Browse Forums General Discussion Re: Slab movement/heaving causing massive cracks 23Feb 23, 2020 11:07 pm Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Slab movement/heaving causing massive cracks 26Feb 24, 2020 9:50 pm Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Slab movement/heaving causing massive cracks 34Mar 21, 2021 2:51 pm Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Slab movement/heaving causing massive cracks 36Mar 23, 2021 11:15 pm I was cross-referencing some of the original structural engineering documents with the recent reports from the builder's inspector. The original reports have a section for "Tree Influence" and it's marked N/A The inspector's report calls out that the pre-existing conditions on the site prior to subdivision commencing involved a great stand of trees running across the front and their rooting system has been detected all the way to the kitchen zone at depth i.e. natural soil level. In addition, we have subdivisional filling having been put on to a depth of approximately 800mm or more in some locations, noted as level I controlled fill but it was less than five years when a soil report was initiated. Further, depending upon when the controlled filling went in, it may have infilled all the cracks within the soil below, noting the natural soil profile would have had cracks as the tree roots would have been drying it out and thus cracks would have been normal, even late into autumn. Thus, we get an amplification of any movement caused by wetting up the soil. Does this mean the original structural engineers completely overlooked this fact? This paragraph in the engineer's report is very distressing "I further note here that irrespective of all actions taken, it may be many years before the ground underneath this property dries out or equalises up in moisture level throughout and creates a more uniform level throughout the whole house. When and if that occurs, further plumbing failures will happen, and they will need to be fixed urgently. This will require a block flood monitoring of the property on a three-month basis for the foreseeable future. We at our wit's end dealing with all this Re: Slab movement/heaving causing massive cracks 37Mar 24, 2021 10:47 am What do you expect the builders engineer to say? As an engineer I can honestly say the Builder isn't off Scot free with another report. OT, The first and second engineer were all hired by the Builder you may need to hire your own independent engineer The person doing the site works and supervising has a duty of care to remove roots and prepare the site properly. my2c, If some builders stopped r!pping into clients with piering, stormwater, etc costs, then clients would be reluctant to opt for minimum engineering. As you have come to realise engineering is a critical factor in the Build You will need to monitor your slab for differential movement over a period of time to determine what further action is required You can get someone to do that at great expense or you can set up a monitoring system using a Line Laser GLL 3-80 CG Professional Here Checking Room Dimensions (XYZ Coordinates) with Bosch Lasers Collect the data, simulations will be used to determine liability hth Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Slab movement/heaving causing massive cracks 39Mar 25, 2021 10:12 am First thing you'll need to do is cut back the apron concrete path sufficiently to get agri pipe and stormwater disposal system in ASAP as we move into the wetter months. Your geotech engineer will calculate the size system based on the rate of fill/discharge. Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Slab movement/heaving causing massive cracks 40Apr 18, 2021 1:07 pm donovanjd Sorry to hear seems not much progress on any definitive answers on determining original source of water or even if there was one. The previous moisture conditions, trees, fill etc. may be playing a secondary role but from what you've posted it just 'feels' like something has been missed somewhere and that is what needs to be found. Reading over the past posts, the attention has been on leaking pipes, water coming into site, poor drainage etc. which is understandable. Just curious, has the house wall cavity drainage (if present) been discounted yet? Weep holes functioning, no irregularities with relative heights of slab checked out? This would have required holes drilled through the external walls and a look around with pinhole camera. If slab construction possibly dubious someone should also check that concrete hasn't been lost externally into the rolled fill around deepened detail at front-will anchor slab if lost 'unseen'. Checking the above may not reveal the answer but are cheap and simple to do and will provide more information which seems a bit short at moment. Currently you have gained enough information for each party to deny liability and are awaiting a fix without being able to clearly define the cause. Understandable that you are over it. Have look at your house plans and you will probably find that brick articulation joint has been missed. Maximum allowable spacing is 6M or 5.5M for a wall with window… 17 16737 Are they stumps or screw piles ? How much fill is there, is the site a class "P" ? A "H2" site is not supposed to have stumps it is supposed to have grid beams according… 1 1349 House movement is always a potential problem and there is a cause. Yes you should have it inspected by a competent and experienced building consultant 2 1320 |