Observation

Most candidates were able to:

• define the term timber conversion;
• state two reasons for converting timber;
• state two reasons why a carpenter would prefer to use green timber to seasoned timber for formwork construction.

However, some candidates were unable to:

• Make a correct sketching of a through mortise and tenon joint in pictorial view.
• State one specific application of a through mortise and tenon joint in joinery.

The expected response to question 8 is as given below:
8.  a)        

(i)         Timber conversion – is the cutting of logs into commercial sizes.

(ii)         Two reasons of converting a timber:

• to make timber available to suit various wood users.
• for easy transportation of timber;
• to get structural sound of pieces of timber;
• To get physically attractive pieces of timber;
• To remove some timber defects;
• For quick drying of timber.

b)         Two reasons for using green timber for formwork:

• Easier penetration of nails;
• It reduces absorption of water from concrete.

(ii)         One specific application of through mortise and tenon joint.

• between jamb and the head of door and window frames;
• between stiles and rails of paneled doors;
• between muntin and rail of paneled doors/windows;
• in construction of kitchen cabinet.