Most candidates were able to:

-           sketch the conventional symbol for the given electrical installation
            fittings;
-           state the functional requirements of a drainage scheme.

However, few candidates were unable to

-           explain the causes of accident during roof construction;
-           state the precautionary measures to be observed when operating a
            concrete mixer. 

The expected response to question 5 is as given below:

(a)      

(b)       Functional requirements of a drainage scheme are:

1. Must be constructed of sound materials.
2. Must have adequate gradient.
3. Must be self-cleansing.
4. Must have means of access for inspection and maintenance.
5. Must have airtight/water tight joint.
6. Must have unobstructed bore.
7. Must be well ventilated.
8. Should prevent back siphonage and built up of explosive gas.

(c)        Causes of accident during roof construction are:

1. Use of inferior materials for its construction.
2. Improper erection of scaffolding.
3. Roof pitch being too steep.
4. Unstable scaffold.

(d)       Precautionary measures to be observed

            -           ensure the protective guard of the mixer is in place
            -           operator must wear nose mask, hard boots, helmet and overall
            -           machine must be in good working condition
            -           machine must be operated by competent person
            -           capacity of mixer must not be exceeded
            -           to be cleaned and oiled after use.