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Certificate II in ConstructionTraining Package CPC08 (V. 7.0)

NSW Course Code: 10202 Certificate II in CarpentryNational Course Code: 20111 Certificate II in Carpentry

CPCCCM2006AApply basic levelling procedures

Workbook

Satisfactory

Theory Result: Yes No

Practical Result: Yes No

Assessor Details

Name

Signature

Student Details:Name:

Signature

Class:

Date:

TAFE NSW Riverina Institute

June 2012

Notice of liabilityEvery precaution has been taken to ensure the content of this text is current and aligned with best industry practice. However, neither the authors, nor TAFE NSW Riverina Institute, accept liability to any person or entity with respect to any liability, loss or damage caused or alleged to be caused directly or indirectly by following the instructions this document contains.

AcknowledgementThis document may (or may not) contain graphics and or text reproduced from a number of preceding educational resources, the original creators of which are obscure. Should it be believed that material has been used without appropriate permission, please notify TAFE NSW Riverina institute so due acknowledgement may be made, or said material removed.

Prepared by TAFE NSW Riverina Institute Building & Construction Department, Albury CampusPO Box 515 Albury NSWPh: 61 02 60582800Fax: 61 02 60582847

Version 1.0

TAFE NSW Riverina Institute Albury Campus Version 1 - 2012 of 59

Candidate’s InstructionsTime allowance: Theory: 1.0 hrs Practical: As Specified

Note: All questions must be attempted Battery operated non-programmable calculators may be used Mobile Phones must not be used Please use blue or black pen in answering – neatness is considered in marking

Available Marks Theory: 100Practical: Competence Demonstrated or Required Score As Specified

IntroductionThis workbook holds the various assessment tasks used to demonstrate competence in the following elements of competency:

1 Plan and prepare

2 Set up and use levelling devices

3 Clean up

What you will be assessed onYour knowledge and skills with regards to this unit will be assessed by means of the following activities:

Nature of assessment Activity Time Frame

Theory

Practical

Note: Timely performance is part of competence. You must complete the tasks within the given time frames.

To demonstrate competence you must Complete a Safe Work Method Statement (SWMS), safety equipment checklist and a tool

and equipment checklist

Satisfactorily respond to all written or verbal questions.

Satisfactorily complete all practical tasks

Pre-requisite UnitsBefore being eligible to undertake these assessment tasks you must have successfully completed the following units: CPCCOHS2001A Apply OHS requirements, policies and procedures in the construction industry


Employability skillsAside from the listed elements of competency, the following employability skills must be demonstrated before competency can be acknowledged:

Communication Planning and organising

Teamwork Technology

OH&SFailure to comply with relevant OH&S practices as relevant to the tasks being performed will conclude the assessment with competency not yet demonstrated being recorded*.

* At the assessor’s discretion the assessment may be continued depending upon the nature and severity of the breech, and the perceived likelihood of reoccurrence.

Assessor Instructions

Unless stated in specific task instructions, all written assessments must be completed on campus or otherwise under supervision.

Formative assessments shall be ‘open book’. Summative assessment: see Theory and Practical elements regarding access to support

materials.

All tasks must be completed within the time frames specified for each task.

Practical activities must be observed with the intent of ensuring that the procedures used by the applicant are appropriate (safe, efficient, sustainable and repeatable).

Failure by candidates to wear required and approved PPE when completing practical tasks means the assessment is ended. At your discretion, the assessment may be recommenced provided that you are satisfied that the breech will not be repeated. Recommencement may only occur once, after which ‘not yet competent’ must be recorded.

A full marking guide for this unit is available on the shared network drive ‘Alf2’ with the file name:

CPCCCM2006A Levelling_procedures.doc_Marking.coc

Theory AssessmentTheory shall be assessed both formatively (during instruction time) and summatively (at the end of the unit).

Formative Assessments

Summative Assessments


Introduction Levelling, and the skilful use of levelling equipment, is a critical aspect of virtually any trade. Many people can ‘see’ if something is out of level or plumb without the use of elaborate levelling devices, and as often as not these people are your clients. So be warned: if you don’t see it whilst your doing, then its going to cost you time and money when they do - after its done!

In addition, if something is out of level, aside from detracting from the overall finish, it may inhibit another trade from completing their work in a timely or appropriate manner. For example a tiler’s task is made unnecessarily complicated if a spa bath and its surrounding frame is not level and plumb. Likewise bricklayers all too frequently have to ‘gain’ 10 or 20 millimetres because a concrete slab runs out of level.

The purpose of this chapter, therefore, is to explore the tools, skills and knowledge used in a variety of basic levelling procedures relevant to the ‘wet’ trades. In doing so the following areas of the unit of competence will be engaged:

Planning and preparing for levelling work Setup and use levelling devices Clean up and maintenance of levelling equipment.


Figure 7.1 Square 1 or Perpendicular

90°

90°

Figure 7.2 Checking for ‘Square’

90°

90° 90°

90°

B

AA

B

Some key terms and concepts

It has been said that a tradesperson may do little wrong if their work is square, straight, level and plumb. To this may be added ‘wind’ (pronounced as in ‘wind up a rope’) ‘true’, and perpendicular. The definition of these basic terms with regards to construction and levelling is as follows:

Square: This has at least two meanings: 1. At 90° to another surface or line as shown in figure 7.1 below. The word

‘perpendicular’, defined below, can also be used in this manner. 2. That the rectangle or square shape (room, box, wall etc.) has all its sides

meeting at 90°. This is often checked by a two step approach: First the sides are checked for parallel; then the diagonals are checked for being equal (see figure 7.2.)

Straight:

1. As it usually means. A straight line, or in a straight line. 2. That everything looks plumb and level in relation to each other and the things

around them. For example, the tiles on one wall ‘look’ flat, level and ‘plumb’ (see below) in relation to a corner, door opening or some other vertical surface. In this context its usually used in conjunction with the ‘true’ (see below), as in “straight and true” (see figure 7.3).


Figure 7.3 A ‘Straight & True’ Corner

Figure 7.4 Plumb

C.L.

Plumb

Level: Horizontal (think of the horizon)

Plumb: Vertical, straight up and down. The term is derived from the tool known as a ‘plumb’ or ‘plumb bob’ (which in turn is derived from the Latin term for lead. See figure 7.4). The word ‘perpendicular’ can also be used to mean ‘plumb’.


Figure 7.5 In Wind Figure 7.6 Out of Wind

Wind: To be ‘out of wind’ is to say that two edges of a surface, or two lines, are not in the same plane as each other. The brick walls on either side of a door opening for example when viewed as in figure 7. 5, should appear parallel if ‘in’ wind. They will appear ‘out of wind’ if one wall is just slightly out of plumb or vertical, compared to the other (figure 7.6). Sometimes spelt ‘Wynd’ (Scottish for a winding narrow road or path).

