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Hi all,
Can someone give an opinion on my slab? Should I be concern about it or it is just normal.
Rear of house - close up
Another spot at rear of house.
Meal room
Any idea what this is and what caused it?? After the slab pour maybe about a couple of hours later it rained heavily.
Bedrooms 2 and 3
Should I be concerned or is it normal???
Thanks in advance
Seeing that would concern me too! However, I'm completely uneducated about these things. Wait for Onc_artisan. He knows exactly what he's talking about. I'll let him know you're here
Hmmm... Thanks for the heads up ani
Polo - That is what is known as 'honeycombed' concrete.
The granos have failed to edge vibe (vibrate the edge of the slab)
and likely not provided enough compaction during the placement of the slab.
What happens here is the mesh(re-in forcing) has minimal if any cover, with lots of air gaps.
Steel mesh corrodes quite easily, exacerbated by ingress of water& air (H2O) and salts.
The edge can be parged to resemble a non-porous finish.
....in reality though the slab itself will be subject to moisture ingress.
What I would do to test this is to take a core sample in a few places, that will be the only way
of determining the structural integrity of the slab.
The core sampling will show immediately the extent of the honeycombing.
No other way you can give a fair account of the properties of the slab.
We do have a resident engineer (T_D_L) I wonder if they will show up
How old is the slab?
When was it placed?
Where are you located?
cheers,
Onc
Thanks Onc,
On the day of the pour, I didn't see the concretors use any vibration machine during the placement, I only see one guy place the concrete, 2 guys rake, one guy screed and another guy using something like a square mop pushing back and forward where the screed guy has finished. I also saw concrete pump guy pouring water into the concrete mixer truck when it arrived. I was to afraid to question why they're not vibrating the concrete and why they pour more water into the mix because they might get offended. Stupid I know and regretting it. I hope people who are about to have their concrete place go there on the day and watch them to make sure they are doing it correctly.
I'm in Melbourne.
The slab was poured last Thursday 11.02.2010, I was told they started the pour at 7 am and wasn't there at 2 pm when I returned.
The weather was sunny during the concreting but it started to rain at about 3 pm and after that it poured heavily.
Onc what do you mean by taking a core sample? and how do I do this?
Is it advisable to get someone in to inspect e.g structural engineer?
Thanks Onc for your help.
Core samples just like drilling you might have seen on tele...
Only a drill is used to recover a sample of the centre of the slab
Just as a matter of interest how much did the slab cost?
Retorical question( no need to answer)
The cost of a sample would be less than 1% of the cost of the slab...
IMHO it would be worth it to see, as the result would have an indication of the
state of your slab.
Should the sample come back looking fine and dandy... then you can be happy it will last the distance 20+ years.
If the sample comes back and has bits falling off it the you would need to take the issues to the next level.
To fill the core holes would be the least of my issues.
Hi Onc,
Thanks.
Who would be the right person to do the testing, is it the structural engineer? I want to get it tested for peace of mind.
Thanks Onc for your help.
Structural eng'
Hmmm I think I would ask a concrete driller/cutter to do the samples and see the result first.
If I am off the pace then the cost will be minimal, other than asking an Eng' to take charge.
I will have a look are you N, S, E, or W?
Hi Onc,
I'm in the northern suburb of melbourne.
Thanks Onc.
I havesent a request for cost:
3 x 80mm(dia) x 120mm(d)
I will PM you when I get a response
Thanks Onc, much appreciated.
My slab had that discolouration after it was laid too. But the colour slowly disappeared over the next 3 weeks. From memory it is an off white(ish) colour now.
But I also have some edges that look like that!!
I also have some edging sticking out of my slab!
I posted a pic when I first had mine laid and my mesh was right to the edge of the slab.
I have hundreds of cracks, most run right across my slab but from what I read they aren't deep or wide enough to make any complaints about??
the piece of mesh sticking out
a sample of one of my cracks - this one runs right across the slab. It does tapper down a little bit
I'm hoping when I get the inspector in before they put up the plaster, he will make comment on the slab if he thinks there is something wrong with it.
The steel sticking out of concrete will definitely need to be fixed. And properly.
Yep that would be my tip to Casa
The steel sticking out of concrete will definitely need to be fixed. And properly.
We have some young friends who are FHO and who have a very similar problem with both Frogger and Polo which now makes me a little worried. With the exposed reo I only spotted it by accident and when I went to show them I couldn't find it. The builders had packed dirt right the way around the lower edges of the slab in an attempt to hid all the defects. It took me 15mins of searching and digging to locate the offending piece of reo and when I did my friends said it wasn't so bad. The edges are honeycombed and it's crumbling back up to 5 - 7 cm in some places which really has me concerned for them and yes it's littered with hair-line cracks across the slab everywhere.
I just suggest to them to get the builder to sign of on a normal slab warranty.
And make sure the builder is aware that he will be liable for it should it fail
After the build is TOO late and inconvenient to repair it
Hi - slab newbie here.
We have just had soakwells installed and the contractor drove over the slab. As a result where he came off the slab small chunks have broken away. Not sure if I need to raise it or if it will have no relevance whatsoever?
Cheers
Hi ya...
best if you could post a photo or 2.
I figure you are building in double brick
Have a photo here of the worst bit - there are a couple more but not as bad:
http://s822.photobucket.com/albums/zz14 ... g&newest=1