Lecture 15: Elements Of Roof Truss PDF

BUILDING DESIGN & DRAWING 11241104 BY GAUTAM BHADORIYA ASSISTANT PROFESSOR CED,MITS,GWALIOR  Types of Roof Truss OBJECTIVE OF THIS LECTURE To understand roof truss, types and suitability, materials use for roof truss with their...

BUILDING DESIGN & DRAWING 11241104 BY GAUTAM BHADORIYA ASSISTANT PROFESSOR CED,MITS,GWALIOR  Types of Roof Truss OBJECTIVE OF THIS LECTURE To understand roof truss, types and suitability, materials use for roof truss with their suitability in building. Prof: Gautam Bhadoriya CED, MITS GWALIOR  Types of Roof Truss COURSE OUTCOMES After completion of this lecture, the students will be able to: CO1: Explain the basic elements of buildings, engg. materials & construction. CO3: Distinguish the suitability of building materials in the construction of elements of buildings. Prof: Gautam Bhadoriya CED, MITS GWALIOR  Roof A roof is the uppermost parts of any building which give protection against animals, and most especially weather, be it rain, snow, sunlight, heat, wind and so on. A roof also beautify a house but the primary purpose of a roof is to protect against any form of weather. Types of pitched Roof: 1. Single roofs 2. Double or purlin roofs 3. Trussed roofs Prof: Gautam Bhadoriya CED, MITS GWALIOR  Roof Requirements of a good Roof: 1. Durability 2. Desirable insulation 3. Structurally stable 4. Well drained 5. Water proofing arrangement 6. Fire resistive Prof: Gautam Bhadoriya CED, MITS GWALIOR  Types of pitched Roof 1. Single roofs : In this types of roof the common rafters are provided to each slope without any intermediate support. Lean to roof Couple roof Couple close roof Collar beam roof Collar and scissors roof Prof: Gautam Bhadoriya CED, MITS GWALIOR  Types of pitched Roof Lean to roof : this is the simplest from of a pitched roof, In this types of roof one wall is carried up sufficiently higher than the other one to give necessary slope to the roof. Span maximum upto 2.40m Prof: Gautam Bhadoriya CED, MITS GWALIOR Types of pitched Roof Prof: Gautam Bhadoriya CED, MITS GWALIOR  Types of pitched Roof Couple roof: In this types of roof the common rafters slope upword from the opposite walls and they meet on a ridge peace in the middle. Prof: Gautam Bhadoriya CED, MITS GWALIOR Types of pitched Roof Prof: Gautam Bhadoriya CED, MITS GWALIOR  Types of pitched Roof Couple close roof: this types of roof is just similar to couple roof except that the legs of the common rafters are connected by a tie beam. Span upto 4.20m. Prof: Gautam Bhadoriya CED, MITS GWALIOR Types of pitched Roof Prof: Gautam Bhadoriya CED, MITS GWALIOR  Types of pitched Roof Collar beam roof Prof: Gautam Bhadoriya CED, MITS GWALIOR  Types of pitched Roof Collar Scissors roof Prof: Gautam Bhadoriya CED, MITS GWALIOR  Types of pitched Roof Double or Purlins roofs Prof: Gautam Bhadoriya CED, MITS GWALIOR THE COMPONENTS OF A ROOF TRUSS WALL PLATE / BEARING TIE BEAM / BOTTOM CHORD RAFTER / TOP CHORD WEBS PURLINS / BATTENS APEX CANTILEVER CLEAR SPAN HEEL JOINTS NAIL PLATE OVERHANG Prof: Gautam Bhadoriya CED, MITS GWALIOR THE COMPONENTS OF A ROOF TRUSS 1 WALL PLATE / BEARING The first timber to be placed, it’s always horizontal and it’s placed at top of the external walls. Structural support of trusses (usually walls) normally with a timber wall plate. 2 TYE BEAM / BOTTOM CHORD Almost same as wall plate, but it’s not place on the wall it’s most time 1.2m apart, purposely use for the placement of ceiling. Horizontal along the spacing of the building. The tie beam is place after the wall plate. 3 RAFTER / TOP CHORD The rafter is in slant form always from one edge of the wall plate to another all meeting at the top of the key post. It’s also most time 1.2m apart. 4 WEBS Members that join the top and bottom chords to form a triangular pattern. Prof: Gautam Bhadoriya CED, MITS GWALIOR THE COMPONENTS OF A ROOF TRUSS 5 PURLINS / BATTENS It’s always been the last. It is put horizontally across the rafter. Which is most time 0.9m apart. 6 APEX Highest point where the sloping top chords meet. 7 CANTILEVER Part of structural member that extends beyond its support. 8 CLEAR SPAN Horizontal distance between interior edges of supports. 9 HEEL Point on a truss which top and bottom chord intersect. 10 JOINTS Point of intersection of one or more web(s) with a chord. 11 NAIL PLATE Galvanized steel plate punched to form a nail pattern integral with the plate and used to connect timber members. 12 OVERHANG Prof: Gautam Bhadoriya CED, MITS GWALIOR  CONCLUSION After completion of this lecture , the students will be understand about the roof truss & suitability. Prof: Gautam Bhadoriya CED, MITS GWALIOR  Questions 1. What are the types of pitched roof ? 2. Draw the neat sketch of the various types pitched roof. Prof: Gautam Bhadoriya CED, MITS GWALIOR THANK YOU