True: A broad term often used to encompass several of the terms above. A ‘true’ line for example is one that follows the path that it should, without bumps or hollows. This line might be straight, or it might be forming a curve. A true wall of bricks would be one that is plumb, all lines (joints, as well as the lay of each brick, and the wall itself) follow that which they should. Tiles that have been laid true would likewise offer a smooth finish, have even joints without lifted edges, and provide a surface that does not undulate (go up and down all over the place). Often used in conjunction with ‘straight’, as in “straight and true” (see Figure 7.3).

Perpendicular: Like ‘square’, has a couple of key meanings for us:1. Vertical - can be used as an alternative to ‘plumb’ in this sense (fig 7.1). 2. At 90° to another surface or line – can be used as an alternative to ‘square’.

Be wary of this usage however as it can lead to misunderstandings (see figure 7.7).

Some examples of how we might use these terms:“Make sure the wall’s plumb and true before you plaster it” – Wall is vertical and straight in both directions, or, if a curved wall, that the curve has no flat spots in it.

“Check that tile inlay for wind with the entrance” – make sure that the tiles line up vertically with corner of the entrance (see figure 7.7)

“Make sure those tiles run true to the wall” – running parallel with the wall.

“Run a level line a metre off the floor and paint in dark green up to that”.


Figure 7.8 Tiles laid ‘Square’ to bath

90°

Figure 7.7 Checking tiles with entrance corner for wind

Figure 7.9 Perpendicular to stair stringer

90°

“Run your floor tiles square to the bath” – Lay the tiles so the joints are at 90° to the bath wall or hob” (Fig 7.8).

“Paint a 100mm wide line a metre long and perpendicular to the stair stringer” - A 100mm wide line is painted at 90° to the stair member that runs down the wall. This is the sort of usage that, whilst technically correct, can lead to mistakes (Fig 7.9).


Figure 7.10 Level bubble. A is correctly levelled.

A

B

A Brief Introductory Word on SafetyIn general, levelling procedures are not particularly dangerous activities. However there are more tools coming to hand that involve lasers, and these come with the inherent, albeit low, risk of eye damage. This is particularly so because we are using our eyes frequently in levelling to line things up and make sure they are running true, parallel, or the like. In so doing we can easily misjudge the location of the laser beam: The more so when using lasers for the likes of levelling suspended ceilings.

This same misjudgement can lead to other risks. These would be comical if not for their real life consequences. Because you will be focused on looking intently at things, moving back and forward to get a ‘good look’ as it were, it is very easy to lose track of your surroundings. This means falling into, over, off, or onto things, or getting hit by others or other equipment.

TAKE CARE: Keep track of you surroundings, the position of laser beams, and those working with you.

The Tool ListThat which follows is a list of the most common, or becoming common, tools for basic levelling. Included is a short description of the item and their use, which will be expanded upon when we look at specific levelling procedures in more detail.

Spirit Level: These come in various lengths and are used for checking horizontal and vertical surfaces (fig 7.12). They usually have two or more vials that are partially filled with a coloured fluid. Due to the shape of the vial, the bubble of air that remains is used to indicated level or plumb (see fig 7.10). The origins of this tool date back to the mid 1600’s, though the contemporary tool we use today came in to being around 1920. These early levels were generally had timber bodies and the position of the vial was adjustable. Most contemporary levels are sealed units and cannot be adjusted. It is important therefore, to purchase a good quality level and look after it well (don’t use it as a hammer, and don’t hammer it!).


Insert: Figure 8.43 Use of line and surface level. From:

Basic Building – Chapter 08a.indd

Page 325.

Note: Change Figure No. and heading as per below

Figure 7.11 Line Level

Figure 7.13 String lines

Insert: Figure 8.39 Use of spirit level with a straight edge. From:


Page 323.


Figure 7.12 Straight edge (with spirit level)

Line Level: Effectively a very small spirit level with hooks for hanging on to a string line (fig 7.11). To have any chance of accuracy they must be hung at mid span of the string. Even so they are not a particularly accurate tool and are not as common on building sites as they once were. Sometimes used for setting up footings and suspended ceilings but rarely now unless the job is not critical and there is nothing better on hand.

Straight edge: Available in various lengths, this is a long timber, metal or plastic tool with parallel sides. Light weight, it is used to aid in drawing long straight lines (like an oversized ruler) and or increase the ‘reach’ of a spirit level (see fig 7.12).

String lines: Contemporary string lines or ‘brickies line’ (bricklayers line) are made of plaited nylon and brightly coloured for visibility (see figures 7.11 & 7.13). Strong, with a good degree of stretch, these lines are used for a variety of purposes, such as: setting out building and boundary lines; brick courses; suspended ceiling set out; indeed the setting out of, or the lining up of, just about anything you can think of.


Insert: Figure 8.46 A plumb rule in use and different types of plumb bob. From:


Page 328.


Figure 7.15 Plumb bobs and frame. Figure 7.14 Chalk Line

Chalk lines: Basically a reel of string line in a container that holds powdered chalk. This chalk is brightly coloured (generally blue or red) for visibility. When held tight between two points and ‘pinged’ (pulled up and let go sharply in the middle), a neat line drawn in chalk is left on the surface. Used to mark out on slabs for tile positions, screws for plaster fixing in ceilings, just about anything that needs a temporary straight line over a long distance.

Safety Note: The chalk is carcinogenic, and at the very least an irritant to the airways. Don’t spread the chalk powder around needlessly or breath it in.

Service Note: The red chalk colour is often a mineral oxide (ochre) base which is very hard to remove or paint over. Use blue chalk for anything that may be painted at a later date.

Plumb Bob: These come in many shapes and sizes and are really nothing more than a symmetrical weight on a string (symmetrical so that they hang straight: see figure 7.4). When this weight is hanging uninterrupted, the string provides a highly accurate guide to plumb or vertical. Plumb bobs can be held ‘free hand’; in a frame (fig 7.15); or from fixed point of a ceiling or wall. Whilst a very old and basic tool (Egyptians are known to have used them as far back as 2600BC) the humble plumb bob remains a useful piece of kit for any tradesperson.

Tape Measures and rulers. The all important tools for measuring or assessing distances. The ‘four fold rule’ (fig 7.16) unfolds to give a full metre of measurement and should be used for the assessment of dimensions smaller than this. Retractable tape measures are used for longer distances and come as small belt clip units up to 10m (Fig 7.17). Longer tapes, generally 30m to 100m in length, are much larger and are wound up by hand (fig 7.18). All of these tools are marked in increments of metres and millimetres.


Insert: Figure 8.21 (c) Rule folds out to a straight 1.0m length. From:


Page 316.


Figure 7.16 Four fold rule. Figure 7.17 8m Retractable Tape Measure

Figure 7.18 100m Wind up Tape Measure

Laser levels: More properly called Rotary Laser Levels, these levels cast a level line that rotates around the instruments centre. Used extensively in construction, from bricklayers for footings, to plasterers for ceilings. Laser levels cast a non visible beam that is read by means of a small receiver. There are three types of rotary laser levels, of which only two are suitable for professional trade craft.

