Florida Sinkhole Highlights State's Geologic Instability 206
An anonymous reader writes "Last Thursday night, a sinkhole took the life of a man (TV news video, with ad) while he slept in his home in Seffner FL, near Tampa. While human fatalies are rare, sinkholes are so common in Florida that the insurance industry successfully lobbied the state lawmakers to pass legislation in 2011 making it more difficult for homeowners to claim sinkhole damages. The bedrock in Florida is limestone, a weakly soluble mineral formed from calcified deposits of sea creatures tens of millions of years ago. Above the limestone is a clay layer called the Hawthorn Formation which shields the limestone from ground water; and above the clay is sand. However, the protective clay layer is thin or nonexistent in some areas of Florida, particularly in the middle part of the state near the Gulf coast, where caves and sinkholes are common. Geologists say that human activity, particularly construction and irrigation, can trigger sinkholes by destabilizing the landscape above caverns by drawing down water tables and massing structures above them."
Who would have thought (Score:4, Insightful)
it was a great idea to start building homes on swamp land?
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...it was a great idea to start building homes on swamp land?
They have to build them someplace. Where would you suggest?
Re:Who would have thought (Score:4, Funny)
There's a lot of empty space in Montana I hear.
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What about water?
I've read that lots of states around the Rockies have water shortages all the time
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near a super volcano, I think not!
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Montana (Score:5, Funny)
Wait, what? No, no empty space here. Not any. You want Texas. It's not being used for much useful other than producing oil, cattle and ignorance (not quite certain which is the state's leading export, actually.) Get some real schools in there, teach science instead of superstition, invite immigrants to help out... you'd have an actual useful state before you knew it.
But not Montana. Please. Besides. I really don't think you'd like our -40 temps in the winter. Texas, on the other hand... perfect.
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Hurricanes.
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Texas Hurricanes.
And Florida doesn't have hurricanes?
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And bushes.
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Texas.
For the frying pan into the fire [bbc.co.uk]: sinkholes too.
Comment removed (Score:5, Interesting)
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...it was a great idea to start building homes on swamp land?
They have to build them someplace. Where would you suggest?
Alaska.
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Re:Who would have thought (Score:5, Funny)
it was a great idea to start building homes on swamp land?
If the castle sinks, you build another one on top of it. Repeat until it stands. (Then, marry a princess with huge...tracts of land.)
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Come on... please quote properly for full comedic effect.
"
When I first came here, this was all swamp.
Everyone said I was daft to build a castle on a swamp, but I built in all the same, just to show them.
It sank into the swamp.
So I built a second one.
That sank into the swamp.
So I built a third.
That burned down, fell over, then sank into the swamp.
But the fourth one stayed up.
And that's what you're going to get, Lad, the strongest castle in all of England.
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that's what they use to do in Venice, then they stopped. sinking of the land still happens.
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If the castle sinks, you build another one on top of it. Repeat until it stands. (Then, marry a princess with huge...tracts of land.)
Move to Minnesota. It's the most geologically stable location on the planet. There's a reason it's called the Iron Range. We have no earthquakes, hurricanes, and our buildings don't mysteriously vanish into holes in the ground. We have access to the largest reservoir of fresh water in the world as well. Global warming? Not a problem up here. Fertile farmland? Got that in spades too. Everything you need to survive just about any natural or man-made disaster is abundant here. We can survive the apocalypse. An
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Yeah,but you have michigan next door. And chicago to the south. And you're possibly not asgeologically stable as you think. No place is perfect.
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Yeah,but you have michigan next door. And chicago to the south. And you're possibly not asgeologically stable as you think. No place is perfect.
Michigan is next door to Minnesota? Check a map...
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North michigan, north minnesota. Lake superior. Oh, and great lakes tectonic zone.
PS:I was born in Wisconsin, you insensitive clods! (I really was, and I have good memories of the years I was there, at the university of Wisconsin housing for grad students with children. It was cold, and we loved it.)
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Yes. It's because there's lots of iron ore there. It has nothing to do with geological stability, though Minnesota is nicely stable. Of course that stability means that what passes for a mountain there is pretty laughable.
Yes, but you do have floods, blizzards, and pestilential mosquitoes in the summer. Your winters are so miserable that people literally li
Re:Who would have thought (Score:5, Informative)
it was a great idea to start building homes on swamp land?
This doesn't have anything to do with swampland really, rather it has to with the limestone that makes up the base of Florida. Same with really anywhere there's limestone, Ontario, Michigan, parts of Quebec, large swaths of the NE US. Some places are more stable than others and don't have to worry about it. And there's no much you can do in some cases, and while the limestone is thick where I live several hundred feet there have been huge sink holes.
