Lesson 3 Taking-Off - Trent GlobalLesson 3 –Taking-Off Taking-Off (Cont’d) Dimensions are...

Lesson 3 – Taking-Off1

Copy Right. ES. 2015.

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Lesson 3 – Taking-Off

Revision for Centre Line

“Scarcement” - An offset where a wall or bank of earth, etc., retreats, leaving a shelf or footing.

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Revision for Centre Line (Cont’d)

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225

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OUTLINE

Taking-Off Paper / Format / List – exercise

The Measurement Process – in brief

Editing the take-off and draft BQ

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Taking-Off

Taking-off is where the surveyor identifies an item of work and records the dimension on paper; clerical techniques of recording information to ease the effort of writing and recording. Adoption of computerized technique widely been used nowadays.

Basic 2 methods in use:-

The Trade-by-Trade Method; and

The Group Method (same as Elemental Method)

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Taking-Off (Cont’d)

All developments in taking-off either manually or using computers are derived from these two basic types and are therefore only variations or combinations of methodology which has been long established.

Measure the whole or over the irregular shape

and follow this with the deduction of the

portion not required.

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Taking-Off (Cont’d) Dimension should be recorded in the following order: length,

width/breadth, thickness/height/depth

The source of all dimensions should be recorded alongside the dimensions; this is called “side noting”

Dimensions required but not given directly on the drawings must be calculated NOT scaled; these ‘waste’ calculation are carried out to the millimeter (mm) and must be recorded alongside the appropriate dimensions and side notes.

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Taking-Off (Cont’d) Dimensions are recorded alongside the appropriate dimensions and side notes.

Dimensions are recorded in metres (m) to two places of decimals – SMM7 General Rules 3.2, page 12

Never ever use an eraser or correcting fluid if you think you have recorded the wrong information. Score out carefully and record the correct information in the next available space. Don’t crowd the work and NEVER EVER over write one dimension with another.

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Taking-Off Paper

The paper on which the measurement is recorded is called “taking-off paper”. Normally “A4 Size” of paper is in used.

The layout differs according to which basic system of taking-off adopt and also which individual practice you happen to work for.

The sheet is ruled vertically into a number of columns each used for one specific purpose (columns from left to right) for:

Binding margin / item number

The item description

Side notes and waste calculation

Dimensions and quantities

Calculation of the final quantities

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Taking-Off Paper (Cont’d)

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Taking-Off Paper (Cont’d)

In addition, surveyors employ an additional column before the dimension column to use for “timesing” when adopting Group Method.

Besides, 2-dimension columns are used in adopting Trade-by-Trade Method, as one for additions and one for deductions (i.e. first for the whole measurement, and then adjustment of void & awantings in subsequent column).

Additional columns with the extension of the right hand side of the paper, for “rate” allowing the take-off to be priced. This allows costs to be obtained for portions of the work as taking-off proceeds (but not practical in Group Method).

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The Trade-By-Trade Method of Measurement (Fundamental)

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Example

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Example

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1. Unit- m2, 3rd Dimension in D’2. D’ – full, clear and descriptive 3. Waste Calculation for centre line

& timesing method4. Transfer sum-up figure to

Column4

timesing




Example

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5. Measurement as a “Whole”, then “Add” and “Dt” – no dims for door & window but to assume. 6. Horizontal Line in C4, means multiply (If m3, will have 3 dims before the line)




Let’s try it…

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11500

23800

Door – 900mm W x 2100mm HtW1 – 1800mm W x 1200mm HtW2- 600mm W x 600mm Ht




Let’s try it…

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2100

150

575




Taking-Off List

It is a good practice to prepare a list of taking off items and this is normally followed the order of construction. As example the order of taking off for “foundation” would be probably be as follows:

Excavation from reduced level

Leveling bottom of excavation

Lean concrete binding to excavated bottom

Reinforcement Bar to foundation

Concrete G30 in foundation

Brick foundation wall up to damp proof course level

Damp proof course

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Query Sheets

When the Architectural Drawings contradict with Structural Drawings, QS must raise this in a query sheet to the Architect to rectify the differences. A query sheet is normally divided into two equal parts to accommodate the queries on the left side and Architect will response with answers on the other side of the sheet.

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Discrepancies Tender Queries / Questionnaires

Request for Information (RFI)




The Measurement Process – in brief Procedures:

Identify items of work in place from 2D drawings;

Record that item as a description and unit of measurement;

Record dimensions from the drawings fro the work on paper;

Calculate the final quantity of that work from the recorded dimensions; and

Prepare a final draft for the Bill of Quantities

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Editing the taking-off and the draft BQ Listing down all the work items as accordance to measurement method

The editing process adds heading and sub-heading to the draft, which clearly define the various sections and sub-sections of the bills (avoid repetition or errors)

To do final checking before printing

The bills so produced were integrated with copies of preambles, conditions of contract and the form of tender, etc

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Lesson 3 Taking-Off - Trent GlobalLesson 3 –Taking-Off Taking-Off (Cont’d) Dimensions are...

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