Lesson Notes By Weeks and Term v5 - Grade 11

Lesson Video

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Performance objectives

• Interpret detailed section drawings (walls, foundations, roofs).
• Identify standard South African architectural symbols & abbreviations.
• Understand and use schedules (door, window, etc.).
• Sketch basic details of building elements.
• Explain how different drawings in a set work together.

Lesson summary

This week, we delve deeper into working drawings, focusing on detailing and interpretation of building plans. Understanding these skills is crucial for any civil technologist in South Africa. From building RDP houses in townships to constructing shopping malls and infrastructure projects, the ability to accurately interpret and detail building plans is fundamental for ensuring safe, efficient, and compliant construction. Imagine overseeing a project where the foundations are incorrectly laid due to misinterpretation of the plans – the consequences could be disastrous!

Lesson notes

2. 1.

Detailed Sections: Unveiling the Inner Structure A section drawing is a "cut-through" view of a building. It's like slicing a cake to see the layers inside. It reveals the construction details of walls, floors, roofs, and foundations. Understanding sections is vital for determining the materials used, construction methods, and overall structural integrity.

Key Elements of a Section Drawing: Scale: Always note the scale (e.g., 1:20, 1:50). This indicates the ratio between the drawing and the actual size. If a wall is drawn 5cm long at a scale of 1:20, the actual wall is 5cm x 20 = 100cm = 1m long.

Materials: Different hatching patterns or abbreviations are used to represent materials like concrete, brick, timber, insulation, etc. A legend (key) on the drawing identifies these symbols. Common materials in South Africa include clay bricks, cement blocks, corrugated iron roofing, and various timber types for framing.

Dimensions: Accurate dimensions are crucial. Look for overall dimensions and specific dimensions for each component (e.g., wall thickness, foundation depth, beam size). Pay attention to units (mm, cm, m).

Levels: Section drawings show levels (heights) referenced to a datum point (usually ground level). This helps in coordinating different building elements.

Annotations: Notes and labels provide additional information, such as material specifications (e.g., "230mm Clay Brick Wall") or construction instructions.

Example: Consider a wall section of a typical South African RDP house. It might show a concrete foundation, brick wall, damp-proof course (DPC), insulation (if any), roof structure (timber rafters and purlins), and roof covering (corrugated iron). The section would also indicate the wall thickness, foundation depth, DPC height above ground, and the pitch of the roof. 2.

2. Architectural Symbols and Abbreviations Building plans are filled with symbols and abbreviations to represent common features and components. Using these allows to keep drawings less cluttered.

Common Symbols: Doors: Various symbols represent different types of doors (e.g., swing doors, sliding doors, folding doors).

Windows: Symbols indicate window type (e.g., casement, sliding, awning) and glazing.

Electrical Outlets: Symbols represent power outlets, light switches, and other electrical fixtures. These will adhere to SANS 10142 regulations.

Plumbing Fixtures: Symbols depict toilets, sinks, showers, and bathtubs.

Stairs: Symbols show the direction and number of risers and treads.

Common Abbreviations: WC: Water Closet (Toilet) DB: Distribution Board (Electrical)

DPC: Damp-Proof Course GL: Ground Level FFL: Finished Floor Level R/F: Reinforced Foundation CL: Center Line O/A: Overall

Example: In a floor plan, a symbol consisting of an arc and a line indicates a swing door. Near the door, you might see the abbreviation "DW," indicating a door width, followed by a dimension (e.g., DW900 - meaning Door Width is 900mm). 2.

3. Schedules: Organized Information Schedules are tables that provide detailed information about specific building elements. Common schedules include door schedules, window schedules, and finishes schedules.

Door Schedule: Lists each door in the building, identified by a unique mark (e.g., D1, D2), and provides information such as: Door type (e.g., solid core, hollow core) Door size (width x height) Frame material (e.g., timber, steel) Ironmongery (hinges, handles, locks) Fire rating (if applicable)

Window Schedule: Similar to the door schedule, but for windows. It lists window type, size, frame material, glazing type, and hardware.

Finishes Schedule: Specifies the finishes for different surfaces in the building (e.g., flooring, walls, ceilings). It might indicate tile type, paint color, wall paper and materials for skirting.

Example: A door schedule might list "D1" as a "Solid Core Timber Door, 813mm x 2032mm, Hardwood Frame, Lever Handle Lock." This allows the builder to easily order the correct doors for each opening without having to search through the entire set of drawings. 2.

4. Sketching Basic Details Sketching details is a fundamental skill. You don't need to be an artist. Instead, you're communicating technical information. Focus on accuracy of proportions and materials.

Example: Sketching a Window Frame: Start with a rectangle: Represents the overall size of the window frame.

Add the glazing bars: Indicate the number and spacing of the glazing bars.

Draw the frame profile: Show the shape and size of the frame members.

Label materials: Indicate the frame material (e.g., "Timber Frame").

Add dimensions: Show key dimensions, such as the frame thickness and glazing bar spacing. 2.

5. Relationship Between Drawings A set of building plans typically includes floor plans, elevations, sections, site plans, and detail drawings. These drawings work together to provide a complete picture of the building.

Floor Plan: A bird's-eye view showing the layout of rooms, walls, doors, windows, and fixtures.