Structural adequacy (FRL)
Structural adequacy is the first FRL criterion: the minutes a load-bearing element keeps carrying load in a fire test. A dash means it is non-load-bearing.
Ask Chalkline about this →Structural adequacy is the first of the three FRL criteria: the time in minutes a load-bearing element keeps carrying its load in the standard fire-resistance test. It is written first in an FRL like 60/60/60. A dash in that first position (for example -/60/60) means the element is non-load-bearing.
A fire resistance level is three numbers, read in order:
- Structural adequacy, can the element keep carrying its load,
- Integrity, does it stop flames and hot gases passing through, and
- Insulation, does it limit heat transfer to the far side.
Structural adequacy applies only where there is a load to maintain: a load-bearing wall, a column, a beam, a floor. For these the figure is how long the element keeps supporting its load under fire before it fails in the test. A non-load-bearing element (a partition that only has to separate, not support) carries a dash here, because there is no structural load to sustain.
For a builder the practical point is to be clear whether the element is load-bearing, because it changes which FRL you need and what that first number means. Specifying or building a -/60/60 system in a position where the wall actually carries load (so it needs 60/60/60) is a real and dangerous error. And the rating only holds if the construction matches the tested system: the structural-adequacy figure assumes the element is built exactly as tested, with the right linings, fixings and framing.
Also known as: Load-bearing capacity (fire), FRL structural adequacy.
Category: Fire / FRL.
Related
See also
References
- FRL (Chalkline) (verified 2026-06-01)
Last updated: 2026-06-01. Verified: 2026-06-01. Quarterly review for currency.