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dtopa

New Member

1

Wednesday, July 22nd 2015, 3:09pm

designing system to put water on house during a wildfire

[font=&quot]Hello.
I live in the Los Angeles area, in the mountains with a lot of thick, dry
chaparral. I've put in a watering system on top of the ground until I can
decide if it is the best I can do. It doesn't throw as much water as I
had hoped, where I would like it, and would like to identify the elements and
see anyone can suggest improvements. Here's what I have:[/font]



  1. Roughly 300' perimeter
  2. 10,000 gallon water tank running
    off a well
  3. The water pump is a vertical type
    that was designed to accommodate remote fire hydrants (as I understand it,
    the pumps ramps up speed as water is demanded)
  4. I have a 2 1/2" water line out
    of pump that goes to the house (where, of course, the pressure is
    regulated to about 65 lbs)
  5. Before split to house, I have a
    2" line (then stepping down to 1 1/2" then to 1") going
    into two in ground water cabinets that use 3/4" rainbird electric
    valves
  6. OK, so off of 3 separate valves, I
    have run 3 lines of 3/4" pvc:


  • 75' with 4 rainbird impact
    sprinklers mounted on 1/2" risers that are 3' tall and aimed at my
    roofs
  • 150' with 7 sprinklers (as above)
  • 125' with 5 sprinklers (as above)


[font=&quot]The reason
different lengths and number of heads is due to trying to maximize desired
water effect and just adjusted lengths and heads based on performance.
For some reason the 150' section performs better, thus has more heads.
I'm just wondering if my design is pretty solid and whether I could pick up
some through flow performance (more volume, more distance, etc.) through a
different configuration. Are the valves restricting the flow?
Should I be taping into the 2 1/2" main directly? Are the rainbird
impact sprinklers the best for throwing a distance, moving back and forth, and
scattering water high and low?
[/font]




[font=&quot]Or, maybe I
don't even know the question I really should be asking? Thanks for any
comments or ideas.[/font]

dtopa

New Member

2

Wednesday, July 22nd 2015, 5:07pm

more info

I could add that the rainbirds throw the water about 25'.

I could add that the rainbirds are throwing the water about 25'.

Wet_Boots

Supreme Member

Posts: 5,133

Location: Metro NYC

3

Wednesday, July 22nd 2015, 6:53pm

this may be more of a survivalist topic - strictly for the money, you might do better to clear a good perimeter around the house

One observation is that you might need to lose every last bit of exposed plastic in your setup, in favor of fireproof galvanized steel or brass or copper.

dtopa

New Member

4

Monday, July 27th 2015, 11:11am

brush cleared

Yes, brush (perimeter) is already cleared (LA County fines you if you don't clear the perimeter). And yes, all above ground pipes, etc. will be metal--I am just waiting to make sure I have the best set up before I bury the lines. Still, my question is: have I maximized the volume of water I can get and am I maxed out in getting water on the house (is there something else I can do to wet the house better in a shorter amount of time)? Thank you.

Wet_Boots

Supreme Member

Posts: 5,133

Location: Metro NYC

5

Monday, July 27th 2015, 1:37pm

How much exposed wood you have probably figures into this. The obvious use of sprinklers for fire protection was for the wood roofing shingles used back in the day. One producer of brass sprinkler heads had a special model to place atop a roof, that would spray a flat-trajectory circle of water that was wide enough to cover a roof from their location at the peak of the roof, spaced about 20 feet apart.

You have to run some numbers to see if your supply is large enough to provide protection. I'm thinking it isn't, but I can't see your house from here.

If you can't run more than one of your zones at a time, then you have maxed out the performance, so nothing to do there.

Biggest question, though, is how will the watering be managed, and where will you be while this is happening, understanding that getting it wrong means everyone in the house is likely to die. (which is why I think you need to take a survivalist look at your situation)

dtopa

New Member

6

Tuesday, July 28th 2015, 2:08pm

survival

Wet_Boots, you are on the money. I do wish I had run a large water line to the roof of the house and let that provide the coverage (although since I have a detached guest house and garage, I'd really need to do this for each = 3 lines). If I am not here, I can manage the sprinklers from remote: I just installed a Rachio wifi controller and, in fact, tested it while sitting on a beach in Spain about 3 weeks ago. Not being here is one of my concerns (if I am here, I can monitor from house and then use fire houses after fire has passed--this is what our fire dept inspector advised).
If I can't run 3 zones simultaneously, I could cycle each for one minute on the idea that I'm wetting each area but then the heat is drying each out. Maybe.
Trust me, I'm looking for a way to die; rather I am looking for a way to reduce the risk to the house and to me. Stay and defend.

Wet_Boots

Supreme Member

Posts: 5,133

Location: Metro NYC

7

Wednesday, July 29th 2015, 8:05am

"Stay and defend" needs some deep thought, if you actually meant to stay on the property as it is swept by fire. That could require something akin to a fallout shelter with its own air supply.

I think if you were doing this from scratch you would have the roof-mount sprinklers, and you would have a much larger water supply. A swimming pool would be a good start. (an Olympic swimming pool holds more than half-a-million gallons)

Ideally, you would have a supply large enough to douse the entire home all at once, for the duration of the peak fire danger. This is where you should hear from the homeowners in similar situations, as to who installed what, and as to what worked and what didn't.

To some degree, construction codes may forever alter situations like yours, as modern composite materials replace combustible exterior materials used in the past.

dtopa

New Member

8

Wednesday, August 5th 2015, 12:22pm

fallout shelter

OK, Wet_Boots. I am giving it some thought. One idea is that I have a detached garage with stucco walls, ceramic tile roof and steel garage doors. It seems to me that the garage is both a safer place and easier to defend. Most of the garage is dug into the ground with nearly all walls made with cement block but of course the interior roof frame is made of wood. Suppose I could even get a couple oxygen bottles. Does this idea seem more rational? N.B. I am troubled by the "Rocky" fire in the north of our state. Descriptions of 'never seen this before,' 'it forms a mushroom cloud of smoke and ash, then drops to the ground causing a 50 mph wind and engulfing more vegetation.' My situation here isn't that different with drought and brush that hasn't burned in years. Very troubling.

Wet_Boots

Supreme Member

Posts: 5,133

Location: Metro NYC

9

Wednesday, August 5th 2015, 5:36pm

Well again, you really need to ask the man who owns one. I think by the time I fashioned my own idea of trustworthy survival space, I could've just as easily come up with storage for 100,000 or more gallons of water, and a sprinkling system to cover the entire home without need to split it into zones. Then I could just turn handles and click a switch and drive a safe distance away.

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