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:
- 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;
- racking back: it is a provision made on wall to allow for future continuation ofthe wall.
- 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)