Unit 7�Graphical Detailing in Construction

Dr Adewale Abimbola, FHEA, GMICE.

www.edulibrary.co.uk

Aim & Objectives

Manual Materials and Equipment

Introduction

• It is important that your drawings are clear and easy to read. You can do this by using the correct materials and equipment. 

Importance of producing clear and easy to ready drawings:

• reduces the risk of misinterpretation among construction stakeholders, thus avoiding errors, delays, and costly rework.
•  Contractors can refer to drawings for guidance on dimensions, materials, and construction methods for accurate implementation.
•  Enable better coordination and collaboration between different trades, minimising conflicts and clashes.

Manual Materials and Equipment

Importance (Cont’d):

• accelerates decision-making and construction progress.
• assist in meeting regulatory and building code requirements.
• help clients visualise the end product, leading to higher satisfaction levels.
• provide legal protection in case of disputes or claims.
• shows a commitment to quality and attention to detail.
• easier to digitise and integrate into Building Information Modelling (BIM) systems.

Manual Drawing Equipment

Figure 1. A pair of compasses

1. A pair of compasses

This is used to draw circles and angles. They can also be used as a divider.

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2. Set Squares

Used to draw vertical lines or lines at an angle. Two set squares are needed: a 45⁰ set square and a combination 30⁰ / 60⁰ set square. You can get adjustable set squares that combine both set squares.

Figure 2. Set squares

Manual Drawing Equipment

Figure 3. Protractor

3. Protractor

Used to set out angles other than 30⁰,

45⁰, and 60⁰.

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4. French curves and flexible curves

Used to draw various types of curves required in drawings.

Figure 4. French curves

Manual Drawing Equipment

Figure 5. Stencil

5. Lettering and number stencils

You can letter freehand, but use a stencil to produce the best effect. The height of the lettering should be between 4 mm and 7 mm, and should be 0.5 mm thick. The spacing, angle and shading of the lettering need to be consistent throughout.

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6. Drawing boards

They are available in various sizes. Some boards can be used on a desktop, while others are mounted on frames (i.e. free standing). An A2 drawing board is generally big enough, though professional architects and draughtspersons will need larger sizes. Drawing boards come with or without a sliding rule attached.

Figure 6. Drawing boards

Manual Drawing Equipment

Figure 7. Erasers

7. Erasers

Are used to erase both pencil and ink. A combination eraser can erase both. Coloured erasers will leave a stain on the paper, so good quality erasers are grey or white. Overusing the eraser will spoil the surface of the paper and can even make a hole in it.

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8. Scale rules

Used to measure and draw according to an appropriate scale. These are available for various scales such as 1:100 and 1:50

Figure 8. Scale rule

Materials

Figure 9. Different paper sizes.

9. Paper

• Paper come in different sizes, from A0 (the biggest) to A5; an international paper size standard (ISO 216).

Figure 10. Tracing paper.

• Tracing papers, or detail papers, are used to trace from the original drawings. These are transparent enough to see through and are available as thin, medium and stout.

Materials

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10. Pencils

• Drawing pencils come in different grades or hardnesses. H means the pencil lead is hard and B means the pencil lead is soft.
• B – shading and texturing.
• HB – for rough sketching.
• F – for printing and general line work.
• H – for dimension lines and hatching.
• 2H – for construction lines.
• Clutch pencils are also called mechanical pencils or propeller pencils. These use leads of various grades and thickness such as 0.3 mm, 0.5 mm, 0.7 mm and 0.9 mm. A number of leads can be kept in the pencil casing. These pencils do not need any sharpening and give lines of uniform thickness.

Figure 12. Clutch pencils.

Figure 11. H and B pencils.

Materials

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11. Pen

• Used to produce drawings in ink and are available in a variety of sizes. Drawings in ink are long-lasting, so they can be stored safely for future use.
• All working drawings can be drawn in ink. Pens should be refilled using good quality ink.

Figure 13. Drawing pens.

Manual Drawing Equipment

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Scale Drawing

• It is impractical to draw buildings, plot of land, and large parts of buildings such as doors, windows to their full size. They simply would not fit on a piece of drawing paper. Instead, they are normally drawn to a smaller reduced size.
• When drawings are drawn in this way, they are called scaled drawings.
• To draw buildings and objects to a scale, recognised ratios called SCALES are used to relate real dimensions and measurements to a drawing.

Figure 14. Scale drawing

Manual Drawing Equipment

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Scale Drawing

• In a house drawing to a scale of 1:10:
• 1mm will represent 10mm.
• 2mm will represent 20mm.
• 10mm will represent 100mm.
• 100mm will represent 1000mm or 1m.

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• To a scale of 1:100 > 10mm will represent 1,000mm or 1m.
• To a scale of 1:50 > 10mm will represent 500mm or 0.5m.
• To a scale of 1:200 > 15mm will represent 3,000mm or 3m.

Figure 14. Scale drawing

Manual Drawing Equipment

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Scale Drawing

The main scales or ratios used in construction drawings are:

• 1: 1 = full size used for unusual details or templates.

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• 1:2, 1:5, 1:10 = Complicated building details (see, a)

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• 1:10, 1:20, 1:50, 1:100, 1:200 = Plans, elevations and cross sections (see, b)

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• 1:100, 1:200, 1:500 = site plans (see, c)

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• 1:1000, 1:1250, 1:2500 = Block or location plans (see, d)

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Figure 15. Scale rule

a

b

c

d

Self-assessment Task

1. Identify FOUR materials and equipment you will need to manually produce a construction drawing? Explain how you would use them.

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2. Complete the table below, filling in the missing scales.

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Self-assessment Task

3. The size of a rectangular-shaped building plan is 4.0 m X 10.0 m. What are the scaled dimensions using scales 1:20, 1:100, and 1:200 [Leave your answer in mm].

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Reference/Bibliography

Pearson (2017) BTEC national construction student book. London: Pearson.

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