Integrity (FRL)
Integrity is the second FRL criterion: the minutes a fire-separating element resists flames and hot gases passing through gaps, the middle figure in 60/60/60.
Ask Chalkline about this →Integrity is the second of the three FRL criteria: the time in minutes a fire-separating element resists the passage of flames and hot gases through cracks, joints or gaps. It is the middle figure in an FRL written as 60/60/60.
An FRL (fire resistance level) is three times from the standard fire test, structural adequacy / integrity / insulation. Integrity is the middle one: does the element stay sealed enough to stop flames and hot gases breaking through to the unexposed side. In the test it fails when sustained flaming occurs on the far side, a cotton pad ignites against it, or gaps open up past a set gauge. An element loses integrity when joints open, a service penetration fails, or the element distorts under heat.
Integrity only means something alongside the other two criteria: the element first has to survive (structural adequacy), and integrity is paired with insulation, which limits how much heat passes even if no flame does.
For a builder the key insight is that integrity is mostly about the joints and penetrations, not the board in the middle of the wall. Most real-world integrity failures happen at service penetrations, control joints, and the head-of-wall junction. Fire-stop them properly, collars on pipes, fire-rated sealant at joints, the correct head detail, or the rated wall will not actually achieve its FRL on site, no matter how good the wall lining is. See opening protection for protecting deliberate openings.
Also known as: FRL integrity, fire integrity.
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.