TERM – 1^ST TERM

WEEK NINE

Class: Senior Secondary School 3

Age: 17 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Technical Drawing

Topic: SECTIONING 3

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

I.) Draw the sectional views of a building through the foundation and roof.

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION

TEACHER’S ACTIVITY

STUDENT’S

ACTIVITY

STEP 1

INTRODUCTION

The teacher guide draw the sectional views of a building through the foundation and roof.

Students listens attentively to the teacher and participate actively .

STEP 2

NOTE TAKING

The teacher writes a summarized

note on the board

The students

copy the note in

their books

NOTE

SECTIONING 3

Drawing the sectional views of a building through the foundation and roof.

To draw a section, there are certain graphical and design elements you need to consider.

1.) Scale: The scale used in drawing a section depends on the scale adopted for the floor plan and roof plan. In maintaining scale 1:100, the drawings will be of a uniform scale. For large buildings, the scale can move to 1:200, however, since sections reveal important details of a building, it will be better to use larger scales such as 1:50 or even 1:25 to show more detail (scale is in millimeters).

2.) Line weight: There are a lot of line weights displayed in a section drawing. The walls, floors, beams roof trusses being directly sliced into have the thickest lines. Openings, ceilings, fixtures and other objects visible within the section are drawn in a medium thickness while floor finishing, wall finishes and dimensions are drawn with thin lines.

3.) Textures: are some textures we adopt in drawing sections.

4.) Labelling and Dimensions: Labelling spaces, objects and materials/finishes are important part of sections. We can proceed to add grid lines and dimensions to the section as final touches.

Generating a section

Drawing a section can be very simple, yet complicating. If you do not have a decent understanding of building construction, it might give you a hard time. Nevertheless, we will try and proceed with this in the simplest way possible. Let’s start with Section A-A

1. A simple trick to use when drawing sections is just to rotate the floor plan in the direction of the section line and just project all the lines for the section from the floor plan.

2. Now indicate the levels and height of walls, floors and openings.

3. Repeat the same steps above for the roof.

4. Now that we have a rough outline for the section, lets begin to add in details of the section. starting with the foundation. The foundation comprises of 6 levels. First, we have the foundation footing, followed by the foundation walls. We then reach the hardcore filling level. On top of that we have the wire mesh and damp-proof membrane. Finally, we have the concrete floor. Due to the scale of the drawing, some thin layers might not be visible like the damp-proof membrane and the wire mesh.

5. After the foundation, we have the walls, openings and any visible beam. We have beams at 2 major spots, one above openings referred to as lintel beams and the other where the roof sits on referred to as overhead course beam.

6. Now we proceed to draw out the roof trusses. We already have the outline of the roof shape. To understand how to draw a section of a roof, you first have to know how roofs are constructed. Examine the images below of a roof carcass.

For this design, we cut through the highest point of the roof. Therefore, we will see a traditional king post truss design.

The overall section will look like the image below.

EVALUATION: 1. Sketch the overall section in Section B-B view.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively

Lesson Notes By Weeks and Term - Senior Secondary 3