Our company recently had an incident where someone was operating a scissor lift and hit a fire sprinkler with it. The sprinkler activated, and the area flooded. This issue, unfortunately, isn’t that uncommon in the electrical, construction, and HVAC trades, but it’s preventable with proper training and attention to detail.

Those of you who work in commercial HVAC or modern multifamily residences with fire protection in each unit will come across fire sprinkler systems every day. This tech tip will cover some common situations that cause fire sprinkler systems to break and how you can prevent this costly issue.

A Fire Sprinkler Went Off—What’s the Big Deal?

Fire sprinklers have their own plumbing circuit; these are either exposed or may be hidden above the ceiling. This circuit contains high-pressure water, and there’s only one little thing preventing that water from spraying a large area.

These sprinklers contain a bulb with heat-sensitive fluid that expands when heat is applied, much like a TXV sensing bulb. (The fluid is usually red, but it may be different colors based on the heat rating. The National Fire Protection Association explains it in one of their articles.) When this fluid expands, the pressure causes it to break its glass casing. That glass bulb is the only line of defense keeping the sprinkler water from flooding the room.

The hazard of shattered glass is the least of our worries. Sprinklers act fast and can start filling a room with water very quickly. At a commercial job site, there may be electrical equipment in the area, which can be damaged and present a hazard to the people working in the area. There may also be expensive tools and building materials, products for sale, or personal possessions (such as in apartments, hotels, or storage units).

While fire sprinklers are safety devices, they are also costly and present their own set of hazards when they break. It’s a liability that NO contractor wants to deal with.

What Causes Fire Sprinklers to Break—Other Than the Obvious?

We’ve seen multiple fire sprinkler systems break in our time in the industry. Most of the time, they’ve broken because of torch work nearby (they are fire sprinklers, after all), or they're struck by a blunt object—a tool, a lighting fixture, a scissor lift that didn’t have enough clearance, the list goes on.

Torch Work

Torch work might be an obvious cause. After all, we’re introducing a fire to the area. However, many of us think about fire sprinklers as objects that stop large structural fires. In reality, no matter how small and contained that fire is, the heat it gives off can cause the fluid in the bulb to expand enough to shatter the glass. 

The best thing we can do is take protective measures anytime we’re brazing near a fire sprinkler. We always talk about protecting the air handler, compressor, valves, and TXV sensing bulbs with a wet rag (or Refrigeration Technologies WetRag) to prevent heat damage. The same principle applies to fire sprinklers. Protect the bulb so that it doesn’t heat up.

Blunt Force

Whenever people have to work near the ceiling, like when they have to install or modify vents, they might accidentally hit a fire sprinkler with a tool, a ladder or scissor lift, or even their own bodies. 

If there’s no way to keep a distance from the sprinkler, then you just have to stay aware of your surroundings. Whenever you’re working near the ceiling with fire sprinklers within reaching distance, make sure you’re minding your overhead space. Watch out whenever you’re moving ladders or scissor lifts. Whenever you hold a tool or fixture, make sure you’re far enough away from the fire sprinkler so that you don’t hit it by accident.

Preventative Measures

While being aware of your surroundings is the best way to avoid setting off fire sprinklers, there are a few practical measures you can also take.

You can find protective coverings for fire sprinklers. These may come in a solid plastic variety or cages. If you’re working with a torch, you can carefully wrap it in a wet towel.

If you’re a commercial tech working on a project that may span several days or weeks, you might consider putting up a sign warning others about fire protection in the area (or asking a supervisor to do so). Some hotels have signs warning guests not to hang clothes on fire sprinklers. Something similar would be useful to have—or maybe on a sign right outside a room with fire sprinklers near the work area. 

If the Fire Sprinklers Activate

If you’re on a job site and you or somebody else accidentally sets a fire sprinkler off, your first course of action should be to make sure that there isn’t a fire. In cases where there is a fire, we want the sprinklers to run. However, if there isn’t a fire and the sprinkler was set off because of controlled heat (i.e., a torch) or trauma, we want to shut them off as quickly as possible.

Locate the shutoff valve(s) on the main fire sprinkler supply pipe (or riser) and shut it off. These will usually be near other utilities in a building or in a labeled room. Shutting the valve(s) will stop the flow of water. 

Once you’ve stopped the flow of water, a water damage professional will need to come in to assess the situation. They can help with cleanup and provide an estimate for the damage. This estimate will come in handy when it’s time to open an insurance claim. The specifics of the insurance process will depend on the location, client, and the work being done.

One Last Word of Advice

If you’re ever at a job with a team of people, keep an eye out for one another. If someone is moving a ladder or operating a scissor lift, make sure they’ve got enough clearance, especially if they seem like they aren’t paying attention. We’re all in this together, and saying something when you see something can prevent property damage, lawsuits, and even personal injury.

Also, in case you’ve never set off a fire sprinkler before, you should know that the water reeks. Don’t subject yourself, your customers, or your team members to it if it’s at all avoidable—it’s a bad time.