Strobes are not required on outdoor signals.

From what I’ve seen they’re not. I’ve seen many strobeless horns for outdoor signals.

That’s a incorrect conclusion.

It depends where you are sometimes factors include building and usage type, how far back it is from the road, etc. Here in my community strobes are required if you have a central station, master or radio box.

All the outdoor signals at UA have strobes. In fact, with the buildings that do have voice evac, all that’s outside are remote strobes.

One possible factor is that until recently, weatherproof strobes weren’t widely manufactured, so they just installed the audible, which just requires a weatherproof backbox.

But like Jake said, there’s many other factors, and of course it depends on your local code enforcer…

Many of the jurisdictions in my area require that the fire department’s sprinkler connection have a horn strobe at the location of said connection on the outside of the building. The ONLY thing that activates that specific device is the waterflow switch(es) on that particular sprinkler riser. As far as outdoor signals being used for general outdoor notification, I have seen buildings that have general fire signals located on the outside of the building, such as schools, hotels, apartments and so forth. Only one job I’ve worked on has had an outdoor signal for general evac and that was on a rootop patio/balcony area only accessible from the upper level of the building. Most of the K-12 schools in our area have outdoor intercom speakers though. Also something some of you may find interesting is that the fire marshal in Oklahoma City requires that the intercom system (in K-12 schools) be active for his final walk through of the building to determine final occupancy. Never been an issue in any other jurisdiction I’ve worked in.


For my area it seems that all exterior water flow alarms must be a horn strobe unit and must be mounted no more than 5 feet away from external shut off valves and connections (Mostly spectra alerts). All regular exterior fire alarms seem to be required to be strobeless and not be located within 25 feet of a flow alarm. (Mostly Wheelock MTs). This is just what I have noticed for my area and may or may not be accurate.

At my school, there is 1 outdoor signal with a strobe (it’s a Wheelock MT) and it’s facing the road. The rest are TrueAlert horns with weatherproof covers on them.

At my school the new building has a SpectrAlert Advance on a pole near the building and one of the frat houses has SpectrAlert Advances on the outside of the building.

It seems that in my area strobes are optional for outdoor signals. I sometimes see horn/strobes, and other times just horns used outdoors.

Are you sure the horn/strobes arnt extioror flow alarms?