Should you consider fire sprinklers?
"We're at the crest of a wave,' claims Ron Coleman, fire chief for San Clemente, California. In 1980, that city became the first in the nation to adopt a fire sprinkler ordinance for new houses. Now, more than 2,000 in the city are equipped with fire sprinklers, and dozens of other cities in the West and throughout the country are following suit.
Why? Residential fires cause more than 5,000 deaths and $3 billion in damage every year. Even though smoke detectors have helped reduce the number of fire deaths by 50 percent in the last decade, detectors don't put out flames. And sometimes firefighters can't reach burning houses before major damage is done.
While municipal fire protection costs have steadily climbed, the costs of efficient, in-house fire protection systems have dropped to more affordable levels. San Clemente and other cities have found they can get by with fewer new fire stations, hydrants, trucks, and firefighters, and possibly avoid or reduce future property tax increases for fire protection. Another potential benefit: reduced fire insurance rates.
But be forewarned: you may have trouble finding a professional in your area willing to retrofit your house with sprinklers. Sprinkler contractors are generally qualified but many are reluctant to enter an unknown market. Plumbers and other tradesmen are just now learning about the materials and installation procedures that meet new standards.
And note also: Sunset found no installer or fire-fighting professional who would recommend it as a do-it-yourself job.
The West leads the way in research
Key component in a modern residential system is the new quick-response sprinkler head. The result of a decade of intensive research, it is much more sensitive than the so-called commercial head.
In 1980, after seven years of testing by the U.S. Fire Administration and the Factory Mutual Research Corporation (FMRC), the National Fire Protection Association (NFPA), an independent research group, established an updated voluntary standard (13D-1980) for the installation of quick-response sprinklers in one- and two- family dwellings. Local and state agencies may use derivations of this standard. In 1981 and 1982, Underwriters' Laboratories (UL) approved and listed the first residential fire sprinklers.
Western cities and states have been at the forefront in testing these sprinklers and writing legislation for them. Government and industry conducted more than 70 test burns in Los Angeles, San Francisco, Phoenix, and Scottsdale, as well as in other parts of the country, to help refine designs and standards.
San Clemente and Corte Madera, California, established the first residential sprinkler ordinances. Alaska reduced by 2 percent the tax assessment on sprinkler-equipped structures. Dozens of cities and counties in Arizona, California, Nevada, and Washington have added provisions to building codes regulating these sprinklers.
Most fire industry experts agree that sprinklers could become standard in all new houses within five years, much as smoke detectors have in the last five.
But what about retrofitting your house with a system? Does it require tearing out walls and ceilings? How much does it cost? Will the heads go off inadvertently? For answers, let's look at how the systems work, what hardware they use, and sources of products and information.
What's in a home psrinkler system?
Basically, it consists of a network of plastic or metal pipes (see drawing on page 116) running from the city water line to the attic, where pipes are strapped to ceiling joists. Sprinkler heads protrude through the ceiling or walls. The system uses the same water as the rest of the house, but has its own set of valves, drains, and gauges, as well as an alarm.
For a new house of about 2,000 square feet, the installed cost would be somewhere between $1,000 and $2,500. (Half or more of the cost is for labor.)
For a same-size existing one-story house, expect to pay $1,500 to $3,500, because of the time-consuming problems of fitting pipes behind already-in-place walls and ceilings; it's usually a one- to two-day job. Older two-story houses are more difficult and expensive to retrofit, since the job may involve hiding pipes behind soffits, moldings, or along beams.
According to the NFPA 13D standard, all rooms should be equipped with sprinklers, except for bathrooms less than 55 square feet, closets less than 24 square feet, open porches, carports, attics not used for storage, and foyers. But many experts think garages and attics need sprinklers too.
Sprinkler heads should be placed to cover the entire area of a room, including the walls. Heads should be spaced 8 to 12 feet apart and 6 to 8 feet away from a wall, depending on their specifications.
Residential sprinklers are designed as lifesafety devices: They should go off before smoke, gases, or heat from flames overwhelm people caught in a room. The latest heads discharge within 6 to 20 seconds of sensing temperatures around 140|.
