Browse Forums General Discussion 1 Apr 28, 2008 5:34 pm Hi I am looking for information on concrete slabs! My New home is up to lock up and they have finally conceded that their is a problem with the slab. It is very powdery, you can twist a nail into it about 20 mm (in every room)and scratch the surface away with your hand. It was poured in the rain, but no precautions taken by the concreter.
Fiona Re: Slabs?? Should they crumble? 2Apr 28, 2008 5:42 pm Internal and External Building and Colour Consultant Online - Worldwide http://www.denovoconcepts.com Re: Slabs?? Should they crumble? 3Apr 28, 2008 5:43 pm fiona Hi I am looking for information on concrete slabs! My New home is up to lock up and they have finally conceded that their is a problem with the slab. It is very powdery, you can twist a nail into it about 20 mm (in every room)and scratch the surface away with your hand. It was poured in the rain, but no precautions taken by the concreter. Fiona Poured in the rain….. Not sure too many concreters do that! Internal and External Building and Colour Consultant Online - Worldwide http://www.denovoconcepts.com Re: Slabs?? Should they crumble? 4Apr 28, 2008 5:52 pm From a previous post:
https://forum.homeone.com.au/viewtopic.p ... c&start=15 to_do_list papa Okay Coolies... Does this affect the quality of the slab and now it's been raining constantly in Melbourne so I'm a little concerned. Thought's people? Won't affect the structural integrity of the slab but may affect the surface quality. If the concrete hardened sufficiently prior to the onset of heavy rain then you should be OK...matter of fact keeping water on curing concrete assists the hydration process (concrete going off). If the concrete hadn't hardened sufficiently then it may wash the cement out of the top surface of the concrete. Therefore you may end up with a weakened surface. You may not see it initially but once you get a bit of traffic on it it may dust up, may flake or scale. Probably not a problem in most parts of the slab but may be a pain in the backside in the garage. But keep in mind you generally need hard rain (and I'm from Melbourne and some of the rains yesterday may have been problematic) but it won't affect the general structural integrity. My advice is to wait a couple of weeks and then test a few spots with a hammer...not too hard...but it should resist a reasonable thump without flakes coming up. Hope this helps.... Late edit....just to add if they covered it with hessian or similar it should be OK generally what's done in the "real" construction industry Late edit 2...just found this on the www http://www.cement.org/tech/faq_rain.asp Sound's like the cover to the reinforcement will not be very durable. Edit: Cookie beat me to the punch.... mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: Slabs?? Should they crumble? 5Apr 28, 2008 5:54 pm from google search
http://www.structuraldesigns.com.au/FAQ ... ncrete.htm Re: Slabs?? Should they crumble? 6Apr 28, 2008 7:25 pm Thankyou to all who answered. The slab was poured on the 25 Feb, noticed powdering on the 27 Feb. It has constantly powdered and bubbled in almost all rooms, They have ground down 5mm so far still powdery/flakey, are intending to grind down until they find hard concrete, how far can they go?. My concerns are what are my walls sitting on and how much hard concrete is my roof ties in? I am trying to find out what the Australian Standard is for the distance from reo to top of slab?
Thankyou again for replying to me Fiona Re: Slabs?? Should they crumble? 7Apr 28, 2008 7:30 pm Ohh Fiona……I didn’t see you were a new member!
Sorry about that! We have another Fiona as well. Welcome to the forum, I wish you luck with your slab! Let us know how you get on. Internal and External Building and Colour Consultant Online - Worldwide http://www.denovoconcepts.com Re: Slabs?? Should they crumble? 8Apr 28, 2008 7:33 pm fiona Thankyou to all who answered. The slab was poured on the 25 Feb, noticed powdering on the 27 Feb. It has constantly powdered and bubbled in almost all rooms, They have ground down 5mm so far still powdery/flakey, are intending to grind down until they find hard concrete, how far can they go?. My concerns are what are my walls sitting on and how much hard concrete is my roof ties in? I am trying to find out what the Australian Standard is for the distance from reo to top of slab? Thankyou again for replying to me Fiona Interior concrete surfaces will be 25 mm and that information will be on the drawings for your slab...you don't need to go to the standard. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: Slabs?? Should they crumble? 9Apr 28, 2008 7:35 pm You may find this reference useful from
https://forum.homeone.com.au/viewtopic.p ... highlight= to_do_list If you want details try the following link site third reference down.... http://www.concrete.net.au/search.php?i ... on=&menu=4 Here's the applicable table, depending on the slab the cover may be slightly higher. Typically H-class slabs are separately specified which is where my 25 mm figure may differ from the table below. http://i241.photobucket.com/albums/ff2/mikeb1968/Cover.jpg I would advise getting someone independent to look at your slab if you have concerns. If they grinding it, they intend to repair it and you want to be sure that the repair is carried out satisfactorily. Take plenty of photos - not only for forumite curiousity - but for the record.... Lets us now how you go..... mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: Slabs?? Should they crumble? 10Apr 28, 2008 7:51 pm Michelle Ohh Fiona……I didn’t see you were a new member! Sorry about that! We have another Fiona as well. Welcome to the forum, I wish you luck with your slab! Let us know how you get on. Sorry, same here welcome to another Fiona....on a lighter note....we like plenty and photos and we are slightly....well..... Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: Slabs?? Should they crumble? 11Apr 28, 2008 8:14 pm Fiona, in my opinion and without looking at any photos I would say that you have a problem and potentially a major one.
