated rafters gable roof, you are ready for installation. The process is divided into stages and give a description of each of them. Will kind of step by step guide that contains additional information about each step.

Bruce is set along the length of the wall, which will draw the rafters.

The log cabins of logs mauerlat role played by the top crown. In buildings constructed of porous material (concrete, foam concrete) or bricks, mauerlat installed along the entire length of the bearing wall. In other cases, it can be installed between the rafter.

Prepared for www.moydomik.net site

Splicing mauerlat with each other (directly lock bolt) Since mauerlat length exceeds the standard sizes of lumber, it has to be spliced.

Compound mauerlat with each other is as shown in the figure.

bars washed down only at an angle &09deg;. Compounds occurs with bolts. Nails, wire, wooden pins are not used.

Installing mauerlat runs on top of the wall. mounting technology provides several ways to mount mauerlat:

  • exactly in the center of the bearing wall;
  • offset to one side.

Mauerlat can not be placed closer than 5 cm. To the outer edge of the wall.

To protect the timber from damage to mauerlat it is laid on a layer of waterproofing material, for which mostly acts usual roofing material.

Are secure mauerlat important aspect of construction. This is due to the fact that the slope of a roof like a sail. Ie, he feels a strong wind load. Consequently, mauerlat need to firmly fix on the wall.

Mauerlat methods of attachment to the wall and the rafters

Mauerlat fastening anchors Anchor bolts. Ideal for monolithic structure.

Mauerlat fastening wooden pins with wooden pins. Used for log cabins of logs and lumber. But, they are always used with additional fasteners.

Fixing mauerlat Staples Staples.

Mauerlat mounting on the studs or stud or rebar reinforcement. It is used in the event that the cottage is built of porous materials (concrete, foam concrete).

Fixing mauerlat sliding bracket mount Moving (articulation). Bundle this way allows for the displacement of rafters from shrinkage at home.

Fixing mauerlat wire annealed wire (knitting, steel). Used as an additional fixture in most cases.

2. Production of roof trusses or pairs

Installation is carried out in two ways:

  • installation directly on the roof bars. Is not often used as to perform all the work, measuring, cutting at height is problematic. But it allows you to fully carry out the installation with their own hands;
  • assembly on the ground. I.e., separate the elements (triangles or couples) can be collected at the bottom, and then to raise them to the roof truss system. The advantage of such a system in a more rapid implementation of high-rise work. A drawback - is that the weight of the assembled structure truss can be significant. Special equipment is required to pick it up.

The collected vapors rise to the top and are mounted on mauerlat. To this end, the bottom of the rafters to do gash.

Ways securing rafter shown.

Ways securing rafter

To begin the installation of roof couples need at the opposite ends of the roof.

Between rafter pairs tensioned string stretched between fixed pairs twine. It will simplify the installation of the next truss pairs. Also, mark the level of the ridge.

Next, set the remaining rafters at a designated distance from each other.

If the truss system is mounted directly on the roof of the house, after the installation of the two outer rafters set support ridge. Next to it is fixed a half rafter pairs.

It should be noted that the views of professionals differ on this issue. Some advised to use the checkerboard pattern attachment that will evenly distribute the increasing burden on the walls and foundation more evenly. This procedure involves the installation of the rafter in a staggered manner. After the part is installed rafters are mounted a pair of missing parts. Others insist that you need to do serial assembly of each pair. Depending on the design and size of the farm configuration, strengthening rafters performed props and racks.

Fixing rafter brackets Nuance. Additional structural elements are connected by means of cutting. Locking clamps are preferably construction.

can be extended rafter foot if necessary.

Methods for splicing rafters are shown in the photo.

Methods for splicing rafters

4. Install the ridge of a gable roof

The ridge of the roof assembly is made by connecting the top of the rafters.

Device ridge:

  • A method without using the reference beam (see. Fig.).

Installing the roof ridge without the use of a reference beam

  • The method using truss beam. Bruce needed for large roofs. In the future it could become a support for rack.
  • Method of lining the bar.

Installation of the roof ridge by lining the timber Installing the roof ridge beam lining on the way

  • A more modern kind of manufacturing a ridge node can be considered as the method shown in the photo.

A method of manufacturing a ridge assembly

Installing the roof ridge by notching

Once installed truss system do major consolidation of all components.

Mounted lath in any case, and is designed for easy movement of the roof during the work, as well as for fixing the roofing material.

Step battens depends on the type of roofing material, such as:

  • under the metal - 350 mm (distance between the two lower batten boards must be 300 mm).
  • under the decking and roofing slate - 440 mm.
  • under the soft roof plank solid crate.

Gable roof truss system with a loft - video:

As you can see, despite its apparent simplicity, installation of roof system gable contains many pitfalls. But, based on these suggestions, you'll have no problem to build a solid design with their own hands.

