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August 12, 2017 18:06

Gable roof : truss system under the metal

design a gable roof is most often chosen for private homes as it is the best option for ease of installation and ease of use, strength and reliability, as well as style solution.Gable roofs differently called gable and has two ramp which can be arranged in relation to each other at the same or a different angle, that is, it may be a front or versatile isosceles triangle.The latter option is more often found among new buildings, as it becomes fashionable style solutions.And besides originality, this cement has some positive features that simplify its use.

Gable roof : truss system under the metal

gable roof: metal roofing truss system under

This type of roof system can be used for all types of roofing materials, but the crate, is fixed to the rafters, for each coating has its own parameters.

gable roof: truss system under the metal which has its own characteristics, should be carefully studied and designed more ahead of time, before buying materials and conduct of its installation.Let's try to sort out these issues.

Species structures gable roof

Article Contents

  • 1 Species structures gable roof
  • 2 main components of a gable roof system
  • 3 Types of roof systems gable roof
    • 3.1 Naslonnaya truss system
    • 3.2 Hanging truss system
  • 4 How to calculate the parameters of a gable roof system
    • 4.1 Loads truss system
    • 4.2 angle of slope roof system and the height of the ridge
      • 4.2.1 Calculator ridge height
    • 4.3 length rafters
      • 4.3.1 Calculator length rafter
    • 4.4 step calculation section rafters and
      • 4.4.1 Calculatordistributed load on the truss leg
    • 4.5 options other lumber
  • 5 installation sequence truss system under the metal roofing and roofing deck
    • 5.1 Video: construction of a gable truss structure under metallocherepichnoy roof

First we need to understand what design gable roofs are, as it is necessary to choose the most suitable for a particular structure.

  • simple equilateral gable design
The simplest version of a gable roof - symmetrical slopes

simplest version of a gable roof - symmetrical slopes

This option gable design can be called traditional and the most used, as it is easy to install and maintain, and are durable and reliable.

symmetry in this system helps to reach the load evenly on mauerlat and load-bearing walls.With proper selection of beam section for arranging and mauerlat truss system, these items will provide the necessary long-term operation for the roof safety margin.Additional reliability design give properly installed rack, struts and tightening.

disadvantage of this system everything for indoor attic space is that after installation of the walls and ceiling of a large area occupied by blind zone in the corner areas of the structure, which remain untapped.

  • Simple asymmetrical gable design
Very interesting to look at home with asymmetrical gable roof

very interesting to look at home with asymmetrical gable roof

Asymmetric gable design is different from the conventional system in that its rays are arranged at different angles.So, one of them is usually greater than 45 degrees, which increases the effective area of ​​the attic space, which is quite possible to build a dwelling, of course, with proper insulation.

Another important advantage of such a structure can be smaller in the ramp area, which is recommended to plan on the leeward side of the structure where the roof is always going to a lot of snow.Small same size, but with a very steep slope will not hold up on its surface large snowdrifts.

The disadvantage of asymmetric design include a more complex calculation to achieve its uniform distribution of the load on the house wall.

  • Bent gable design
One ramp " broken up " to cover the side of the house extension

One ramp "kinked" to block the extension side home

This gable truss system can be called a rarity, though thanks to this arrangement, rays in the attic space is formed quite a large room, which can beused for residential or utility room.

Besides a truss system to the sloping gable design can be attributed to the attic rafters installation option.

