Catastrophic failure leading to the property loss of millions of dollars spreading across 3 multi-storied hotels. Poole Fire Protection's roll was to evaluate the loss and existing system in order to determine what caused the failure. Poole Fire Protection scope included traveling to and from all sites, conducting site observation of commercial building sprinkler, fire alarm and general building construction, and provide verbal and written report of findings.
There was a severe freeze that covered a large part of the Midwest on the date of the loss. In some areas this event was categorized as severe catastrophe. This freeze resulted in frozen pipes breaking in the attics of all three hotels. Investigating possible contributing causes other than weather conditions was the main analysis to be conducted for all three sites.
All risk locations are multi-storied hotels, each having 3 stories. They are wood framed structures with EFIS exteriors. They all have automatic fire suppression systems and all the amenities of a mid-range hotel. The interior surfaces are made up of carpet, tile and laminate wood floors, painted drywall walls and ceilings with sprayed on popcorn acoustic on the ceilings that are not covered by a suspended acoustical tile ceiling.
Poole Fire Protection performed a fire modeling scenario to show how the fire reacted within the environment as to which it was set.
Poole Fire Protection conducted an initial failure investigation report, observing the initial conditions of the system as well as gathering additional information from the employees at each hotel. Items verified included Failure Date and Time, Length of time water flow occurred due to failure, and Prior maintenance/system issues that have been documented. At the time of our observations damages to the interior finishes and overall construction of all facilities appeared to have be partially repaired. Poole Fire Protection expressed concerns that the repairs be completed after our initial visits in order to prevent existing deficiencies from being covered up.
Evaluations verified by site visits and discussions with property management that the fire sprinkler system designed to serve the facility were indeed the correct systems (Dry system for the attic and Wet system for areas not exposed to freezing).
Wet-pipe sprinkler systems are normally filled with water under pressure and utilize closed sprinklers equipped with thermal elements. This system was equipped with pressure gauges to ensure that adequate pressure is being provided to the system for proper operation.
Dry sprinkler systems are designed to be utilized in sub-freezing environments. A dry-pipe sprinkler system is one in which pipes are filled with pressurized air (sometimes nitrogen) rather than water. This air holds a remote valve, known as the dry pipe valve, in a closed position. Located in a heated space, the dry-pipe valve prevents water from entering the pipe until a fire causes one or more sprinklers to operate. Once this happens, the air escapes and the dry pipe valve releases. Water than enters the pipe flowing through the open sprinklers.
Poole Fire Protection concluded through observations and research that the dry sprinkler system failure occurred when the dry system was partially full of water, rather than being completely full of compressed air. The presence of water within the system can be due to a few issues; there were installation issues found at each site, including improperly sloped systems which would result in drainage concerns. In addition, maintenance failure could have been a probably if draining procedures were not implemented properly by the contractor during the most recent inspections.
Jack Poole, PE, FSFPE, is a registered Professional Engineer in Fire Protection, licensed in over 50 states and territories. Principal of Poole Fire Protection, he is involved in the day-to-day activities of code consulting, life safety analyses, design of engineering alternatives, fire protection system design, and construction management services.
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