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This doesn't have anything to do with swampland really, rather it has to with the limestone that makes up the base of Florida. Same with really anywhere there's limestone, Ontario, Michigan, parts of Quebec, large swaths of the NE US. Some places are more stable than others and don't have to worry about it. And there's no much you can do in some cases, and while the limestone is thick where I live several hundred feet there have been huge sink holes.
Does Michigan even have much in the way of sinkholes or caves? My understanding was that glaciers in the last ice age scrubbed away most of the rock that was conducive to cave formation.
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Does Michigan even have much in the way of sinkholes or caves?
It sure does. [michigantrailmaps.com]
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it was a great idea to start building homes on swamp land?
I dunno... ask the people in New Orleans who built homes on drained swampland that was below sea level that required constant pumping of water into canals (where the canal water level is higher than the hour ground levels).
http://upload.wikimedia.org/wikipedia/commons/2/20/New_Orleans_17th_Street_Canal_filling.JPG [wikimedia.org]
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Actually the swamp land is very stable since it's always filled with water. It is the high and dry areas you have to watch out for.
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it was a great idea to start building homes on swamp land?
Who keeps tossing this stereotype around? The swamp land was what 1920s real estate developers sold to Yankees. These days we try to keep them as "protected wetlands". Despite the developers screaming about the goddam gubmint interfering with their rights.
Most of Florida, actually, is built on dirty beach sand with occasional layers of clay.
But underneath the layers of sand and clay - and the swamps - is a limestone substrate. Unlike, say granite, limestone can be eaten up relatively quickly (in geological
Florida state website about it (Score:5, Informative)
The state's Department of Environmental Protection has a nice collection of sinkhole resources [state.fl.us], including a database of incidents, and a poster with a map [state.fl.us].
Aquafilter pumping (Score:5, Interesting)
Let's pump massive amounts of water out of the aquafilter. What could possibility go wrong? (Living in West Central Florida on the edge of a well field).
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Aquifer. I don't think this is connected to groundwater pumping.
Re:Aquafilter pumping (Score:5, Informative)
Aquifer. I don't think this is connected to groundwater pumping.
It can be the start of a sink hole. Drawing out too much water can make the aquifer collapse. It can create a void where rain water flows into washing away the collapsed parts of the aquifer creating an actual void. With broken water lines they can form in days or weeks this one could have taken years. What's scary is they used to be rare events but they are getting more common so something has changed. Just building housing developments changes the flow of water with unknown effects. Most seem to happen along coastal areas, say 20 or 30 miles of the ocean so drained aquifers and redirected water would be the likely causes. look at it this way, aquifers have been stable for thousands of years then we remove billions of gallons from them in a few decades and don't expect a problem? Think of them as big water beds. What happens to your water bed when the water drains out? Now picture it with porous rock only you stick a hose in and start intermittently flushing water in and out. When there was water in the rock it would buffer the affect of the new water but now it flushes freely through the voids washing parts away. Parts of Florida are a ticking time bomb. Personally I think the bigger problem is brackish water flooding the aquifers. The aquifers are retreating at several feet a year so eventually the fresh water will all be miles inland. All those private wells will be pumping sea water.
Re:Aquafilter pumping (Score:5, Funny)
sounds like god is getting his chain saw out to cut florida out of the USA.
It is only old folks and cubans anyways there really isn't anything to be missed there.
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This is it. Farmers are taking the water for their crops. Not to irrigate them, but to run water on the night after night to stave the frost. The net result is more and more property are sinking because the aquifers have lost most of their water.
Farmers and the counties need to work on using reclaimed water for frost prevention, and not steal the public water table at the costs of people losing their homes.
Tech Angle (Score:5, Interesting)
Perhaps someone can come up with some seismic sensing technology that can detect underground voids. Similar to what the oil and gas people use, but optimized for shallower depths.
Communities could do a periodic survey in populated areas and give property owners some advanced notice to evacuate their property. The down side is that existing property owners won't want a pre-sale seismic survey to become common practice.
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This sort of sensing usually involves setting off explosives, collecting data with seismographs placed around the area of interest, then correlating the data via tomography [wikipedia.org].
Unfortunately, because of the explosives part, I'm pretty sure anyone trying to provide this service would eventually be sued out of existence for "causing
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You can use seismic rumbler trucks as a source instead of explosives.
Right. And as the voids you are looking for are much shallower and involve a larger discontinuity, it probably wouldn't need a high amplitude rumble.
Nevertheless, don't overlook an opportunity to blanket Florida with demolition charges.
