Browse Forums Building A New House 1 Nov 14, 2021 4:00 pm Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ We are in the process of building our first home and we have realised that there is a large varience between our FFL and the NGL shown on our plans. At the point in the images we were meant to have a 760mm step up to the NGL, here we are over 1.6m. Could anyone please assist me with the implications involved with this on the overall build? Obviously we are up for excavation, retaining, engineering and drainage costs but is this something the builders will have to rectify? Also block has a council building envelope and everything has required DA approval. We also have a sewer running along our rear boundary (3m from dwelling) and because the slab is lower, now worried this won't meet approvals from syd water and the range of influence around the sewer pipe itself- could this now need concrete encasing? Thanks for any advise. Re: House Slab too low- Approx 700mm too low 2Nov 14, 2021 5:15 pm Lis347 Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ We are in the process of building our first home and we have realised that there is a large varience between our FFL and the NGL shown on our plans. At the point in the images we were meant to have a 760mm step up to the NGL, here we are over 1.6m. Could anyone please assist me with the implications involved with this on the overall build? Obviously we are up for excavation, retaining, engineering and drainage costs but is this something the builders will have to rectify? Also block has a council building envelope and everything has required DA approval. We also have a sewer running along our rear boundary (3m from dwelling) and because the slab is lower, now worried this won't meet approvals from syd water and the range of influence around the sewer pipe itself- could this now need concrete encasing? Thanks for any advise. Lis347 I'll do my best to explain, however you haven't mentioned where you are from. So my advice is based on NSW procedures. Unless I am misunderstanding your post, you believe that the builder has set your slab 700mm or so lower than the FFL on your approved plans. Basically during the build, there are set steps or stages that the certifier needs to receive and site certificates from various trades. Without listing them all, they will need a surveyor to confirm the slab set out and roof heights etc. Call the certifier ( as they work for you not the builder) and ask for this confirmation. Tell your certifier your concerns, put it in writing etc. If the builder has set your slab out incorrectly then they will have to rectify it. Cheers Simeon Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: House Slab too low- Approx 700mm too low 3Nov 14, 2021 5:33 pm Ashington Homes Lis347 Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ We are in the process of building our first home and we have realised that there is a large varience between our FFL and the NGL shown on our plans. At the point in the images we were meant to have a 760mm step up to the NGL, here we are over 1.6m. Could anyone please assist me with the implications involved with this on the overall build? Obviously we are up for excavation, retaining, engineering and drainage costs but is this something the builders will have to rectify? Also block has a council building envelope and everything has required DA approval. We also have a sewer running along our rear boundary (3m from dwelling) and because the slab is lower, now worried this won't meet approvals from syd water and the range of influence around the sewer pipe itself- could this now need concrete encasing? Thanks for any advise. Lis347 I'll do my best to explain, however you haven't mentioned where you are from. So my advice is based on NSW procedures. Unless I am misunderstanding your post, you believe that the builder has set your slab 700mm or so lower than the FFL on your approved plans. Basically during the build, there are set steps or stages that the certifier needs to receive and site certificates from various trades. Without listing them all, they will need a surveyor to confirm the slab set out and roof heights etc. Call the certifier ( as they work for you not the builder) and ask for this confirmation. Tell your certifier your concerns, put it in writing etc. If the builder has set your slab out incorrectly then they will have to rectify it. Cheers Simeon Thanks for your reply Simeon. We are in NSW so perfect advice for us. We have actually tried to contact the certifier multiple times, but he hasnt returned any calls or emails. We have also asked the builder for the surveyors reports but they have not supplied and ignored our requests. We have also asked for our own surveyors to attend the site but they have not confirmed/ approved access. They have also written to us stating our build is now on hold, but have breached their own contract by not supplying any prior notification or reasoning behind this. To add... they are