Manually levelled : Originally the cheaper end of the market, manually levelled lasers rely upon the operator, being set up using an inbuilt spirit level. Manual levelling is, however, also a feature of some of the contemporary high end self levelling units using remotely controlled servo motors. Manual only units are not usually very accurate and if moved without your being aware then you may continue to work, only to find out later that you are in error. At the time of writing there were very few purely manual units being marketed.


Figure 7.19 Manual Laser Figure 7.20 Pendulum Auto Levelling

Figure 7.21 Self Levelling Laser

Pendulum Automatic levels (Fig 7x): Initially set up with the aid of an inbuilt bubble level, these laser levels use a pendulum system that ensures that the laser only casts a level beam or shuts off. This system compensates for up to about 3° error. It also shuts off if knocked out of level whilst in operation. Automatic laser levels are reliable and relatively inexpensive to maintain or service. These are currently the mainstream tools of the domestic construction industry.

Self Levelling Lasers (Fig 7.x): The higher end of laser levelling units. These use a set of servo motors to self align to a level plane. They are a set and forget sort of tool that you simply turn on and they do the rest. They are, however, more expensive to service or recalibrate. The best of these units are used by professional surveyors for large building works, engineering, mining and the like. They are coming down in price and are becoming common to the domestic construction field.


Figure 7.22 A Multi line Laser Line Generator. Laser array shown at right.

Figure 7.23 An automatic optical level or ‘dumpy’ (note staff in background)

Laser Line Generators and Dot Lasers. A very different tool to the rotary laser level, these tools are used to cast a level or plumb line on to a surface, or several surfaces at the one time. Available in various forms, from task specific laser ‘squares’ (projecting two fine beams at 90° to each other out from a corner) to multi line generators that produce effectively a wall of light to measure from (fig 7.22). Unlike most rotary lasers, line generators produce a visible beam of light. Powerful lasers, these pose a greater risk to the eyes and skin but are a very quick and efficient tool for producing either level or plumb lines, or a ‘dot’ on the ceiling and floor that are literally ‘plumb’ in line with each other.

Optical Automatic levels: Frequently called ‘Dumpy’ levels, these are basically a self levelling telescope with cross hairs for sighting (fig 7.23). Very early ‘Dumpy’ levels were simple tubes without any lenses, and a tribrach that actually had four, not three, levelling nuts. Much depended upon the skill of the user in setting up the instrument and in determining that the target was centred before taking a reading. Today almost all optical levels purchased have good quality optics (lenses) and are auto levelled by means of a pendulum and prism system. These tools are very accurate when used correctly and looked after. Like any level, laser, spirit or otherwise, they must be constantly checked for accuracy prior to use on anything of importance.


Figure 7.24 Survey Staff

Insert: Figure 8.44 Hydrostatic level in use From:


Page 326.


Figure 7.25 The Water Level in use.

Survey Staff: Effectively a very large, collapsible ruler for use with either laser or optical levels (fig’s 7.23 & 7.24). When held correctly (plumb), the staff may be read by sighting through the optical level, or by the positioning of a laser receiver. Being able to read a staff accurately is an important part of many basic levelling procedures

Water level: Little more than a clear flexible plastic hose or tube filled with water that can be used to transfer heights with great accuracy. Shown in figure 7.25, the hose, when filled with water, must be free of all air bubbles and have about 300mm of water free length at either end. These ends are sometimes made of glass tube to make reading easier, however this is not essential as the tube itself must be of clear material so as to ensure all air has been removed.


Figure 7.27 “End for End” check on a surface: Level accurate, surface out.

A

A

Figure 7.26 Checking a Level by “End for Ending”

A

A

The ‘basic’ basic procedures.

Levelling & Plumbing lines and surfaces.

The Spirit LevelDrawing a level or horizontal lineFor this we generally use a spirit level of the appropriate length. Usually this means the biggest one that will fit the area we are working on. And so we come to Rule One of levelling: Never trust a level - always check it, or work with it so as to reduce the influence of error on you job.

Checking a spirit level for error. (Figures 7.26 to 7.28) Place the level on a wall (vertical or horizontal, depending upon which bubble you

are checking) and centre the bubble as accurately as possible. Draw a line along its length. Turn the level end for end and place it back on the line. Check the bubble and see if it is still exactly in the centre. If it is not then the level

is ‘out’ (not giving a true reading of level).

This may also be done on any moderately level or plumb surface without drawing a line. It is how you check your level whilst in use: place the level on the surface, note the position of the bubble, end for end the level and reposition in the same place check that the bubble is in the exactly the same position. If it is, the tool is accurate, if not, its out.


Figure 7.28 “End for End” check on a surface. This level is out, the surface, however, is level.

A

A

Figure 7.29 End for Ending a spirit level to draw a long line.

AA

Marking that line. (See figures 7.x – z)If the line has to go for longer than one length of the level do as follows:

1. Place the level on the surface or wall to be marked at the required height and centre the bubble exactly

2. Using the level like a ruler, draw a line on the wall the full length of the level. 3. ‘End for end’ the level (as if you were checking it for error) 4. Place the level on the surface or wall again at the end of the previous line and

centre the bubble again. Draw the continuation of the line. 5. Repeat this ‘end for ending’ of the level until you have the line required.

In this way any small error in the level, or any tendency that you may have of reading the bubble just a little left (or right) of centre, will be reduced. In the first direction it will go down (or up) and in the second it shall go back up (or down) again, thereby eliminating the error.

Extending the ‘reach’ of a level – The value of straight edges. ‘End for ending’ (as above) is OK up to a point. Wherever possible, though, it is better to use a straight edge to extend the length or reach of a level (see figure 7.12 previously). Even straight edges have their limits however, so should you need to use these over two or more lengths, then once again end for ending is the best way to reduce error.


Figure 7.30 Centring an arch – plumb bob.

C.L.

Plumb

EqualEqual

Checking a surface for levelUses the same principle of end for ending. Place the level on the surface and check the bubble for being in the centre. Note carefully its position, then end for end the level and check the bubble position again. If it is exactly in the centre again then the surface is level (or is if the level is slightly out, in the exact opposite position – see figure 7.28 previous pages).

Plumbing a line Using a spirit level Much the same as the previous examples for levelling a line, only this time the level is held vertically. Again it is good practice to end for end the level as a allow for error in the level itself.

Using the Plumb BobMany plumbing procedures can be carried out using a plumb bob instead of a spirit level. The level is generally used because it is easier to hold still in most cases (against a wall for example). However if you wish to know that the centre of that plaster arch is in fact central to the hall way floor, then the plumb bob is a quick and sure way to check (see figure 7.28). Mark the centre line on the floor, hold the string at the apex of the arch and allow the plumb to swing freely close to

the floor. When the plumb settles down, check its position is over the line, if not, then you

need to adjust your arch to suit. Should you need to use the plumb bob outside in a light breeze, you can reduce its movement by having the weight sit in a bucket of water as shown in figure 7.x.


Figure 7.32 Plumbing a wall – Sighting a plumb bob Figure 7.31 Plumbing a wall – Plumb bob in parallel

C.L.

Plumb

Equal

Equal

Checking a surface for plumbUsing a spirit level Once again very much like checking for level only on a vertical surface. Again end for end the level just to be sure.

