A house fire is often a homeowner's worst nightmare. Fires can spread quickly, cause tremendous damage to the home and your possessions, and injure or kill any people or pets who are trapped inside.

Sprinkler systems are common in commercial buildings, but they are a rare sight in homes. Yet these systems can be cost-effective to install, and they can be invaluable in containing fires and limiting their damage.

How sprinklers work

A sprinkler system works by connecting sprinkler heads throughout the home to your plumbing. Lisa Kaplan Gordon, writing for the National Association of Realtors, says your pipes should have at least 100 pounds per square inch of water pressure to support a sprinkler system. Otherwise, a holding tank and pump will need to be installed to feed the sprinklers.

Each sprinkler head is triggered by an increase in temperature in the room. The Home Fire Sprinkler Coalition, a nonprofit advocacy group for residential fire sprinklers, says most sprinklers are set to go off in the early stages of a fire, when the temperature reaches 135 to 165 degrees.

This temperature is sufficient to activate the sprinkler's trigger mechanism by melting its solder or breaking a liquid-filled glass tube. Once this occurs, the sprinkler head will spray water on the surrounding area. Gordon says the system can also be connected to an alarm system to alert the fire department once the sprinkler is activated.

Installing sprinklers

It is easiest to install a sprinkler system as part of a larger renovation in your home. If the walls are already open for other work, it is easier and cheaper to install the system.

Installing sprinklers as a standalone system can be more expensive. This process will require a contractor to cut into your ceilings and walls to put in new piping, then patch and repaint these areas.

Although homeowners often believe that a sprinkler system will be excessively expensive to install, the costs are actually rather modest. Paul F.P. Pogue, writing for Angie's List, says the average cost of installation is $1.35 per square foot. In some markets, the installation can be accomplished for less than a dollar per square foot.

Sprinkler installation isn't a project you should tackle yourself. You should find a licensed contractor for the job.

Benefits

The main benefit of a residential sprinkler system is, of course, increased safety. According to the National Fire Protection Association, a sprinkler system in the home reduces the chance of a fatal fire by about 80 percent. The average property loss in a fire is about 70 percent less compared to homes without sprinkler systems.

These benefits are particularly important due to the fire risks in modern homes. Pogue says engineered wood used in newer homes will burn faster than traditional construction materials. This means that fires in newer homes spread faster, and that firefighters may not be able to safely enter the home after arriving. Newer homes and home possessions also include more plastics and synthetics, which can burn faster and at higher temperatures.

The Home Fire Sprinkler Coalition says the prompt activation of a sprinkler system is often enough to extinguish the flames. Alternatively, it can help control the fire and smoke, giving occupants more time to escape and limiting the damage until the fire department's arrival.

According to the Massachusetts Executive Office of Public Safety and Security, the average sprinkler system will use 341 gallons of water to control a fire. By comparison, fire hoses typically spray 2,935 gallons of water in and on your home during firefighting efforts. Sprinkler systems will cause some water damage when controlling a fire, but not nearly as much as a fire hose.

Since a sprinkler system can reduce the extent of damage caused by a fire, your insurer is often willing to reward you. According to the home improvement site HomeAdvisor, the average homeowner saves 8 percent on their insurance after the installation of a sprinkler system.

Maintenance and concerns

Homeowners may not like the appearance of a sprinkler head hanging down from their ceiling. However, it is possible to install sprinklers so that they are flush with the surface or even concealed.

Anyone who has had to silence a smoke alarm after burning a meal will likely worry that a similar incident will cause a sprinkler to douse their kitchen. But since the sprinklers are triggered by heat rather than smoke or steam, there's no need to worry about this type of accidental activation.

Similarly, the activation of one sprinkler won't cause all others on the system to go off. Sprinkler heads are triggered individually, so they will only spray water in rooms where the temperature has risen significantly.

Homeowners do need to be aware of some ways a sprinkler can cause water damage, however. Kauffman Co., an automatic sprinkler company in Houston, Texas, says sprinklers can be activated due to accidental overheating. This can occur when the sprinkler head is exposed to hot work lamps, or even if they are located near a skylight. Sprinklers located in areas subject to higher temperatures can be adjusted to go off when the temperature reaches 200 to 300 degrees.

As with any water pipe in your home, the sprinkler system can cause water damage if its pipes freeze during the winter. Damage to the sprinklers, such as tampering or corrosion, can also cause leaks or accidental activation.

A professional should inspect the sprinkler system at least once a year to make sure it is in proper working order. You should also periodically check to see that sprinkler heads are not blocked, water valves are open, and any storage tanks on the system are full.

Once a year, conduct a flow test using the system's outdoor valve. Gordon says this test will ensure that the system is working and properly pressurized. If the system is connected to an alarm, let your alarm company know that you are doing the test so they don't dispatch the fire department to your home.