Sprinklers extinguish fires, but isn't there still damage due to water discharge?

The argument that sprinklers may extinguish a fire but still cause an excess of water damage is incorrect for many reasons. Contrary to popular belief, only one head activates at a time, the head closest to the area with the highest temperature. Usually, one head is enough to extinguish the fire.

Sprinklers only release 8 to 24 gallons of water per minute, and on the average, run for only 3 minutes. Besides, sprinklers generally only cover 250 to 300 square feet. Compared to that of a fire hose, which sprays 50 to125 gallons of water per minute and can soak an entire house before extinguishing a fire, sprinkler damage is minimal.

Insurance companies offer discounts for homes equipped with sprinklers, but doesn't the threat and preventive maintenance of leaks, water damage, and mildew offset the discount?

Insurance companies generally offer 10 to 15% discounts for sprinkler systems. Some offer as much as 20 to 25%. Sprinkler leaks occurring from faulty installation or frozen piping can cause damage; however, if caught within a reasonable time, the damage is minimal. Accidental activation of a sprinkler system is extremely rare and usually only occurs with improper usage.

Is it true smoke alarms save lives and fire sprinklers save property?

Smoke detectors increase the chances of alerting sleeping residents to a potential fire but do nothing to notify authorities, extinguish the fire, or protect those physically unable to escape on their own (i.e., the elderly, or small children). Sprinkler systems, in most cases, extinguish a fire or at least contain it until authorities can arrive. With the addition of a flow switch, sprinkler systems contact authorities upon activation.

Aren't fire sprinklers expensive?

Permit costs in the jurisdictions generally elevate costs associated with sprinkler systems. Sprinkler systems make up about 1% (on average) of the total building cost (similar to the new carpet). A recent report by Newport Partners states that the national average price per square foot for a sprinkler system in a new single-family home is $1.61.

While residential fire deaths have sharply declined in the U.S. from 1979 to 1999, isn't this due to better building materials such as Plexiglass, fire-rated drywall, etc. – not fire sprinklers?

While it is true that residential fire deaths have declined, a sampling from a study done in PG County from 1990 to 1993 shows that 22 deaths and 46 injuries still occurred. While this is a marked decrease, it is reasonable to decrease death and injury further where possible to do so.

How is the installation of fire sprinklers in new residential construction going to reduce fire death?

Installing fire sprinklers in new residential construction will certainly reduce fire deaths, as shown in several studies in test areas in the United States. Using Prince Georges County as a pertinent reference: In the 1980s, this county reported an average of 14 fire deaths a year and 104 fire injuries occurring annually, with 89% of these losses occurring in residential properties. After the application of sprinkler law passed, an estimated 154 lives were saved from potential fire-related deaths, and only seven injuries were reported from 1989 to 1999.

Have jurisdictions with residential sprinkler requirements (Montgomery and Prince Georges Counties) seen a reduction in fire deaths?

As shown by our research, Prince Georges County HAS demonstrated a significant decrease in fire deaths. As Montgomery County has only recently passed a sprinkler law, the significant figures for or against sprinkler systems are unknown.

Why is it that smoke alarm manufacturers recommend replacing batteries twice a year, and sprinkler head manufacturers recommend changing them every 10 years?

The recommendation is for the replacement of smoke detectors every 10 years in residences. In residential homes, sprinklers do not need to be changed every 10 years. Commercial buildings must follow the rules of NFPA 25 for inspections and replacement of sprinkler heads. (Residential structures are not required to conform to NFPA 25. However, it is a good practice to get the sprinkler system tested once per year and the backflow preventer replaced every 5 years.)

Facts for the answers came from the AFSA, NFPA, and the case study "Residential Sprinklers: One community's experience twelve years after mandatory implementation" by Ronald Jon Siarnicki.

To get additional answers to your questions about sprinklers and fire safety, turn to the experts at Metfire.