NZQA registered unit standard
20754 version 2
Page 1 of 3
Title
Demonstrate knowledge of mechanical stress grading of timber
Level
2
Credits
5
Purpose
People credited with this unit standard are able to demonstrate
knowledge of: mechanical stress grading and its application in
the timber industry; and operating principles of mechanical
stress grading equipment.
Classification
Solid Wood Manufacturing > Timber Grading
Available grade
Achieved
Explanatory notes
1
All evidence requirements must be demonstrated and assessed in accordance with
the reference text: Mechanical Stress Grading, published by Competenz and
available from Competenz at http://www.competenz.org.nz, or Competenz, PO Box
9005, Newmarket, Auckland 1149.
2
International standards relevant to this unit are:
AS/NZS 1748:2006 Timber – Mechanically stress-graded for structural purposes;
AS/NZS 4490:1997 Timber – Stress-graded – Procedures for monitoring structural
properties;
AS/NZS 4063.1:2010 Characterization of structural timber – Test methods;
AS/NZS 4063.2.2010 Characterization of structural timber – Determination of
characteristic values;
NZS 3622: 2004 Verification of timber properties.
These documents are available from Bennett’s Government Bookshops or online at
http://www.standards.co.nz/.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of mechanical stress grading and its application in the timber
industry.
Evidence requirements
1.1
Role and purpose of mechanical stress grading in the timber industry are
described.
1.2
Advantages of mechanical stress grading are compared with visual grading of
timber.
Competenz
SSB Code 101571
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
1.3
20754 version 2
Page 2 of 3
The identification grades and colours for all MSG grades that are detailed by
NZS 3622 are identified.
Outcome 2
Demonstrate knowledge of operating principles of mechanical stress grading equipment.
Evidence requirements
2.1
Factors affecting timber stiffness are described.
Range
2.2
evidence of three factors required.
Methods used to mechanically stress grade timber products are described.
Range
2.3
constant load, constant deflection, sonic wave, X ray.
The terms modulus of elasticity and modulus of rupture, as they relate to
structural timber, are explained.
Planned review date
31 December 2013
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
18 December 2006
31 December 2012
Rollover and
Revision
2
15 April 2011
N/A
Consent and Moderation Requirements (CMR) reference
0173
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA, or
an inter-institutional body with delegated authority for quality assurance, before they can
report credits from assessment against unit standards or deliver courses of study leading
to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Competenz
SSB Code 101571
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
20754 version 2
Page 3 of 3
Consent requirements and an outline of the moderation system that applies to this
standard are outlined in the Consent and Moderation Requirements (CMR). The CMR
also includes useful information about special requirements for organisations wishing to
develop education and training programmes, such as minimum qualifications for tutors and
assessors, and special resource requirements.
Comments on this unit standard
Please contact the Competenz at info@competenz.org.nz if you wish to suggest changes
to the content of this unit standard.
Competenz
SSB Code 101571
 New Zealand Qualifications Authority 2016