Both slope " kinked " - a clear gain in the usable area of ​​attic

Both slope "kinked" - a clear gain in the usable area of ​​attic

broken line Roof truss system is able to provide for the structure of a full second floor with spacious rooms, and for reinforced insulation, they can be used at any time of the year.

main components of a gable roof system

Now consider the main structural components of frame of roof gable roof

The scheme is well underlined the main elements of a gable roof

The scheme is well underlined the main elements of a gable roof

  • mauerlat is a board, stowed and securedcarrying on the long wall of the house.This structural element is designed to distribute the load on the walls, which gives the truss system that helps protect the structure of the deformation and fracture.
Mauerlat placed on the wall to evenly distribute the load on them

mauerlat placed on the wall for uniform load distribution on them

Bruce for mauerlat it must be made of wood, resistant to moisture damage and pests, as well as having a certain solidity.This can be Larch (optimal) or pine - they are the most popular breeds for the construction of roof system.The cross section of the beam may be 120 × 120,150 × 150 mm or more - in this size range depending on the size of the roof structure and wall thickness.

Rafter - the main carrier details of the entire system

rafters - the main carrier details of the entire system

  • Rafter leg - is the main carrier element of the system, forming the roof slopes.Rafters are made of lumber, boards or logs, and the size of the material depends on the design parameters of truss system, the distance between the rafters, the weight of the roofing and the level of external loads.
Filly serve to lengthen the rafters during the formation of the eaves

filly serve to lengthen the rafters in the formation of eaves

  • mare - this element is optionally present in the roof system, but it is necessary in the case where the rafter is not long enough to form the eaves of the roof.When building rafter, filly mounted on her lap in the 450 ÷ 500 mm.
Connection rafters and run in the ridge area

Connection rafters and run in the ridge area

  • Skate - is the pinnacle of the roof, and it is formed by the upper edges of the rafters fixed to each other and to the ridge pole.For example, in the illustration shown fixing rafters to the ridge board, but, in addition, that part of the system can be configured in other ways:
Several methods of fixing rafters to the ridge

few tricks fixing rafters to the ridge

a) rafter boards fastened together withusing wooden or metallic pads, which are cut in the form of skating and angle are fixed on both sides connected trusses;

b) rafters are fixed to the ridge board to be mounted on the edge;

in) in this case fixed to the rafters of the ridge board and additionally fixed on both sides of wood or metal plates.

A few more ways to connect rafters and ridge pole

few more ways to connect rafters and ridge pole

This figure shows the connection of two trusses, mounted overlapped and fastened together using screws or bolts.Another option - a compound of rafters on the ridge run at an angle with the further strengthening both sides of the junction plates of wood or metal.

Composite ridge parallel run of the two boards

composite ridge pole of the two parallel boards

  • Ridge Run is a binding element for the rafters.It may consist of one plank, two planks or timber.
Run , pinched between the pads .

Run, pinched between the pads.

Run mounted on racks mounted on the sill, which is located at the bottom of the system and running parallel to the ridge.In addition, it may be fixed between the two plates, the fastening at the top of the rafters.

In the attic, and sometimes in a simple gable system side girders are installed, which serve for the formation of a two-tier arrangement of the rafters in the attic or to stiffen the slopes in a simple structure.

On the roofs of a large area of ​​truss system is enhanced by vertical uprights

on the roofs of a large area of ​​truss system is enhanced uprights

  • Racks - is retaining vertical elements of roof system made from timber and installed in different places, depending on the size and layout of the attic.They fixed on the bottom of the beam attic floor, are the framework for the floor of the attic and ceiling spaces at home, or on the sill mounted on beams:

- in the middle of the truss system - in this case, the upper edge of the rack props roof ridge;

- under the rafters, along the side edges of the attic.

Racks make the design more rigid and reliable, as well as contribute to the removal from the walls of the structure load.

These parts of the system may also be part of the framework for the walls of the attic or under the mounting batten paneling of the attic space.

Puffs make design more reliable truss pairs

Puff make design more reliable truss pairs

  • tightening (bolt) - this element is installed between the rafters, as if pulling them.The delay can be mounted at the bottom of the rafters, enclosing farm triangle and at the same time acting as a beam attic floor or on top of the farm, and this becomes the basis for crates of the installation of the ceiling paneling.At the end of the roof, sometimes bolt is installed in the middle of the triangle.

