Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 3rd Term
Week: 2
Age: 15 years
Duration: 45 minutes
Subject: Building Construction
Curriculum Theme: Building Construction
Previous Lesson: Ground Floor: Functions and Types of Floors.
Topic: Ground Floor: Functional Requirements and Floor Production
Subject Matter: Functional requirements of ground floor, preparation of base, damp proof considerations, mixing and laying concrete, leveling and finishing, basic curing ideas.

Specific Objectives

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

Cognitive Domain:

Define a ground floor.
State at least three functional requirements of a ground floor.
Outline the steps involved in the preparation of the ground floor base.
Explain the importance of damp proof considerations in ground floor construction.
Describe the process of mixing and laying concrete for a ground floor.
List at least two methods of leveling and finishing a concrete floor.
Mention two basic ideas for curing a concrete floor.

Affective Domain:

Appreciate the importance of proper construction techniques for ground floors.
Develop an interest in practical aspects of building construction.

Psychomotor Domain:

Sketch a simple cross-section of a ground floor showing key layers.
Demonstrate, in a simulated environment, the basic steps of concrete mixing and laying.

Collaborate effectively during group discussions and practical demonstrations.
Communicate ideas clearly regarding the production of ground floors.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Basic Technology (JSS 1-3).
State Unified Scheme of Work for Senior Secondary Schools.
Building Construction for Senior Secondary Schools by E.K. Obianyo.
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.build-review.com/wp-content/uploads/2020/08/Building-Construction.pdf&ved=2ahUKEwjT7p-E9_aEAxXqPUQIHZ6zC2cQFnoECBIQAQ&usg=AOvVaw0_oK4G0-N-pQz4Z3Q0y2z4
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.concrete.org.uk/fingertips-nuggets/What-is-concrete.asp&ved=2ahUKEwjT7p-E9_aEAxXqPUQIHZ6zC2cQFnoECBQQAQ&usg=AOvVaw3V3sP2L0Y_wQ6n7b-m0Q0N

Instructional Materials

The teacher will teach this lesson with the aid of:

Spirit level
Trowel
Head pan
Lines
Straight edge
Wooden float
Samples of cement, sand, and gravels
Diagrams or charts illustrating ground floor construction.

Rationale for the Lesson

This lesson helps pupils understand how the ground floor of a building is constructed and why it needs to meet certain requirements. Knowing these processes enables pupils to appreciate the quality and durability of buildings around them and provides foundational knowledge for future careers in construction.

Prerequisite/Previous Knowledge

Pupils are expected to have basic knowledge of building materials like cement, sand, and gravel, and some understanding of basic site preparation from previous lessons.

Lesson Content/Board Summary

Ground Floor: Functional Requirements and Production

What is a Ground Floor?

A ground floor is the lowest floor of a building that rests directly on the ground or on a sub-base constructed on the ground.

Functional Requirements of a Ground Floor

A properly constructed ground floor must meet the following requirements:

Provide a firm and level base for the occupants and furniture.
Prevent dampness from rising from the ground into the building.
Be durable and resistant to wear and tear.
Provide adequate thermal insulation.
Be resistant to insect and rodent infestation.
Be easy to clean and maintain.

Preparation of the Base for Ground Floor

The preparation of the ground floor base involves several steps to ensure a stable and durable foundation:

Site Clearance: Removing all vegetation, debris, and topsoil.
Excavation: Digging to the required formation level, ensuring uniform depth.
Compaction of Sub-grade: Firmly compacting the natural ground to prevent settlement.
Laying Hardcore: Placing a layer of broken bricks or stones (hardcore) and compacting it to provide a firm, stable, and well-drained base.
Blinding Layer: A thin layer of lean concrete or sand laid over the hardcore to provide a smooth, level surface for the damp proof membrane.

Damp Proof Considerations

Damp proofing is essential to prevent moisture from rising through the floor. Key considerations include:

Damp Proof Membrane (DPM): A layer of impervious material (e.g., thick polythene sheet) placed over the blinding layer to block moisture. It must be continuous and linked with the wall’s damp proof course (DPC).
Proper Drainage: Ensuring adequate external drainage to prevent water accumulation around the building.

Mixing and Laying Concrete

Concrete for the ground floor is typically a mix of cement, sand, gravel, and water. The process includes:

Batching: Measuring the correct proportions of materials (e.g., 1:2:4 for cement:sand:gravel).
Mixing: Thoroughly mixing the dry ingredients before adding water gradually until a workable consistency is achieved (can be done manually or with a concrete mixer).
Transporting: Moving the mixed concrete to the point of placement without segregation.
Placing: Depositing the concrete evenly over the DPM within the formwork.
Compacting: Removing air voids from the concrete by tamping or vibrating to increase its density and strength.

Leveling and Finishing the Concrete Floor

After laying, the concrete needs to be leveled and finished:

Screeding: Using a straight edge (e.g., timber or metal battens) to level the surface of the wet concrete to the desired height.
Floating: Using a wooden float to work the surface, closing minor irregularities and bringing a paste of cement to the surface.
Trowelling: Using a steel trowel for a very smooth, hard, and dense finish, often done after the concrete has stiffened slightly.

