Scales are used in construction drawings to reduce the size of buildings, land plots, and large components so they fit on paper. Common scales include 1:1 for templates, 1:10 for details, 1:50 for plans/elevations/sections, and 1:500 for site plans. Hatching is used to indicate materials, with lines representing brick, dots for concrete. Abbreviations and symbols are used to efficiently provide information on drawings. Working drawings contain elevations showing external finishes and openings, plans with room layouts and fittings, sections with construction details, and a site plan locating the building on the land.
1. Using Scale in Drawings
Students Notes
Bricklayers, as skilled and responsible construction workers, must be able to read drawings
accurately. These notes suggest some first steps towards the development of this
essential skill. Students should also take every opportunity to study drawings and wherever
possible compare them with a building under construction.
Scales
It is impractical to draw buildings, plots of land, and large parts of buildings such as doors
and windows to their full size. They simply would not fit on a piece drawing paper.
Instead they are normally drawn to a smaller reduced size.
The size they are reduced will be to a ratio of the real item -:
• Twice as small 2:1
• Ten times smaller 10:1 etc
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.
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2. The main scales or ratios used in construction drawings are-:
1:1 Full size used for unusual details or templates
1:2
1:5 Complicated building details
1:10
1:20
1:50 Plans, elevations and sections
1:100
1:200
1:200
1:500 Site plans
1:1250
1:1250 Block or location plans
1:2500
Task 1
Complete the table below, filling in the missing scales
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Scale Drawing is: Scale Drawing is:
1:1 The same size as the object 1:100 100 times smaller than the
object
1:5 5 times smaller than the object 1:200
1:10 1:500 500 times smaller than the
object
1:20 20 times smaller than the object 1:1250 1250 times smaller than the
object
1:50
3. Task 2
(If the number used in the scale is multiplied by the measurements used to draw the plan, the
actual measurements can be found )
Look these drawings of two walls. A scale of 1:50 has been used for Wall A whereas a scale
of 1:100 has been used for Wall B. They both look the same on paper but in real life they
would be very different sizes!
What is the height in real life?
25mm × 50 = 1250mm
Divide by 1000 to convert mm to m = 1.25m
What is the height in real life? _____ mm
The bigger wall in real life is Wall _____
Try this
Write in the scale that would make Wall C
5 times bigger than Wall B in real life.
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80m on site
120m on site
1 on drawing =
2500
on site
SCALE RULE
4. Hatching
Hatching is a term given to the markings on a cross sectional drawing used to indicate the
material that it is constructed of.
They are official British Standards and can be found in BS: 1192 which controls drawing
practice across all sections of the Construction Industry
Task 3
From the powerpoint slide complete the missing hatching titles.
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5. Abbreviations
Abbreviations are a simple way of conveying information on drawings, reducing words to
first letters, e.g. rain water pipe becomes R.W.P.
They allow the maximum information to be included on the drawing in a concise way.
Abbreviations have to be used in context e.g. MS stands for Mild Steel in the context of
construction but it could also be an abbreviation for some other word in another situation.
Avoid making up your own abbreviations as these can lead to confusion.
Abbreviations
Aggregate agg
Air brick Ab Graphical Sybols
Aluminium al
Asbestos asb
Asphalt asph
Bitumen bit
Boarding bdg
Brickwork bwk
BS Beam BSB
Building bldg
Cast iron CI
Cement ct
Column col
Concrete conc
Copper cu
Damp proof course dpc
Discharge pipe DP
Foundation fdn
Hardcore hc
Hardboard hdbd
Hardwood hwd
Inspection chamber IC
Insulation insul
Tongued and grooved t&g
Joist jst
Plasterboard pbd
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6. Reinforced conc RC
Graphical Symbols
These are small standard pictures used to reduce the amount of drawing detail required on
individual drawings.
Abbreviations and graphical symbols are often used together to give complete information.
Representation of components - fittings
Sink Bath Bidet Toilet
Hot & Cold Cold
water Hot Water Stop Valve
Water drain off Cistern Cylinder
Radiator Towel rail Boiler Cooker Pump
Drain or Sewer Flow Foul water Rainwater head
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7. Surface water Rainwater outlet Gulley
Task 4
Complete the following section through the foundation of a building up to window level with
the correct hatchings.
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8. Working Drawings
A working drawing and written specification should contain the total information required
For a building team to convert the architects proposed building into a completed structure.
To enable this to happen the following information should be found in the following
locations.
ELEVATIONS:
1. External finish to walls and roof
2. Position of window and door openings
Scale used 1:200, 1:100, 1:50
PLANS:
1. Overall dimensions of the building
2. Position of internal walls, room sizes
door and window openings
3. Position of fitments, baths, sinks
toilets, stairs etc
Scale used 1:200, 1:100, 1:50
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9. SECTIONS:
1. Provide vertical dimensions
2. Provide constructional details of
foundations, floors, walls, roof,
damp proof membranes and ground
levels
SITE PLAN:
1. Position of the building in
relation to the site
surroundings
i.e. adjoining
buildings, roads,
boundaries, etc.
2. Provision of access
3. Drains and main sewer
4. North point
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10. BLOCK PLAN:
1. Location of site in relation to
surrounding district. This is
taken from local authority’s
ordance survey map.
COMPONENT DRAWINGS:
1. These show the basic sizes of
standard components such as
doors, windows and kitchen
fitments. scales most commonly
used are 1:100, 1: 50, 1: 20.
LEGAL or TITLE PANEL:
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11. 1. Site Address
2. Scales used on drawing
3. Drawing Number
4. Client
5. Date of drawing
DETAIL DRAWING:
These drawings will include every
detail required to make the product.
The information from these details
is used to manufacture various
components .
These drawings are usually produced
by the architect and are produced
in scales ranging from 1:1, 1;5, or
1:10.
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12. ASSEMBLY DRAWING:
These drawings are very
important to the builder.
They show in detail how the
architect requires the
construction to be
constructed and what
materials should be used .
The scales usually used for
these drawings are 1:20, 1:10,
1:5 and should be fully
dimensioned and annotated.
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Key Points
• Select drawing required consulting
Index if available
• Ensure it is the latest amended version
• First, get an overall picture before looking at details.
• Check the sum of intermediate dimensions equals the
overall dimension
• Do not scale from drawings
• Take every opportunity to compare drawings with the
current construction