The ins and outs of rooflight safety with NARM

  • 1 Feb 2022

NARMMark Wilcox, Safety Representative for NARM, the National Association of Rooflight Manufacturers, explains the role that NARM is playing in improving safety standards for workers outside on the roof – as well as for those inside the building.

“NARM was formed in the late 1990s, to provide a unified voice for the UK’s rooflight industry and to identify and promote best practice in rooflight specification and installation. Although a relatively small trade association, NARM has always ‘punched above its weight’ and today occupies a respected position, informing government and standards bodies in respect of all aspects of rooflighting, as well as supporting member companies and the wider construction industry.

Over the years, a number of topics have remained central to NARM’s work, key among these being safety. In my role as NARM’s safety representative and sitting on the UK’s Advisory Committee for Roofsafety* (ACR), I’m proud to be playing a part in this important work.

Outside on the roof – safety for workers

NARM works in close collaboration with ACR, which is the organisation behind the widely referenced Red Book: ACR(M)001 ‘Test for Non-Fragility of Large Element Roofing Assemblies’. This defines a test for non-fragility which can be applied to any roof assembly, intended to indicate whether the roof can support the instantaneous loads imposed on it by a person falling or stumbling on it. It is not a product test but products such as rooflights can be tested as part of a roof assembly.

NARM built on that excellent work by collating extensive rooflight test data from members, to create a Technical Document entitled NTD03 Application of ACR[M]001 ‘Test For Non-Fragility of Large Element Roofing Assemblies to GRP Profiled Rooflight Sheeting’. This provides comprehensive coverage of non-fragility requirements for industrial rooflights.

In the case of glass rooflights, there are unique safety issues which require a different testing standard. Glass may pass the ACR soft body impact test, but it is particularly susceptible to hard body impacts that do not form part of the ACR test.

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.

Red Book

These are referenced in the latest issue of ACR’s Red Book and NARM has recently published a document entitled Understanding CWCT Classifications of Rooflight Types, providing practical guidance for installers and specifiers.

We have also published guidance designed to clarify definitions of ‘walk-on’ rooflights, to avoid potentially dangerous specification errors. Our Technical Document NTD11 Understanding the differences between ‘non-fragile’ rooflights and ‘walk-on’ rooflights for deliberate foot traffic provides details and definitions.

I’m happy to report that due to ongoing safety initiatives, to my knowledge there have been no recorded fatalities caused by falls through rooflights of any kind manufactured since 2005.

However, the risk remains in locations where older rooflights are still in use and there is never any room for complacency when workers are required to access potentially fragile roof constructions.

When accessing roofs, for avoidance of doubt, ACR’s Orange Book, a good practice guide for work on profiled sheeted roofs, states: ‘Before commencing any work on an existing roof, it is absolutely essential that you find out whether your roof is fragile or non-fragile. This is a key decision, which should only be made by persons competent to do so. If there are any doubts, assume that the roof is fragile.’

Inside – protecting building occupants

In recent years, NARM has been made aware of a number of complaints from individuals or organisations who have installed what they believed to be high quality rooflights, only to be disappointed. More importantly, a number of these complaints have highlighted major safety concerns for building occupants.

Some of these complaints relate to products which are clearly unfit for purpose, including standard DGUs mounted horizontally to a timber frame, to form a rooflightof sorts. Others, however are less obvious but potentially equally dangerous. The use of inappropriate glazing materials in a seemingly correctrooflight is a case in point.

Current British Standards define that inner panes on rooflights must be laminated in applications more than five metres above floor level (increased to 13 metres in limited circumstances) or are located over water (eg swimming pools).

However, the relevant standard permits use of toughened glass inner panes in other applications, if a risk assessment is carried out and confirmation provided that this does not present additional risk to those below the rooflight. 


The term toughenedimplies a degree of safety which in the case of rooflights, is misleading. Toughened glass inner panes actually bring a risk of shattering and falling into the room beneath.

Therefore in my view, its difficult to see how use of a toughened rather than laminated glass inner pane doesnt present a risk to anyone beneath a rooflight, whatever the position or height of the installation. For this reason, I maintain that any risk assessment of a toughened inner pane is largely irrelevant.

NARM is currently running a campaign to address this anomaly and to bring pressure on the BSI to amend the standard. Look out for our Laminated Inner Panetick symbol on manufacturer information. You can find out more at

It should be noted that NARM’s commitment to safety also encompasses fire performance in respect of rooflights. This important subject is addressed by the Association’s fire sub-committee, to whom I defer in terms of information or guidance.

Their recent work has informed recent updates concerning fire safety, to our Technical Document entitled NTD01.3– An introduction to natural daylight design through rooflighting’, in response to the issue of new Building Regulations for each of the devolved nations of the UK.”

To access any of the documents outlined in this article, or for further information about our work, please visit

For further information, please contact NARM using the contact details on our website, where you will be directed to the appropriate person.

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