The Insight: Redundant Non-Structural Systems within AS5216:2021

17 November 2021
The Insight: Redundant Non-Structural Systems within AS5216:2021
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Design of redundant non-structural systems

Redundant non-structural systems (RNSS) apply to post-installed fasteners connecting statically indeterminate non-structural light weight systems in cracked and un-cracked concrete base material. Simply put this type of design typically applies to applications like suspended ceiling systems, pipe support systems and other types of MEP (Mechanical, Electrical and Plumbing) applications with multiple fixing points. Testing and assessment of post-installed fasteners that comply with RNSS design for safety critical applications is covered under Appendix E of AS 5216:2021.In Europe fasteners which have been tested and comply for use in RNSS hold an ETA in accordance with EAD 330747-00-0601 (Fasteners for use in concrete for multiple use for non-structural systems).


Design of RNSS means that the possible number of fixing points connecting the system cannot be less than three (3). If multiple fasteners are used at a single fixing point, these fasteners must be of the same type and dimension. The key to RNSS is that the non-structural system shall allow transfer of the load at any fixing point without significantly affecting the performance of the system. This means that if in the event of a failure or excessive slip of a fixing point, the load on the fastener in question is transferred to adjacent fixing points without damage or failure to the system. 


RNSS design however is based on a maximum design load per fixing point that is lower than that of a single point fixing design.

RNSS Design loads


- 2 kN (max.) if the number of fixing points is 3
- 3 kN (max.) if the number of fixing points is > 3

infographic demonstrating the deformation of cracked concrete

ICCONS has a complete suite of RNSS compliant fasteners which can be designed into your application using the new ICCONS DesignPRO software providing design calculations in accordance with AS 5216:2021. 


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