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The Red Book -Test for non fragility

ACR materials standard

ACR(M)001-2014 [fifth edition] “Test for non fragility of Profile Sheeted Roofing Assemblies”

This publication describes a test standard which can be applied to any product which will form a roof or part of a roof and is intended to provide information about whether it can support the instantaneous loads imposed on it by a person stumbling or falling on it.

Assemblies, when tested by a competent person, may be classified as :

      • Non Fragile -Class A
      • Non Fragile - Class B
      • Non fragile - Class C

 If an assembly fails this test it must be classified as   “fragile ”.

The 5th edition incorporates glass rooflights for the first time by the inclusion of double skin glazing into the standard and reference to the Centre for Window and Cladding Technology (CWCT) Technical guidance notes 66,67 and 92 .

The previous 4 editions of this standard did not preclude glass, but had not accounted for the unique safety issues associated with glass.  Whilst glass may pass the ACR soft body impact test set out in this document,  it is particularly susceptible to hard body impacts that do not form part of the ACR test. These may cause it to shatter, and may allow shards of glass to fall onto people below.

This has been recognised by the glass industry for some time and as a result the Centre for Window and Cladding Technology (CWCT) devised specific non-fragility tests for large area glazing. These are based on the ACR soft body impact test, together with additional hard body impact tests, and limit the size of shards of glass falling from broken panes, to minimise risk to any personnel beneath. 

CWCT, working in conjunction with ACR, have been able to develop a simplified test method, and also a “deemed to satisfy”
solution, for these applications, where maintenance personnel will not walk intentionally on the glazing, but might accidentally step or fall onto the glazing.

Other important changes  are highlighted on page 2 of the new edition and all Test Providers must ensure that they fully understand these changes.

In particular there has been a more detailed determination of the height of the second drop of the sand bag impactor

 Roofs incorporating fragile assemblies constitute a “fragile surface” under Regulation 2 of the Work at Height Regulations 2005  requiring appropriate safety precautions to be taken to comply with the legal requirements of Regulation 9  (utilizing work equipment selected in accordance with the hierarchy  detailed in Regulation 6) of those regulations.

For the correct way to reference the  Red Book in publications please see the Red Book FAQs and for “acceptable use” of the Red Book see ACR’s Legal page

Second edition published 2000

Third edition published 24/4/2005

Fourth Edition published 7/11/2011

Fifth Edition published 31/05/2014

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The Advisory Committee for Roofsafety [ACR] is a body dedicated to making working on roofs safer.  Its membership is made up of nominees from the major roofworking Federations and Associations and the Health & Safety Executive, who provide the experience of many years of involvement in working on roofs in the advice given in their documents.Every care and attention is taken to ensure the accuracy of the information included in their documents and this website, however the committee or any individual committtee members can not accept responsibility for any errors or omissions contained therein