That's usually after flames build up, say, from a wastepaper basket fire to engulf a couch or curtains, but before the room reaches the flashover point, when the entire room can burst into flame. The heads won't discharge if someone lights a cigarette or a flame leaps briefly from a stove--or if a head is hit by accident.
Putting it all together
You'll want to discuss with your installer which combination of the following components best suits your house.
Header. The header connects to the existing water main and rises up to the attic pipe network. Fittings are off-the-shelf plumbing items: a check valve, drain valve, water flow shut-off valve, p.s.i. (pounds per square inch) pressure gauge, an electric water flow switch that connects to an alarm bell, and an anti-water-hammer device. Local jurisdictions might omit some of these.
When water begins flowing through any of the sprinkler heads, the alarm goes off. It can be a siren, bell, or an electronic signal that rings the nearest fire station directly.
Pipe. Steel and copper pipe are the most common; they're strong, resist expanding or contracting in heat, and the fittings can easily withstand the pressures of a sprinkler system. But they're relatively expensive, heavy, and hard to install in tight attics or other awkward spaces.
The NFPA 13D standard allows other pipe, such as flexible polybutylene plastic pipe, only if it has been approved by an independent agency testing for the fire protection market. At our press time, only one manufacturer of polybutylene pipe (Trojan Plastics; see list on page 126) had been approved by FMRC; at least three others are waiting in line. Because it's light, flexible, and easy to snake into tight spaces, polybutylene is considered the easiest to install, especially in retrofits. It can withstand high attic temperatures and freeze-thaw cycles without loss of strength.
However, polybutylene is best joined with a heat fusion device, which literally welds plastic fittings to the pipe. Though it makes for foolproof joints, the device operates at 500| or hotter and must be used with extreme caution in attics and other tight spaces. Moreover, not many tradesmen have the tool. You can write or call the polybutylene distributors we list for professionals in your area with heat fusion devices.
Another plastic pipe, CPVC (chlorinated polyvinyl chloride, primarily for hot-water plumbing) is sometimes used, though it isn't approved by the 13D standard. It's light, costs less than steel or copper, and is usually joined with solvents and cements. A CPVC system can be largely preassembled before going up, but its stiffness can also make longer lengths difficult to handle in tight spaces.
Sprinklers. Two companies (Grinnell Fire Protection Systems and Central Sprinkler Corporation) now make nearly a dozen types of residential sprinkler heads listed with UL; as we go to press, another dozen by other companies are awaiting listing with UL or other testing facilities.
Pendent or sidewall heads cover at least 144 square feet (about a 13 1/2-foot circle); some cover up to 324 square feet (about a 20-foot circle), depending on water supply and pressure. Each releases an umbrella-shaped spray that should reach high on the room's walls. Some heads mount flush with the ceiling or wall, others protrude up to 2 inches, as shown at left.
To limit water damage, only two sprinklers within the system should discharge at any one time, and usually only the one closest to the flames. Based on standard home water pressure of 35 pounds or more per square inch, one head will discharge at least 18 gallons per minute.
A new breed of sprinklers, possibly available next year, will have a mechanism to shut off water flow after temperatures drop. As of now, the system must be turned off manually at the shut-off valve.
In an emergency . . .
Is water damage from a sprinkler system a problem? Relatively speaking, it's not nearly as harmful as the spray from a fireman's 1 1/2-inch hose, which can quickly cause more damage than the fire itself. But there will be some damage. You can reduce it by acting quickly.
First, if you hear a smoke detector or sprinkler alarm go off, get everyone out of the house and call the fire department. If it's safe to do so, quickly investigate to see if the fire has been put out by the sprinklers. If so, close the flow shut-off valve and wait for help to arrive.
If there are still flames or heavy smoke, vacate the house and leave the system running. Don't go back into the house until firemen say it's safe. Charred floorboards or smoldering furniture could injure you. There may also be live electric circuits indoors--deadly with water around. When firemen think it's safe, turn off both the house's electricity and the sprinkler system, then check the damage.