Using the Plumb BobFigure 7.31 shows how this is done. Hang the plumb bob a small distance away from the wall Measure the distance between the wall and the string at both top and bottom. If the same, then the wall is plumb. Alternatively: Position the plumb bob so that the string and the wall are in line with each other

and then sight to see if they are parallel (figure 7.32).

Finding the difference in height between two points. Using a spirit levelThis a basic form of ‘traversing’, whereby a series of level lines are used to ‘step’ up and or down from a known point to an unknown point. As figure 7.33 shows: Locate pegs or marks at the furthest reach of the level or level and straight edge

combination. By means of levelling out to a rod, ruler or tape measure held vertically over each

peg, the height difference between each point is recorded. The sum of these heights is the difference in height between the first a last points.

This same approach can be used by marking along a wall instead of putting pegs in the ground.


Insert: Figure 8.41 Straight edge and level used to measure the difference in elevations between known points. From:


Page 324.


Figure 7.33 Basic Traversing

Insert: Figure 8.40 Transferring levels with a spirit level and straight edge. From:


Page 324.


Figure 7.34 Transferring heights with a spirit level and straight edge.

Transferring a heightUsing a spirit levelThis is the same as marking a line, you simply don’t draw the line. Likewise it may or may not include a straight edge, depending upon the distance or location of the point you need to transfer to. Identify the height you need to transfer Select the most appropriate (longest) spirit level available. If transferring across

an empty space (tile or paint line across a hall opening, or from one brick pier to another), you may need to use a straight edge. This way you can ensure that the level, or the straight edge, can be held firmly at either end.

Place one end of the level or straight edge on the height to be transferred and place a mark at the other end where required (see figure 7.34)


Using the water levelA tool seldom used today but which still has some instances where it may come into its own. As shown in fig 7.25 previously, a water level can be used around walls and inside rooms when other levels would need constant changing of position, possibly leading to error. This can be a good way to transfer the dado height for wall tiles or paint lines for example.

Laser Line Generators. Lasers are fast becoming the tool of choice by many tradespeople for their ease of use and one person operation. In addition, they can be used to ‘mark’ a level or plumb line on a wall, or from ceiling to floor, without actually drawing anything on the wall at all. Many of the tasks dealt with above can be done using one of these instruments. Figure 7.35 – 38 show a simple and relatively inexpensive yet high quality self levelling laser line generator in action. 7.5 shows a level line, in 7.6 the same unit producing a plumb line, and 7.7 shows the cross hair. Finally, 7.8 shows the dot laser producing points plumb above one another in a room.

The Up and Down of Lasers.The up side:Fast set upRelatively inexpensiveSmallLightSingle person operationCan cast lines over long distances Easy to see in dim light (such as in when tiling in bath rooms etc.)

The down sideMore easily knocked out of calibration than a spirit level (I.e. so they no longer produce a ‘level’ line)Harder to check to for accuracy (which must be done frequently)Have the potential to damage eyes and skinMore dangerous to eyes in dim light. (the pupil is more open in dim conditions letting more light in, and takes longer to close).

Safe use of Laser Line GeneratorsClasses of LasersLaser line generators generally use Class 2M or 3R lasers. Class 3B and 4 lasers are not permitted in the building industry. The higher the number the greater the strength and visibility of the beam, and the greater the accuracy and distance. However, the higher the number, the greater the risk to the eyes and skin. Small Rotary Laser Levels are often Class 1, 1M, and 2 lasers as these do not a visible beam.

Identifying the laser class.All laser equipment must labelled with a warning stating the class of laser such as shown in figure 7.39.


Figure 7.39 Laser warning labelling .

Australian Standards The manufacture and use of lasers comes under two Australian Standards: AS/NZS 2211.1:2004: Safety of laser products AS 2397-1993: Safe Use of lasers in the building and construction industry.

These standards require the following with regards to each class:

Class 2M lasers are low-powered and present a minor hazard. The normal blink and avoidance response to bright light is sufficient protection. Some administrative controls should be in place regarding training and use

Class 3R lasers produce a stronger light and more stringent administrative precautions. It is particularly important to ensure that optical instruments (such as a dumpy level or theodolite) are not used in the immediate area as these could concentrate the beam into the eye.

Note: There is some confusion in laser classifications between the two standards. AS 2397-1993, the older but still operational standard, offers Classes, 1, 2, 3A and 3B (Restricted) as being relevant to the building industry (followed by 3B and 4); AS/NZS 2211.1:2004 has the newer list of classes: 1, 1M, 2, 2M, 3R, 3B and 4. This chapter is based upon the new classifications. I.e. Classes 3A, and 3B (Restricted) have been replaced with 3R.

The standards also require that all operators of Class 2M and Class 3R lasers be trained in their use, have access to all operational manuals, and that a copy of AS 2397-1993 be kept on site.

The operator (you) must ensure that the tool is used in accordance with the instructions in these manuals and guidelines in the standards.


Figure 7.40 Laser warning signs.

Because Class 2 and stronger Lasers have the capacity to cast a line beyond the immediate area of use, a warning sign (fig 7.40) must be in place at all points of access.

Laser Safety Officers AS 2397-1993 requires that a laser safety officer be in place at all sites where Class 2 lasers or stronger are used. It is this persons responsibility to ensure all tools are correctly maintained and that the beams of the more powerful line generator types are confined to the site of use (not allowed to shoot across the street for example). In small, one or two person (tradesperson/employer & apprentice for example) this responsibility lands on the employer.

Lasers and the wet tradesIt is important for workers in these fields to become very knowledgeable very quickly of lasers levelling tools. These are quickly becoming the ‘norm’ rather than the exception on site. Tilers for example can now set up a level line accurately around a room with the flick of a switch. Likewise can painters. Plasterers and bricklayers can check the centre of that arch with a laser plumb line generator instead of trying to find a way of pinning a string and weight to the ceiling. Most frequently of all, plasterers use them for levelling suspended ceilings almost without exception.

It is equally important however for the tradesperson not to lose their ‘eye’ for true lines, be they plumb, level, straight or or curved. And, as with spirit levels, don’t simply rely on lasers being right, check them – constantly (see two and four point tests, page xx).


DatumIn this case Sea Level

Station

Permanent Bench Mark (PM or PBM)

Often located in pavements Temporary Bench Mark (TBM)

Usually positioned by a licensed surveyor

Figure 7.22 A Multi line Laser Line Generator. Laser array shown at right.

Other levelling proceduresLevelling procedures that are considered ‘basic’ in the construction industry cover much more than the use of spirit levels, plumb bobs and laser line generators. Other types of procedures that you may be required to do are:

1. Maintaining, marking or establishing a continuous height around various parts of a building or site.

2. Determining the difference in height between one point and another. 3. Determining the relative heights of various points with regards to a datum

In each of these cases, and the many variations of them that are possible, you may be required to use either an optical or rotary laser instrument. Before we can go further however, there are some terms or words you need to become familiar with.

