Non-Fragility
To reduce the risk of falls through roofs the Advisory Committee of Roofsaftey (ACR) along with the Health & Safety Executive commissioned and published material standard ACR[M]001:2000 ‘Test for Fragility of Roofing Assemblies’.
It was agreed that Non-Fragility cannot be claimed of a single component in isolation. It is only the installed system combination, including the profiles, rooflights, fasteners and sealants, that can be described as Non-Fragile and only when successfully tested as an 'assembly'.
Non-fragility Test Criteria: 45kg bag dropped from 1200mm height onto test sample
Fragile: The bag drops through or creates a hole large enough for a person to fall through
Class C (Non-fragile): The bag is retained for five minutes minimum
Class B (Non-Fragile): Bag is retained for a further five minutes following a second drop on the same area
Class A (Non-Fragile): No significant damage to the test sample (Concrete roofs only)
The fourth edition of the ACR document has recently been issued; ACR[M]001: 2011 ‘Test for Non-Fragility of Profiled Sheeted and Large Element Roofing Assemblies’.
All CA Building Products' roof systems, when fully and finally fixed, achieve Class B classification. The Non-Fragility tests have been undertaken to the following criteria;
- ≤1800mm purlin centres
- 1.5mm (minimum) thick purlins
- ≤70° hip angles
- ≥45m self-curved roofs
- ≤45m crimp-curved roofs
- Therma-light rooflights installed over metal on both side laps
- Single, double and multi-spanning metal liners and top sheets
- Double and multi-spanning liner and external rooflights only, (i.e. no single spanning rooflights)
- All edge distances, (liner, GRP Therma-light liner, top sheet & GRP Therma-light top sheet) fixing patterns and sealants as stated in the installation guide
Terminology
- Non-Fragile – In the event of a fall you will not go through the roof - May not be walkable
- Walkable – In the event of a fall you could go through the roof - May be walkable but not advised
- Non-Fragile and Walkable – It is safe to walk across the roof without damage or fear of falling through
For further help and advice please see the following Technical Information papers (TIPs)