Browse Forums Building A New House 1 Sep 02, 2009 8:43 pm We had our slab down 2 days ago (Monday) and today (Wednesday) I go to look and a backhoe has been there and driven over it to put some more sewer pipes in, they also ripped out some of the footings. There is also is a crack extending from one side of the house to the other, i know concrete cracks but its only been down for 2 days! Is this normal and/or anything to worry about? Re: Slab down for 2 days and Backhoe is driving on it 2Sep 02, 2009 10:13 pm Tell them to get off! It depends on the MPa of the concrete, but I would guess that you have 20 MPa, so you need at least 7-10 days before any significant loads. As I understand it 32 MPa you could probably be on it after about 3 days. As for cracks you should have nothing bigger than 1 mm. Dan Re: Slab down for 2 days and Backhoe is driving on it 4Sep 03, 2009 12:09 pm eXume - Watch that crack to see if it is still live onc_artisan Where you are coming from is where you are going to... Re: Slab down for 2 days and Backhoe is driving on it 5Sep 04, 2009 8:38 pm Thanks for the replies peoples. I rung the supervisor and asked him what was going on. He said it is ok to drive on it as was only a small loader. He noticed the crack as well and said will keep an eye on it, but what are they going to do if it grows, rip the house up? They also failed to put vapour plastic down on the rear of one of the bedrooms, could this cause any issues? Re: Slab down for 2 days and Backhoe is driving on it 6Sep 04, 2009 9:19 pm We couldn't drive on our concrete driveway for about a week as I recall! I haven't heard the term "vapour" plastic. You're not talking about the plastic under the slab are you? Re: Slab down for 2 days and Backhoe is driving on it 8Sep 05, 2009 10:14 pm The crack, it extends for 6.6m across the slab. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ http://www.mypicturehost.com/show.php/57041_cracks.jpg.html The bedroom where no plastic was put down. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ http://www.mypicturehost.com/show.php/57042_padnoplastic.JPG.html The living room where plastic was put down after the footings were put in. The footing is at the bottom, slab at the top and sandpad coming out of the hole. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ http://www.mypicturehost.com/show.php/57043_slabwithsand.jpg.html I went there and pulled the rio up from the living room where they had just put it on sand, but the bedroom i didnt because it was interwoven. I thought they would have used their initiative before laying over the top but im worried they didnt. Re: Slab down for 2 days and Backhoe is driving on it 9Sep 05, 2009 10:41 pm Well that looks pretty ordinary I wonder if they used mesh chairs to hold the mesh off the plastic to the minimum cover of 50mm? I am a bit suss on the crack but you will have to watch that as it is hard to see from the photos if it is a cold join or is in fact a shrinkage crack Concrete on sand is a Where you are coming from is where you are going to... Re: Slab down for 2 days and Backhoe is driving on it 11Sep 05, 2009 11:51 pm Try 'building codes of Aust' But mesh/reo needs to have a minimum of 50mm coer all around Where you are coming from is where you are going to... Re: Slab down for 2 days and Backhoe is driving on it 12Sep 06, 2009 9:12 am One of my favourite web sites since I started our build. Go to Google australia and type "CCAA Guide to Concrete for Housing" It should be top of the list. Download the PDF and read away. also http://www.concrete.net.au/publications/pdf/Res Floors Web.pdf The one you need though is http://www.ccaa.com.au/publications/pdf/Dampness.pdf In it it says "The Building Code of Australia (BCA) requires that houses ‘be constructed to provide resistance to moisture from the outside and moisture rising from the ground’." and as such a Damp Proof Course or PVC sheet is installed. Looking at your photos, I think that it does not comply with the building code, I would seek advice before teh house is too far committed. Dan Re: Slab down for 2 days and Backhoe is driving on it 14Sep 06, 2009 11:17 pm eXume - I don't know what an inspector can do with regards to the plastic sheeting now that the slab is poured. I got a quote from Houspect and their cost for slab inspection is $250. They will inspect any cracks and tell you if they are significant. Do you mind if I ask who you are building with? Re: Slab down for 2 days and Backhoe is driving on it 15Sep 06, 2009 11:26 pm dragon did you accept ? If so did they help? Where you are coming from is where you are going to... Re: Slab down for 2 days and Backhoe is driving on it 16Sep 07, 2009 10:39 am Bricks are being delivered today so will see it cracks up, also have a meeting with the SS on wednesday. Yeh i know, there is no way to prove if they did it or not now that the slab is down unless they cut a piece of the slab out but i doubt that will happen. I know of someone that managed to get one ripped up and relayed but am unsure why. Im just going to do a letter up and give it to the SS with my concerns so that theyre on record at least. danc12 - thankyou for the resources Dragon - what was the reason you needed to get an inspection and did it help. Im building in perth with R3d1nk Re: Slab down for 2 days and Backhoe is driving on it 17Sep 07, 2009 1:28 pm eXume - I did PM you Where you are coming from is where you are going to... Re: Slab down for 2 days and Backhoe is driving on it 18Sep 07, 2009 1:41 pm I got Houspect to quote for all inspections during the construction process. Luckily I have not had to use them yet. No problems with our slab so didn't need to them. Re: Slab down for 2 days and Backhoe is driving on it 20Sep 16, 2009 5:07 pm Ok so all ended up being ok. Someone came to check it out, thanks Ivan! I chipped some slab away at the rear and the plastic sheeting was there, just hiding. Thank goodness. Bricks are starting now and all looks to be going well. Thanks all for your help! Special thanks to Ivan, what a champ! 8 6119 I'll be here once a week, lets make that Mondays. If you have a question, this will be the day I will log in for a look around.. If your lucky, sooner. Ask away...… 0 6336 How long is a "long period"? For a few weeks, it should be ok. It also depends on the area you live in...I would let your neighbours know that you will be away too and… 1 28544 |