Coming to terms with a few more words. DatumThis is a point to which all other heights are referenced. It is a beginning point. The datum may refer back to a mean sea level or Geoid height, the new Ellipsoid height (the Geocentric Datum of Australia or GDA) used by global positioning systems (GPS). On other occasions the datum may be a temporary mark to which a ‘nominal’ height, usually 100m, may be offered.

The purpose of a datum is to allow such things as the difference in height between the finished floor level of a building and such things as the likely flood level to be known. By this way councils can ensure buildings are located appropriately. Alternatively the datum may simply provide a point of reference to ensure that differing floor levels, window heights, tile heights, ceiling heights, and the like, are correctly maintained.

On a building site the datum is generally an easily identifiable peg or mark of known


or nominated height from which the tradesperson may work. This peg or mark is identified on a set of building plans (see fig 7.41) as a TBM (Temporary Bench Mark), BM (Bench Mark), or PM (Permanent Mark): The latter however is generally only to be found outside of the site boundary on a pavement or some council serviceable location.

Benchmarks (Fig 7.42): Permanent (PM) or Temporary (TBM) marks of known height above the original datum (sometimes these are used as the datum with a nominated height).

Permanent Bench Mark (PM)These are marks set into a pavement or other fixed structure and stamped with a reference number which is lodged at local, state and national offices. By referencing this number an accurate height above sea level (or the relevant ellipsoid or geodic datum) may be called up. This height is constantly being updated as the earth moves and the accuracy of technology improves.

Temporary Bench Mark (TBM)This sort of bench mark often no more than a nail in a fence, tree or pavement, or a pen mark on the same. At other times it is a white painted peg placed out of harms way on the site by a licensed surveyor. The surveyor having traversed this height from a nearby PM of which the height would be known (Fig 7.x).

Reduced Level or R.L. This is the height given to a point relative to, or ‘reduced from’, the datum. The word ‘reduced’ meaning in this context ‘to take from’ or ‘taken from’. So if our datum has a height of 100.00m, and the point we are measuring is 1.000m lower, then we would say that it has an R.L. of 99.00m. Note that the datum itself is always expressed as an R.L. also: so our datum in this case is said to have an R.L. of 100.00m.

Station (Figure 7.42): This is the location of the levelling instrument. Depending upon distance our undulations in the ground, there may be more than one ‘Station’ in a survey.

Stadia Lines: These are lines on the cross hairs of an optical level that can be used to determine distance (Fig 7.x). This is done by multiply by 100 the number of millimetres between the top and bottom stadia as read on the staff through the instrument. The resultant figure is the distance from the instrument to the staff

Readings: These are the heights relative to the line of collimation extending from your instrument that you ‘read’ off the staff. In the case of a laser, this is the height or distance from the peg, ground, or suspended ceiling batten, that you measure when put your receiver in line with the laser beam (fig 7.x). In optical instruments, it is this same distance or measurement that you can read off the staff or ruler when looking through the telescope (fig 7.x).

Line of Collimation: Correctly speaking this is optical centre line of the telescope on a Dumpy or automatic optical level (or any optical instrument for that mater). It can, however, also be used to refer to the line that a laser beam ‘should’ take if


correctly calibrated (set by the manufacturer or repairer to produce a perfectly level beam of light).

Choosing the right toolFor the procedures listed at the beginning of this section, either a rotary laser or an optical instrument may be chosen and used successfully. However for speed and accuracy, the laser is the better option for procedure 1 (marking or establishing a given height or level over a site). An automatic optical, or ‘dumpy’ level, on the other hand, is easier to use when trying to determine the rise and fall of the land, or simply the difference in height between two points. The down side of the optical level, however is the need generally for a second set of hands to hold the staff.

The how and why behind this type of levelling procedure The principle behind this form of levelling, be it by laser or optical instrument, is the casting of a level line from which all other points of interest are measured. This is know as the Line of Collimation. Fig 7.x shows this line being cast around the instrument a bit like a flat, perfectly level, disc. This is your level ‘plane’ (a flat horizontal surface passing through the air). With a laser, this is exactly what is occurring and in a certain light is actually visible. With an optical instrument, this is the line of sight you will have as you turn the instrument through 360°.

When trying to find the height difference between just a couple of points, your task is then fairly simple: Measure from the this ‘disc’ down to the peg or point you want (peg C) now go and do the same for the other point(s) (peg B) Subtract one from the other and you have the difference in height between these

two points. Example from Fig 7.xxPeg A is measured at 0.600m below the level plane or discPeg B is measured at 1.100m below the level plane or disc. => 1.100 – 0.600 = 0.500m 0.500m is the difference in height between Pegs A and B.

If you need these heights referenced back to a datum (say peg C) then: reference your ‘disc’ over that point. I.e. you find the height of the level plane

above the datum point or peg. Add this amount to the R.L. of the datum, this is the reference height of the level

plane. Take each of your other readings Take each reading away individually from the reference height to find the R.L. of

each peg. Example: Fig 7.xx shows a datum R.L. height of 100.00m. The ‘disc’, reference plane, or sight line, is shown as being 0.800m above this point. This means the sight line is referenced at 100.800mPeg A is measured at 0.600m below the discPeg B is measured at 1.100m below the disc. The R.L. for Peg A is 100.200 (100.800m – 0.600m)


Reading at ‘disc’ height0.800

DatumR.L. 100.00



Peg A

Peg B

The R.L. for Peg B is 99.700m (100.800m – 1.100m)

This is a very basic way of using either an optical level or laser level. It is referred to as the ‘Height of Instrument’ or ‘Line of Collimation’ method and has been shown here for its instructional value. It clearly demonstrates the how and why behind more complex approaches. It also helps to explain what is happening in the following procedures.

However, you would only use this method for identifying one or two heights on any occasion. It is not the preferred approach for doing multiple sightings. For multiple sightings you should use the rise and fall method of ‘booking’ readings. The rise and fall method is demonstrated towards the end of this section.

2. Maintaining, marking or establishing a continuous height around various parts of a building or site. This is a fairly simple levelling procedure that may be done by either laser or optical instrument, with the laser being the preferred tool due to speed and one person operation. A laser line generator is equally good if not better for this purpose.

This procedure is used when boxing up for a concrete footing, setting up tile heights to a dado line, or installing a suspended ceiling for plastering. Following the concepts laid out previously the procedure is as follows:

Set up the instrument as per the manufacturers instructions as central to the work as possible (this reduces any minor error that may be in the instrument). As mentioned previously, generally lasers are sit up lower than eye level so that you or other workers are less likely to accidentally stare into the beam.


Move staff and receiver combination up and down until it signals as being on the laser beam. The underside of the staff is now the same height as your origin point.

Lock receiver to staff at this height

Origin Point

If you already have a point set at the height to be transferred (fig 7.x): place your staff vertically upon this spot or mark. Place the laser receiver on the staff, or even a simple stick of timber, and slide it

up and down until it is correctly aligned with the laser (generally a flat line is shown on the screen. With sound on, the beeps will stop and a steady tone will be emitted).

Lock the receiver onto the staff or stick at this point. You now can move the staff and receiver around the site wherever you choose.

