What we found
A ceiling-mount sprinkler head loaded with dust and corrosion on the fusible element. Heads in this condition look fine from across the room but won’t open at their listed activation temperature — and if they do, they’ll dump the wrong flow.
What we did
Isolated the affected branch line, swapped the deteriorated head for a new listed head of the same temperature rating and K-factor, restored service, and noted the replacement in the inspection report.
Why it matters
Sprinkler heads are listed for the conditions they’re installed in. Corrosion, paint, and heavy dust loading all degrade the activation curve. The fix is cheap; the failure mode it prevents — the system not opening when it needs to — is not.