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Types of gable roof truss system: for small and large homes

At the core of each of the roof is a large number of beams, rafters, struts and girders, which are collectively referred to as the rafter system. Over the centuries the forms and methods of organization have accumulated a lot, and each has its own characteristics in the construction sites and vrubok. Learn more about what can be truss system gable roof and in this case must be fitted rafters and other elements of the system talk more.

The design of gable roof truss system

The gable roof section is a triangle. It consists of two rectangular ramps. These two planes are connected at the highest point in the unified system of the ridge beam (girder).

Scheme pentroof

Now about the components of the system and their purpose:

  • Mauerlat - bar, which connects the roof and walls of the building serves as a support for the rafters and other elements of the system.
  • Rafters - they form inclined roof plane and are under the support battens for roofing material.
  • Ridge Run (beads or horse) - unites two planes roof.
  • Tightening - crosspiece which connects the opposite rafters. It serves to increase the rigidity of the structure and compensation bursting loads.
  • Ledge - bars along mauerlat. Redistribute the load from the roof.
  • Side girders - supporting rafters.
  • Racks - transfer the load from the girders to the sleepers.

The system may still be present grasshopper. This board, which extend rafters to form overhang. The fact that the protection of the walls and foundation of the house from the rain, it is desirable that the roof came to an end as far as possible from the walls. To do this, you can take long rafters. But a standard length of 6 meters of sawn timber is often not enough for this. To order non-standard - very expensive. Therefore, just doraschivat rafters and boards that do are called "grasshopper".

Constructions roof systems are many. In the first place they are divided into two groups - with naslonnymi and hanging rafters.

The difference in the structure and hanging rafters naslonnyh

This system, in which the rafters are based only on the exterior walls without intermediate supports (bearing walls). For pitched roofs the maximum span of 9 meters. When the vertical supports and braces system can increase it up to 14 meters.

Suspension type truss system gable roof is good, that in most cases there is no need to put mauerlat, and this makes the installation rafters easier: no need to do notching enough to mow the board. To contact the walls and rafters used lining - wide board, which is attached to the studs, nails, screws, bolts. With this structure of most of the bursting stress offset, the effect on the wall is directed vertically downward.

Types of roof systems with hanging rafters for different spans between load-bearing walls

Gable roof truss system for small homes

There cheapest option truss system when it is a triangle (pictured below). Such a structure is possible if the distance between the outer walls not more than 6 meters. For such a roof system can be calculated from the slope do: horse should be raised to a height of over tightening is not less than 1/6 of the span.

But this construction rafters experiencing significant bending loads. For their compensation or take rafters larger cross-section of the ridge or notching do so to their partially neutralized. In order to give greater rigidity nailed wooden or metal plates, which are securely fastened vertex of the triangle (also not see the picture) at the top of both sides.

The photo also shows how to grow rafters to create a roof overhang. Vrubka done, which is to go beyond the line drawn from the inner wall up. It is necessary to shift the position of the notch and reduce the likelihood of fracture rafters.

Ridge assembly and fixing rafter to underlay board in a simple embodiment of the system

Option with the installation of bolts - used in the organization under the roof of the dwelling - attic. In this case, it is the basis for filing the ceiling of the underlying premises. For reliable operation of such systems, vrubka pins must be bezsharnirnoy (hard). The best option - poluskovorodnem (see the figure below). Otherwise, the roof becomes unstable to stress.

Gable truss system with roof raised and tightening the assembly bolts notching

Note that in this scheme, there is mauerlat and rafters to increase structural stability must extend beyond the walls. vrubka done in a triangle for their fastening and joining with mauerlat. In this case, an uneven load on the skates, the roof will be more stable.

Under this scheme is almost the entire burden falls on the rafters because they need to take a larger cross-section. Sometimes elevated tightness strengthen suspension. This is necessary to prevent it from bending, if it serves as a support for the headliner material. When tightening a short length, it is possible to insure the center on both sides of planks nailed nails. When large load and length of insurance may be several. In this case, too, enough planks and nails.

With a significant distance between the two outer walls and struts mounted headstock. Such a construction has high rigidity, because the load compensated.

Gable roof truss system for large span and notching units ridge and rafter

With such a long span (up to 14 meters) to make puff-piece is difficult and expensive, because it is made of two beams. It is connected directly or oblique prirub (figure below).

Straight and oblique prirub tightening compound

For reliable docking junction amplified steel plate planted on the bolts. Its size should be larger than the notching - extreme bolts screwed into the solid wood at a distance of not less than 5 cm from the edge of the notching.

In order for the scheme will work properly, you need to properly make the braces. They transmit and distribute some of the load from the rafters in the inhaling and provide structural rigidity. To enhance the metal compounds used laths

Fixing braces for the roof system hanging rafters

When assembling a gable roof with rafters lumber hanging section is always ahead of the rafters with naslonnymi systems: a load transmission points less on each element therefore have a large load.

