Browse Forums Building A New House 1 Oct 30, 2013 11:19 am I received a soil test on a block of land stating P Class but mentions H1 properties, i am wondering when it comes time to build what sort of slab costs will i incur? Would it be a H class or a H1 or worse? Or could it be changed back an M or something any idea what costs i would be up for a 300m2 slab on a lowset house? SITE CLASSIFICATION: Class P - due to trees & low bearing (class H1 properties) BEARING CAPACITY This site has been given a P classification in accordance with Clause 2.1.3 (a) and Clause 2.4.5 of AS2870-2011, as our investigation indicates that the founding soils have a bearing capacity of less than 50kPa, which is the minimum to support a residential slab on ground. The minimum bearing capacity required to support isolated pad or strip footings is 100kPa. The design engineer must ensure that footings are appropriately designed to account for the low bearing strength. INFLUENCE OF TREES This site has been given a P classification in accordance with Clause 1.3.3 and Clause 2.1.3(e) of AS2870-2011, as our investigation indicates that trees were noted within or adjacent to the footprint of the proposed building. Trees remove moisture from the soil and result in abnormal moisture conditions occurring on the site. On removal of these trees, or if they remain in place, damage to a proposed building may occur without additional treatment. The design engineer must ensure that footings are appropriately designed to account for the effect of the trees. We refer the design engineer to Appendix H and Appendix CH of AS2870-2011 as guides on the design of footings for trees. To assist, we have estimated yt, the potential additional surface movement due to trees, and ys + yt / 0.7 http://www.betterthansheets.com.au - Why use sheets for curtains in your brand new home use Better Than Sheets Temporary Paper blinds instead! Re: What Class Slab would i need (soil test info inside) 2Oct 31, 2013 9:24 am any ideas? http://www.betterthansheets.com.au - Why use sheets for curtains in your brand new home use Better Than Sheets Temporary Paper blinds instead! Re: What Class Slab would i need (soil test info inside) 3Oct 31, 2013 12:04 pm For the right answer you will have to engage structural engineer to design your slab however given the low load bearing capacity of the soil it is likely that the design will be slab on piers. Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog 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 13099 The Soil classification has little to do with piers. The purpose of the classing of the soil is to identify the clay content and the "average expected range of movement… 2 9855 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 37143 |