Whenever you align the receiver and staff combination with the laser beam, the base of the staff will be at the height you want.

If you have a datum point and a height above or below this which must be used (fig 7.x): go to the datum/bench mark and set up you staff on this point. Place the laser receiver on the staff and slide it up and down until it is correctly

aligned with the laser (generally a flat line is shown on the screen. With sound on the beeps will stop and a steady tone will be emitted).

Read off the measurement on the staff (figure 7.x) and then add or subtract the amount that you need to get to the desired height.

Lock the receiver onto the staff or stick at this new point. You now can move the staff and receiver around the site wherever you choose.

Whenever you align the receiver and staff combination with the laser beam, the base of the staff will be at the height you want.


Datum Point

Place staff on datum and read height. From this measurement subtract the height that the tile, paint or brick line is to be above the datum. Lock the receive in at this new height and proceed as with the previous example

3. Determining the relative heights of various points with regards to a datum

This sort of work is seldom done by painters, tilers or plasterers. Unless something very particular by way of curved ceiling work or sculpted tiling was being undertaken. It is however work that bricklayers may well have to undertake.

The basic way of doing this, the height of instrument method, has been described earlier. Using this method on more than three or four point however gets rather laborious and its easy to make mistakes. The Rise and Fall method was developed to reduce the chances of error, improve accuracy, and make the process faster.

This levelling procedure may be done with either laser or optical instruments. In this example an automatic optical level will be described.

Taking a Reading (Optical Levels)The surveyor’s staff (fig 7.x) is marked in solid block increments of 10mm. When reading any measuring tool, the most accurate one can be is one half of one graduation. With staffs of this type therefore, you can only work to 5mm increments. Trying to read finer is generally pointless as you are using them on rough ground or rough sawn pegs whereby the smallest stone is going to shift your reading by two or three millimetres anyway. When needing to read more accurately (and therefore over shorter distances) you would use a staff graduated like a standard ruler (fig 7.x).


When looking through an optical level you will see the image as shown in figures 7.x. You will note that, aside from the cross hairs passing through the centre, there are two other lines. These are stadia lines (see Using Stadia Lines below) and you must be wary of them. It is easy to accidentally take your reading off one of these lines, rather than the central cross hair. Figure 7.x shows a reading of 1.0m

The “Rise & Fall” method: This is a system for booking (recording) the readings taken off a survey staff. The booking sheet looks something like that shown in figure 7.x.

Readings are booked, or written down, in the order that they are taken. The value of this system is that it has a built in system for checking that you have added up your values correctly, and it provides you with the Reduced Levels (R.L.) or height in relation to your datum point, at the same time.

The term ‘rise and fall’ refers to the relationship between one reading and another. One peg or staff position being seen as either higher or lower than the previous peg, or that to be read next. Figure 7.x shows how this works: Peg B records a rise from A, whilst C records a fall from B.


Backsight IntermediateSight

Foresight Rise Fall Reduced Level

Notes

B

A

C

Peg C records a Fall when sighted after Peg B

Peg B records a rise when sighted after Peg A

Sighting Terms (Yeah, more words)This brings us to a few more terms to pick up. Figures 7.x, 7.x & 7.x help to explain these concepts.

Backsight: Oddly enough this is the term for the first sighting of any survey. It is also the first sighting taken when you change position of the instrument and begin taking readings again (change station). It refers to looking back at something to which you already have the R.L. or is nominally your starting height (100m for example). Memory tool - Think of looking to the past.

Foresight: The last sighting taken before moving your instrument (changing station) or ending the survey. Memory tool - Think of looking to the future.

Intermediate Sight: All sightings taken in between the backsight and the foresight.

Rise: An increase in height between a reading and the one taken immediately before it.

Fall: A decrease in height between a reading and the one taken immediately before it.


Peg AR.L. 75.250

From Previous survey.

Peg BR.L.

75.450

Backsight 1.200 Foresight 1.000

Ground rises 0.200m

Sea Level or ‘Datum’ R.L. 0.000

This means the ground at Peg A is 75.250m above sea level

Station 1

Station 2

Figure 7. x: Line of sight from station 1 is too low to reach the higher pegs

Booking a basic site survey. In this example surveying for a strip footing for bricks on a sloping block. As shown in figure 7.x the land is sloping too much for the level to sight a staff at all the points from the one position: the line of sight either running into the ground, or being too high to read the TBM. This means that two station positions will be required.

Figure 7.x shows the layout of the survey needing be done including the location of each station.


N

8 000

1 000TBM RL 107.200

NW NE

SW SE

1st Station

2nd Station

N

TBM RL 107.200

NW NE

SW SE

1st Station

Reading on Staff:2 500

Figure 7. x shows the level set up at Station 1 so that a sighting can be taken ‘back’ to the temporary bench mark (TBM) . This first reading is a backsight, and is ‘booked’ in the backsight column as shown in figure 7.x

Note that included in this entry is the known reduced level or R.L. for the TBM and that the name of the peg (TBM) is entred in the notes column


N

TBM RL 107.200

NW NE

SW SE

1st Station


The next sighting (figure 7.x) is a foresight to peg NW - the last sighting taken from this station before the instrument is moved.

This information is then booked as shown in figure 7.x. Note that the Change Point (CP – the point at which the level is removed to a new location) is listed in the ‘Notes’ column beside the name of the Peg: in this case ‘NW’. The next sighting will look ‘back’ to this peg.


N

TBM RL 107.200

NW NE

SW SE

2nd Station


N

TBM RL 107.200

NW NE

SW SE

2nd Station

Readings on Staff: NE 910 SE 1 255 SW 2 365

The instrument is now move to the 2nd station and a backsight is taken ‘back’ to peg NW (Fig 7.x). As there is only one ‘peg NW’ the backsight is always recorded on the same line as the previous foresight to the same peg (fig 7.x).

Sightings are now taken to all the remaining pegs. These will be ‘Intermediate Sights’ (I.S.) except for the last one: which will be a Foresight (F.S.).


It is important that sightings are recorded as they are taken, in the order that they are taken, and in the correct columns (figure 7.x). Also that all peg names or locations are correctly identified in the notes.

The Reduced Levels (R.L.) for each location are now found by adding the ‘fall’, or subtracting the ‘rise’, to the R.L. of the peg preceding it. For example the R.L. for The ‘Rise’ & ‘Fall’ for each location is now calculated by subtracting each sighting from the one preceding it. If the result is ‘positive’ it is recorded as a rise. If ‘negative’, it is recorded in the fall column.

Checking the booking - Step Three: • Subtract the initial R.L. from the last R.L.

Check that totals found from each of these steps are equal. • If not equal there is a booking or calculation error that must be found.

Checking the booking - Step Two: • Add all the Rises together.• Add all the Falls together• Subtract the Falls total from the Rises total

Checking the booking - Step one: • Add all the backsights together.• Add all the foresights together• Subtract the foresight total from the backsight total


= 0.780 = 0.780= 0.780

+

++ +

Checking your levelling equipment As stated earlier, it is critical that you do not take levelling instruments for granted. Such tools, leaser, and optical levels particularly, are easily knocked out of calibration and this can lead to significant, time-consuming (and there for expansive) error.

