Indeed. I have driven a car onto blue high density foam no problems. It takes the weight. Spread the tyre contract patch out and white foam is fine too.
My guess is that this was a bad build - they over excavated and used foam to fill.
I do agree Tim. You'd certainly think that most would have noticed this. But I'm constantly surprised how little some apparently clever people even notice such things. Let alone transfer it to a practical application.
Mate's 80s house is built on a concrete slab. With 4" poly on top, and chipboard on that for the floor.
I hadn't realised there'd be rebar in it to spread the load. Thanks!
It's good for a good few tonnes/m2 and yes, the concrete slab on top is spreading the load (or it would crack).
I did hear somewhere that large swimming pools sometimes have a special valve fitted so that if the water table rises whilst it is empty it doesn't just pop out of the ground.
Chris
I saw that too. There seemed to be an enormous amount of expanded polystyrene had floated up. Looked to be at least 1200mm thick?????? Why would anyone put any expanded polystyrene under the floor of a car park exposed to outdoor elements? Weird!
When I was involved, unwanted holes like that were made up with a cheap weak concrete mix. Ie very little cement.
Not exactly a novel concept in civil engineering, at least in Norway:
Obviously they never put a drain under it.
Expanded polystyrene was being phased out when I was involved in favour of expanded polypropelene.
I think this is down to how we 'see' stuff. Like, when I look at a car I don't see the colour or the styling (particularly) but see it like an exploded diagram. I do that because I am more interested in the mechanics of something that I might have to fix. Access to (and the price of) spares is right up there for me along with general reliability.
And this 'interest' and practical (non arty) 'bent' is something I've had since everyone who knows me can remember. Mum (who worked at my primany school) would bring broken electrical stuff home for 'Tim to take to bits' (because they knew I liked doing such things) and they would often get them back the next day all cleaned up and working again. A secondary school I had a Saturday job in a shop that bought and sold pretty well anything (pre-boot sale days) and anything broken or needed attention would be given to me to fix (and again, I often did) and then resell.
If you can't see something for it's component parts then it must be difficult to then take that forward.
The thing is, we aren't born with such skills but we might be born with an innate attitude to enquire. From that we learn and we can then build upon that to learn (or predict) more stuff.
The problem being like that is the more you know you more you realise you don't know. For all the others I guess it's 'ignorance is bliss'? ;-)
A mate has asked me to look at a hand basin he has in a new extension he only had built 18 months ago. The basin is currently sitting on a small wall mounted unit and that in turn is only held on the wall by two small adjustable brackets. So, one of the brackets broke, the whole lot was starting to collapse and a handyman has made up a couple of wooden blocks to go between the bottom of the 'cabinet' and the floor.
So, speaking to the suppliers of the basin it is *supposed* to be fixed to the wall (and therefore self-supporting) and so the small brackets on the under-basin cabinet wouldn't have to take that much weight.
Now, the basin should be supported by two double ended 'studs', one end has a long woodscrew and is supposed to be fixed securely into the wall and the other a machine screw to take a nylon washer, steel washer then nut. The problem is I have no idea what is behind holes though the tiles where the fasteners should be and therefore how to help him out of this situation.
Now, if there really is no studwork the only thing I can think of is cutting a 'letterbox' type hole across the (stud) wall (the shower is on the other side) under the sink and trying to get some battens (vertically) or blocks behind the plasterboard to give us something substantial to screw into and spread the load but all that is a big unknown and carries some risk (plastic water / waste pipes + other unknowns behind there).
I would much rather remove all of the tiles / plasterboard and properly fix extra studwork to the existing but that's making the job even bigger. ;-(
I think the first thing to do will be to get the basin and unit off and see what my stud finder can pick up and go from there ... or find a portable X-ray camera so I can get my mental 'exploded diagram' ... ;-)
Cheers, T i m
Fascinating ... showing there is little difference between an empty swimming pool and a concrete barge ... or a multi-story car park floor and a pontoon or crude car ferry. ;-)
Cheers, T i m
In message , T i m writes
The people who sold me a plastic pond liner were quite jovial about Thameside dwellers finding their pools emptying as the local water table changed.
Standard construction method back then.
Unfortunately the cheepo 'expanded' polystyrene (unlike the better quality extruded variety) is open cell so water can seep into it, and in places like the foot wide strip in front of kitchen units, or well used doorways, it can start to compress with age and give you a bouncy floor.
This happened to my cousin who bought a new-build house in the 80's which was timber framed as well, sitting on a beam and block ground floor itself overlaid with EPS and chipboard.
I wonder if TML incorporated something like that at the very big underground chunnnel interchange at Sangatte ?.
Or the Mulberry pontoons, built in 1941 and 1942, then sunk to hide them, then pumped out, and floated across the Channel and sunk again.
If you head to Lepe country park near Fawley (Southampton) you will find the remains of the onshore contruction and ramps used to build the things prior to 'launching'.
That's because a hollow concrete structure is as strong as a solid version and is cheaper to build. The EPS is just being used a non-removable former, while the outside formers will have been made on site with 18 mm ply, plus ready made shuttering.
Concrete takes ages to cool down. When the Hoover dam was built they poured the concrete in cubes in a specific pattern to allow each cube to cool sufficiently to allow the ajoining cube to be poured.
Utterly irrelevent since the water came up under the soil and lifted the insulation up. Anyone who thinks that the laws of physics can be negated with a drain needs a better education (or brain).
The poly has survived OK. More than can be said for the chipboard floor in the kitchen.
Some bits never made it ,
And some bits came back to be reused. Many a happy holidaymaker once drove across this section of roadlink on their way to the Isle of Wight until about 45 years ago when the vessels got bigger,
it now rests rusting unnoticed at the Southampton terminal.
G.Harman
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