BIM News

Rooflight Fragility Testing and the Importance of Compliance


In spite of rooflighting being incorporated, in some form or other, into architecture for generations, it has only been in the past thirty years or so that they have been expected to be safe for humans to walk on. Gone are the days when rooflights were merely for improved lighting conditions. Nowadays, rooflights are for light, ventilation, fire safety and even emergency evacuation, so it is little wonder that there is a need for at least some kinds of rooflight to be able to withstand the weight of a person under various conditions. Especially in light of falls through rooflights and fragile roofing materials being the number one cause of roofer and construction worker deaths by an alarming margin. Construction companies and their managers being sued for thousands, if not millions, for their negligence is not uncommon, and rooflight fatalities have become worryingly common.

This is why official bodies, such as the Advisory Committee for Roofsafety and the National Association of Rooflight Manufacturers have come to formation, and taken steps towards improved health and safety conditions for roofers in working environments. One of the most significant such steps is the composition of formal regulations with which to test the safety of roofs and rooflights, known as the ACR[M]001, or Red Book.

The Red Book details the official testing procedure that modern roofs and rooflights must pass in order to be determined safe to work on and able to support instantaneous loads. The criteria of the Red Book tests award each site a non-fragility grade from A-C, with A being the most non-fragile, and C being the least. However, several variables mean that despite best efforts, neither the ACR[M]001 or any other testing method will be 100% fool proof. For instance, testing is carried out on brand new rooflights, at which point installations are likely to be in their best condition. However, no forecasts are made about the rate of deterioration which is unfortunately to be expected. Over time, rooflight materials, such as acrylic, are liable to become brittle and breakable, even when there is no outer sign of wear and tear. It is very important to remember that only rooflights specifically identified as ‘walk-on’ should support the weight of a person, regardless of non-fragility grade. The Red Book test should be carried out on every single installation without fail in order to remain a company of good repute and with proper consideration for the health and safety of their customers and employees.

The prominence of rooflight-related deaths and injuries has forced construction companies and governing bodies to make health and safety a bigger focus than ever before, with severe punishments and fines issued to non-compliers. Compliance with ACR[M]001 is essential to holding on to the trust of employees, customers and regulators and continuing to operate a healthy and well-respected construction company.

About the Author: 

Will Goodenough  - Key Account Manager at Whitesales.

Will works with his team to provide roof glazing solutions to enhance internal environments through the use of natural light. This involves working with specifiers, contractors and merchants providing condition reports, site surveys, detailed design solutions, budget costs and ultimately delivery to site, including installation where necessary. Whitesales team are committed to working closely with their clients to understand their needs in order to deliver tailored design and cost solutions. You can find Whitesales website here:

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