This element contributes to the removal of the load, which provides a roof on the buildings walls.It is especially necessary in the hanging truss system, which will be discussed below.

For long rafters sludge should be strengthened bottom braces .

For long rafters sludge should be strengthened bottom braces.

  • Struts - is retaining elements reinforcing structure, usually set at an angle of 45 degrees.They are mounted in order to avoid sagging rafters, with possible strong winds or snow loads.Struts can be mounted in truss system not only on the central post, but also on the sides.They are especially important for the roofs of houses being built in areas with snowy winters and strong winds.
Lejeune is located below and parallel to the ridge serves as a support for the legs or struts

Lejeune is located below and parallel to the ridge serves as a support for the legs or struts

  • Lejeune - an element that serves as a support for the central and lateral struts and braces for fixing.
Crate - the basis for fixing the roofing material

Crate - the basis for securing roofing material

  • Crate fixed on the rafters perpendicular to them, and is intended for mounting on her roofing material.Step install it depends on the type of cover-so, crates are infrequent, frequent and continuous.In our case, ie for a metal tile, it depends on the transverse leaf waves.
Dimensional diagram for metal crates (parameters are shown in the table below)

Dimensional scheme crates for metal (parameters are shown in the table below)

mm
Step transverse wave of metal, mm Step battens «a», mm Step battens «b»,
300 230 300
350 280 350
400 330 400

Types of roof systems gable roof

gable truss system is hanging from the rafters and naslonnymi.As one or the other scheme can be applied to everything from metal roof.In order to know how they differ from each other and from which the elements are made, it is necessary to consider each of them.Here it should be noted that the circuits shown below are indicated only the main elements of roof systems, but they may be reinforced with additional details, which were discussed above, if necessary.

Naslonnaya truss system

Gable truss system naslonnogo type is based on the internal wall of the building

gable truss system naslonnogo type is based on the internal wall of the building

Naslonnaya truss system consists of the following elements:

1 - Load-bearing walls.

2 - mauerlat.

3 - Rack mounted on the sill.

4 - Rafter.

5 - Crate.

Naslonnaya system is different from the hanging that is installed on the structure, which has the internal capital partitions.Capital inner walls used to secure them sleepers on which to fix the rack, holding up the ridge pole, which are held together by the upper ends of rafters.Then the rafters fixed batten boards.

This design is more popular than hanging, as reliable and simple to install.

Hanging truss system

Hanging rafters are based only on the side walls of the building and connected to the ridge

Hanging rafters are based only on the side walls of the building and connected to the ridge

scheme hanging truss system looks as shown in the illustration, and includes the following main elements:

1 -Load-bearing walls.

2 - mauerlat.

3 - Rafter.

4 - Crate.

5 - tightening (bolt).

Hanging rafters system is mounted on the two outer bearing walls, which are pre-assigned mauerlat.This variant of the roof can be applied only if the distance between the load-bearing walls is not more than 7000 mm, as besides them additional support for the roof truss construction is absent.Such a system is usually equipped with bongs, backed by slopes - these items will be removed from the structure of the wall load.

addition naslonnyh and suspension systems, there are combo options that include some elements of both designs.

When the truss system is chosen, it is recommended before purchasing materials to make a detailed drawing of the roof with a dimensioned - it will be easier to calculate the number of all the required and the amount of their purchase.In addition, such a scheme will significantly help to make installation work.But in order to make the drawing, will have to do some calculations.

How to calculate the parameters of a gable roof system

correctly calculate the parameters of the elements for assembly work - is very important.To do this, first recommended to make a list of all the necessary steps and make the calculation.All payments should be made with a margin of 10 ÷ 15%, not allowing excessive saving, which will be to the detriment of the quality and strength of the structure.

If this part of the operation decided to run independently, it is necessary to consult the technical documents developed by experts, for example, placed in the SNP.

main directions of the calculation will be three interrelated values ​​- the steepness of the slope, the height of the ridge above the floor and the length of rafters.