A fire watch is required in Michigan when a fire protection system is out of service and the fire code official calls for one. Notify the fire department and the fire code official immediately, then evacuate the building or post an approved watch until the system returns to service.
That comes from Section 901.7 of the International Fire Code, which Michigan builds its fire prevention code on.
Notice what the sentence above leaves out. Nowhere in that requirement does a specific number of hours appear.
The number you were quoted comes from a different code
Search this question and the answers arrive fast: four hours for a fire alarm, ten hours for a sprinkler system.
Those figures are correct. They come from NFPA 101, the Life Safety Code, and from NFPA 25, the standard covering water-based fire protection systems.
Michigan’s fire prevention code is built on the International Fire Code. The Bureau of Fire Services administers it, within the Department of Licensing and Regulatory Affairs.
IFC 901.7 sets no threshold in hours. It requires immediate notification, and it gives the fire code official the decision on whether the building is evacuated or watched.
The NFPA figures apply where NFPA 101 or NFPA 25 governs the property. Hospital accreditation, insurer requirements, and occupancy standards pull those thresholds back in.
For a Metro Detroit office building, plant, or retail center, the practical answer is shorter. Call it in, then do what the fire code official says.
The edition your city adopted changes the details
Michigan jurisdictions adopt IFC editions by local ordinance, and those editions differ from city to city.
Ann Arbor began enforcing the 2021 International Fire Code in April 2025. Other Michigan cities work from the 2021 edition, and some have moved toward the 2024 edition.
Section numbers and specific provisions shift between editions. Before a planned impairment, confirm the edition with the authority having jurisdiction for your address.
What the code requires of the watch itself
The IFC defines a fire watch as a temporary measure providing continuous and systematic surveillance by one or more qualified people. The purpose is to spot fire hazards, detect early signs of fire, raise an alarm, and notify the fire department.
Three requirements decide whether your watch is compliant.
The person on watch performs constant patrols of the protected premises and watches for fires. Under 901.7, that is their only duty.
The watch has at least one approved means of notifying the fire department. A cell phone with no signal in a stairwell fails that test.
The watch continues until the system returns to service.
That single word “only” in the code is where most watches fail an inspection. A maintenance tech asked to walk the building between other tasks is not a fire watch. Neither is a front desk attendant covering the lobby.
Someone has to own the impairment
The building owner designates an impairment coordinator. Absent a designated person, the code treats the owner as the coordinator.
The coordinator handles notification, tags the system to show it has been removed from service, and manages the return to service.
When the system comes back, the coordinator verifies the restoration steps. That includes advising supervisors in the affected areas and advising the fire department that protection has returned.
Write the coordinator’s name into your impairment procedure before you need it. During an unplanned outage at 11pm, that question burns twenty minutes.
Situations beyond a system outage
A fire code official can require a watch for reasons other than an impairment.
Overcrowding at an assembly event can trigger it. So can the nature of an activity on the premises, or hot work such as welding and cutting. Repeated nuisance alarms can also prompt a watch until the system is repaired.
Hot work brings its own set of rules, including a required watch period after the work stops.
Planned outages are the easy case
A scheduled sprinkler modification, an alarm panel replacement, or a system test is a known date on a calendar.
Call the fire code official during business hours, before the contractor arrives. Arrange coverage for the full window rather than the estimated window.
Unplanned outages are the expensive ones, which is why the number for fire watch services belongs in your phone before a panel fails. On a jobsite, the same applies to construction fire watch during welding and cutting.
When the panel goes down tonight
Metro One Security posts fire watch coverage across Wayne, Oakland, Macomb, and Washtenaw counties, with documented patrols and hourly logs.
Call (248) 436-4799 or request a quote. Confirm your requirement with your local fire code official, since the authority having jurisdiction makes the final call on your building.