Hip The hip roof has four sloping sides. Bearing A structural support, usually a wall, that occurs at the top or bottom chord or between the end points of a roof or floor truss. Download Download PDF. Maximum truss span 16 m. In-depth construction photographs by the author are complemented by. The ITC-SA ensures that prefabricated nail-plated timber trusses are manufactured according to set standardsRoof trusses are made up of three components: the. The truss pdf , Truss design examples based on the design strengths of the new IIW Abutments, sawn timber trusses and other ebezpieczni.
A truss-frame consists of a roof truss and a floor truss joined by exterior wall studs. Timber Roof Trusses" publication. Light weight for ease of. Crescent roof trusses 3. The demo version comes with many feature restrictions, e. A gable roof has a ridge at the center and slopes in two directions. If you think back to your early geometry classes, you might remember that the pitch of a triangle is the rise over the run. Palludo et al. Triangular Roof Trusses: These contain the most common types of trusses used for building.
Stubbed DUO with raised ends in support areas is used at higher loads because this design is able to withstand higher roofing and snow loads than DUO timber trusses.. It builds on knowledge and skills acquired through training, both off and on-site. Solved Example. Offering numerous custom design options, our trusses present an economical and struc-turally superior method for rapid erection.
In most cases the fastening of timber to timber requires little skill or knowledge of design. It is the strongest type of roof because it is braced by four hip rafters. Roof trusses come in all shapes and sizes to suit almost every single design of roof, and are the large wooden members that comprise the framework of the roof and give it its strength.
The top chords are straight. Metal plate connected trusses are used to create arches of all types. Tailor Made Designs Ltd manufacture timber roof trusses for individuals, builders and developers for use in builds ranging from small domestic extensions to large commercial projects. Hundreds of steel structures have been observed, analyzed and appraised for this book. Truss centres, cladding material and design wind velocities should all be in accordance with the truss design data given on relevant design drawings or MiTek Software output.
Truss design is facilitated by the use of computer software that designs all truss members and connections and produces a design drawing with all the essential truss information. COM 2.
Roof covering [EGA sheet design] The roof system of this project is a truss roof system. The type of sheet used is EGA sheet and the trusses and purlins are steel. COM For the distributed load 2. For 1. RT with a wall thickness of 3. COM 4. Load of chip wood per 1. COM Note: with the same procedures shown above for the main truss, the inner and outer joint loads and the member forces for trusses 1 was computed and prepared in table format as shown below.
COM Fo the above load, we have taken a square tube of section index ST section, consequently, the truss analysis was carried using sap software, and the following result was obtained. So the section is obviously safe!
Download PDF. The nodes in roof trusses are assumed to be pinned joints for purposes of analysis. Hence, the roof truss members are not subjected to any bending as the loads through the purlins are transmitted at the pinned joints.
They are subjected only to axial loads, compressive or tensile. The roof trusses are normally supported at their ends on columns steel or reinforced concrete or masonry walls. Steel base plates are used for transferring the loads from the truss to the support. One of the base plates is fixed and the other is of sliding type, representing a fixed hinged support and a roller support respectively for statical calculations.
The truss is analysed by using the principles of statics as laid out in Section 2. You are required to go through it once again before proceeding in this unit. After determining the forces in the truss members they are designed as tension or compression members as the case may be. The purlins are designed as flexural members. There are various terms, as given below, having special meaning when used in context of roof trusses. These terms are explained here. It is the horizontal distance between supports of the truss.
When supported on wall bearings, the distance centre to centre of bearings is the span. In case of trusses framed into supporting steel columns, the clear distance between the column faces is the actual span Figure 8. The vertical distance between the apex and the line joining the support is the rise of the truss.
The roof pitch depends upon the rain or snow which falls on the roof and has to be drained off. The pitches are steeper in areas of greater rainfall or where snowfall takes place. It also depends upon the nature of roof cladding used Table 8. Slope Slope of the roof is the angle which the inclined roof surface makes with the horizontal and may be expressed in terms of degrees or as 1 vertical to x horizontal 1 V : x H.
Thus, value of slope is numerically twice that of pitch. The spacing of trusses is the distance centre to centre between adjacent trusses. This may vary between 4 m to 10 m depending upon their size. It is the line joining the lowest point of the roof trusses, on either side, where the drained water is collected and lead to rainwater pipes.
The uppermost line of members extending from the eaves to the ridge is the top chord. It is also called the principal rafter.
The lowermost line of members extending from support to support is known as the bottom chord. It is also known as main tie. The point where more than one member meet; they are usually connected to a gusset plate by means of welds or rivets; and are known as welded or riveted joints.
0コメント