ROOFS

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• Q1: Define Roof.
  Ans: A roof is the uppermost covering of a building that protects it from rain, sun, wind, and other weather effects.
• Q2: What are the main functions of roofs?
  Ans: Some of the functions are:

  • ➔ Protection from weather
  • ➔ Thermal insulation
  • ➔ Providing shelter and privacy
  • ➔ Supporting building aesthetics
• Q3: To fulfill the main functions, what are the functional requirements to be satisfied by roofs in its design and constructions?
  Ans: Some of the requirements are:

  • ➔ Strength and stability
  • ➔ Weather resistance
  • ➔ Thermal insulation
  • ➔ Durability and economy
• Q4: Define hip roof.
  Ans: A hip roof is a type of sloping roof where all sides slope downwards to the walls, usually with a gentle slope.
• Q5: How are roofs generally classified?
  Ans: Following are the classification:

  • ➔ Flat roofs
  • ➔ Sloping (pitched) roofs
  • ➔ Curved/shell roofs
• Q6: What are the advantages of steel roof truss over timber sloping truss?
  Ans: Following are some advantages:

  • ➔ Stronger and more durable
  • ➔ Fire-resistant and termite-proof
  • ➔ Can cover larger spans
  • ➔ Requires less maintenance
• Q7: Define Gabled roof.
  Ans: A gabled roof has two sloping sides that meet at a ridge, forming a triangular shape at the ends (gables).
• Q8: Define Ridge.
  Ans: The ridge is the horizontal line at the top where two sloping roof surfaces meet.
• Q9: Define Eaves.
  Ans: Eaves are the lower edges of a roof that overhang beyond the wall to throw water away.
• Q10: Define Valley.
  Ans: A valley is the internal angle formed by the intersection of two sloping roof surfaces.
• Q11: Define Purlin.
  Ans: Purlins are horizontal members in a roof that support rafters and roof coverings.
• Q12: Define Rise in roofs.
  Ans: Rise is the vertical distance between the ridge and the wall plate of a sloping roof.
• Q13: Define Sloping Roof.
  Ans: Sloping (pitched) roofs have an inclination greater than 10°, used in areas with heavy rainfall or snowfall.
• Q14: Define Couple cross roof.
  Ans: A couple roofs with cross beams for stability, commonly used in small-span buildings.
• Q15: Define Principal Rafter.
  Ans: Principal rafters are the main inclined members of a truss that extend from ridge to eaves, supporting purlins.
• Q16: Define Collar beam roof.
  Ans: A collar beam roof is a pitched roof where horizontal collar beams are provided between pairs of rafters to resist spreading.
• Q17: What are the advantages of flat roofs?
  Ans: The advantages are:

  • ➔ Can be used as a terrace/play area.
  • ➔ Easy construction and maintenance.
  • ➔ Economical for small spans.
  • ➔ Useful for water tanks and solar panels.
• Q18: What are the disadvantages of flat roofs?
  Ans: The disadvantages are:

  • ➔ Not suitable in heavy rainfall/snow areas.
  • ➔ Poor drainage.
  • ➔ Higher chances of leakage.
  • ➔ Less durable than sloping roofs.
• Q19: Define Dome.
  Ans: A dome is a curved roof structure resembling a hemisphere, used to cover large circular or polygonal spaces.
• Q20: What are the advantages of sloped roofs?
  Ans: The advantages are:

  • ➔ Durability
  • ➔ Efficient Drainage
  • ➔ Thermal Insulation
  • ➔ Aesthetic Appeal
• Q21: What are the disadvantages of sloped roofs?
  Ans: The disadvantages are:

  • ➔ High cost
  • ➔ Complex design
  • ➔ Space limitation
  • ➔ Maintenance difficulty
• Q22: What are the main divisions of dome structures?
  Ans: These are:

  • ➔ Hemispherical dome
  • ➔ Segmental dome
  • ➔ Pointed dome
  • ➔ Onion dome
• Q23: Define jack arch flat roof.
  Ans: A jack arch flat roof is a type of flat roof constructed with small segmental arches of brick or concrete between steel joists.
• Q24: Define shell roof.
  Ans: A shell roof is a thin curved slab (usually RCC) designed to cover large areas with minimal thickness.
• Q25: Define thatch covering.
  Ans: Thatch covering is a roof made of straw, reeds, or palm leaves, commonly used in rural areas.
• Q26: Define shingles.
  Ans: Shingles are small, flat roofing units of wood, slate, asphalt, or other materials, laid in overlapping fashion.
• Q27: Define tile covering.
  Ans: Tile covering is a roof made of clay or concrete tiles placed in overlapping layers for weather protection.
• Q28: Define Cleat.
  Ans: Cleats are some blocks of wood or steel that are fixed on the principal rafters to support purlins.
• Q29: Define King Post Truss.
  Ans: A King Post Truss is the simplest type of truss, consisting of a central vertical post (king post), two diagonal struts, and a horizontal tie beam. It is commonly used for short spans (up to 8 meters).
• Q30: Define Queen Post Truss.
  Ans: A Queen Post Truss is similar to the king post but has two vertical posts (queen posts) instead of one, allowing it to span a longer distance (up to 10 meters).
• Q31: Define Mansard Truss.
  Ans: A Mansard Truss is a roof truss that forms a double-pitched roof with a steep lower slope and a flatter upper slope, creating extra living or storage space.
• Q32: What are the advantages of Shell roofs?
  Ans: The advantages are:

  • ➔ Aesthetic Appeal
  • ➔ Spacious
  • ➔ Load bearing
  • ➔ Light-weight structure
• Q33: What are the disadvantages of Shell roofs?
  Ans: The disadvantages are:

  • ➔ Complex construction
  • ➔ High cost
• Q34: Name some roof covering materials.
  Ans: These are:

  • ➔ Shingles
  • ➔ Thatch
  • ➔ Tiles
  • ➔ Slate