Class: Junior Secondary School 3 (JSS3, JSS 3)
Term: 1st Term
Week: 4
Age: 14 years
Duration: 45 minutes
Subject: Basic Science And Technology
Curriculum Theme: Basic Technology
Previous Lesson: Conversion and Seasoning of Wood
Topic: Processing of Wood (Part 3)
Subject Matter: Manufactured Board, Defects, Preservation.

Specific Objectives

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

Cognitive Domain:
(a) Identify different types of manufactured boards.
(b) Explain common wood defects and their causes.
(c) State methods of preserving wood.
Affective Domain:
(a) Appreciate the need for proper handling and preservation of wood.
Psychomotor Domain:
(a) Demonstrate simple ways of preventing defects and preserving wood samples.
Social Domain:
(a) Participate actively and cooperatively during group discussions and demonstrations.

Reference Materials

The following resources was used in planning this lesson:

9 Years Basic Education Curriculum
Lagos State Unified Scheme of work for Junior Secondary Schools
Carib Teak – Wood Defects Glossary
Relevant Textbooks

Instructional Materials

The teacher will teach this lesson with the aid of:

Samples or pictures of manufactured boards (plywood, particle board, blockboard)
Diagrams showing wood defects
Wood preservatives (paint, oil, varnish)
Charts showing causes of wood defects
A piece of untreated and treated wood for comparison

Rationale for the Lesson

This lesson enables pupils to understand how wood is processed into useful boards, recognize common defects, and learn preservation techniques that improve durability and quality.

Prerequisite/Previous Knowledge

Pupils have learned about natural wood and its processing stages in previous lessons. They can identify types of timber and basic wood conversion methods.

Lesson Content/Board Summary

Processing of Wood

Manufactured Boards

Manufactured boards, also called engineered wood, are materials made by binding or joining wood pieces, veneers, or fibers together using adhesives or pressure to form larger, stronger sheets.

The following are the main types of manufactured boards:

Plywood: Made from thin layers (veneers) of wood glued together with grains at right angles for strength.
Blockboard: Made from strips of softwood sandwiched between veneers of hardwood.
Particle Board (Chipboard): Produced by compressing wood chips or particles with resin.
Fibreboard: Made from wood fibers bonded together under heat and pressure.
Hardboard: A dense board made from highly compressed wood fibers.

These boards are widely used in furniture making, construction, and interior design due to their strength and smooth surfaces.

Defects in Wood

Wood defects are faults or imperfections that reduce the quality, strength, or appearance of wood. They can occur naturally or during processing and storage.

The following are common defects in wood:

Knots: Circular imperfections where branches were attached to the tree.
Warping: Bending or twisting caused by uneven drying.
Splits and Checks: Cracks caused by shrinkage during seasoning.
Decay or Rot: Damage caused by fungi or dampness.
Insect Attack: Holes and tunnels made by termites or borers.
Shake: Separation between growth rings due to stress or aging.
Stain: Discoloration caused by fungi or chemical reaction with metals.

Defects can reduce the strength, appearance, and value of wood products.

Preservation of Wood

Preservation of wood involves applying treatments to protect it from damage caused by moisture, insects, fungi, and decay. This increases its lifespan and maintains its quality.

The following are methods of wood preservation:

Painting or Varnishing: Coating the surface to prevent moisture penetration.
Oil Treatment: Applying linseed oil or similar products to protect from water and insects.
Creosote Treatment: Using chemical preservatives to protect wood from rot and termites.
Seasoning: Properly drying the wood to remove moisture and prevent warping.
Tar or Bitumen Coating: Applying a thick coating for outdoor uses like poles and fences.
Storage Under Shade: Protecting timber from rain and sunlight during storage.

Proper wood preservation ensures longer use and reduces maintenance costs.

Teaching Methods/Instructional Techniques:

Discussion, Lecture, Explanation, Demonstration, Question and Answer, Visual Aids, Group Work

Instructional Procedures

To deliver this lesson, the teacher will adopt the following steps:

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher displays different wood samples and asks pupils to recall how natural wood is processed.
Pupils’ Activity: Pupils respond and identify types of wood seen before.
Learning Point: Pupils recall previous lessons on wood processing and prepare for the new topic.

Step 2: Manufactured Boards

Time: 10 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher explains the concept of manufactured boards and shows examples of plywood, blockboard, and particle board.
Pupils’ Activity: Pupils observe samples, touch, and compare textures.
Learning Point: Pupils identify different types of manufactured boards and their features.

Step 3: Wood Defects

Time: 10 minutes
Teaching Skill: Discussion
Teacher’s Activity: The teacher discusses various wood defects, shows images, and explains their causes.
Pupils’ Activity: Pupils describe observed defects and discuss their possible causes.
Learning Point: Pupils understand types and causes of wood defects.

Step 4: Wood Preservation

Time: 10 minutes
Teaching Skill: Demonstration
Teacher’s Activity: The teacher demonstrates how to apply oil or paint as wood preservatives and explains their uses.
Pupils’ Activity: Pupils participate in applying oil or paint under supervision.
Learning Point: Pupils learn basic methods of preserving wood.

Step 5: Note-Taking

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher dictates or writes the board summary for pupils to copy.
Pupils’ Activity: Pupils copy the notes neatly into their notebooks.
Learning Point: Pupils have accurate written records of the lesson.

Step 6: Evaluation/Review

Time: 3 minutes
Teaching Skill: Questioning
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Mention three types of manufactured boards.
List any three common defects in wood.
State three methods of preserving wood.
Pupils’ Activity: Pupils answer the questions orally and in writing.
Learning Point: Pupils demonstrate understanding of the lesson objectives.

Step 7: Conclusion

Time: 2 minutes
Teaching Skill: Reinforcement
Teacher’s Activity: The teacher summarizes key points and advises pupils to observe preserved wood around their environment.
Pupils’ Activity: Pupils listen and ask final questions.
Learning Point: Pupils appreciate the importance of proper wood preservation.

Lesson Keywords

Manufactured Board – wood material formed by combining pieces or fibers with glue or pressure.
Defects – faults or imperfections in wood that reduce quality.
Preservation – treatment to protect wood from damage and decay.
Warping – bending or twisting of wood during drying.
Creosote – chemical substance used to preserve wood from insects and rot.

Differentiation

Teacher simplifies explanations for slower learners using real samples, while faster learners lead demonstrations and identify additional examples.

Note for teachers using this lesson plan

Ensure students handle samples safely. Emphasize real-life applications such as furniture, carpentry, and construction. Demonstrate preservation techniques in an open, ventilated area.