Winter Prep: Protecting Your Fire Sprinkler System From Freezing

A frozen sprinkler pipe is one of the few fire-protection failures that causes damage on its own, before any fire is involved. Water expands as it freezes, and a burst pipe in a wet system can flood the exact space it was installed to protect -- something we see a handful of times every winter across Central Ohio, almost always in preventable spots.

Where freezing actually happens

It's rarely the main runs through heated space that freeze. The usual suspects are unheated areas that don't get a second thought the rest of the year: attic spaces, loading docks, stairwells with an exterior door propped open, and dry-system piping in spaces that swing colder than the rest of the building.

What to check before cold weather sets in

• Confirm heating is actually working (not just present) in any room or enclosure with sprinkler piping -- a broken unit heater in a mechanical room is the single most common cause we find.
• Check that low-point drains on dry systems are drained and free of trapped water, which is what actually splits a pipe when it freezes.
• Look for doors, windows, or loading dock openings that let cold air onto piping that was designed to stay above freezing.
• For dry-pipe systems, confirm air pressure is holding where it should -- a slow leak that's fine in summer can become a real problem once temperatures swing.
• If antifreeze loops are part of your system, confirm the solution concentration is still correct -- it can drift over time and needs to be checked, not assumed.

This is a facilities job, with one exception

Most of this is a building-maintenance checklist, not something that requires a licensed inspector -- keeping heat on and doors closed doesn't need special training. The exception is anything involving the system itself: air pressure, antifreeze concentration, or a dry-pipe valve that isn't behaving the way it should. If something there looks off, that's worth a call before winter, not after a pipe splits.