Basic Curing Ideas

Curing is the process of maintaining adequate moisture and temperature in concrete for a period after placing to ensure proper hydration of cement and strength gain. Basic ideas include:

Wetting: Keeping the concrete surface continuously wet by sprinkling water or ponding for at least 7 days.
Covering: Covering the concrete with damp hessian sacks, polythene sheets, or sand to prevent rapid evaporation of water.
Applying Curing Compounds: Spraying a liquid membrane-forming compound on the surface to seal in moisture.

Teaching Methods/Instructional Techniques

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

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction/Questioning
Teacher’s Activity: The teacher greets the pupils and initiates a brief discussion by asking: “What is the lowest part of a building that rests on the ground called?” and “Why do you think the floor needs to be strong and dry?” The teacher then introduces the topic: Ground Floor: Functional Requirements and Production.
Pupils’ Activity: Pupils respond to the questions and listen attentively to the topic introduction.
Learning Point: Pupils are engaged and the lesson topic is introduced.

Step 2: Functional Requirements of a Ground Floor

Time: 7 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher explains what a ground floor is and discusses its key functional requirements using charts or diagrams. The teacher emphasizes the importance of each requirement for the durability and usability of the building.
Pupils’ Activity: Pupils listen, take notes, and ask questions for clarification. They identify and list the functional requirements.
Learning Point: Pupils understand the definition and importance of a ground floor and its functional requirements.

Step 3: Preparation of Base and Damp Proof Considerations

Time: 8 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains and demonstrates (using sketches or diagrams) the steps involved in preparing the ground floor base, including site clearance, excavation, compaction, hardcore, and blinding layer. The teacher then explains the importance of damp proofing and how a DPM is incorporated.
Pupils’ Activity: Pupils observe the sketches, listen to the explanations, and take notes on the preparation steps and damp proofing.
Learning Point: Pupils learn the sequential steps for base preparation and the role of damp proofing.

Step 4: Mixing and Laying Concrete

Time: 8 minutes
Teaching Skill: Explanation/Practical Demonstration
Teacher’s Activity: The teacher explains the proportions for concrete mix (batching) and demonstrates the process of mixing cement, sand, and gravel with water (using samples if available). The teacher then describes how concrete is placed and compacted on the prepared base.
Pupils’ Activity: Pupils observe the material samples, listen to the explanation of mixing ratios, and describe the steps involved in placing and compacting concrete.
Learning Point: Pupils understand the composition and practical steps for mixing and laying concrete.

Step 5: Leveling and Finishing

Time: 7 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher explains and demonstrates, using models or sketches, the tools and techniques used for leveling (screeding) and finishing (floating and trowelling) a concrete floor. The teacher highlights the purpose of each finishing stage.
Pupils’ Activity: Pupils observe the demonstration, identify the tools, and describe the different finishing stages and their purposes.
Learning Point: Pupils learn the methods and tools used for achieving a level and smooth concrete floor surface.

Step 6: Basic Curing Ideas

Time: 5 minutes
Teaching Skill: Explanation/Questioning
Teacher’s Activity: The teacher explains what curing is and why it is important for concrete strength. The teacher then discusses basic methods of curing, such as wetting the surface, covering with damp materials, or using polythene sheets.
Pupils’ Activity: Pupils listen, ask questions, and state the purpose and methods of concrete curing.
Learning Point: Pupils understand the concept of concrete curing and its practical application.

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 ground floor.
Mention three functional requirements of a ground floor.
Outline the main steps in preparing the base for a ground floor.
Why is damp proofing important in ground floor construction?
List two methods for leveling and finishing a concrete floor.
State two basic ideas for curing a concrete floor.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 1 minute
Teaching Skill: Summarization
Teacher’s Activity: The teacher briefly summarizes the key points of the lesson, reiterating the importance of proper ground floor construction. The teacher then assigns homework: “Sketch a simple cross-section of a ground floor, labeling the different layers.”
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: The lesson is reinforced and pupils have a task to consolidate learning.

Lesson Keywords

Ground Floor – The lowest floor of a building that is level with or just above the ground.
Functional Requirements – The necessary conditions or attributes a ground floor must possess to perform its intended purpose effectively.
Hardcore – A layer of broken inert material, such as bricks or stones, used as a base for concrete floors or foundations.
Blinding Layer – A thin layer of lean concrete or sand laid over hardcore to provide a smooth, level surface.
Damp Proof Membrane (DPM) – An impervious layer, usually of polythene, installed in a floor to prevent moisture rising from the ground.
Screeding – The process of leveling the surface of wet concrete using a straight edge.
Floating – The process of smoothing the surface of concrete with a wooden float after screeding.
Trowelling – The process of achieving a very smooth and dense finish on concrete using a steel trowel.
Curing – The process of maintaining moisture and temperature in concrete after placing to ensure proper hydration and strength development.

Differentiation

The lesson will cater to diverse learning styles by incorporating visual aids (diagrams, material samples), verbal explanations, and opportunities for discussion and practical demonstrations. More advanced pupils can be challenged with additional research questions on specific construction standards, while those needing extra support will receive focused guidance during practical activities and review sessions.

Note for teachers using this lesson plan

Teachers should adapt this lesson plan to suit the specific needs and context of their pupils and available resources. Practical demonstrations, even simulated ones, are highly recommended to enhance understanding. Encourage pupils to ask questions and relate the concepts to buildings in their environment.