Browse Forums Paving & Concreting 1 Jul 23, 2016 12:02 am We have just a new home and upon our warranty inspection with the builder I told him I was worried about the movement cracks in the home as there seemed to be quite a few of them and they are around 2-3mm wide and quite long. Their structural engineer then came out to inspect and told me that our concrete perimeter around the home has been poured so it has either no slope on it or it has been sloped towards the house.
I don't know what to do now or know if the concrete perimeter is the cause of the cracks in the home and if so, how can the aggregate concrete be rectified? If anyone has any advise I would be very grateful. Re: Concrete Perimeter around home 2Jul 23, 2016 12:58 am It is always best to state what area you are in and photos are a definite must in cases like this. How long have you lived in the house and how long ago was the concreting done? The slope away from the house must be 1:20 (50mm over the first metre) for compliance. Did you take photos during the build that show the surface levels around the house perimeter prior to concreting or any evidence of ponding and were temporary downpipes installed after the roof and gutters went on? The first thing to do would be to confirm or otherwise the slope, you only need a spirit level and a straight edge. Don't trust anything that anyone employed by a builder tells you. Always check for yourself. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Concrete Perimeter around home 3Jul 23, 2016 9:21 am SaveH2O Don't trust anything that anyone employed by a builder tells you. Always check for yourself. Couldn't agree more.. there are enough posts and warnings on this forum....with a bit of research and asking question you could have avoided this problem. Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Concrete Perimeter around home 4Jul 23, 2016 9:24 am I don't know where you are located but I'm afraid my (limited) experience of concreters in Victoria is that they will say anything to you before they do the job. Concreters in Victoria also don't have to be licensed and the ones I have come across don't know the building regulations. In Victoria the VBA now recommends that on reactive soils you ensure there is a minimum slope of 70mm for the first metre. See:
Ensure there is a minimum slope of 70mm for the first metre away from the house in very reactive soils. http://www.vba.vic.gov.au/__data/assets ... _FINAL.pdf If the concrete is not sloping away from the house, or even worse, is sloping towards the house, it has to be removed and you should be contacting the concreter to come and rectify his work at his cost. Hopefully you did not pay cash in hand. Re: Concrete Perimeter around home 6Jul 23, 2016 3:28 pm Liliana In Victoria the VBA now recommends that on reactive soils you ensure there is a minimum slope of 70mm for the first metre. See: http://www.vba.vic.gov.au/__data/assets ... _FINAL.pdf The document is overdue but is the reference to a 70mm slope over the first metre away from the house a new regulation? I think that advice in such documents should stick to the facts but if they post recommendations, they should state them being as such and also state what the actual regulation is with a reference. It is very disappointing that the VBA have not given a caution about the 1:60 (17mm over the first one metre) slope stated in the CSIRO's slab maintenance document given that this document is given to new house buyers by the builders. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Concrete Perimeter around home 7Jul 23, 2016 6:09 pm jennifer_sml Our home is in Truganina and the concrete got poured in March. Cracking does not happen immediately, it takes time and the path has only been there for 4 months or less. It is essential that you verify the slope but my gut feeling strongly tells me that the cracking is the result of other longer term influence(s). Fortunately (or unfortunately), the crack sizes as described I believe do not constitute a defect but I stand to be corrected on that, however, given your location, you have rights for concern. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Concrete Perimeter around home 8Jul 23, 2016 8:44 pm We are in a new area and the land behind our home is getting excavated, could this cause more and bigger than normal movement cracks? Most cracks either horizontal or diagonal and are around 2-3mm in the top corners or around door frames. I hope they are just normal new home movement cracks. I see other homes in our street have also laid a concrete perimeter but theirs looks flat too without a slope. In regards to fixing the concrete could I grind the aggregrate down possiby 10-20mm to slope towards away from the home and then polish the concrete and add an antislip seal? Having a smooth surface that has a little slope would direct the water away from the edge of the home wouldn't it? I would also do a waterproof sealent around the edge of the wall/concrete footpath perimeter as well. If anyone could let me know if that was at all possible that would be much appreciated? Re: Concrete Perimeter around home 9Jul 24, 2016 11:26 am jennifer_sml We are in a new area and the land behind our home is getting excavated, could this cause more and bigger than normal movement cracks? Excavations can result in cracking but it is variable. Impossible to comment further. I can only repeat (again) that you have to first determine as to whether what you have been told about the concrete's slope by the builder's representative is factual. It would be high incompetence if the concrete didn't have some slope and hard to believe given your discussion, his experience and his association with the ss, quite unimaginable really. The text below that I have made bold could be very relevant to your situation if the slope is less than 50mm but greater than 25mm. The BCA states: "3.1.2.3 Surface water drainage Surface water must be diverted away from Class 1 buildings as follows: (a) Slab-on-ground — finished ground level adjacent to buildings: the external finished surface surrounding the slab must be drained to move surface water away from the building and graded to give a slope of not less than (see Figure 3.1.2.2)— (i) 25 mm over the first 1 m from the building in low rainfall intensity areas for surfaces that are reasonably impermeable (such as concrete or clay paving); or (ii) 50 mm over the first 1 m from the building in any other case. (b) Slab-on-ground — finished slab heights: the height of the slab-on-ground above external finished surfaces must be not less than (see Figure 3.1.2.2)— (i) 100 mm above the finished ground level in low rainfall intensity areas or sandy, well-drained areas; or (ii) 50 mm above impermeable (paved or concreted areas) that slope away from the building in accordance with (a); or (iii) 150 mm in any other case." The BCA has hierarchy over Australian Standards. A low intensity rain area is one that has a 1:20 Intensity Frequency Duration (IFD) of 125mm or less per hour. I entered the Truganina latitude and longitude (37.8140° S & 144.7193° E) on the BOM IFD and the 1:20 IFD came up as 125mm per hour. Both the BCA and AS/NZS 3500.3 show Average Recurrence Intervals (ARI) that exceed 125mm per hour but the ARIs are based on the IFD and are not site specific whereas the IFD is site specific, for example, both the BCA and Australian Standards show Melbourne but not the nearby areas. I have always believed that given the ARIs are based on the IFD, the IFD would be accepted if a ruling was to be made for a specific location given that the BCA and Australian Standards do not list all specific locations. The Bureau Of Meteorology BOM supplies the IFD and they state: The Truganini 1:20 IFD is shown below. Intersect 5 minutes with 20 years in the above chart. Hope this helps. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Concrete Perimeter around home 10Jul 24, 2016 12:29 pm Thanks for all the info it is of great help. I went to get a leveler and I put it on the concrete perimeter path. It has absolutely no slope and towards the edge/fence part it actually slopes in (towards the house) a little. There are two drain trenches as well but looking at it the drains are not capped on the sides. Not sure if this is an issue. I am worried that as the perimeter path has only been laid for 4 months and that even though we have had rainfall this past month or so it hasn't rained that much I would say for cracks to be showing in nearly every room of the home!! Would it? Some of my neighbours dont even have perimeter paths, wouldn't their home be even more prone to these issues? Re: Concrete Perimeter around home 11Jul 24, 2016 12:57 pm jennifer_sml I went to get a leveler and I put it on the concrete perimeter path. It has absolutely no slope and towards the edge/fence part it actually slopes in (towards the house) a little. On a related matter, how high are the weep holes above the concrete? Given the short time frame between now and when the concrete was laid, it seems more plausible that the cause of the cracking lays elsewhere. When did you first notice the cracking? The VBA and other industry experts who have investigated these matters have found that most cases of heave are caused by faulty plumbing but water pooling against the slab during construction due to insufficient site drainage is also a major cause. The best advice for new home buyers is to take heaps of photos during construction, even if you don't know what you are taking photos of. Have you taken photos of the slab perimeter during construction? As for the concreting, you need to contact the concreter and communicate everything in writing. You should also contact the VBA and also speak to a good solicitor. There are slab heave class actions happening but you first need to establish the fact and the cause. If it was me, I would have the plumbing inspected first. Insider is the H1 resident expert on these matters and I hope that he sees this thread. There are also some other very knowledgeable forum members who I hope also see this thread. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Concrete Perimeter around home 12Jul 24, 2016 1:22 pm The weep holes are about 20mm to 50mm above the concrete. It varies as the concrete is higher in some spots. I first noticed a long crack which was during the inspection just before we settled. The ss told me not to worry as that will be fixed during warranty inspection together with other movement cracks which are very normal he said. After buying our section we thought we would choose an award winning reputable builder who has good reviews as we were going through a tough time with family medical issues and didn't want to have issues (like this). I guess I was silly enough to fully trust our builders. I didn't get to take any photos during construction as during construction our disabled daughter and baby were having a few medical issues at that time. Though we came out to inspect the construction we didn't get a chance to take photos unfortunately. However, we have a photo of the front of the home when the home was nearly ready and I do not see any slope away from the home either. The concreter probably laid the concrete right on top to whatever was there. Re: Concrete Perimeter around home 13Jul 24, 2016 2:30 pm Hi jennifer_sml, So disappointing to read your posts. I agree with SaveH20 that there may be other issues contributing to the cracking, including ground levels left by the builder and lack of drainage during construction. The weepholes should be 75mm above paving unless they are under cover. If your weepholes are not under cover then the concreter must remove his paving and re-do it properly at his expense. If you have a receipt for payment then you have proof he did it. If he doesn't respond to a verbal request to rectify the work then write him a registered letter setting out the facts including that the paving was not done to regulation and needs to be removed and done again. We had to remove quite a bit of our paving for this reason. It is also disappointing, as SaveH2O points out that the VBA is happy to set out guidelines for owners that are not regulations. I wonder whether you were even given this document. Re: Concrete Perimeter around home 14Jul 24, 2016 2:44 pm Hi Liliana, We have an email copy of his quote and I replied with an email stating we accept it. Other communications were done via SMS including payment. He wanted to pick up the payment in cash which I obliged to. When he came out to do the quote we had discussed about the design and requirements and I specifically asked him it will have a slope away from the home right?, and he responded 'well of course I am not going to slope it towards the house'. I guess with such a great recommendation from our ss I didnt think much else of it and fully trusted he would do a good job. Our ss even said our concrete looked great when he saw it. Honestly, if I had the money I would rip it out and redo straight away but with medical costs and us putting everything we have towards the build of our home, we just cannot find any extra cash to make this right. I don't want to have to choose between stopping my daughter's medical treatments in making our home safe and sound. Re: Concrete Perimeter around home 15Jul 24, 2016 4:10 pm The concrete is not compliant for slope and weep hole height. I would follow Liliana's advice as she is one of the best members on this forum and also speaks from personal experience re this situation. I wonder how many other non compliant jobs he has done and it appears that the ss doesn't know his common building regulations either. