Lesson Notes By Weeks and Term v5 - Grade 10
Introduction to civil drawings and reading building plans – Week 3 focus
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Introduction to civil drawings and reading building plans – Week 3 focus
Download the Lessonotes Mobile South Africa app for faster lesson access on Android and iPhone.
Subject: Civil Technology
Class: Grade 10
Term: Term 4
Week: 3
Theme: General lesson support
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Civil drawings and building plans are the fundamental language of the built environment. Understanding them is crucial for anyone involved in construction, from architects and engineers to builders, contractors, and even homeowners. In South Africa, with its diverse housing needs and ongoing infrastructure development, the ability to interpret these plans is especially vital. Imagine being able to understand the blueprints for a new RDP house in your community, or participating knowledgeably in discussions about upgrades to local schools.
This week builds on our prior understanding of drawing types (plans, elevations, sections) and scales. We will focus on decoding the specific information contained within the drawings. 2.1 Symbols and Abbreviations: Building plans use symbols to represent various components in a concise manner. These symbols are generally standardised, but slight variations may occur. Familiarity with common symbols is essential for accurate plan interpretation.
Here are some key examples: Walls: Walls are typically represented by thick lines. Differentiate between external (thicker) and internal (thinner) walls. Hatching patterns within the wall outline may indicate the wall material (e.g., brick, concrete block). A double line with insulation hatching signifies an insulated wall.
Doors: Doors are represented by an arc showing the direction of the swing, and a line indicating the door leaf. The size of the door opening is typically indicated by a dimension (e.g., "900" for a 900mm door). Look for different door symbols indicating hinged, sliding, or folding doors. The swing direction can affect space planning.
Windows: Windows are shown as a series of lines within the wall outline. A single line indicates a single-pane window; double lines indicate double-pane. The window dimensions are also often provided.
Look for different window types: casement, sliding, awning.
Electrical Outlets: Symbols vary but often include a circle with lines indicating the type of outlet (e.g., single, double, three-pin). A lightning bolt or "DP" (Distribution Point) symbol indicates the location of the electrical distribution board.
Plumbing Fixtures: Toilets (WC), sinks, baths, and showers are represented by simplified outlines. Water supply and drainage lines are shown as dashed lines. The position of taps and wastes are marked.
Stairs: Stairs are shown as a series of parallel lines indicating the treads, with an arrow indicating the direction of ascent. The number of risers and the overall dimensions are usually indicated.
Drainage and Water Reticulation: These plans are crucial for understanding how water enters and exits a building.
Look for symbols representing: Manholes: Usually a circle with diagonal lines.
Drainage Pipes: Dashed lines, often labeled with diameter and material (e.g., "110mm PVC").
Water Pipes: Solid lines, often labeled with diameter and material (e.g., "20mm Copper").
Water Meter: A specific symbol indicating its location.
Sewer Line: A thicker dashed line connecting to the municipal sewer.
Common Abbreviations: FFGL: Finished Floor Ground Level - The final height of the floor. GL: Ground Level – The natural ground level before construction. WC: Water Closet (Toilet). DB: Distribution Board (Electrical). WP: Waterproofing. RL: Roof Level DP: Distribution Point (Electrical)
O/A: Overall Dia: Diameter 2.2 Site Plans and Floor Plans Site Plan: A site plan shows the building's location on the plot of land.
It includes important information such as: Property Lines: Boundaries of the property.
Building Setbacks: Minimum distances the building must be from property lines. Crucial for legal compliance with municipal regulations.
Orientation: North direction indicated by a North arrow.
Existing Structures: Any structures already on the property.
Access Roads and Driveways: Locations and dimensions of roads and driveways.
Services: Location of water, sewer, and electrical connections.
Contours: Lines indicating the elevation of the land. Important for understanding drainage patterns and potential for flooding.
Floor Plan: A floor plan is a bird's-eye view of the building, showing the layout of rooms, walls, doors, and windows.
It includes: Room Dimensions: Length and width of each room.
Wall Thickness: Thickness of interior and exterior walls.
Door and Window Sizes: Width and height of door and window openings.
Furniture Layout (Optional): Sometimes furniture is shown to illustrate space planning.
Location of Fixtures: Position of plumbing fixtures, electrical outlets, and other built-in elements. 2.3 Worked
Examples: Example 1: Interpreting a Door Symbol A building plan shows a symbol for a door. The symbol consists of a line representing the door leaf and an arc showing the swing. The dimension next to the door is "813".
Interpretation: This indicates a hinged door with a width of 813mm. The direction of the arc shows which way the door opens (swinging into or out of the room). In South Africa, door widths commonly adhere to standards (e.g., 813mm is a standard internal door size).
Example 2: Calculating Room Area A floor plan shows a rectangular bedroom with dimensions of 3.5m x 4.2m. Calculate the area of the bedroom.
Solution: Area = Length x Width Area = 3.5m x 4.2m Area = 14.7 m² Therefore, the area of the bedroom is 14.7 square meters. Knowing this is vital for planning furniture placement and understanding room size relative to other rooms in the house.