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The technology for mapping subsurface voids has been around for decades, at least the 1960s, the most common method is Direct Current / Resistivity Surveying. An electric current is passed though the ground between four electrodes and the apparent resistivity (in Ohms/meter) of the subsurface is measured & mapped. Voids, filled water or clay or even empty space, have a completely different resistivity compared to the surrounding rock.
Modern survey instruments are automated, they use dozens of computer c
An Acceptable Risk (Score:2)
Especially when you look at the loss of life and property caused by other natural phenomenon. If sinkholes in Florida are such a problem that we question the rationality of building homes there, then surely no one should live in Southern California where loss of life and property are several orders of magnitude higher than that caused by Florida sinkholes due to wild fires and earthquakes.
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Not to mention that, even in Florida itself, hurricanes are a much larger risk than sinkholes.
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Ya, its the 5 gallon bucket effect. A small child is much more likely to die in a 5 gallon bucket with a few inches of water in it than many of the scary local news stories like cell phone radiation and power lines. Its the things that kill few people, but can't me mitigated by individuals that freak people out.
Pump in sand? (Score:4, Interesting)
Perhaps if you could identify where this was happening, it could be remediated by pumping in a slurry containing solids that would lock in place and resist leaching like coal ash and some kinds of sand?
Any civil engineers care to comment on that?
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Pump in coal ash and you can call it carbon sequestration.
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No you can't. There isn't much carbon in coal ash. It's what's left over after they burn (nearly) all of the carbon out of coal.
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Not a civil engineer, but the volumes required would make this a very costly solution.
Take a look at the size of a sinkhole, even the small ones are big. Would take a shitload of trucks to fill one in.
Can you see Florida Bob, or his insurance company, springing for this remedial work after - presumably - some type of currently nonexistent survey? Nope. Cheaper to move house.
Re:Pump in sand? (Score:4, Insightful)
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Well, the sinkhole in question is believed to be 100' across and 15' - 30' deep. That's about 4400 cubic yards of fill material, which is *not* lightweight. The material would be staged on or near unstable ground and the work would no doubt be hazardous. It'd be a complicated and dangerous engineering project; maybe if a sinkhole like this developed under Monticello, but we're talking about a couple of ramshackle ranch houses. It'd make more economic sense to put up a fence and let them fall into the grou
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Perhaps if you could identify where this was happening, it could be remediated by pumping in a slurry containing solids that would lock in place and resist leaching like coal ash and some kinds of sand?
It's called Grouting. There was a highway improvement project back where I used to live (in Pennsylvania), involving lots of construction over porous Limestone formations. Extensive grouting was required to stablize the ground, which apparently cost quite a bit while also delaying the project.
the insurance industry (Score:2)
"the insurance industry successfully lobbied the state lawmakers to pass legislation in 2011 making it more difficult for homeowners to claim sinkhole damages"
Are you trying to say the insurance industry owners shouldn't be allowed to trick uneducated and become billionaires because of that? If so, say it clearer so the politicians can understand you. Some politicians are pretty thick polo players.
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The politicians are the ones who passed the laws after some friendly bribes (campaign contributions) from the insurance industry. The politicians understand the situation perfectly.
Abandon the central and southern parts of Florida? (Score:2)
I feel for the friends and family of the poor guy, and wish them the best, and I'm sure it's an impractical suggestion, and in no way is it likely to happen, but In my opinion modern humans have no business living on what is essentially a giant sand bar that supports a delicate (and slowly dying) ecosystem. Though I'm admittedly biased. I simply don't like the place. The weather is almost unlivable. It's cold in the winter and unbearably hot and humid all summer. Culturally, it's not my cup of tea eith
California vs Florida (Score:3)
When I lived in Miami we used to say that California might slide into the Pacific Ocean but Florida would disappear into it's own asshole.
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"... on it is asshole"? Yeah, I am an asshole. :P
[off topic] Add geological to the long list (Score:2)
Of course we've known about the state's emotional and mental instability forever. Still the only state with its own Fark tag!
https://twitter.com/_FloridaMan [twitter.com]
http://www.fark.com/topic/florida/ [fark.com]
Yeah, it figures. (Score:4, Interesting)
Insurance companies might have to pay some money out, so they buy the state legislature to write laws allowing them to screw the insurance purchaser.
How long will insurance companies keep getting their way? They did the same with health care. If someone is sick they don't want to insure them because they might have to actually pay out some money. The insurance industry is more evil than cell phone and cable TV companies combined.
We are stupid and deserve the government we elect. The human race is doomed to extinction before we figure out how to get off this rock.
