Browse Forums Building A New House 1 Aug 26, 2014 8:04 pm Hi All We received our soil test back on land which is sloping. The good news is that it is S Class The bad news is that appears to be all on weathered rock and we need to some major site works due to the slope. Has anyone encountered weathered rock and it been an issue? Just want to know what we may be in for. We need to cut in around 2 metres at the worst point. We also got an N3 wind rating, any idea on what this adds to the cost of a standard build. Cheers Re: Soil Test - Good news/bad news? 2Aug 26, 2014 8:50 pm Thats bad news, if your site have rock bed around excavation area then get rock excavation. depends how deep it stays on your ground. good luck with your builder Re: Soil Test - Good news/bad news? 3Aug 26, 2014 9:09 pm Thanks Cameron 32 I just called the earthworks guy and he said it shouldn't be a problem as his equipment will chew through it, having said that I am still concerned. I also went the house next door and he said he only had a problem on the other side of the house but it was quite easy on our side, still unsure as it is a bit of a gamble. Re: Soil Test - Good news/bad news? 4Aug 26, 2014 9:26 pm Depends what sort of rock and degree of weathering can vary from virtually soil to hard base bedrock.In the report did they give much of a description of the rock and were they able to drill into the rock or did their drill rig stop at a shallow depth? Re: Soil Test - Good news/bad news? 5Aug 27, 2014 7:09 pm Thanks Insider, I happened to be on the block when they were doing it. The report says 400mm but they did go deeper and he said it didn't seem very hard. On one he got down to about 700mm and this is an auger with a lawnmower engine. My concern is the likelihood on harder rock like basalt of or something. Saying they 300mm of the 400mm was top soil the developer put on top to hide it which according the drillers is common practice to sell the block nice and green... Re: Soil Test - Good news/bad news? 6Aug 27, 2014 7:32 pm Kaindec I know what they are saying I have been bogged in that 300mm-400mm many times. On the report they should state the geology so this could give you a glue.If it is basalt or granite you may hit very hard rock all of sudden if it is silt/mudstone not so bad. Re: Soil Test - Good news/bad news? 7Aug 27, 2014 7:42 pm Thanks Insider Below is what the report said for all the bores - the auger didn't really stop they just stoped it when they realised it was rock, on one he showed me how far it would go which was about 700mm and seemed to come out a really fine grain Depth (mm) Group Symbol Soil Description 0 - 300 CL Silty clay, dark brown, with some gravels, moist, stiff 300 - 400 XW Weathered rock, grey, dry, hard 400 Termination of log. Auger refused due to weathered rock Re: Soil Test - Good news/bad news? 8Aug 27, 2014 8:01 pm As you said earlier, site going to cut 2m around worst point. biggest issue is leveling your site i think. Re: Soil Test - Good news/bad news? 9Aug 27, 2014 8:10 pm Cheers, the earthworks guy said he will chew through it, how do you mean about levelling the block? Problem is that I am not sure who to believe, I can still pull out but don't want to. Re: Soil Test - Good news/bad news? 10Aug 27, 2014 8:27 pm I mean, if they cut your site to 2m deep then need a rock excavation. few house behind my street having rock beds, don't know what type of rocks, whole site sit above rocks(roughy 400mm from top and it goes more deep as well). i saw they use big machinerys and hammered more than two weeks time. that's really terrible. Re: Soil Test - Good news/bad news? 11Aug 30, 2014 10:09 pm Rock cost lots to excavate but is the best to build on. Your house will be "rock solid" no pun intended. It will not suffer any of the problems of cracking found in highly reactive clay sites. Thanks for your reply. I will just wait and see I guess. Trying to get some more information from our builder. 9 11696 We were lucky in that our old house was so small (86 square metres) compared to the new house, they were able to take enough readings around the old backyard house before… 8 24697 Three options 1 Ask the liquidator 2 Find another PD customer and ask the source of their report 3 Pay for new report 3 6479 |