Browse Forums Building Standards; Getting It Right! 1 Jul 23, 2013 12:06 pm Hi everyone New to the forum, got a couple of questions if you can answer (just hope that I am phrasing it correctly): Have a house to be demolition to build new, I would have the relevant house plans for submission to council. Three quotes came back with the usual ‘allowance’ clause - $16k for footing for both and one at $21k – to build a 200m2 house – 175m2 living. 1) Will it be better that I get quotes from the demolition companies by myself and submit to councils or get a builder to organise this? Potential savings on any ‘add-on’ fees by the builder. 2) Footings - getting a soil tests and levels done and providing it to the builder before paying them the deposit or just leave it to the builder after we sign the contract? Potential of not being ‘ripped off’ – heard stories from people who signed contractors who quotes $X amount on footings and then after soil test, footings came back at $Y amounts – totally blow their budget. 3) What is class as Standard footings? One builder had this: 450 x 200, x n16 top and bottom to Engineer’s specification, another quoted based on ‘S’ Class. Cheers boosta http://boostaoakfordsa.wordpress.com Site works: 26/8/14 Trench: 2/9/14 Slab: 8/9/14 Frame: 18/9/14 Bricks: 24/10/14 2nd fix: 24/11/14 Handover: End Feb 2015 Re: Demolition / footing questions 2Jul 24, 2013 11:34 am I would have a soil test done & a level survey. Most Geotechnical firms will undertake both. There are no standard footing sizes. That is determined from the soil report. A class 'S' or 'A' (sandy soil) will be the cheaper. Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: Demolition / footing questions 3Jul 29, 2013 7:58 am To answer your questions: 1/ I'd probably get a quote to demo the house myself and also have the builder quote it as separate option. 2/ Definitely get a soil test done first. As you are building on a demo site it'll probably be a "p" class slab and most builders would want both the soil test and engineering for the slab to give you an accurate quote. Without those pieces of information it will be an uninformed guess at best. Even when there is a quote there are risks you will find something unexpected during excavation and you may have an unexpected bill. The builder is obligated to give you a price based on what is known or what he should have known based on the information provided. If the soil test and engineering calls for a (say) M class slab and shows only silty clay etc the builder will price it accordingly and probably put in a provisional sum of $X. If during the excavation of the footings you find some fill that didn't show up on the soil test and instead of a normal footing you need a far deeper beam and/or piles (etc) then you will be up for the bill. Unfortunately neither you, the engineer nor the builder has a crystal ball and these are the risks when building. Since it's your house then ultimately the bill will be yours. I'd be suspicious of a builder who didn't put a site like yours in as a provisional sum tbh. Re: Demolition / footing questions 4Jul 29, 2013 10:01 am Thanks for the advice. One builder suggested that I get a soil test done even though the existing property is still there. I prefer a soil test after the demolition though does it matter? http://boostaoakfordsa.wordpress.com Site works: 26/8/14 Trench: 2/9/14 Slab: 8/9/14 Frame: 18/9/14 Bricks: 24/10/14 2nd fix: 24/11/14 Handover: End Feb 2015 Re: Demolition / footing questions 5Jul 29, 2013 11:11 am Definitely. Soil test after demolition. As previously mentioned the soil report should come back as a class P due to the variation in soil moisture content between the the exposed soil & the currently covered soil. Generally if the site is allowed to 'sit' for a period of time after demolition the soil profile will level out. Ideally it would be good to allow the cleared site to sit for 6 to 12 months but this is not always feasible. Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: Demolition / footing questions 6Mar 19, 2014 8:34 pm Just received my soil report and it does not look good - site classification - E-D/P (fill). Soil assessment - the soils on this site consisted of at least 550mm of fill overlying highly reactive clay horizons to the extent of testing. 3 boreholes taken and the current house to be demolished is still at the block. Came back with grillage raft (I searched but not much on forum). Beam A (900mm depth)/ 250mm / 1N32 (top) / 1N32 (bottom) / W8@1000 (hangers) Beam B (900mm depth)/ 250mm / 1N28 (top) / 1N28 (bottom) / W8@1000 (hangers) Slab 120 with SL92 Builder's standard FOOTINGS EXTERNAL: 450mm X 300mm reinforced with 6/N12 bars INTERNAL: 450mm X 250mm reinforced with 4/N12 bars SLAB: 100mm thick with 1 layer of F72 mesh Will ring to find out how much extra I have to pay. Sigh.... http://boostaoakfordsa.wordpress.com Site works: 26/8/14 Trench: 2/9/14 Slab: 8/9/14 Frame: 18/9/14 Bricks: 24/10/14 2nd fix: 24/11/14 Handover: End Feb 2015 Re: Demolition / footing questions 7Mar 26, 2014 8:06 am The footings for our place are similar but a bit deeper. Ours came in at about $55,000 Dimensions: 1200mm depth) 250mm wide Reinforcement: 1-N32T, 1N32B Ligatures: W10@800 Re: Demolition / footing questions 8Jun 16, 2014 2:21 pm boosta Just received my soil report and it does not look good - site classification - E-D/P (fill). Soil assessment - the soils on this site consisted of at least 550mm of fill overlying highly reactive clay horizons to the extent of testing. 3 boreholes taken and the current house to be demolished is still at the block. Came back with grillage raft (I searched but not much on forum). Beam A (900mm depth)/ 250mm / 1N32 (top) / 1N32 (bottom) / W8@1000 (hangers) Beam B (900mm depth)/ 250mm / 1N28 (top) / 1N28 (bottom) / W8@1000 (hangers) Slab 120 with SL92 Builder's standard FOOTINGS EXTERNAL: 450mm X 300mm reinforced with 6/N12 bars INTERNAL: 450mm X 250mm reinforced with 4/N12 bars SLAB: 100mm thick with 1 layer of F72 mesh Hi all, I have received my footings and site costs and it came in at $16k ($1k below budgeted $15k footing allowance and $2k site cost). Is this too good to be true (price-wise) for single storey 174m2 total living? Cheers boosta (SA) http://boostaoakfordsa.wordpress.com Site works: 26/8/14 Trench: 2/9/14 Slab: 8/9/14 Frame: 18/9/14 Bricks: 24/10/14 2nd fix: 24/11/14 Handover: End Feb 2015 Re: Demolition / footing questions 9Jul 03, 2014 8:28 am Hi Boosta...where about are you building your house. I'm also doing a demolition and subdivision/build in inner north suburb. I've had my spoil report done already as well but the house isn't demolished yet. Re: Demolition / footing questions 10Jul 03, 2014 9:38 am Ninka Hi Boosta...where about are you building your house. I'm also doing a demolition and subdivision/build in inner north suburb. I've had my spoil report done already as well but the house isn't demolished yet. Hi Ninka Building at Parkside. cheers boosta http://boostaoakfordsa.wordpress.com Site works: 26/8/14 Trench: 2/9/14 Slab: 8/9/14 Frame: 18/9/14 Bricks: 24/10/14 2nd fix: 24/11/14 Handover: End Feb 2015 We had this happen to us last year and got charged a variation. Try and give away as much as you can that is usable to charity otherwise if you are in Sydney I have a… 1 4501 yep sounds good make the footing bigger to to allow for the pipe in the middle 3 7321 PM me your email. I have a build excavation calculator you can use based on your plans to double check what your builder is telling you. Cheers Simeon 1 10244 |