Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: 1st Term
Week: 11
Age: 15 years
Duration: 45 minutes
Subject: Machine Wood Work
Curriculum Theme: Technology
Previous Lesson: Timber Conversion: Through And Through, Tangential And Quarter Sawing.
Topic: Timber Conversion
Subject Matter: Board sizes, Plank sizes, Scantling sizes, Timber market classification

Specific Objectives

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

Cognitive Domain:

Define timber conversion.
Differentiate between board, plank, and scantling sizes.
List common market classifications for timber.

Affective Domain:

Appreciate the importance of standard timber sizes in woodworking.
Value accuracy when identifying and measuring timber.

Psychomotor Domain:

Identify samples of boards, planks, and scantlings.
State typical dimensions for different timber forms.

Participate actively in group discussions about timber classification.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Senior Secondary Schools.
State Unified Scheme of Work for Senior Secondary School Machine Wood Work.
Introductory Technology for Senior Secondary Schools, Book 1.

Instructional Materials

The teacher will teach this lesson with the aid of:

Samples of boards.
Samples of planks.
Samples of scantlings.
Measuring tape.
Charts showing different timber sizes.

Rationale for the Lesson

This lesson helps pupils understand the different standard sizes of timber used in woodworking and construction. Knowing these sizes is important for selecting the correct materials for various projects and for effective communication in the timber market. It also enables efficient use of wood and reduces waste.

Prerequisite/Previous Knowledge

Pupils should have basic knowledge of different types of timber and an understanding of simple measuring techniques.

Lesson Content/Board Summary

Timber Conversion: Market Sizes

Introduction to Timber Conversion

Timber conversion is the process of cutting logs into usable forms such as planks, boards, and scantlings. This process makes timber suitable for various construction and woodworking purposes.

Board Sizes

Boards are pieces of timber that are generally wider than they are thick. They are commonly used for general carpentry, flooring, and paneling.

Typical dimensions for boards often include:

Thickness: Up to 50mm (2 inches)
Width: More than 100mm (4 inches)
Length: Varies (commonly 2.4m to 4.8m)

Plank Sizes

Planks are pieces of timber that are thicker than boards and often wider. They are used for heavier construction, bridge decking, and robust furniture.

Typical dimensions for planks often include:

Thickness: From 50mm to 100mm (2 to 4 inches)
Width: More than 100mm (4 inches)
Length: Varies (commonly 2.4m to 4.8m)

Scantling Sizes

Scantlings are small pieces of timber, usually square or nearly square in cross-section. They are often used for framing, battens, and light structural work.

Typical dimensions for scantlings often include:

Thickness: Up to 100mm (4 inches)
Width: Up to 100mm (4 inches)
Length: Varies (commonly 2.4m to 4.8m)

Timber Market Classification

Timber is classified in the market based on its converted form and intended use.

The main classifications include:

Logs: Whole tree trunks, usually without branches.
Sawn Timber: Timber that has been cut into various shapes and sizes like boards, planks, and scantlings.
Plywood: Engineered wood product made from thin layers of wood veneer glued together.
Particle Board (Chipboard): Made from wood chips, sawmill shavings, or sawdust, pressed and bound together with resin.
Medium Density Fibreboard (MDF): Made from wood fibres defibrated into fine particles, mixed with wax and resin, and pressed into panels.

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 greets the pupils, checks attendance, and reviews the previous lesson briefly. The teacher then introduces the topic by asking pupils to name different forms in which wood can be bought from the market.
Pupils’ Activity: Pupils respond to the greetings, state forms of wood, and listen attentively.
Learning Point: Pupils are prepared for the new lesson and connect it to their prior knowledge.

Step 2: Explanation of Timber Conversion

Time: 5 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher explains what timber conversion means and its purpose in making wood usable for various applications.
Pupils’ Activity: Pupils listen and take notes, asking questions for clarification.
Learning Point: Pupils understand the basic concept of timber conversion.

Step 3: Explanation of Board Sizes

Time: 7 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher explains what boards are, their typical uses, and their common dimensions. The teacher shows a sample board and demonstrates how to measure its thickness and width.
Pupils’ Activity: Pupils observe the sample, listen to the explanation, and note down the characteristics and dimensions of boards.
Learning Point: Pupils can identify boards and state their typical sizes.

Step 4: Explanation of Plank Sizes

Time: 7 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher explains what planks are, their typical uses, and their common dimensions. The teacher shows a sample plank and highlights the differences in dimensions compared to a board.
Pupils’ Activity: Pupils observe the sample, listen to the explanation, and note down the characteristics and dimensions of planks.
Learning Point: Pupils can identify planks and differentiate them from boards by their typical sizes.

Step 5: Explanation of Scantling Sizes

Time: 7 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher explains what scantlings are, their typical uses, and their common dimensions. The teacher shows a sample scantling and points out its characteristic square or near-square cross-section.
Pupils’ Activity: Pupils observe the sample, listen to the explanation, and note down the characteristics and dimensions of scantlings.
Learning Point: Pupils can identify scantlings and state their typical sizes.

Step 6: Explanation of Timber Market Classification

Time: 7 minutes
Teaching Skill: Discussion/Listing
Teacher’s Activity: The teacher discusses how timber is classified in the market beyond just sawn timber, introducing other forms like logs, plywood, and particle board. The teacher uses charts or diagrams to illustrate.
Pupils’ Activity: Pupils participate in the discussion, ask questions, and list the different classifications of timber.
Learning Point: Pupils understand the broader classification of timber in the market.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

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

What is timber conversion?
Differentiate between a board and a plank, stating typical dimensions for each.
Describe what scantlings are and mention their common dimensions.
List three ways timber is classified in the market.

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 knowing different timber sizes and classifications for practical applications. The teacher assigns homework.
Pupils’ Activity: Pupils listen to the summary and note down the homework.
Learning Point: Pupils consolidate their understanding of the lesson and are aware of further study requirements.

Lesson Keywords

Timber Conversion – The process of cutting logs into usable forms like boards, planks, and scantlings.
Board – A piece of timber generally wider than it is thick, typically up to 50mm thick and over 100mm wide.
Plank – A piece of timber thicker than a board, typically 50mm to 100mm thick and over 100mm wide.
Scantling – A small piece of timber, usually square or nearly square in cross-section, typically up to 100mm thick and 100mm wide.
Sawn Timber – Timber cut into various shapes and sizes for construction and woodworking.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to sketch the different timber sizes with their typical dimensions. For pupils who require more support, the teacher will provide additional visual aids and spend more time explaining the differences between each timber size using the physical samples.

Note for teachers using this lesson plan

Ensure that actual samples of boards, planks, and scantlings are available for pupils to touch and measure. This hands-on experience will significantly enhance their understanding. Encourage active participation and questions throughout the lesson. Emphasize the practical relevance of knowing these classifications in real-world woodworking and construction scenarios.