Water lies dormant in a fire sprinkler after an activation. The weather turns cold and the water freezes and expands. It expands so much that tiny cracks form in the pipe. Spring rolls around and the floodgates open in your brand new lobby. Thousands of dollars in damage happen in the fifteen minutes it takes for the water supply to be turned off. If you don't think this can happen to you, see the examples below that happened in the last few years.
Burst Fire Sprinklers in the News
In February 2015, around 500 students slept in an arena at the University of Buffalo when a frozen fire sprinkler pipe burst and caused a power outage. The frozen pipe began to melt, exposing hairline fractures, and the water dripped onto an electrical panel, shutting down the electricity and heat in the building.
Around the same time, a senior home fire protection system froze when an exterior wall's temperature got as low as 11 degrees. The pipe burst and poured 600 gallons of water onto the dining hall and 8 residential rooms.
In January 2015, an empty store at a Grand Rapids Mall didn't have heat, causing the fire sprinkler pipes to freeze. The pipe burst and triggered a water flow alarm. It seriously compromised the fire protection for three other businesses in the store as well. "Everybody's down, the whole suppression system is shut down, so everyone on the north end of the mall is without a sprinkler system," said Fire Chief Gregg Moore. When Moore arrived, water was pouring from the ceiling.
In February, 2013, the cast of "Joseph and the Technicolor Dreamcoat" were rushed from a theater when frozen fire sprinkler pipes burst and flooded the interior area. The fire department got a call about an odor of smoke and fire sprinklers activating. When the crew arrived, they found a burst fire sprinkler pipe. It was discovered that the fire sprinkler pipe froze sometime during the previous week.
"Then it just blew," said Torrington Fire Department Captain David Starr. "The water was flowing in and they (the cast members) had to get out of there quick. There's a little alley area between the two theaters and that's where the pipe is."
The Cause of Fire Sprinkler Failure
While fire sprinkler failure is rare, 87% of fires that ignite in sprinklered buildings are swiftly extinguished or contained, they do still happen. The top five reasons that fire sprinklers either did not operate or were ineffective were system shut off, inappropriate system for the type of fire, water discharge did not reach the fire, lack of maintenance, or problem with water supply/not enough water discharged. Of the five top reasons for fire sprinkler failure, four can be attributed to frozen fire sprinkler pipes.
How Do Fire Sprinkler Pipes Freeze?
Frozen fire sprinkler pipes can happen at any time during the life of a building. During construction, wet-pipe fire sprinklers can be installed during any phase of the construction; however, that does not necessarily mean that the heat is circulating through the building yet. If the fire sprinklers are installed in areas of the building not yet heated and the temperatures get below forty degrees, a pipe could freeze.
Another common issue that causes frozen fire sprinkler pipes is unheated areas, such as exterior areas, attics, or storage rooms that have dry-pipe, pre-action, dry-pendent, or dry sidewall sprinklers that have activated. If the fire sprinklers were not properly drained, the left over water could run the risk of freezing.
When water freezes, it expands in the pipe by 10%. This can cause hairline fractures in the pipe. The fractures will go unnoticed until the next warm up. The ice will begin to melt and expose the fractures. Once this occurs, water will begin pouring from the pipe, potentially causing major damage to the property. On average, 30 gallons of water a minute will be released from a burst pipe.
The most common areas for fire sprinkler pipe freezes are short-runs of pipe that are generally found in exterior walls and attics. Because they are out of the way, they are often forgotten about when the fire sprinkler system needs drained. The typical cost of a pipe burst is at least $30,000 per event.
Another side effect of frozen pipes is inadequate water supply. If a fire ignited, and a portion of the pipe was blocked by ice, it would inhibit the water flow and the nearest sprinkler head may not activate.
Prevent Frozen Fire Sprinkler Pipes
Your first opportunity to prevent frozen fire sprinklers is during the design phase. Choose a well-respected fire protection designer who knows how to design fire protection to mitigate the risks of frozen fire sprinklers. By installing dry-pipe, pre-action, dry-pendant, and dry-sidewall sprinklers, businesses will know that water is not sitting in the system unless the fire sprinkler activates. If the fire sprinkler does activate, property managers should immediately call their fire protection contractor to drain the pipes.
Once the fire protection is installed, you can take another step to prevent frozen fire sprinkler pipes. Take this five step action plan.
1) Assign an employee to be alert of weather warnings.
2) Assign someone to regularly check the fire protection during cold months.
3) Insurance companies recommend to always use a trained professional for fire protection services.
4) During annual fire protection inspections, have all valves tested by your contractor.
5) Choose a fire protection company that will train personnel on how to shut down valves in case of a burst pipe.
Keep your property safe from unnecessary damage by taking the simple precautions needed to keep fire sprinkler pipes above freezing temperatures. All it takes is a simple mistake - not draining the pipe completely or leaving a window open - to cause tens of thousands of dollars in damages.