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August 12, 2017 18:06

Calculation of the rafters with his hands

Rafter system - "skeleton" of any roof structure.From the correctness of its manufacture and installation depends directly on the reliability, quality and durability of the roof.If desired, with the arrangement of roof system can be managed independently.Want to know how?Examine the following guidelines!

Rafters with their hands

rafters with his hands

Elements of a roof truss system

elements truss roof system

Species roof systems

Article Contents

  • 1 Species roof systems
    • 1.1 Video - Rafter system
  • 2 design roof system
  • 3 what do rafters?
    • 3.1 Video - roof construction errors
  • 4 Preliminary calculations
    • 4.1 Table 1. Selecting a step rafters, depending on their length and cross section
    • 4.2 Video - Calculation of the rafters with his hands
  • 5 Transform wooden beam in the rafters
    • 5.1 Video - rafter system gable roof
  • 6 assembly Procedure farm
  • 7 Installing truss
  • 8 Video - rafters with their hands.Pent roof
    • 8.1 Video - hip roof.Rafter system

There naslonnye and hanging truss system.Acc

ording to statistics, the most commonly used design naslonnogo type.When constructing such a system rafters abut mauerlat.The function performs a simple central ridge pole.To increase the strength of the beam support system installed.

Variety of roof systems

Species roof systems

The device gable roof truss system

device gable roof truss system

In the case of hanging rafters system design is completed by additional struts, contributing to the optimal distribution of the load over the entire area of ​​the roof structure.

Types of rafters

Types rafters

Production and installation of trusses of both species carried out in the same sequence, but with the features and the differences listed above.

Video - Rafter system

design of roof system

The design of roof system

design of roof system

Any truss system consists of the following major components:

  • rafters.Are mounted parallel to the slopes.Prevent sagging roof structure;
  • run.Is a cross-beams, mounted lengthwise on top;
  • sills and pillars - supporting truss construction girders;
  • braces - components podstropilnoy farms that give additional stability rafters.

    Driving rafters

    scheme rafters

What do rafters?

What do rafters

What do rafters

Node attachment to the beam

assembly mounting to the beam

The most common rafters are made of softwood.It is relatively inexpensive, fairly durable and easy to process material

In the case of independent production rafters best to use bar section 10x10 or 15x15 cm.

Also, when choosing a timber you need to pay attention to its moisture content.The maximum allowable rate - 20%.At higher values ​​of the material will shrink, causing disruption of the entire roofing system configuration.

Video - Errors roof construction

Preliminary calculations

Rafter roof system

Rafter roof system

calculates the optimal length of the rafters.The standard length of products factory production of 450 or 600 cm. If necessary, you can change the length of the rafters.

To determine the optimum cross-section beams need to know the following:

  • length of the rafters;
  • step mounting elements;
  • estimates of future loads.

required information is given in the following table.

Table 1. Selection step installation rafters, depending on their length and cross section

length rafters, m distance between the rafters, see section size timber trusses, see
Up 3 120 8x10
Up to 3 180 9h10
Up to 4 100 8x16
Up to 4 140 8h18
Up to 4 180 9x18
Up to 6 100 8h20
Up to 6 140 10x20

remaining elements of the roof system should have the section:

  • mauerlat - 10x10 or 15x15see also allowed the installation of mauerlat bar section 10x15 cm.;
  • diagonal rafters and valley - 10x20 cm;
  • tightening - 5x15 cm;
  • runs - 10x10, 10x20 cm;
  • struts - 10x10 or 15x15 cm;
  • Hem board - 2,5h10 cm;
  • crossbars - 10x15 or 10x20 cm

    The calculation of the load on the rafters

    Load Calculation of the rafters

Knowing the length and cross section of the rafters, and the step of installation, you can easily calculate the required number of items, focusing on the structure of the length of the wall..

The calculation of roof system

Calculation truss system

addition should be made to the calculation of the rafters sag.That is, you need to learn how rafters can bend until they break.For example, when designing a mansard roof truss design calculation should be done so that the deflection was not more than 1/250 of the length of the section, which is under pressure.

The calculation of roof system


truss system Based on the above, if the line length is 500 cm, the maximum deflection value will be 0.2 cm. The indicator seems insignificant, but in case of exceeding the deflection of the roof will be visually noticeable, and on reliabilitydesign it will affect not the best way.

