Lesson Notes By Weeks and Term v5 - Grade 12

Lesson Video

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Performance objectives

• Identify the purpose of key building services.
• Draw and interpret standard SANS symbols for services.
• Detail a simplified water supply layout.
• Detail a simplified sanitation layout.
• Explain the importance of coordinating services with structural elements.

Lesson summary

This week, we delve into the crucial area of building services and their representation in civil engineering drawings. Building services are the systems that make a building habitable and functional. They include water supply, sanitation, electrical reticulation, ventilation, fire protection, and increasingly, data and communication networks. Understanding how these services are planned and depicted in drawings is fundamental to ensuring buildings are safe, efficient, and comply with South African building regulations (SANS 10400). Without properly planned and detailed building services, buildings can be unsafe, unhealthy, or simply unusable.

Lesson notes

2.1 Introduction to Building Services: Building services are the systems installed in buildings to make them safe, comfortable, and functional for their occupants. They are essential for providing basic amenities and ensuring the building meets safety standards. In South Africa, these services are designed and installed according to the South African National Standards (SANS) codes and regulations, particularly SANS 10400. 2.2 Key Building Services: Water Supply: This system brings potable (drinkable) water into the building for drinking, washing, and other uses.

It includes: Main Water Connection: Connection to the municipal water supply.

Water Meter: Measures water consumption.

Pipes: Distribute water throughout the building (typically copper or plastic).

Valves: Control water flow.

Fittings: Connect pipes and fixtures.

Fixtures: Taps, showers, toilets, sinks, geysers (water heaters).

Sanitation (Drainage): This system removes wastewater and sewage from the building.

It includes: Waste Pipes: Carry wastewater from fixtures.

Soil Pipes: Carry sewage from toilets.

Vent Pipes: Allow air to enter the drainage system, preventing siphoning of water traps.

Traps: Water-filled bends in pipes that prevent sewer gases from entering the building. Crucial for public health. S-traps, P-traps, and bottle traps are common.

Inspection Chambers (Manholes): Provide access for cleaning and maintenance of the drainage system.

Sewer Connection: Connection to the municipal sewer system or a septic tank.

Electrical Reticulation: This system provides electricity for lighting, appliances, and equipment.

It includes: Main Power Connection: Connection to the electricity grid.

Distribution Board (DB Board): Distributes electricity to different circuits in the building.

Wiring: Carries electricity to outlets and appliances.

Outlets (Sockets): Provide points to plug in appliances.

Switches: Control lighting and other electrical devices.

Lighting Fixtures: Provide illumination.

Earthing System: Protects against electrical shocks.

Ventilation: This system provides fresh air and removes stale air, preventing the build-up of pollutants and moisture. It can be natural (windows and vents) or mechanical (fans and air conditioning). Good ventilation is essential in South Africa to reduce the risk of TB and other respiratory illnesses, particularly in densely populated areas.

Fire Protection: This system protects the building and its occupants from fire.

It includes: Fire Alarms: Detect and alert occupants to a fire.

Fire Extinguishers: Portable devices for putting out small fires.

Fire Sprinkler Systems: Automatically release water to suppress fires.

Fire Hydrants: Provide a source of water for firefighters.

Fire-Resistant Materials: Used in construction to slow the spread of fire. 2.3 Standard Symbols and Conventions: Engineering drawings use standardized symbols to represent building services components. These symbols are defined in SANS standards. Learning these symbols is crucial for accurately interpreting drawings.

Some examples: Water Tap: A circle with a line extending from it.

Toilet: A small rectangle or square.

Shower: A circle with an "X" inside.

Distribution Board (DB): A rectangle with "DB" inside.

Light Switch: A circle with a line extending from it, often with a specific designation (e.g., S1, S2).

Inspection Chamber: A circle with crosshairs. (Refer to relevant SANS standards or EGD textbooks for a complete list of symbols). 2.4 Detailing Water Supply Systems: A typical water supply system consists of the following: Connection to the Municipal Water Supply: Indicated on the site plan.

Water Meter: Located near the connection point. Drawn to scale on the floor plan.

Main Water Pipe: Runs from the meter to the building. Represented by a solid line with a specific diameter (e.g., Ø20mm).

Distribution Pipes: Branch off from the main pipe to supply water to fixtures. Represented by solid lines with varying diameters depending on the fixture (e.g., Ø15mm for taps, Ø20mm for geysers).

Valves: Placed strategically to isolate sections of the system for maintenance. Represented by their specific symbols.

Fixtures: Taps, showers, toilets, and geysers. Represented by their specific symbols.