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Concrete Perimeter around home 16Jul 24, 2016 4:29 pm I got hold of the concreter and he has agreed to come and meet me tomorrow. I have just told him to come over to discuss the concrete and not told him what it is about yet as I am afraid he might not show up if I did. He might even run after discussing it with him tomorrow. If he were to redo the concrete I am afraid he might damage other parts of the landscaping as I have done a deck, laid artificial grass and have had a front gate installed since. Is the builder responsible as well? It was their ss who referred me onto him and after the concrete was laid said it was a really great job. Their ss was the one who gave me his business card and told me to contact him as he does most of their homes and does a great job and will look after me. I have talked to a few concrete specialist over the phone and they said anyone who pours a concrete perimeter without a slope has no right being in the business as that is a basic rule and for our ss to recommend him we should also get the builders to make this right. Anyways, I will let you know what the concreter says tomorrow. Thanks everyone for all their help and advice. Re: Concrete Perimeter around home 17Jul 24, 2016 8:45 pm jennifer_sml Is the builder responsible as well? It was their ss who referred me onto him and after the concrete was laid said it was a really great job. Their ss was the one who gave me his business card and told me to contact him as he does most of their homes and does a great job and will look after me. The implications are a rich tapestry and it requires a qualified legal opinion. By logical thinking, the ss represents the builder and the builder is responsible for his representative's actions but as is well known, the law is an a$$. *Note: this refers to the English colloquial name for a donkey, not the US 'take'. I wonder whether the ss receives a kickback? It would be very interesting to know the number of other jobs the ss has successfully referred to the concreter. An audit of all of his work is in order but I don't know if the VBA has the power to do this. *Haha, the word filter must be American! 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Concrete Perimeter around home 18Jul 24, 2016 9:06 pm I found out the ss is no longer working for the builder and have been advised by another concreter (who I was getting quotes to try and rectify this problem) is to take it up this matter to the Construction Manager or Director of the building company. My cousin who is in the US and works for a big law firm says for me to go after the builders for 'Referral Negligance' as they have referred and recommended me onto a contractor that did the job that may void their structural warranty and it may seem that even the ss did not know the requirements of the concrete regulation, however, I am afraid this might be turn out to be a David vs Goliath match! Re: Concrete Perimeter around home 19Jul 24, 2016 10:09 pm It really is one step at a time at the moment but I think that one of the first urgent steps is to have all of the drainage pipes and fittings examined for fractures as well as looking for the presence of clay trench plugs as required per AS2870 when building on reactive soil. The other culprit could be poor site drainage during construction but having no photos is a killer here. I would also have your roof stormwater drainage examined by an expert for compliance. Non compliant roof drainage is endemic in Victoria. Did you get anything in writing after the structural engineers report? You need to get some heavy weights on side but the building industry is a mine field. I don't know what help the VBA would be but it wouldn't hurt talking to someone there. Hopefully a more knowledgeable H1 member than I will be able to advise about procedure. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Concrete Perimeter around home 20Jul 24, 2016 10:40 pm Thanks SaveH2O for all your help. I hope some more building experts will also be able to read this forum and give me some advise on how to proceed as well. Getting in inspectors etc cost quite a bit and that is money that we do not have at the moment. I am just trying to find out as much as I can by trolling the net at the moment. The structural engineer is from the builder and he recorded his findings and just told me the concrete perimeter is incorrect and that was all. I am worried that as he works for the builders they are coming up with a case to void my structural warranty. I am just preparing in the case that if worse comes to worse and no one admits fault we at our own cost will need to find a way to remove and re-pour the concrete perimeter and driveway and do it properly so the builders cannot void our warranty, it will just come at the expense of my daughter's medical treatments which is what is really killing me. Yes, unless you are in a low intensity rainfall area or the area is protected from rain. Do you have access to NCC Part 2 or can you download it? I can email you a copy… 10 10372 i had the my concreters concrete right up to the fence. I have pits all along my path, so the water tends to drain away from the house and into the pits. There's only one… 7 9697 Grab a hose, insert it at the top of the inlet/down pipe and turn the water on and see where the water is escaping from. Then you'll know. 3 6343 |