Class: Senior Secondary School 2 (SS2 / SSS2)
Term: 3rd Term
Week: 7
Age: 16 years
Duration: 45 minutes
Subject: Building Construction
Curriculum Theme: Building Services
Previous Lesson: Drainage Installation: Laying of drainage.
Topic: DRAINAGE INSTALLATION
Subject Matter: Methods of testing drainage (leak test, flow test)

Specific Objectives

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

Cognitive Domain:

Define drainage testing.
Explain the purpose of leak tests in drainage systems.
Describe the procedure for conducting a flow test.

Affective Domain:

Appreciate the importance of proper drainage testing for building safety and hygiene.
Develop an interest in adhering to construction standards.

Psychomotor Domain:

Outline the steps involved in performing a leak test (water test) on a drainage pipe.
Identify the basic equipment required for drainage testing.

Collaborate with peers to discuss different drainage testing scenarios.

Reference Materials

The following resources were used in planning this lesson:

Senior Secondary Schools Education Curriculum
State Unified Scheme of Work
Oyewole, A. (2018). Building Construction for Senior Secondary Schools.

Instructional Materials

The teacher will teach this lesson with the aid of:

Shovel, digger, head pan, lines and pegs (for demonstrating installation context)
Diagrams illustrating drainage pipe layout and testing procedures
Water, stoppers/plugs, measuring tape, and a stopwatch (for demonstrating testing concepts)

Rationale for the Lesson

This lesson helps pupils understand the critical methods used to ensure drainage systems are functional and leak-free. Knowing how to test drainage prevents future problems like water damage and sanitation issues, which is important for maintaining healthy buildings.

Prerequisite/Previous Knowledge

Pupils should have prior knowledge of basic drainage components, pipe materials, and the general principles of pipe laying and trench excavation.

Lesson Content/Board Summary

DRAINAGE INSTALLATION

Methods of Testing Drainage

After drainage pipes are laid, they must be tested to ensure there are no leaks and that water flows correctly. This is important for the system’s efficiency and to prevent damage to the building structure and environment.

The following are common methods for testing drainage:

Leak Test (Water Test)
Flow Test

Leak Test (Water Test)

The leak test, often a water test, checks if the drainage pipes are watertight and free from leaks. It is usually performed before backfilling the trenches.

Procedure for Water Test:

Step 1: Seal all openings. Seal off all outlets and inlets of the section of the drainage system to be tested using suitable stoppers or plugs.
Step 2: Fill with water. Fill the pipe system with water from the highest point until it reaches ground level or a specified test head (e.g., 1 meter above the highest point of the section being tested).
Step 3: Observe for leaks. Allow the water to stand for a specified period (e.g., 30 minutes to 1 hour). Carefully observe the joints and pipe sections for any signs of leakage or a drop in the water level.
Step 4: Rectify and retest. If any leaks are detected, drain the water, repair the faulty section, and repeat the test until the system holds water without any leakage.

Flow Test

The flow test checks if water can flow freely through the drainage system without blockages or inadequate gradients. It ensures that waste can be carried away efficiently.

Procedure for Flow Test:

Step 1: Introduce water. Release a controlled amount of water (e.g., from a bucket) into the highest point of the drainage system.
Step 2: Observe flow. Watch the water as it moves through the pipes, observing its speed and checking for any stagnation or slow movement.
Step 3: Time the flow. If possible, use a stopwatch to time how long it takes for the water to travel a known distance or to emerge from the lowest outlet.
Step 4: Check for blockages. Ensure that the water flows out smoothly and completely without backing up, indicating no blockages or insufficient fall (gradient).

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 topic by asking pupils about the importance of proper drainage in buildings and what might happen if drains are faulty.
Pupils’ Activity: Pupils respond, sharing their ideas on drainage importance and potential problems.
Learning Point: Pupils are reminded of previous knowledge about drainage and its significance.

Step 2: Explanation of Drainage Testing Importance

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher explains why it is essential to test drainage systems after installation, emphasizing safety, hygiene, and structural integrity.
Pupils’ Activity: Pupils listen attentively and ask questions for clarification.
Learning Point: Pupils understand the critical reasons for drainage testing.

Step 3: Leak Test (Water Test) Explanation

Time: 10 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher explains the concept of a leak test, focusing on the water test method, and outlines the step-by-step procedure using diagrams or visual aids.
Pupils’ Activity: Pupils observe the diagrams and listen to the explanation, taking notes as required.
Learning Point: Pupils learn the definition and procedure of a leak test.

Step 4: Pupils’ Practical Engagement (Simulated)

Time: 10 minutes
Teaching Skill: Practical Application
Teacher’s Activity: The teacher guides pupils to discuss in groups how they would simulate a water test on a section of a drainage pipe if provided with the materials.
Pupils’ Activity: Pupils engage in group discussions, outlining the steps and materials needed for a simulated water test.
Learning Point: Pupils apply their knowledge of the leak test procedure in a practical context.

Step 5: Flow Test Explanation

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher explains the concept of a flow test, detailing its purpose and the step-by-step procedure for conducting it.
Pupils’ Activity: Pupils listen and note down the steps and importance of the flow test.
Learning Point: Pupils understand the definition and procedure of a flow test.

Step 6: Pupils’ Practical Engagement (Simulated)

Time: 5 minutes
Teaching Skill: Practical Application
Teacher’s Activity: The teacher asks pupils to consider how they would observe and confirm proper flow in a drainage system during a flow test.
Pupils’ Activity: Pupils suggest ways to conduct a flow test, like observing water speed and checking for blockages.
Learning Point: Pupils reinforce their understanding of the flow test by considering practical aspects.

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 the main purpose of testing a drainage installation?
Describe the procedure for conducting a water (leak) test on drainage pipes.
Explain why a flow test is important for a drainage system.
Mention two materials needed for a leak test.

Pupils’ Activity: Pupils answer orally and in writing.
Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 5 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, reiterating the importance of thorough drainage testing for safe and functional buildings. The teacher then assigns homework related to the topic.
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils consolidate their learning and receive further tasks.

Lesson Keywords

Drainage – A system for removing water or waste liquids.
Leak Test – A test to check if a pipe system is watertight and free from leaks.
Flow Test – A test to check if water flows freely and effectively through a drainage system.
Gradient – The slope or inclination of a pipe, important for proper flow.
Excavation – The process of digging a trench or hole in the ground.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to research alternative drainage testing methods (e.g., air test). For those needing more support, the teacher can provide simplified diagrams and re-explain procedures individually, focusing on one test method at a time.

Note for teachers using this lesson plan

Teachers should emphasize the practical safety measures involved in drainage work and testing. If possible, a field trip to a construction site or a practical demonstration with actual pipe sections would greatly enhance understanding. Ensure pupils understand the consequences of poorly tested drainage systems.