... how would you protect yourself against sinkholes?
Would it be better to make a much stronger "unbreakable" concrete raft or might it be better to use more conventional founds and timber floors on the basis that it might fail more gracefully and give you some warning of subsidence?
Any other options?
Tim
Houseboat.
Oh drat, those alligators.
The solution is simple. Before you build, you have some trial boreholes drilled to make sure there are no voids beneath the site.
Commonly done in mining areas in most countries.
+1
Down here in Cornwall, old unrecorded mineshafts previously inadequately capped a century or so ago, open up in the garden, or worse, under the house, every few years. You do occasionally see such boreholes being drilled, but there's no guarantee they will intercept a shaft, even if it's there.
Ground penetrating radar may also be an option; not sure how deep it penetrates though.
Florida is mostly karst, with the result that if you bore for cavities there is a fairly good chance of discovering one. The problem is working out whether it is large enough to pose a problem and whether it is likely to do so during the lifetime of the house. There is also no guarantee that, if you don't find one with a bore hole, there isn't one or that the action of water over time won't form one.
As sink holes large enough to swallow a major part of a house are very unusual, the answer would probably to be to build the house so that it retains structural integrity even if part of the ground below it disappears. That could be achieved by having a structural frame, in the manner of a traditional British timber frame house, although it would probably be made of aluminium or steel these days.
Most sink holes can be filled when they occur, so you could even mount the house on rails, so it can be pulled clear to allow access to the hole to fill it. Alternatively, you could do what most people living on karst do and not worry about the very remote possibility of a dangerous sink hole forming.
Colin Bignell
On 04/03/2013 08:00, Chris Hogg wrote: ...
That depends upon the conductivity of the soil and can vary from a few centimetres to a few metres. Oil prospecting techniques give a much deeper image of the land.
Colin Bignell
Ground penetrating radar surveys?
Brian
Just down the road from here when I were a lad there was a quarry. It was filled in with all sorts of old crap, clinkers, old cars and the like. They then built a thick raft and put houses on it in the early 770s. Now however the thing appears to be sinking, the road has a downward kink in it and several people have lost their porches and parts of their front gardens.
This is in the UK so beware of so called mitigation of sinking, they only last so long. Brian
Need to go to Guatemala for that...
Isn't the risk from tropical storms or hurricanes some what higher?
I'd go for a large below ground concrete bunker with enough space for the family and important possesssions and let the rest blow away. Digging out the hole for the bunker would find any void fairly close to the surface...
On Monday, March 4, 2013 9:36:08 AM UTC, Andrew Gabriel wrote: snip
How did they ever fill that ?
And if you're lucky, you might find some oil.
The houses I saw on TV in the sinkhole area didn't look strong enough to stand up to wind let alone ground collapse. Light wooden sheds costing a few hundred quid. Maybe the answer is to support them with balloons or just build them according to UK regs - so not on these sites at all.
It seems these voids enlarge over time. So what might be ok at one time won't be later on. And drilling bore holes isn't cheap. It would also depend on just how common this occurrence is - this example was so widely publicised it would seem not.
Doesn't stop such things happening here on new estates.
I don't know. A previous one was filled with concrete, but that was subsequently decided to have been a very bad idea because it concentrates any potentially erroding water flows around it.
Incidentally, these are not natural, but are man-made - caused by leaking drains washing away the subsoil, which is why they tend to happen at road junctions where the drains join up.
It's interesting to look at some satellite images of Florida. It looks like you'd have to work pretty hard to find a "safe" spot.
Tim
If it's taken 1200 years WTP?
tim
By immediately thinking "WTF am I doing?", selling the plot and buggering off with the dosh as fast as possible back to civilisation.
That's incredibly circular and straight-sided. It looks like it was bored.
That's really the point, unfortunately. These were cheap homes, jerry-built, for poor folk. They couldn't have afforded to pay for strong, void-proof floors.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.