Site Preparation And Setting Out JSS2 Basic Technology Lesson Note

SITE PREPARATION & SETTING OUT

During site preparation;

1. The center line of the walls is calculated. Then the centre lines of the rooms are set out by setting perpendiculars in the ratio 3:4:5. Suppose the corner points are a, b, c, d, e, f, and g which are marked by pegs with nails on top.
2. The setting of the corner point is checked according to diagonals ac, bd, cf, and eg.
3. During excavation, the centre points a, b, c, d, e, f, and g may be removed. Therefore the centre lines are extended and the centre points are marked about 2m away from the outer edge of the excavation.

     Thus points A1, A2, B1, B2, and likewise, are marked outside the trench. Centre lines are shown clearly by stretching thread or rope. The centre points fixed 2m away from the excavation         are marked with sit-out pegs.

4. From the plan details, the width of excavation to be done is also marked by thread with pegs at appropriate positions.
5. The excavation width is then marked by lime or by a furrow with spades.
6. If the plan is much too complicated and follows a zigzag pattern, then the centre pegs are kept at suitable positions according to site conditions.

QUESTIONS

1. What is site preparation
2.         List 5 tools used for site preparation