The ‘tow-peg test’ is a simple, quick, test that should be used frequently on all optical instruments, and particularly before and major work over long distances. It is a test than can also be used on laser line generators, although these tools ge4nerally come with a basic testing procedure described in the operator’s manual. The ‘four-pet test’ is designed for rotary laser levels as these must be tested over two axis, not one.

The two peg testThe steps for a two-peg test are as follows:Step 1.

Establish the instrument on reasonably flat ground giving clear sighting for 15 – 20m in each direction if possible.


Equal Equal

Peg A Peg B

Locate the first peg so that a staff can be easily read, but far enough away to make any error in the instrument noticeable.

Locate the second peg exactly the same distance from the centre of the instrument on the opposite side.

Where possible make the two pegs and the instrument in line with each other.

Step 2. Take and record a reading at Peg A Take and record a reading a Peg B

(For this example we will use 1.200m and 1.000m respectively)

Calculate the difference between these two readings.

I.e.


Peg A Peg B

1.2001.0000.200

In carry in these two steps correctly you will have established a known level line height that runs between the two pegs. If the instrument is correctly calibrated then this level line passes through the optical centre of the telescope. I.e. It is on the line of collimation, but we won’t know this until the completion of the test.

Should the instrument be out and reading either uphill or downhill then a level line is still established – except that this line is actually above or below the centre of the instrument. But again, we won’t know this until all the following steps are taken.

Step 3. Move the instrument to a second station approximately 5-10m beyond, but in line with, Pegs A and B.

Step 4. Readings are now taken back over the two pegs and recorded as shown below. Again the difference is calculated. This result is then compared to the difference between the original sightings. If the difference is greater than 3mm then the instrument is suspect and needs professional servicing.


1st Station

2nd Station

Peg A Peg B

Peg APeg B 2nd

Station

1.410m

1.210m

How it works and what to look for

Level correctly calibrated:The difference in height between the new sight lin and the ‘datum’ (first sight line) as read at each staff is equal. Hence there will be no difference between the two calculated figures as shown in the above table.

Level sighting up:The difference in height between the sight lines as read at each staff is unequal. This means an error would show up in the table.


0.000 (Nil Error)

1.4101.2100.200

Level sighting down:Again, the difference in height between the sight lines as read at each staff is unequal. Likewise this means an error would show up in the table.


1st Station

Pegs placed at a radius of 10 – 15m

2nd Station

3rd Station Laser head aligned the same direction at each station

This method checks the instrument in two directions across the horizontal plane

A

D

C

B

Read/Record 1st (A-B) Station

& 1st (C-D) Station

Read/Record 2nd Station

A-B

Read/Record 3rd Station

C-D

Rotating Laser LevelsThe same approach is used as previously described however 4 pegs are used instead of one. This is because the instrument needs to be checked in two directions (at 900 to each other) across the horizontal plane.

Effectively the test is performed twice: Once ‘North – South’ and again ‘East – West’A ‘Plan’ view of the layout of pegs and stations is as follows:

Book the readings as shown below. Check for variation in difference as shown by the arrows.


Difference between 1st (A-B) and 2nd stations should be less than 3mm,

likewise between 1st (C-D) and 3rd stations.

1.0200.900

0.120

0.7500.8900.140

1.2201.100

0.1200.5700.7100.140

Cleaning and storageLevelling instruments are extremely sensitive, lasers and optical instruments particularly. It is important to store and or transport them in a manner that will reduce the risks of them being bounced around .

It is good practice to: Store laser equipment in the cushioned cas supplied for it by the

manufacturer Place such tools carefully in the toolbox or carry them in the cab of the

vehicle on the floor (so they can’t fall any further) Place spirit levels in a padded carry bag, or at least place them carefully in

a secure position in the toolbox Position straight edges such that they cannot slide around or have other

things slide into them Store all your levelling equipment away from containers of wet powered

materials.

A closing wordLevelling is a critical aspect of all trades. The tools and procedures discussed in this chapter are aids in achieving that all important goal of square, straight, level and plumb. They are only tools however, and the result is totally dependent upon the skill of their user. In addition to using the right tool for the right job, you should never forget to develop skill in the use of the most important tools of all, your eyes and hands. Don’t just trust technology, test it. Test it with your eyes and hands: if it doesn’t look level, in wind or plumb, or if it doesn’t feel flat and true, then ti probably isn’t, so do something about it.


(7000 words max)

(7000 words max) Date this document was generated: 23 October 2012

CPCCCM2006A Apply basic levelling procedures

Modification HistoryNot Applicable

Unit DescriptorUnit descriptor This unit of competency specifies the outcomes required to

carry out levelling in a single plane for the purpose of establishing correct and accurate set out of buildings components. It includes the set up, testing and use of levelling devices, and establishing and transferring heights using a range of levelling equipment.

Application of the UnitApplication of the unit This unit of competency supports achievement of skills to

undertake levelling work using a variety of methods and equipment commonly used in the construction industry, which includes working with others and as a member of a team.

Licensing/Regulatory InformationNot Applicable

Pre-RequisitesPrerequisite units

CPCCOHS2001A Apply OHS requirements, policies and procedures in the

of 59© Commonwealth of Australia, 2023Glenn & Treena Costin


Prerequisite units

construction industry

Employability Skills InformationEmployability skills This unit contains employability skills.

Elements and Performance Criteria Pre-ContentElements describe the essential outcomes of a unit of competency.

Performance criteria describe the performance needed to demonstrate achievement of the element. Where bold italicised text is used, further information is detailed in the required skills and knowledge section and the range statement. Assessment of performance is to be consistent with the evidence guide.

Elements and Performance Criteria



ELEMENT PERFORMANCE CRITERIA

1. Plan and prepare. 1.1.Work instructions, including plans, specifications, quality requirements and operational details, are obtained, confirmed and applied from relevant information to prepare for basic levelling activities.

1.2.Safety (OHS) requirements are followed in accordance with safety plans and policies.

1.3.Signage and barricade requirements are identified and implemented.

1.4.Tools and equipment selected to carry out tasks are consistent with job requirements, checked for serviceability, and any faults are rectified or reported prior to commencement.

1.5.Environmental requirements are identified for the project in accordance with environmental plans and statutory and regulatory authority obligations, and are applied.

2. Set up and use levelling device.

2.1.Heights or levels to be transferred/established are identified from project plans or instructions for levelling procedures.

2.2.Levelling devices are set up and tested in accordance with manufacturer instructions, including levelling device tolerance checks.

2.3.Levelling staffs are accurately applied.2.4.Levels are shot and heights transferred to required

location and marked and/or recorded to job requirements.

2.5.Results of levelling procedure are documented to organisational requirements.

3. Clean up. 3.1.Work area is cleared and materials disposed of, reused or recycled in accordance with legislation, regulations, codes of practice and job specification.

3.2.Tools and equipment are cleaned, checked, maintained, including levelling device operator maintenance, and stored in accordance with manufacturer recommendations and standard work practices.