still working and have trades onsite more than ever. We're under the assumption they are aware of what they have done and are just going to try and ride it out until we run out of funds for legal assistance. But I was just curious what they would actually have to do to fix it, and if they would have to demolish and rebuild? Thanks again. Re: House Slab too low- Approx 700mm too low 4Nov 14, 2021 5:36 pm Lis347 Ashington Homes Lis347 Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ We are in the process of building our first home and we have realised that there is a large varience between our FFL and the NGL shown on our plans. At the point in the images we were meant to have a 760mm step up to the NGL, here we are over 1.6m. Could anyone please assist me with the implications involved with this on the overall build? Obviously we are up for excavation, retaining, engineering and drainage costs but is this something the builders will have to rectify? Also block has a council building envelope and everything has required DA approval. We also have a sewer running along our rear boundary (3m from dwelling) and because the slab is lower, now worried this won't meet approvals from syd water and the range of influence around the sewer pipe itself- could this now need concrete encasing? Thanks for any advise. Lis347 I'll do my best to explain, however you haven't mentioned where you are from. So my advice is based on NSW procedures. Unless I am misunderstanding your post, you believe that the builder has set your slab 700mm or so lower than the FFL on your approved plans. Basically during the build, there are set steps or stages that the certifier needs to receive and site certificates from various trades. Without listing them all, they will need a surveyor to confirm the slab set out and roof heights etc. Call the certifier ( as they work for you not the builder) and ask for this confirmation. Tell your certifier your concerns, put it in writing etc. If the builder has set your slab out incorrectly then they will have to rectify it. Cheers Simeon Thanks for your reply Simeon. We are in NSW so perfect advice for us. We have actually tried to contact the certifier multiple times, but he hasnt returned any calls or emails. We have also asked the builder for the surveyors reports but they have not supplied and ignored our requests. We have also asked for our own surveyors to attend the site but they have not confirmed/ approved access. They have also written to us stating our build is now on hold, but have breached their own contract by not supplying any prior notification or reasoning behind this. To add... they are still working and have trades onsite more than ever. We're under the assumption they are aware of what they have done and are just going to try and ride it out until we run out of funds for legal assistance. But I was just curious what they would actually have to do to fix it, and if they would have to demolish and rebuild? Thanks again. OMG!! yes they would have to demolish and rebuild. Let's take this offline and I will see what I can do to help find you a solution. I have a lot of contacts that can help. if you are free tomorrow call me on 0431712792 and we can work on a plan cheers Simeon Architectural Homes & Duplexes - specialising in custom designing homes to your budget Get a Free Onsite Consultation Today or send a PM for information, questions or advice. Re: House Slab too low- Approx 700mm too low 5Nov 14, 2021 8:20 pm Lis347 It would take someone with a dumpy or laser Level 5 minutes to work out if your floor level is built according to the approved plans. There is no excuse for it not being built as per the approved plans. There is often a note on plans allowing for a small variation in height (maybe 100mm) but your approved plans have to be adhered to by your builder. My only question would be, are you certain the slab is 700mm low? It may appear that way due to the surrounding existing NGL and it will certainly need retaining and I'm amazed that the builder would build that close to a cut without first retaining, but get the RL's checked before you go throwing accusations. Accessible Carpentry & Cabinets accessiblecarpentry@gmail.com accessiblecarpentry.com.au https://www.facebook.com/pages/Accessible-Carpentry-Cabinets/583314911709039 Re: House Slab too low- Approx 700mm too low 6Nov 14, 2021 8:44 pm chippy @Lis347 It would take someone with a dumpy or laser Level 5 minutes to work out if your floor level is built according to the approved plans. There is no excuse for it not being built as per the approved plans. There is often a note on plans allowing for a small variation in height (maybe 100mm) but your approved plans have to be adhered to by your builder. My only question would be, are you certain the slab is 700mm low? It may appear that way due to the surrounding existing NGL and it will certainly need retaining and I'm amazed that the builder would build that close to a cut without first retaining, but get the RL's checked before you go throwing accusations. Hi chippy, We actually casually asked our site supervisor to check in the beginning but never updated us (in 3 weeks). Our contact states a 100mm varience. Someone was kind enough to check with laser level and confirmed the FFL is approx. 