Most candidates were able to state the reasons for preserving timber. However, they failed to:
- state the reasons for using widening joints;
- sketch loose tongue and groove joints
- name the timber suitable for making the given items for specific purposes.
The expected response to question 2 is as given below:
2(a) Reasons for preserving timber
- to prevent insect attack
- to prevent fungi attack
- to protect the timber from other wood destroying agents
- for durability
- to prevent distortion in timber (e.g. cupping, warping)
- to prevent the timber from deterioration.
(b) (i) Reasons for using widening joints
- to obtain wider boards
- to obtain stable boards
- to enhance surface decoration
(ii) Sketch of loose tongue and groove joint
(c) Suitable timber
- Mahogany, teak, walnut(cedar), mansonia, afromosia
- Iroko, teak, abura, kusia, danta
- Obeche, silk wood/cotton tree
- Iroko,abura, teak.