Rafters pent roof

Rafters pent roof

If possible , designing a house , it is desirable to make the rafter length does not exceed 6 meters

possible, designing a house, it is desirable to make the rafter length does not exceed 6 meters

To determine the length of the rafter use the Pythagorean Theorem

To determine the line length, use the Pythagorean theorem

Calculation section rafters of the roof depends on the material

section Calculation of trusses dependsthe material of the roof

Video - calculation of the rafters with his hands

Transform wooden beam in the rafters

Produce template by which will be carried out further work.Rafters have the same design, so that the template will save you time and energy.

For marking and cutting rafters , use a template

for marking and cutting of trusses using

For marking and cutting rafters , use a template

template for marking and cutting of trusses using

template connects two boards on one edge of the nail.As a result, you should get a design that resembles a pair of scissors.

Making template

Master Making

The circuit pattern

diagram template

Put the free edge of the "scissors" to support the points of the future placement of the rafters.This will determine the slope of the roof slope.

Take an extra pair of nails and fix the angle set between the boards.This template is ready.Additionally fix it crossbeam.To set the angle of slope of the roof slope has not changed under the influence of loads, attach with screws bar.

Be extremely careful when creating the template.Even for the slightest deviation can spoil the whole structure.

Then make a new template for the preparation of installation gouge on the elements of the system.Use plywood thickness of 0.5 cm. To strengthen the use of 2.5-centimeter board.Dimensions gouge selected taking into account cross-section used in the rafters.

With the help of ready-made templates make gouge and begin to collect the farm.

Marking the opposite end of the rafters

Marking the opposite end of the rafters

Marking the opposite end of the rafters

Marking the opposite end of the rafters

The full-size pattern rafters

full-size pattern rafters

Video - Rafter system gable roof

How to assemble the farm

For convenience, you can build a forest

Forconvenience, you can build a forest

design includes support legs and connecting components.Farm resembles a triangle.Perform work in the specified sequence, and finished construction can adequately carry all loads coming.

Installation of ridge beams and rafters first

Set ridge beams and rafters first

Farm can be done on the ground with a further rise of the top or else directly on the roof.The first option is more convenient and simple in execution.

Another rafter in place

Another rafter in place

View installed trusses

View installed trusses

roof trusses assembled in the following order.First, cut the harvested material to a desired size, butted bars upper edges and are fastened with screws.To prevent cracks in the bonding pre-drilled holes in the bars with a diameter slightly smaller than the fasteners.

Installing rafters

Installing rafters

ridge beam

ridge beam

also to connect rafters use the deadbolt.Fixing is done on two feet below the top of the binding elements.Crossbars will enhance the rigidity of the structure and will eliminate the risk of depression.Mounting bolts perform in recesses previously furnished to the rafters by punching.

If necessary, rafters are cut at an angle, especially if it is required to equip the roof structure.

Installing truss

Possible tie- beam trusses in

Options notching the rafters in the beam

measurements and markings hip rafters

Installation of roof trusses is performed in the following sequence:

  • assemble extreme farm;
  • fix the central farm.

Installation extreme farms adhere to the following important rules:

  • base triangle set on mauerlat or the upper frame in the case of arrangement of the wooden structure of the roof;
  • previously done at the base of a few holes for subsequent bonding with log cabins;
  • necessarily control the straightness of the installation of the farm.To do this, we use a plumb line, attached to the girder;
  • base truss anchoring only after the flatness of its installation;
  • to provide additional farm sustainability anchoring jib from log to the rafters.The length is selected according to the situation of fundamental importance, it does not have;
  • before tightening the jib screws again we see the straightness of its placement.
    rafter system

    Rafter system

    Production of the lower belts trusses

    Manufacture lower belts trusses

    Assembling truss

    assembly truss

    Assembling truss

    assembly truss

    Roof trusses are installed in the design position

    Trussed rafters are installed in the design position

Aftercomplete the installation of extreme farms turn to the central fixation and subsequent designs, if their accommodation provided by the project.Optimal farm installation step -. 100 cm

to secure the central rafter of a triangle using temporary jib.After you have installed the visor, jib can be removed.Recommendations for attachment and the rest of the central truss are the same as in the case of extreme designs.

After all the design elements are starting to mount crates and further arrangement of the roofing system: moisture, heat and paroizolirovaniyu, as well as installation of the selected finish.

Frame house with rafters

frame house with rafters

Successful work!

Assembling ridge farm

assembly ridge farm

Installation of ridge farm

Installation ridge farm

Installation of rafters

assembling rafters

Installation of rafters

assembling rafters

Video - rafters with their own hands.Pent roof

Video - hip roof.Rafter system