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Sprinklers on Roof Offer Home Protection : Fires: For greater safety in brush fires, a sprinkler system can be fashioned from plastic pipe and a garden hose.

November 18, 1990|GARY ABRAMS | Abrams is a Los Angeles general contractor and a free-lance writer

"I grabbed my garden hose and climbed up on the roof. Pretty soon I was completely surrounded by fire. My T-shirt caught fire and I turned the hose on myself to put it out."

These are the words of 60-year-old Gerry Hon, a retired truck driver describing his successful effort to save his house during the huge Santa Barbara fire last June.

"I thought I could save it," he said, "they wanted me to leave but I refused to go because there is a lifetime of mementos in there. . . ."

Hon was lucky. Despite his flammable wood roof, he was able to keep his home from burning during the Santa Barbara inferno.

Fire statistics indicate that during almost all the major brush fires of the last 30 years, some people have done exactly as Hon did and saved their wood-roofed homes using nothing more than a garden hose, while neighboring houses went up in flames.

While the preferred roof material on houses in brush fire areas is one that is non-combustible, not everyone can afford to spend thousands to replace their wood roof.

For those people, installing rooftop sprinklers is a far less dangerous and more effective alternative to fighting a fire with a garden hose, or simply doing nothing.

Although local fire officials are reluctant to recommend sprinklers because they do not work in all wind conditions and there is not always an adequate water supply, many of them do concede off the record that sprinklers have helped save lots of homes during fires.

Installing the sprinklers is a do-it-yourself job that is actually a lot easier than most people would imagine.

With a little planning, the typical house can be sprinklered in an afternoon or less using relatively inexpensive half-inch PUC plastic pipe with impulse sprinklers ("Rain Bird," "Lawn Genie," "Toro," "Champion," etc.). And the whole job can be completed without having to turn off the water main.

Before starting, check with your local Building and Safety Department about permit requirements. In some cities, a permit is needed.

Of course, this job requires some common-sense safety rules about using a ladder and working on a roof:

1--Look at the slope of the roof. If it looks too steep to safely walk on, it probably is, and you should not attempt this project.

2--Check the ladder. All the rungs should be securely attached to the side rails, the rails should be free of cracks and the "feet" should be in good condition to avoid slippage.

3--If using an extension ladder, place it on a firm, flat spot where it is to be used before raising the extension. The bottom of the ladder should be set one-quarter of the ladder's length from the base of the house.

4--The ladder should extend at least two feet above the edge of the roof.

5--Before climbing the ladder, check your shoes. You need non-slip, preferably rubber sole shoes.

6--Keep your hips between the rails when reaching out from the ladder. Keep one hand on the ladder at all times, and the other free for work.

7--When on the roof, walk carefully to avoid damaging shingles and to reduce the risk of slipping.

8--To re-mount the ladder, grab the upper portion of either rail and place your foot in the center of the rung just below the roof edge. Facing the roof, grab the other rail and swing your body onto the ladder.

9--Stay off the roof in windy or inclement weather.

With those precautions in mind, it's time to get started. Begin by finding a hose bib with normal water pressure on the side or rear of the house to supply the roof water.

Make a trip up the ladder to measure the length of the ridge, or high point, of the roof. If you have a flat roof, measure its long axis.

Also measure the distance from the hose bib to the roof edge and from the roof edge to the ridge. This total distance tells you roughly how much one-half-inch PUC pipe (schedule 40) to purchase. Add 10% to be safe.

The pipe will be placed just below the ridge toward the back of the house so they are not seen from the front of the house.

Along with the pipe, you need to buy elbows, couplings and T-fittings.

Elbows are fittings that allow you to join pipes at 90 or 45 degrees. Couplings allow you to join straight pieces of pipe, and T-fittings are placed in the system wherever the sprinklers will be located.

To determine how many impulse sprinklers you need, bear in mind that each one will spray a circle roughly 40 feet in diameter.

Calculate the number needed by imagining a series of 40 foot diameter circles across the roof, overlapping each other about 15 feet. What is the minimum number of circles needed to cover the whole roof?

The answer to this gives you the number and approximate placement of each sprinkler. The average home needs three or four. A diagram is often helpful.

Next come the fittings. When you know the number and position of each sprinkler, imagine straight lines (which represent the pipe) between all of them and over the edge of the roof down to the hose bib.

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