700mm lower. But nothing formal/ in writting. If they had checked and had shown us the surveyor report all good and well but the illusive behaviour makes us believe we are onto something. Would love to get it fomally checked but as above they have 'suspended' the build and have not supplied us with approval for access. Re: House Slab too low- Approx 700mm too low 7Nov 15, 2021 11:32 am This underscores the importance of having your own independent inspector for stage inspections. If you had one then the problem with levels should have been raised before the slab was poured. Experienced consultant will certainly know your levels have anomaly even from a visual inspection alone and then it is not hard to confirm it. Not long ago I had a VCAT case with owner builder alleging his excavating contractor over cut the site by 2M. As it happened, I established excavation was correct but the land contour levels were wrong. Land surveyor made a mistake on his drawings. Can you post some site elevations? 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 Re: House Slab too low- Approx 700mm too low 8Jun 05, 2023 9:26 am Hi all, I have run into a similar issue where slab has been poured 100mm lower than the FFL. Is there anything that can be done in this situation and/or is it a major concern? Could they top up the level with more concrete doweling into the slab and then pouring on top? Re: House Slab too low- Approx 700mm too low 9Jun 05, 2023 12:11 pm building-expert This underscores the importance of having your own independent inspector for stage inspections. If you had one then the problem with levels should have been raised before the slab was poured. Experienced consultant will certainly know your levels have anomaly even from a visual inspection alone and then it is not hard to confirm it. Not long ago I had a VCAT case with owner builder alleging his excavating contractor over cut the site by 2M. As it happened, I established excavation was correct but the land contour levels were wrong. Land surveyor made a mistake on his drawings. Can you post some site elevations? If surveyor made a mistake, excavator shouldn't have cut the site until the mistake is resolved by the surveyor first. I think that wise co-ordination between the trades is the most important thing in building. Re: House Slab too low- Approx 700mm too low 10Jun 06, 2023 9:40 pm alexp79 building-expert This underscores the importance of having your own independent inspector for stage inspections. If you had one then the problem with levels should have been raised before the slab was poured. Experienced consultant will certainly know your levels have anomaly even from a visual inspection alone and then it is not hard to confirm it. Not long ago I had a VCAT case with owner builder alleging his excavating contractor over cut the site by 2M. As it happened, I established excavation was correct but the land contour levels were wrong. Land surveyor made a mistake on his drawings. Can you post some site elevations? If surveyor made a mistake, excavator shouldn't have cut the site until the mistake is resolved by the surveyor first. I think that wise co-ordination between the trades is the most important thing in building. That is exactly the point owner builder was making, who could hardly speak english and had no building experience (clueless) but he thought that excavator operator should have known. Good point, yes in an ideal world but how is the guy who dropped out in year 10 to drive an excavator going to know and understand land surveyors drawings? The operator was given the job, shown the benchmark to achieve and that is what he did. He had no idea that the contours were wrong. Its not his job to supervise, check and run the building job. The bottom line? The builder is in charge, the builder is the captain and the buck stops with the builder. Where was the builder? If the captain is blind, or his rocks are going off in the cabin with exotic dancer, just ask Captain of Costa Concordia) the ship will hit the rocks, dont blame the sailor. I was working for the owner but that does not mean I don't call it as it is. 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 Thanks! I'm spoke to the builder I'm not sure if this is all true but basically went along the lines of they considered all options and if I was to compact and fill it… 2 12984 Those span tables can be pushed a little for a low deck if you dont mind a little flex. Last deck I did, I pushed it a little and it was still rock solid - no noticeable… 6 22091 DIY, Home Maintenance & Repair Thanks. I was thinking of using either Extreme Joist or LOWDECK timbers for joists. Any idea what sets them apart and which… 2 19756 |