building construction Paper 2 May/June 2015

Question 3

  1. a)   State three advantages of a pitched roof over a flat roof.

b)   List five major operations involved in hanging a wooden door to an existing frame in a  
sandcrete blockwall.
c)   Define the following in relation to wall construction:

  • racking back;
  • toothing.
  •  

    Observation

    Most candidates were able to:

  • state the advantages of pitched roof over flat roof;
  • define the terms toothing and racking back.
  • However, few candidates were unable to:

    • list the five major operations involved in hanging a wooden door to an existing frame in a sandcrete blockwall correctly.
    • The expected response to question 3 is as given below;

    • advantages of pitched roof over a flat roof:
    • better thermal insulation;
    • adequate ceiling space for accommodation of services facilities;
    • provides better eaves overhangs to protect the external walls from weather elements;
    • adequate roof drainage;
    • more aesthetics;
    • better sound insulation.
    •  

    •  Five major operations involved in hanging a wooden door to existing  frame:
    • trim the door to fit the opening;
    • provides clearance with a wedge;
    • mark and cut the position of lock/handle/knob;
    • mark and cut the position of hinges;
    • fix the hinges to the door and frame
    • fix the lock.
    • check the door for free movement.
    • Definition of the terms:
    • Racking back -  provision for future extension in which each course of the wall is set back.           
    • Toothing -          the recesses formed in alternate courses of a wall to facilitate future extension.
    •