You really need an independent person to look at this immediately. Are you in Melbourne? If so, then we have used Don Hunt 0438 320 412 or (03) 9803-6394 - he knows his stuff on concrete (that is his specialist consultant area) and can help advise the builder how to fix it - if it is fixable. Sorry to be the bearer of bad news but concrete simply shouldn't do what you have explained! PM me if you want to talk on the phone or if you cannot get a hold of Don tomorrow morning and I will try and point you in the right direction. Builders are people too.... Re: Slabs?? Should they crumble? 12Apr 28, 2008 8:22 pm Yes I agree this is serious but the company i have gone with dont want to do much but fob me off continually. Unfortuantly I am in Queensland Narangba a Nothern suburb of Brisbane. I will pm you as any information i can gather hopefully will make them listen.
Fiona Re: Slabs?? Should they crumble? 13Apr 28, 2008 8:29 pm Hi
You have said exactly what i have thought since the slab was put down When I can scratch a 10mm chunk out of the slab with my fingernail I became seriously worried. I amamazed they have let this go to lockup stage before they stoped work which actually only happened when the Wet Seal guys walked off the job because it was so bad, and they couldnt get their product to seal. Fiona Re: Slabs?? Should they crumble? 14Apr 28, 2008 8:31 pm fiona Yes I agree this is serious but the company i have gone with dont want to do much but fob me off continually. Guess that's why Builda and others are suggesting an independent assessment, they can talk the talk and won't be fobbed off. There's definitely a problem here which can't be brushed away by the contractor. Hope it works out.... mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard Re: Slabs?? Should they crumble? 15Apr 28, 2008 9:08 pm Fiona, you must call the QBSA tomorrow.
http://www.bsa.qld.gov.au/Home/ContactUs/ They will organise an inspection and whats more they will ensure this is fixed or rebuilt. Of course, this will likely be more effective if your builder is licenced etc? Crossing fingers for you here! If so then you are very lucky you are in Qld - otherwise in any other State you would be on your own, facing off with your builders solicitors at 30 paces. Please keep us up to date on this issue. Builders are people too.... Re: Slabs?? Should they crumble? 16Apr 28, 2008 10:23 pm Fiona
Sorry to hear of your delema I suggest tell your bank or lender not to give the builder any more money Best Price Wardrobes Sliding door robes | Walk in robes Deco panel | Mirror | Melamine 26 to 28 Cottage lane Hackham M: 0402 927 376 http://www.bestpricewardrobes.com.au Trade welcome Re: Slabs?? Should they crumble? 17Apr 30, 2008 6:32 pm Sorry to hear the troubles fiona hope it gets sorted promptly even though your are not owner builder it seems that sadly you still have to be vigilant with the builders you probably should have had independant inspector investigate then put a stop to the work until it was rectified.
I know it doesnt help you now to say what should have been done but at least others reading this can learn to be a bit more vigilant as the builders dont seem as interested in the quality as the owners are. As I will be building owner builder i dont have the luxury of going to qbsa if any problems arise i'm on my own so will have to be extra vigilant maybe even anal thoughout the whole proccess. Re: Slabs?? Should they crumble? 18May 01, 2008 4:28 pm Hi everyone,
Well I have called the BSA they wont do anything until the contract is completed. We had a Smidt Hammer test 2 days ago, some grinders came in and worked for 2 hours and left the site as the grinder they were using was too small (100kg) now they are saying they need a 400kg machine to grind down 10mm to find hard concrete. One day They might finally work out what the problem is and how to fix it. Fiona Re: Slabs?? Should they crumble? 19May 01, 2008 4:37 pm Have you got any photos...there are a some professional builders on the forum who could probably provide some more advice if you have piccie.
One tip is to have a tape measure pulled out a standard length (say 1 m or 30 cm) for the photos. It helps to get a sense of scale when all you are looking at is grey concrete. I would seriously recommend engaging the services of an independent inspector to give you some advice and to help assess the efficacy of any repair. I don't want to be alarmist but this sort of major rework on slabs I would not consider to be commonplace. mmm....donuts Homer Simpson 1956- Links: Site Costs Ready Reckoner | H1 Addiction Medical Advice | Château TDL: The Backyard my suspicion - some builders, they do usually make 'odd' settings in their site plan / pricing as their standards - being hopeful that first - the initial price is… 9 2440 Ask the council if there is a chance of getting build over easement exemption. Sometimes easements are unused and 24cm is not all that much. Good luck. And yes any builder… 2 13723 |