Block laying Paper 2 WASSCE (SC), 2019

Question 4

(a)    State the purpose of each of the following in relation wall construction:

          (i)         arch;
          (ii)        racking back;
          (iii)       indent.


(b)    (i)   Sketch a section through a concrete raft foundation.
(ii)  State the main reason for the choice of foundation in 4 (b) (i).

(c)   List three materials used for stair construction.

Observation

Most candidates were able to:


  • Sketch a section through a concrete raft foundation;
  • List three materials used for stair construction;

However, Majority of them were unable to State the purpose of each of the following in relation wall construction:
-           arch;
-           racking back;
-           indent.        


The expected response to question 4 is as given below:

4  ( a)   Purpose of each of the following in relation to wall construction:


  1. arch:
    • it is used for bridging an opening in a wall;
    • it is used to support the portion of the wall above the opening;
    • it gives an aesthetic effect/purpose;
  2.  racking back: it is a provision made on wall to allow for future continuation ofthe wall.


  3. indent: it is a provision on a wall made to allow for partition or a gap made on a wall for building a new wall.

(b)  (i) A section through a concrete raft foundation:

(ii) Main reason for the choice of foundation in (b)i

it is suitable in areas where the soil is soft or made-up ground or waterlogged.


(c)    Materials used for stair construction:


  • concrete;
  • timber;
  • stone;
  • plastic;
  • glass;
  • metal (steel, aluminum)