Hi has anyone actually had a scan done to locate where/if there is steel in existing concrete? Or, has anyone actually done a scan?
I'm wondering how to accomplish this, and what the cost might be, for my cement floor in my house. There are no records on file for the original structure. I don't actually need to locate the specific position of rods or mesh, just to know that there is some, and what size it is.
trade4us2,
Oct 8, 1:35am
An electronic stud finder should work.
Yes it finds the steel in my kitchen floor.
bcohen,
Oct 8, 1:42am
I tried the stud finder, and it wasn't effective. It randomly turned on and off in locations, then didn't on a second scan. What stud finder did you use? Maybe yours is better than mine. I have a zircon.
gunhand,
Oct 8, 3:56am
Call the cops and tell them you think you have a dead body under it but they are not allowed to bust it up unless sure. They will bring a Xray scanny thing, and while they are at it.
rover79,
Oct 8, 3:59am
Find someone with a metal detector, or go hire one, I'm sure it woulldn't cost much.
bcohen,
Oct 8, 4:51am
I could shove some dead possum bodies under there. But actually, I've read that your typical metal detector doesn't actually work for this. You might have to go through several inches of concrete to reach the metal mesh or steel bar. Have you tried it, and made it work?
It looks like the state of the art is GPR - ground penetrating radar. The equipment costs thousands, and I don't yet know if I can hire someone to do the detection for a reasonable cost.
gpg58,
Oct 8, 4:55am
Just had ground testing done for eqc, there machine could find pipes 2-3ft down, under a 6 inch deep layer of rock chip.
trade4us2,
Oct 8, 6:56am
I have steel mesh in the concrete and the finder beeped about every 100mm.
andrewcg53,
Oct 8, 7:07am
Council will have records
bcohen,
Oct 8, 4:37pm
You have great faith! Council does not have records for this structure.
bcohen,
Oct 8, 4:40pm
Oh, fantastic! Who did you use? What did it cost?
bcohen,
Oct 8, 4:41pm
Cool! What brand and model of stud finder do you have? I'll surely try it!
pauldw,
Oct 8, 6:28pm
Why do you want to know? If someone else needs this info what standard of proof would they accept?
martin11,
Oct 8, 7:37pm
Strange mesh was normally 150mm or 6" in the grids . Been like that for many years . 668 the most common one was 8g wire at in 6" squares
iluvmuse,
Oct 8, 8:10pm
Did you try the Deep Scan mode on your Zircon? (if it has it)
bcohen,
Oct 8, 8:35pm
I want to know, because I want to build up my roof for insulation, but I need this info to find out of the slab can take the extra weight.
I have 2 storys, with a chalet ceiling with collar ties (cross members?) and no ridge beam, so all of the weight is carried by the walls. There is no info at the council, but I sliced off a section of the concrete on the other side of the slab a while back for a reno, and there was grid mesh in there, and what I recall seeing was 8g in 6" squares. The slab was all one pour, so it would be likely to be there, but I feel a need to be sure.
When I tried the deep scan mode of my zircon, it would immediately go into error mode (beep beep beep flashing) as soon as it was moved. It could be that a better stud sensor would do a better job? My zircon is about 20 years old.
Which stud sensor did work? Also, If I can afford it, I'd get an actual scan. Does anyone know what that might cost?
andrewcg53,
Oct 8, 8:43pm
If they don't have the records then it won't have steel in the concrete
johotech,
Oct 8, 8:46pm
Half of what you wrote makes little sense.
Whether there is "mesh" in the slab makes no difference. It would be really unusual for any slab not to have some sort of reinforcing.
But the part you actually need to know about are the perimeter footings or beams under the slab. You're not going to find out any of that with a stud finder.
If you need to do modify your roof structure, then you should contact a structural engineer.
ross1970,
Oct 8, 8:54pm
100mm mesh ?
trade4us2,
Oct 8, 10:33pm
I've tried it again. There are lots of beeps, but maybe the steel is too far down to be consistent. Perhaps it's just registering when the steel joins.
Why don't most shops give the grid size? Bunnings and others don't.
I was not allowed to rest a wall on the middle of the concrete floor, even with mesh in it. I had to dig a deep hole or have a beam along the top of the wall. I chose a beam.
bcohen,
Oct 8, 11:35pm
This is part of a larger repair job, and there is and will be a structural engineer involved. However, I've hit a point at which having a better understanding of the original construction will benefit me, if I am to get the right results, that I'll be satisfied with.
It's good to know that you think the footing of the slab has more importance. Means I have some digging to do, and I'll definitely do it.
I still want to know what steel is in that concrete, if at all possible.
gpg58,
Oct 9, 12:26am
forgotten who and no idea of cost as done by eqc. But google "geotech reports" for your area may find someone.
johotech,
Oct 9, 12:56am
Why not? How do you know that?
bcohen,
Oct 9, 2:24am
Years ago, I went to the council to get the construction details of the place, which was a bach, built before 1995. The council said all they had was construction details from 1995, regarding the adding on of a deck and outdoor stair, and that what they had was virtually unreadable. I got what there was to get.
The text is unreadable, but the images are readable. But while the plans filed for the deck and stair did have some house structure details, they don't match the house. The stair and deck did match on the plans, though.
I tracked down the person who drew the plans, and he told me there was no detail to work from for the house, so he drew "typical details" for the features of the house itself. And those images are labelled in readable letters "Typical Detail"!
That's where it's at.
bcohen,
Oct 10, 3:38am
OK, I've contracted someone to come and do a scan and imaging. I've been told to budget approximately 400 + GST. In case anyone wants to know.
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