Browse Forums Building A New House 1 Sep 01, 2014 12:24 pm we are doing a KDR in the hills area of NSW with Alkira Homes. CDC plan classified the site is M, but the structure engineering report classified P. and the geotech report saying so: Site Classfication The classification has been prepared in accordance with the guidelines set out in the “Residential Slabs and Footings” Code, AS2870 - 2011. Because there is an existing house and tree present, abnormal moisture conditions (AMC) prevail at the site. (Refer to Section 1.3.3 of AS2870). Because of the AMC present, the site is classified a problem site (P). Provided the footings bear in natural soils, the site may be reclassified moderately reactive (M). anybody has any ideas? Re: Site Classification _please contribute , thanks in advan 2Sep 01, 2014 3:18 pm The geotech report states that it is a problem site... Quote: Because there is an existing house and tree present, abnormal moisture conditions (AMC) prevail at the site. They can't test all the areas of the building footprint as your existing house is obviously still there. They are probably covering their backsides a bit too. Who classified it as M ? The builder, you ? Provided you have the footings bearing on natural ground you may be able to get it re-classified as M. Once the house has been demolished and the new footings are dug the engineer may want to come and do an inspection again. What kind of slab are you having - waffle pod or raft slab ? Stewie Re: Site Classification _please contribute , thanks in advan 3Sep 01, 2014 3:59 pm Thank you Stewie, The architecture plan from CDC classified M. we are having waffle pod. the geotech report also said weathered shale underneath, around 1.5 meter. Can I ask you another question: the site is slopping, have some cut and fill, plus split levels, drop down 600mm in garage and 1100mm in the living area, will the cut and fill affect the classification as well? Re: Site Classification _please contribute , thanks in advan 4Sep 01, 2014 5:18 pm There are a couple of issues: Different subsoil moisture over site. If your new house is partially over old house and partially over garden area there can be different rates of settlement as the area under the new house dries out and shrinks. Building on a cut and fill area has particular problems. See http://www.anewhouse.com.au/2012/08/bui ... ete-piers/ The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Site Classification _please contribute , thanks in advan 5Sep 02, 2014 2:36 pm Thanks for your contributions. we asked the builder, builder said they would not have a second test after demolition. they classified it as P, the architecture plan for CDC classified as M was wrong. therefore,blahhh Re: Site Classification _please contribute , thanks in advan 6Sep 02, 2014 2:40 pm what we also found out : Geotech report said the soil is not saline soil, but the engineer overlooked it, took it as saline soil and added extra treatment But at the same time, the engineer also added treatment for sulfate Saline and Sulfate are two totally opposite thing, like water and fire, -unbelievable! Really worry me a lot! because its not being managed properly. Also "properly" is too broad and too subjective a term to be able to pinpoint a single event as not being managed properly.… 1 2729 I am not sure whether Perth has its own way of doing things in regards to this. Most of Perth has class A (sandy soil), except for some areas near rivers or hills. 2 8260 |