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The moat won’t work as well as you probably think. A lot of the problem comes from the sky raining down embers on flammable roofs and such...

by dav 5y ago

nradov 5y ago
This is why the building code in high risk areas should require Class A fire resistant roofs. This won't protect homes from huge firestorms but they're effective against falling embers. https://www.thisoldhouse.com/roofing/21018219/fire-resistant-roofing-and-siding https://www.thisoldhouse.com/roofing/21018219/fire-resistant...
hellbannedguy 5y ago
A moat is not a horrid idea. When Paradise was burning I was thinking if I lived in a fire prone envionment; I would have sprinklers on roof of my home. It would be a simple 1/2" copper pipe feeding a few sprinkler heads on the roof. Maybe a few mercury switches placed around the property, or remotely controlled through the phone line, wifi, or sat phone enabled? Nothing too elaborate. It wouldn't protect everyone. It might save a few house fires that were started with embers though? I know there one company selling roof fire sprinklers. I know of one small city who's experimenting right now with roof sprinklers. Hell, I wouldn't mind firing a bunch of Firefighters, and seeing that money go to Roof Sprinklers. (I haven't quite figured out exactly what Firefights do all day, with the hard exception of Paramedics. Buildings in cities don't burn like they used too. Wood stick homes in the country are another story.) I heard one guy say that there wouldn't be enough water pressure if everyones roof was on, but that doesn't make sence either. Not everyone's roof sprinklers would be going off simultaneously if properly implemented, and designed. Firehouses could be in charge of which houses sprinklers go off? Right now in CA, if you live in a fire prone area, Insurance (Property) is not suspose to be higher. As much as I despise Insurance companies--this provision needs to be nixed. (I don't think it will happen because Insurance companies use it to raise our city insurance rates, and politicians have northern cabins.
- Johnny555 5y ago
  A small residential fire sprinkler head outputs around 15gpm of water. While keeping a roof wet is different than wetting down a room on fire, a roof is big and you need to be sure it stays wet, so let's say you want to keep it wet with 30gpm. And lets say you have to keep it wet for 24 hours until the fire danger passes. That's around 40,000 gallons of water. Where are you going to get that water? You can't count on the local utility keeping pumps running. If you're lucky you have a well, but a good residential well would yield around 10gpm, and if you and your neighbors are all pulling out water at the max rate together for hours or days, it may run dry while you wait for water to percolate in. So you need a huge tank of water - a 50,000 gallon tank is around 35 feet in diameter and 7 feet high. Hope you have a big yard and lots of money, the tank alone will probably cost $30K. So figure around $50K to install the system. I hope you have a big back yard for it. That bunch of firefighters you want to get rid of help protect many square miles of land, putting that $50K sprinkler system on 10,000 homes would cost $500M - that's a lot of firefighters and equipment. I think there are better ways to keep your roof from burning, but even a metal roof is no guarantee that your house will survive a large wildfire unless you also keep the land devoid of fuel. And you could still fall victim to a piece of flying ember that happens to land on a vulnerable spot of your house.
  - benplumley 5y ago
    Don't forget that most of the water you sprinkle onto the roof will collect in the gutters which can feed immediately back into the tank, so you only need enough water for a few cycles plus 24 hours of evaporation loss - still a decent amount of water, but a lot more like a large garden water-butt than an industrial tank.
    - OneEyedRobot 5y ago
      Huh. That's clever and I've never seen it. Probably not of much value as roofs are (or can be) relatively fireproof. The issue is vents, decks, windows to some extent.
  - Dylan16807 5y ago

The moat won’t work as well as you probably think. A lot of the problem comes from the sky raining down embers on flammable roofs and such...

by dav 5y ago

The moat won’t work as well as you probably think. A lot of the problem comes from the sky raining down embers on flammable roofs and such...

nradov 5y ago

This is why the building code in high risk areas should require Class A fire resistant roofs. This won't protect homes from huge firestorms but they're effective against falling embers. https://www.thisoldhouse.com/roofing/21018219/fire-resistant-roofing-and-siding https://www.thisoldhouse.com/roofing/21018219/fire-resistant...

hellbannedguy 5y ago

A moat is not a horrid idea. When Paradise was burning I was thinking if I lived in a fire prone envionment; I would have sprinklers on roof of my home. It would be a simple 1/2" copper pipe feeding a few sprinkler heads on the roof. Maybe a few mercury switches placed around the property, or remotely controlled through the phone line, wifi, or sat phone enabled? Nothing too elaborate. It wouldn't protect everyone. It might save a few house fires that were started with embers though? I know there one company selling roof fire sprinklers. I know of one small city who's experimenting right now with roof sprinklers. Hell, I wouldn't mind firing a bunch of Firefighters, and seeing that money go to Roof Sprinklers. (I haven't quite figured out exactly what Firefights do all day, with the hard exception of Paramedics. Buildings in cities don't burn like they used too. Wood stick homes in the country are another story.) I heard one guy say that there wouldn't be enough water pressure if everyones roof was on, but that doesn't make sence either. Not everyone's roof sprinklers would be going off simultaneously if properly implemented, and designed. Firehouses could be in charge of which houses sprinklers go off? Right now in CA, if you live in a fire prone area, Insurance (Property) is not suspose to be higher. As much as I despise Insurance companies--this provision needs to be nixed. (I don't think it will happen because Insurance companies use it to raise our city insurance rates, and politicians have northern cabins.

Johnny555 5y ago
A small residential fire sprinkler head outputs around 15gpm of water. While keeping a roof wet is different than wetting down a room on fire, a roof is big and you need to be sure it stays wet, so let's say you want to keep it wet with 30gpm. And lets say you have to keep it wet for 24 hours until the fire danger passes. That's around 40,000 gallons of water. Where are you going to get that water? You can't count on the local utility keeping pumps running. If you're lucky you have a well, but a good residential well would yield around 10gpm, and if you and your neighbors are all pulling out water at the max rate together for hours or days, it may run dry while you wait for water to percolate in. So you need a huge tank of water - a 50,000 gallon tank is around 35 feet in diameter and 7 feet high. Hope you have a big yard and lots of money, the tank alone will probably cost $30K. So figure around $50K to install the system. I hope you have a big back yard for it. That bunch of firefighters you want to get rid of help protect many square miles of land, putting that $50K sprinkler system on 10,000 homes would cost $500M - that's a lot of firefighters and equipment. I think there are better ways to keep your roof from burning, but even a metal roof is no guarantee that your house will survive a large wildfire unless you also keep the land devoid of fuel. And you could still fall victim to a piece of flying ember that happens to land on a vulnerable spot of your house.
- benplumley 5y ago
  Don't forget that most of the water you sprinkle onto the roof will collect in the gutters which can feed immediately back into the tank, so you only need enough water for a few cycles plus 24 hours of evaporation loss - still a decent amount of water, but a lot more like a large garden water-butt than an industrial tank.
  - OneEyedRobot 5y ago
    Huh. That's clever and I've never seen it. Probably not of much value as roofs are (or can be) relatively fireproof. The issue is vents, decks, windows to some extent.
- Dylan16807 5y ago