The gable roof with naslonnymi rafters ends, they rely on the wall, and the middle part are based on the load-bearing walls or columns. Some schemes bursting walls, some are not. In any case, the presence mauerlat necessary.

The simplest version naslonnyh rafters

Vrubok-spreading circuits and components

Houses built of logs or timber react badly to stress spacers. For them, they are critical: the wall may collapse. For wooden houses gable roof truss system should be non-spreading. On the forms of such systems will talk in more detail.

The simplest of rafter-spreading circuit system is shown in the photo below. It rests on the rafter foot mauerlat. In this embodiment, it operates in bending, not raspiraya wall.

Easy-spreading system gable roof with rafters naslonnymi

Pay attention to the options for fixing rafters to mauerlat. In the first, bearing pad is usually mowed, its length in this - no more than the beam section. Notching depth - not more than 0.25 of its altitude.

Top rafters placed on the ridge beam without fastening it with the opposite rafter. Prepared by two lean-roof structure, which abut the upper part (but not connected) with one another.

Such a scheme is not recommended without experience: at the slightest inaccuracies appear spacers perform strength and the structure becomes unstable.

Much easier to assemble alternative staple in the ridge of the rafter. They almost never give a thrust to the wall.

Optional mounting rafters without thrust on the walls

For the operation of this circuit rafters are attached at the bottom with the help of mobile connection. To fix the rafter to top mauerlat hammered one nail or placed below the flexible steel plate. Options fixing rafters to the ridge pole with a photograph.

If the roofing material you plan to use heavy, it is necessary to increase the load-bearing capacity. This is achieved by increasing the cross section of elements of roof system and the strengthening of the ridge assembly. He is shown in the photo below.

Amplification ridge node under heavy roofing material or at considerable snow loads

All schemes pitched roof above are stable in the presence of uniform loads. But in practice this is not seen. Prevent sliding of the roof is more load side in two ways: installing at a height of about 2 meters scrum or braces.

Variants of roof systems with contractions

Installing contractions improves the reliability of the design. To make it work properly, at the point of intersection with the drains need to fix them with nails. The cross section for the fight timber used is the same as for the rafters.

Schemes of roof systems pitched roof with contractions

To the rafters are attached with nails or bots. They can be mounted on one or both sides. Node bout fixing to the rafters and the ridge pole, see below.

Fixing the fight to the rafters and the ridge beam

To the system was rigid and not "crawled" even when the emergency load is sufficient in such an embodiment to provide a rigid mount ridge beam. If there is no possibility of its displacement in the horizontal, the roof will withstand even heavy loads.

Systems naslonnyh trusses with struts

In these embodiments, for greater rigidity added podstropilnye legs, also known as braces. They are set at an angle of 45 ° relative to the horizon. Their installation increases the span length (14 meters) or reduce the cross section of the beams (trusses).

Brace simply substituted at the desired angle to the joists and nailed on the sides and bottom. An important requirement: brace must be cut precisely and fit snugly to the posts and rafters, excluding the possibility of its deflection.

Systems with podstropilnymi legs. Top spacer system below - non-spreading. Nodes proper cuttings for each nearby. Below - possible schemes strut mount

But not all the houses mean bearing wall is located in the middle. In this case, it is possible to set the angle of the struts with respect to the horizon nnaklona 45-53 °.

trusses system with an off-center vertical girder

Systems with braces needed if possible substantial differential shrinkage or basement walls. Walls sit differently can on wooden houses, and foundations - to the layered or puchnistyh soils. In all these cases the device in roof systems of this type.

System for homes with two internal load-bearing walls

If the house has two load-bearing walls, set podstropilnye two beams, which are located on each of the walls. On the intermediate load-bearing walls are stacked sleepers, podstropilnyh load of beams transmitted to the sleepers through the racks.

Systems with beams podstropilnymi

In these systems, a ridge run do not put: it gives the spacing force. Rafters in the upper part are connected to one another (trimmed and joined without gaps), the junction reinforced with steel or wood plates, which are nailed.

The top-spreading system bursting neutralizes the force tightening. Please note that the tightening is being run. Then it works effectively (upper diagram in the figure). Stability can be provided stand, or jointing - beams, installed diagonally. The spacer system (in the picture at the bottom of it) cross bar - is a bolt. It is installed on the run.

There is a variant of the system with racks, but without podstropilnyh beams. Then to each rafter is nailed rack, which second end is supported by an intermediate bearing wall.

Mounting the rack and tightening in the rafter system without podstropilnogo run

For mounting racks used dlyanoy nails and bolts 150 mm 12 mm. The dimensions and distances on the figure given in millimeters.

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