Required Skills and Knowledge



REQUIRED SKILLS AND KNOWLEDGE

This section describes the skills and knowledge required for this unit.

Required skills

Required skills for this unit are:

communication skills to: determine requirements enable clear and direct communication, using questioning to identify and

confirm requirements, share information, listen and understand follow instructions read and interpret:

documentation from a variety of sources drawings and specifications

report faults use language and concepts appropriate to cultural differences use and interpret non-verbal communication, such as hand signals

identifying and accurately reporting to appropriate personnel any faults in tools, equipment or materials

numeracy skills to apply measurements and make calculations organisational skills, including the ability to plan and set out work teamwork skills to work with others to action tasks and relate to people from a

range of cultural and ethnic backgrounds and with varying physical and mental abilities

technological skills to: use a range of mobile technology, such as two-way radio and mobile phones voice and hand signals to access and understand site-specific instructions.

Required knowledge

Required knowledge for this unit is:

application and requirements for line, level and plumb in construction projects basic construction processes basic mathematical techniques associated with levelling construction terminology job safety analysis (JSA) and safe work method statements levelling device types, characteristics, technical capabilities and limitations levelling techniques related to essential tasks processes for interpreting engineering drawings and sketches processes for setting out project quality requirements site and equipment safety (OHS) requirements site isolation and traffic control responsibilities and authorities symbols and construction terminology of construction plans.



Evidence Guide



EVIDENCE GUIDE

The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment This unit of competency could be assessed in the workplace or a close simulation of the workplace environment, provided that simulated or project-based assessment techniques fully replicate construction workplace conditions, materials, activities, responsibilities and procedures.

Critical aspects for assessment and evidence required to demonstrate competency in this unit

A person who demonstrates competency in this unit must be able to provide evidence of the ability to:

locate, interpret and apply relevant information, standards and specifications

comply with site safety plan, OHS regulations and state and territory legislation applicable to workplace operations

comply with organisational policies and procedures, including quality requirements

safely and effectively use tools and equipment communicate and work effectively and safely

with others transfer levels and record differences in height

on one project to job specifications using: a spirit level and straight edge levelling with water technique laser levelling devices optical levelling devices

confirm accuracy of the readings taken for all above, including set-up and movement of device in two locations

conduct a two peg test with an automatic level to confirm that instrument meets manufacturers' tolerances

accurately record the results of each levelling procedure to organisational requirements.

Context of and specific resources for assessment

This competency is to be assessed using standard and authorised work practices, safety requirements and environmental constraints.Assessment of essential underpinning knowledge will usually be conducted in an off-site context.Assessment is to comply with relevant regulatory



EVIDENCE GUIDE

or Australian standards' requirements.Resource implications for assessment include:

an induction procedure and requirement realistic tasks or simulated tasks covering the

mandatory task requirements relevant specifications and work instructions tools and equipment appropriate to applying

safe work practices support materials appropriate to activity workplace instructions relating to safe work

practices and addressing hazards and emergencies

material safety data sheets research resources, including industry related

systems information.

Reasonable adjustments for people with disabilities must be made to assessment processes where required. This could include access to modified equipment and other physical resources, and the provision of appropriate assessment support.



EVIDENCE GUIDE

Method of assessment Assessment methods must:

satisfy the endorsed Assessment Guidelines of the Construction, Plumbing and Services Training Package

include direct observation of tasks in real or simulated work conditions, with questioning to confirm the ability to consistently identify and correctly interpret the essential underpinning knowledge required for practical application

reinforce the integration of employability skills with workplace tasks and job roles

confirm that competency is verified and able to be transferred to other circumstances and environments.

Validity and sufficiency of evidence requires that:

competency will need to be demonstrated over a period of time reflecting the scope of the role and the practical requirements of the workplace

where the assessment is part of a structured learning experience the evidence collected must relate to a number of performances assessed at different points in time and separated by further learning and practice, with a decision on competency only taken at the point when the assessor has complete confidence in the person's demonstrated ability and applied knowledge

all assessment that is part of a structured learning experience must include a combination of direct, indirect and supplementary evidence.

Assessment processes and techniques should as far as is practical take into account the language, literacy and numeracy capacity of the candidate in relation to the competency being assessed.Supplementary evidence of competency may be obtained from relevant authenticated documentation from third parties, such as existing supervisors, team leaders or specialist training staff.



Range Statement



RANGE STATEMENT

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Information includes: diagrams or sketches instructions issued by authorised

organisational or external personnel manufacturer specifications and instructions maps material safety data sheets (MSDS) memos organisation work specifications and

requirements. plans and specifications relevant Australian standards safe work procedures related to performing

levelling signage verbal or written and graphical instructions work bulletins work schedules.

Basic levelling activities include: setting up of devices recording of heights or level and the transfer of

data points transferring levels/heights for formwork shooting levels for concrete slabs recording ground levels at respective critical

set out points recording slab or pad levels for placement of

steel columns or masonry piers recording or checking levels in drainage positioning offsets and recovery pegs for

construction projects.

Safety (OHS) is to be in accordance with legislation, regulations, codes of practice, organisational safety policies and procedures, and project safety plan and may include:

emergency procedures, including extinguishing fires, organisational first aid requirements and evacuation

handling of materials hazard control hazardous materials and substances safe operating procedures, including the

conduct of operational risk assessment and treatments associated with:



RANGE STATEMENT

earth leakage boxes lighting power cables, including overhead service

trays, cables and conduits restricted access barriers surrounding structures traffic control trip hazards work site visitors and the public working at heights working in confined spaces working in proximity to others working with dangerous materials

organisational first aid personal protective clothing and equipment

prescribed under legislation, regulations and workplace policies and practices

use of firefighting equipment use of tools and equipment workplace environment and safety.



RANGE STATEMENT

Tools and equipment include: chalk lines hammers marking equipment measuring tapes and rules, spirit levels and

straight edges plumb bobs saws, bolt cutters and saw stools signage for laser levelling string lines and laser targets water levels, laser levels, optical levels and

automatic levels wooden and steel pegs.

Environmental requirements include:

clean-up management waste management.

Statutory and regulatory authorities include:

federal, state and local authorities administering applicable Acts, regulations and codes of practice.

Heights or levels may be indicated by:

chalk or nail mark and marks on vertical surface

datum and survey peg drawing or sketch verbal or written instructions.

Levelling procedures: include open or closed traverse using height of instrument or rise and fall methods of reduction

may be completed in a team arrangement.

Levelling devices: include: spirit level, levelling using water, laser

level, optical level, string line, tape measure, automatic level, survey pegs, levelling staff and plumb bob

may include: boning rods, inclinometers and batter

pegs/boards.

Levelling device tolerance checks include:

reverse readings for spirit level two peg test for automatic level.

Levelling device operator maintenance:

includes: authorised servicing cleaning monitoring, recording and reporting of

faults



RANGE STATEMENT

may include conduct of authorised minor replacements.

Unit Sector(s)Unit sector Construction

Co-requisite unitsCo-requisite units Nil

Functional areaFunctional area


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