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Insurance companies maximize their own wealth by maximizing cash coming in and minimizing cash going out. They do everything they can to NOT insure people who may require a payout (identify and insure good drivers, healthy people, homes/businesses not located in flood plains, etc.) and it means doing everything they can to deny payouts to customers they have (ever tried calling a health insurance company about a claim they denied for a covered service? You get to talk to an idiot chosen for the job specif
Disappoint (Score:2)
As a Florida resident... (Score:2)
... this story makes me want to stay up late pouring a couple extra foundations for my house. I mean seriously: "Earth swallows man while he sleeps"?!?!? FUCK!
people are stupid (Score:2)
There have been scientific reports about sinkholes, reversal of water flow in aquifers (i.e. salt water working its way into former fresh sources), damage to the protected swamp areas, etc. in Florida for years now. But the only thing that put a damper on new housing developments was the mortgage securities crash. Just this year, a reasonably intelligent (!!) friend of mine - Steve D. if you happen to read this, sorry for outing you -- decided to buy a retirement spot in Fla. Steve, I'll miss you if yo
South Wales (Score:2)
Much of our area is limestone, with no clay or anything on top. And it RAINS a lot.
A few big sink holes have appeared on roads, and there are lots of cave systems.. My house doesn't even have foundations - it's built direct on the limestone.. I often wonder if the limestone is just a few feet thick, with a big cavern below.
Still - seems our weasly insurance companies aren't as weasly as yours!
Re:What's The Tech Angle? (Score:5, Insightful)
What's the tech angle to this story? It's a sinkhole. Ground cover collapse is not a Slashdot story.
Oh, I don't know.. Geology? Engineering? Perhaps involving technology to detect and prevent these things?
Something like this perhaps?
Re:What's The Tech Angle? (Score:5, Informative)
Some tech input will show up regardless of what's in TFS/A. General science articles are always welcome for me at any rate. Regarding this topic, here's a good photo gallery: Notable sinkholes from around the globe [baltimoresun.com].
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Something like this perhaps?
. . . I was thinking /dev/null . . . how an improper implementation could cause OS instability . . .
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Limestone is technology!
"Perhaps involving technology to detect and prevent these things?"
Never happen when money is on the line. I remember, back in Pennsylvania, the creekbeds always had a good stretch of uninhabited land around them (usually treated an unofficial parkspace).
One year someone bought up some of that land and built a bunch of brand new houses right up against the creek... ...and people (presumably from out of state) bought them. Then the next big rains came, and the creeks flooded, and the h
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This is just a shit happens thing.
No, it isn't
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Underground water management?
Above ground water management for mapped out sensitive areas?
Dimwit.
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The state runs the insurance company that most people in Florida have to use now, called Citizens. It wasn't a "problem" until the state had to start paying out, before when it was just private insurance companies this wasn't as big of an issue.
Re:Pretty clever (Score:5, Insightful)
Smart of the insurance industry to make themselves useless. Now, if they never fork out, why should I have an insurance?
Because the bank requires that you pay for insurance as part of the mortgage.
Because the state requires that you pay for insurance to drive legally.
The insurances companies have been tremendously smart. Securing mandates that you pay more and more for their products, acquiring guarantees of profits, all while reducing their liability and payouts.
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Traditional insurance assumes a payout of around 1% of people filing claims per year. The idea is you pay for decades and file one huge claim in that time that would bankrupt you otherwise
Only health insurance is structured for you to use as much or more of what you pay in premiums
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I pay more for health insurance in one year than the total of my entire life's expenses for health services (and I am old).
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Re:Pretty clever: Not dead yet. (Score:2)
I plan to die quickly (and cheaply) at an old age.
Best way to do this is to stay away from doctors... kind of hard since I am a doctor but I don't, as a rule, give myself advice.
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I pay more for health insurance in one year than the total of my entire life's expenses for health services (and I am old).
So now we know that:
1) you're a doctor
2) you've been lucky enough not to suffer significant either organic or physical injury
3) When it comes to statistics you're a fucking moron.
FWIW, I'm not an MD but have both friends and family members who are. I don't know any of them who would make as foolish a statement about insurance as you did here.
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Fairly rude comment but I'll respond.
I spoke only about my personal experience, not statistics.
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Ok, so you choose to deny your own ignorance? Did you ever so much as open a copy of NEJM in your life? "The plural of anecdote is not data." If that's not clear enough for you: your personal experience is 100% irrelevant, and you do yourself and the public a disservice by posting as though it were informative or indicative of any suggested action.
