Browse Forums Owner Builder Forum 1 Jul 04, 2012 11:25 pm Hi We are going to owner build a house which the contour survey done, house plan approved, bulk excavation completed years ago. The site foundation is very stable, sandstone base with sandy loam soil on top and very well drainage. Therefore the excavated site still in the same shape except some low vegetation re-growed after the bulk excavation. We now want to get the project moving again and talked to a draftman for minor amendment to have one section of rear exterior wall pull back one meter so we can have a larger backyard. We were told we need to re-do the contour survey. We think that is not necessary as the details excavation had not been done, prior to the commencement of the building work, we would need to have the site cleared, a surveyor to do the detail set out for the footing, slab , wall and building level according to the amended plan. Any extra earth work requires due change of the plan or site over time can be figured out at the detail building set out and fixed at the time of detail excavation. Is our thinking on the right track? posting.php?mode=post&f=38# Re: Update contour survey after bulk excavation? Advise plea 2Jul 24, 2012 3:48 am Don't quite understand the term "bulk excavation" but if u mean the "levels" are about right, u will need to remove vegetation & perhaps backfill to allow for the "vegetation scrape" taken off. IMO the main thing on any site is too make sure that the floor levels are high enough to enable u to have sufficient fall to reach ur sewage outlet where ever it is on the block - hard to make wastes run uphill!!!! all that said, the type of base (concrete slab or wood floor etc) of the house is also a very determining factor for final levels. hope thats not too confusing best of luck - tony Re: Update contour survey after bulk excavation? Advise plea 3Jul 26, 2012 6:40 pm Thanks Tony, Yes, the bulk excavation cut to the levels as per the plan. Since the levels are about right, the site clearing would only remove the vegetation and a bit of top soil that needs to backfill. After the site clearing we would do the detail set out for footing excavation and recheck the level to see if further trimming or filling is required. Therefore I am not able to see the value of a update contour survey (cost $1K). The site is sloping down toward the road that the house design follows the land with a self contain unit on ground level (80m2) and a one meter step down garage (36m2). The main living area is on upper level (188m2). Are the final levels to be determined by the excavated level, the engineer specification on the slab (sand, steel, concrete...etc); for the timber floor, the height of the pier, bearer and joist sizes plus the ground clearance for ventilation? As a first time OB, I have done a lot of research and reading (books, technical manuals and forums) to be familiar with the building process. However my knowledge is on paper without practical experience that it is to be safe to ask and check whenever in doubt. Totally agreed with you that it is critical the floor level at sufficient height to allow the sewerage run by gravity to the main sewer. My friend's builder did not check the sewer main level prior to laying the waste pipe and poured the slab. After an inspection Sydney Water disallowed the connection to the sewer main due to insufficient height. The only remedy is to have a sewerage pump station installed (cost $$K) and the owners signed an indemnity statement to have yearly inspection/maintenance and the responsibility to all consequential damages caused by the malfunction of the pump. The indemnity must be disclosed to all future owners with their signature to accept the conditions. The pump does not operate without electricity and the toilets can only have limited use due to the pump tank capacity and possibility of backflow. Michelle Re: Update contour survey after bulk excavation? Advise plea 4Aug 02, 2012 2:49 am Hi Michelle, have u got the plans drawn up, & did the plans specify footing details. have u got ur building permit? i would have thought u would have had to have soil testing done b4 u could have got the footing design done & b4 u could apply for ur permit? one of the hardest things to do as an OBer is ur setout. i'm an oldtimer and will never mover beyond profiles for the layout - i know a lot of builders us lazers & pegs, the big problem with this is getting back to where u know things were right!. i would strongly suggest u get someone who has already done a few layouts to help u. IMO its not the contour level that is that important - a long as it is within 1/2 meter of overall level.....its knowing where ur floor levels are firstly, and then finding out what the foundations have to be, thats where soild testing is important. u have to know what the footings are going to sit on. I don't know the east coast or ur area, but soil tests will determine if its clay and needs sand overlay & how deep etc. or if its sand, what is the compacting ability of the sand - not all sand compacts well - even grained sand "rolls" on itself, irregular gains compact better. so IMO b4 u go any further, unless u already know, i suggest u check about soil testing. i think there is a check list of what progresses to what somewhere in this forum. Hope this hasn't completely confused u. there is nothing so frustrating than building ur own house, but there is little in this life so rewarding than living in a house u built for urself. good luck T. Re: Update contour survey after bulk excavation? Advise plea 5Aug 13, 2012 1:27 am The house being built is part of approved DA for land subdivision to build two detached houses A & B. I designed and drafted both houses plans and a draftsman drawn that up for council approval long time ago under the old rules (before basix and NSW Housing Code). The plans are architectural that do not have structural and footing details as they were not required for council approval We organized the excavation for the entire site and acknowledged the land foundation is sandstone rock. The area was a new development that the neighbor sites excavation also found rock under. We had a builder who managing the building of house A (single storey split level design) and sorted things along the way. At that time a geotech engineer inspected the excavated site and done a soil test. The test report stated that the site foundation is rock with bearing capacity of 600 kPa. The depths of footing were estimated to be 500mm average. We had an engineer inspected the footing (piers and perimeters wall to support bearers and joists) and confirmed that the footing of house A is sitting on rock however advised the bearing capacity is 250 kPa. Council inspected the footing and timber frame. We also had another building inspector to check the works at critical stage. The house was completed in 2001 and we live in there since. Recently, I discussed with council building inspector of our area on commencing the works for house B (the project was commenced on time allowed by the DA and no time limit for completion). He told me that the whole area is on rock foundation. As per the approved plan for house B and contour survey, about 20m2 of the slab area required average 500mm fill (deepest 800mm) and the rest is on cut. From memory, the excavated material was used to the fill. When amendment of the plan is finalized, I would have a soil test, then to consider the type of slab that is cost effective to build, eg, raft or footing slab (soil compaction to the requirements of AS 1289, piering of footing, formwork, deep edge beam, two concrete pour...etc) and the detail building working drawings done. I cannot hammer a nail properly that I’m not dare to do the building set out. I'm going to get a slab set out plan on relevant levels, locations and dimensions of the slab and stumps, recesses, step-downs, rebates, and plumbing drainage then to have a surveyor to do the slab set out. Give "Holt Surveying" they are based around Eight Mile Plains 3 8741 Hmmm, I have checked your past posts and it seems that you are in NSW, not WA as I had thought. It pays to show your State in your avatar. Retaining wall regulations… 5 7857 No one can give you a meaningful answer without looking at your building contract, what happened on site and who designed your house You should get experienced building… 1 10211 |