One note: standard homeowner's fire insurance should cover any damage due to sprinklers but check with your insurance company before you install the system.
What about retrofitting?
In existing houses, installers have to crawl through attics, working around already-in-place insulation and ducts. In two-story houses, they may have to remove sections of floor. After marking the location of each sprinkler and preassembling the system as much as possible, they will lay out pipes in the attic, then drill holes in ceilings. Once all heads are in place and pipes are connected, the whole system will be tested for leakage, usually with an air compressor.
Before you hire an installer to put in a system, make sure he has put them in before. Ask to see other sprinkler jobs he's done and talk with those homeowners.
Before you buy, ask your local fire inspector for advice on ordinances and codes. He may come out to your house to see if there are any major problems to anticipate. Houses with cathedral ceilings, well-water systems, or hard-to-reach secondstory areas, for example, may require special designs.
Also, check with your insurance company for possible reductions in your fire insurance rates. Recently, the Insurance Service Organization, a national insurance advisory group, recommended a 15 percent reduction in premiums for houses with sprinkler systems. Some companies offer up to 30 percent reductions if burglar and smoke detectors are included.
The California division of the Central Sprinkler Corporation and Grinnell offer a retrofit service. Central will find a qualified person in your area to give you an estimate; if they can't find someone, they will send one of their own people. You might also arrange to send them your house plans so they can preassemble and install a plastic pipe system. Grinnell will send their own representatives to give estimates and install retrofit systems.
Both Central and Grinnell have readily assembled kits of all the necessary components for new constructions.
To learn more about sprinkler systems and standards, write or call any of the following:
Agencies. National Fire Protection Association, Batterymarch Park, Quincy, Mass. 02269; (617) 770-3000. NFPA has developed and continually updates the 13D standard for automatic residential sprinklers; write for a $6 copy of the standard and for installation advice.
Federal Emergency Management Agency, U.S. Fire Administration, Residential Fire Sprinkler Program, The Presidio, Building 105, San Francisco 94129; (415) 556-8794, or toll-free (800) 638-9600. Since 1976, FEMA has promoted research and development of residential systems. Ask for free brochures.
National Fire Sprinkler Association, Robin Hill Corporate Park, Route 22, Box 1000, Patterson, N.Y. 12563; (914) 878-4200. NFSA will send you a free, frequently updated list of manufacturers of residential sprinkler heads, and sample brochures.
Companies. Central Sprinkler corporation, 1270 Sunshine Way, Anaheim, Calif. 92806; (714) 630-4733.
Grinnell Fire Protection Systems, 564 Mateo St., Los Angeles, Calif. 90013; (213) 687-9990.
Three companies supply polybutylene pipe and fittings for fire sprinkler installations:
Trojan Plastics, 2211 N. 38th St., Tampa, Fla. 33605, (813) 242-4211 (produces the only polybutylene pipe that has been approved by Factory Mutual in accordance with 13D standard); Vanguard Plastics, Box 346, McPherson, Kans. 67460, (316) 241-6369; and Westflex Manufacturing, 1880 Garden Tract Road, Richmond, Calif. 94801, (415) 233-6670.
Photo: Pendent sprinklers go in San Clemente house as it's framed. New residential systems cost about $100 per head installed
Photo: Residential sprinkler system branches from city water line, through "header' valves and gauges, to pipe network in attic; vertical sections lead to sidewall locations under cathedral ceiling
Photo: 1. Joining sections of rigid plastic pipe, professional installer uses solvent, cement, plastic-cutting tool
Photo: 2. Drilling through gypsum board ceiling, hole saw makes 1 1/4-inch opening
Photo: 3. Sprinkler head screws into drop pipe, will fit flush with ceiling
Photo: Rising up the side of house, steel pipe header is "trimmed' with valves, pressure gauge, flow switch, fire alarm
Photo: Installer uncoils length of pre-measured polybutylene pipe with T-fittings for sprinkler heads heat-fused in position
Photo: Three types of UL-listed sprinklers include two pendent and one sidewall head. Escutcheon plates sit flat against surface
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|Date:||Oct 1, 1984|
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