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Traditional insurance assumes a payout of around 1% of people filing claims per year. The idea is you pay for decades and file one huge claim in that time that would bankrupt you otherwise
Only health insurance is structured for you to use as much or more of what you pay in premiums
Health Insurance works exactly like other insurance. The problem is that hardly anybody actually has health insurance, and the current administration is trying to get rid of health insurance in favor of health PLANS.
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Smart of the insurance industry to make themselves useless. Now, if they never fork out, why should I have an insurance?
Because the bank requires that you pay for insurance as part of the mortgage.
Because the state requires that you pay for insurance to drive legally.
The insurances companies have been tremendously smart. Securing mandates that you pay more and more for their products, acquiring guarantees of profits, all while reducing their liability and payouts.
God help us if they ever make health insurance required.
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Re:Pretty clever (Score:4, Informative)
Because the state requires that you pay for insurance to drive legally.
Only if you don't have the money to cover the minimum liability. If you do have money, as long as it is set aside in one of couple ways so it can't disappear before needed, you don't need insurance to drive.
Are you speaking just of Florida? Because it's different in every state. Here in Georgia you have to have liability coverage at minimum to legally operate a vehicle, even if you have thousands in a savings account named "just in case I'm a bad driver". There was a time when you didn't have to have insurance in Alabama, but a few years ago they mandated minimum liability insurance coverage as well.
I'm normally not keen on the government telling us how to live our lives, but having mandatory liability coverage is a no-brainer for the vast majority of poor and middle-class citizens who simply can't be assumed to be responsible enough to have a personal insurance savings plan, and can't afford a huge payout if they do cause an accident. I'd rather pay $50/month to insure that I won't be sued and bankrupted because I made a mistake driving, than bank that money and hope that I've saved up enough to fight said lawsuit.
On the other side of the coin, I'd much rather the person who hits me has liability coverage, so their insurance company takes care of me instead of leaving me to chase after their assets in court. Also, I wouldn't be surprised if states without mandatory liability coverage have more hit-and-run accidents than other states.
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Emphasis added.
First of all - fuck you.
Secondly - fuck you some more.
If you're poor, how the fuck are you supposed to put money aside for a personal insurance savings plan
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The problem with the way self-insurance works is that it is only feasible for the very wealthy, and those are the types who can afford to shop around and get a much better rate than us peons. So self-insurance is completely off the table for pretty much anyone who makes less than $100k per year.
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Most houses in Florida, particularly outside of the panhandle, are just concrete slabs poured on level ground. There's a bit of a trench to anchor it in, but no foundation like you're thinking of. Hardly anyone has a basement. Maybe if they live on the side of a hill, one story will be dug into the hill on one side.
This is because the ground usually doesn't freeze, it's cheaper, easier, and faster. Most of the state was developed after the war and after home air conditioners became affordable. So crappy tra
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No basement, because you're likely to hit water within the first 10 feet of digging. That floor collapse sounds a bit dodgy even for Florida (there's supposed to be steel reinforcing that concrete), but I did get to see a lot of modern Florida homebuilding techniques when I was a kid, so it's not a complete surprise.
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There was a large detached garage, so not a shed. And there was a hot tub on the patio adjacent to the house; the pad was in the middle of a lawn behind the patio, about 20-30 feet from anything.
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That's been the best guess, but it's no pit; just a slab on the ground. And no scorch marks or other indications that it was ever used for that as I recall.
I just think of it as the mystery square.
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I like that, except it was built in the late 80s, when it was fairly obvious that a nuclear war with the USSR was unlikely. Plus I think those were usually built at ground level in that neck of the woods, then covered with dirt to make a mound like a barrow, and there would've been dirt; there's a pool. But I've never seen one in person.
Anyway, it's a square about 3-4 feet on a side; perhaps the blueprints for the house were originally in the wrong unit, a la spinal tap, and the slab was poured before anyon
Just Very Sad (Score:2)
It's pretty sad that calling a troll out for making offensive Jew jokes on Slashdot get's modded "flaimbait".
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Given the current political bent of the average Slashdotter today, I suppose the above post will be modded "insightful".
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Y'know, you can claim to be any religion you like, but just claiming something doesn't automatically make it true. Wolves in sheep's clothing, etc.
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Beats California.
Worked there for 23 years, never really very close to being able to qualify for a mortgage, even at the end with the crash, on a home within reasonable distance of work (reasonable being 90 minute commute). Maybe a condo that wasn't too big near the end of my stay, but not much of one.
Moved to FL this year, already have a largish house in a very nice neighborhood. The money I wanted to try to put down in California on a place (but couldn't qualify for the mortgage) covered closing costs a
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It's not God who opens a hell mouth to claim payment on his deals. But, yes, the other guy is fallible.