ROOF - Building Materials short notes and previous year questions

ROOF

• Heavy rainfall / snowfall : sloped roof 
• Normal rainfall : flat roof 
• Architectural : curved roof 

TERMS 

1. WALL PLATE : transfer load from inclined member to vertical column 

2. TEMPLATE : distribute the load over a larger area 

3. HIP : if external angle > 180 

4. VALLEY : if external angle < 180 

5. PRINCIPLE RAFTERS : carries entire load of truss or roof 

6. COMMON RAFTERS : carries load of roof covering materials 

7. HIP RAFTER : rafter connecting hip points 

8. VALLEY RAFTER : rafter connecting Valley points 

9. JACK RAFTER : rafter smaller than common rafter 

10. VERGE : edge of the gable in a pitched roof 

11. BARGE BOARD : wooden plank connecting eaves board and ridge



KING POST TRUSS  
• Span 5 - 8 m 
• Pitch 30 - 40 
• King post carries tension loads 
• Struts carry compression loads 
• Joint connecting principle rafter and king post : mortice and Tenon joint 

QUEEN POST TRUSS
• Span 8 - 13 m 
• Pitch 60 - 70 
• Queen post carries tension load 
• Struts carry compression loads 
• Straining beam carry compression loads



STEEL TRUSS 
• Span > 12m 
• Economical & safe 
• In compression member spacing of rivet : 15 cm 
• In tension member 20 m 

MANSARD TRUSS ( 18 M ) 
• Lower part : queen 
• Upper part : king

BELFAST/BOWSTRING/LATTICED ROOF (30M) 
• Central rise : 1/8 span

COMPOSITE ROOF 
• Combination of steel, timber, iron etc



PREVIOUS YEAR REPEATED QUESTIONS BASED ON ROOF 


Comments

Post a Comment

Popular posts from this blog

UNITS OF MEASUREMENTS, PAINTING COEFFICIENT, OUT TURN, QUANTITY CALCULATION

Image
  DEDUCTION  • MASONRY : < 0.1 m2 - no deduction  • PLASTERING :  < 0.5 m2 - no deduction  0.5 - 3 m2 - one side deduction  > 3 - both side deduction  • End of beams, rafters, purlins < 0.05 m2 - no deduction  • Bearing of floors, roof slabs etc. - no deduction DIGREE OF ACCURACY  • Volume - 0.01 m3  • Area - 0.01 m2  • Dimension - 0.01 m  • Weight - 1kg  QUANTITY CALCULATION  PCC  • Maximum size of aggregate 40 mm  • For 1 m3 PCC - 0.95 m3 coarse aggregate is required  RCC  • Maximum size of aggregate 20 mm  • For 1m3 RCC - 0.90 m3 coarse aggregate is require  RCC For 1:1.5:3  Wt of cement = (1/3) x 0.90 x 1440 = 432 kg  Wt of sand = (1.5/3) x 0.90 x 1600 = 747 kg  PCC For 1:4:8  Wt of cement = (1/8) x 0.95 x 1440 = 171 kg  Wt of sand = (4/8) x 0.95 x 1660 = 760 kg PLASTERING  1:3 - 0.14 m3 / 10 m2 (sand) cement = (1/3) x 0.14 x 1440 = 67 kg...
Read more

SCAFFOLDING, SHORING, UNDER PINNING

Image
• When height above floor level exceeds 1.5 m a temporary structure is erected for a safe working platform for worker and space for materials  TERMS  1. STANDARDS : vertical members of framework, supported on the ground  2. LEDGERS : horizontal members // to the wall  3. PUTLOGS : transverse members, one side supported on ledgers & other on wall  4. TRANSOM : both the edges are supported on ledgers  5. BRACES : diagonal pieces fixed on standards  6. BRIDLE : a piece used to bridge an opening to walls and support putlog  7. GUARD RAIL : rail parallel to ledgers at working level for safety  8. TOE BOARD : board placed // to ledger & supported by putlogs  9. RAKERS : inclined support  TYPES OF SCAFFOLDINGS  1. SINGLE / PUTLOG / BRICKLAYER SCAFFOLDING  • Most common type  • Mostly used in brickwork  • Spacing b/w standards : 2 - 2.5 m  • Vertical distance b/w ledgers : 1.2 - 1.8 m  • Horizont...
Read more