Class: Senior Secondary School 2 (SS2 / SSS 2)
Term: 3rd Term
Week: 10
Age: 16 years
Duration: 45 minutes
Subject: Technical Drawing
Curriculum Theme: Building Construction / Architectural Drawing
Previous Lesson: Details of Parts of Buildings: Foundations, Walls, Floors and Lintels.
Topic: DETAILS OF PARTS OF BUILDINGS
Subject Matter: Roof types (pitch roof, gable roof, hipped roof), roof members (rafters, wall plates, king post, purlins)

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Define different types of roofs.
Identify various roof members used in building construction.
State the function of each roof member.

Affective Domain:

Appreciate the importance of correct roof design and construction.
Show interest in learning technical terms related to building structures.

Psychomotor Domain:

Draw simple representations of pitch, gable, and hipped roofs.
Sketch common roof members such as rafters, wall plates, and king posts.

Collaborate effectively during practical drawing sessions.
Discuss and share ideas about different roof designs.

Reference Materials

The following resources were used in planning this lesson:

Senior Secondary Schools Education Curriculum
State Unified Scheme of Work
Akinola, O. (2018). Technical Drawing for Senior Secondary Schools. Ibadan: University Press PLC.
https://www.youtube.com/watch?v=example-roof-types
https://www.archisoup.com/architecture-guides/roof-types

Instructional Materials

The teacher will teach this lesson with the aid of:

Diagrams of various roof types and members.
Actual models or pictures of different roofs.
Drawing instruments (T-square, set squares, pencils, drawing sheets).
Chalkboard/Whiteboard.

Rationale for the Lesson

This lesson helps pupils understand the structural components of buildings, specifically roofs. It enables them to identify and draw different roof types and their members, which is essential knowledge for future studies in architecture, engineering, and construction trades.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of building components and fundamental technical drawing skills.

Lesson Content/Board Summary

DETAILS OF PARTS OF BUILDINGS

Roof Types

A roof is the covering on the uppermost part of a building, providing protection from weather elements. Different roof types are chosen based on aesthetics, climate, and structural considerations.

The following are common roof types:

Pitch Roof: This is a roof with a slope or pitch, typically consisting of two sloping sides that meet at a ridge. It is effective for shedding rainwater.
Gable Roof: A type of pitched roof with two sloping sides that form a triangular shape at each end, called a gable. It is one of the most common and simplest roof designs.
Hipped Roof: A roof type where all sides slope downwards to the walls, usually with a gentle slope. It has no vertical ends or gables.

Roof Members

Roof members are the individual structural components that make up the framework of a roof, supporting the roof covering and transferring loads to the walls.

The following are key roof members:

Rafters: These are sloping structural timbers or steel beams that extend from the wall plate to the ridge, forming the main support for the roof covering. They are typically shown as parallel lines in a section drawing.
Wall Plates: These are timbers laid horizontally along the top of the walls, providing a bearing surface for the rafters and distributing the roof load evenly over the wall. They are usually represented as a rectangular section on top of the wall.
King Post: A vertical compression member that extends from the apex (ridge) of a truss down to the tie beam. It helps to support the ridge and prevent the tie beam from sagging. In drawings, it appears as a central vertical member in a truss.
Purlins: Horizontal beams that span between roof trusses or rafters, providing intermediate support for the common rafters or roof covering. They are often shown as rectangular sections supporting rafters.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher introduces the lesson by asking pupils about the different parts of a building they know and specifically what covers the top of a building.
Pupils’ Activity: Pupils respond by mentioning various parts of a building and identify the roof as the top covering.
Learning Point: Pupils recall previous knowledge and are introduced to the lesson topic.

Step 2: Explanation of Roof Types

Time: 10 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains different roof types (pitch, gable, hipped) using diagrams and visual aids, highlighting their unique features.
Pupils’ Activity: Pupils observe the diagrams, listen to the explanations, and ask questions for clarification.
Learning Point: Pupils understand the characteristics of various roof types.

Step 3: Drawing Roof Types

Time: 10 minutes
Teaching Skill: Demonstration/Practical Activity
Teacher’s Activity: The teacher demonstrates how to draw simple representations of pitch, gable, and hipped roofs on the board, guiding pupils on key lines and angles.
Pupils’ Activity: Pupils practice drawing these roof types on their drawing sheets, following the teacher’s demonstration.
Learning Point: Pupils develop practical skills in sketching different roof forms.

Step 4: Explanation of Roof Members

Time: 7 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher explains the function and appearance of various roof members (rafters, wall plates, king post, purlins) using detailed diagrams.
Pupils’ Activity: Pupils identify the different members in the diagrams and listen to their functions.
Learning Point: Pupils learn about the individual components that form the roof structure.

Step 5: Drawing Roof Members

Time: 8 minutes
Teaching Skill: Demonstration/Practical Activity
Teacher’s Activity: The teacher demonstrates how to sketch individual roof members and their arrangement in a typical roof section.
Pupils’ Activity: Pupils practice drawing the roof members on their drawing sheets.
Learning Point: Pupils acquire the skill to represent roof members graphically.

Step 6: Review of Drawings

Time: 5 minutes
Teaching Skill: Feedback/Correction
Teacher’s Activity: The teacher moves around the classroom, inspecting pupils’ drawings and providing constructive feedback and corrections where necessary.
Pupils’ Activity: Pupils make corrections to their drawings based on the teacher’s feedback.
Learning Point: Pupils refine their drawing skills and correct errors.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define a roof.
List three types of roofs.
Mention two common roof members.
Describe the function of a rafter in a roof structure.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, emphasizing the importance of understanding roof details in technical drawing. The teacher assigns homework.
Pupils’ Activity: Pupils listen attentively and copy the homework assignment.
Learning Point: Pupils consolidate their learning and are given tasks for further practice.

Lesson Keywords

Roof – The covering on the top of a building.
Pitch Roof – A roof with a slope.
Gable Roof – A pitched roof with two sloping sides forming a triangle at each end.
Hipped Roof – A roof where all sides slope downwards to the walls.
Rafters – Sloping beams that support the roof covering.
Wall Plates – Horizontal timbers on top of walls supporting rafters.
King Post – A central vertical member in a roof truss.
Purlins – Horizontal beams supporting rafters or roof covering.

Differentiation

For pupils who grasp the concepts quickly, advanced tasks like drawing a detailed roof section showing multiple members can be provided. For pupils needing more support, the teacher can provide pre-drawn outlines for tracing or focus on identifying parts rather than drawing them from scratch.

Note for teachers using this lesson plan

Ensure that all pupils have access to appropriate drawing instruments. Encourage neatness and accuracy in drawings. Use real-life examples or pictures of local buildings to make the lesson more relatable. Emphasize the practical application of understanding roof details in construction.