Browse Forums General Discussion 1 Aug 26, 2022 11:49 am Hi guys,
I'm currently in the process of getting a 12mx12m metal kit shed built in my backyard. I've gone through the process of getting a draftsperson/engineer/geotech etc and finally got my building permit... Hooray! Or so I thought.. Upon talking to concreters, I've come across a hiccup where a few of them are saying that they do not agree with the need for my slab design and that it is overkill for the purpose of a shed. I have huge respect for engineers/concreters/designers etc and what they can achieve from turning complicated drawings into physical structures. So I feel I am not in a position to question either of them. If what the concreters are saying is correct, it will mean that the cost of getting a variation on my building permit and getting new plans drawn up will still be way cheaper in the long run. I have never dealt with 'P' class soil so I am unsure if it would be unreasonable for me to go back a few steps and get some changes made. Would love to hear if anyone else has been in this situation before and if so, what approach you took and how it ended up ? Cheers! Edit: forgot to mention that a few concreters suggested asking for bored piers instead as it will greatly reduce the need to excavate so much earth like suggested in the current drawings. Are footing types interchangeable like this ? Some online calculators state that even if I were to get, for example; 50 holes at 3 meters deep and 450mm wide, it will still be less excavation and cost than if I were to go ahead with the current plans that I have. Re: Is my engineered slab overkill ? 2Aug 26, 2022 2:49 pm unless your concreters are engineers, I would follow the engineering. I really don't understand why the concreters are even getting involved in advising you on design, they will make more money following the design. If you feel the concreter's advice is valid, talk it through with the engineers and see if they agree. They may be able to give you some more insight into their design or reconsider it. Dark matter scientist, can breathe underwater, mind reader and can freeze matter just by willing it. Trust me, its in my sig. Re: Is my engineered slab overkill ? 3Aug 26, 2022 3:03 pm Noname unless your concreters are engineers, I would follow the engineering. I really don't understand why the concreters are even getting involved in advising you on design, they will make more money following the design. If you feel the concreter's advice is valid, talk it through with the engineers and see if they agree. They may be able to give you some more insight into their design or reconsider it. I made contact with the engineer and awaiting a response once they've reassessed their drawings. I figured I'd ask here to see if anyone has been through a process of getting revisions done on their engineering is all. "I really don't understand why the concreters are even getting involved in advising you on design, they will make more money following the design." Perhaps they are nice honest people that are looking out for potential clients! Re: Is my engineered slab overkill ? 4Aug 27, 2022 8:36 pm Vilnow ...Perhaps they are nice honest people that are looking out for potential clients! I've heard this argument before from both New Homes Salesman, home sketch Artists and concretors Goes something like this " since I'm the first one in and out I should get paid the most, before the client runs out of money..." (humour.. lol, the project's just starting) Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Is my engineered slab overkill ? 5Aug 28, 2022 10:30 am The obvious answer is to get a second opinion from another independent structural engineer 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: Is my engineered slab overkill ? 6Aug 28, 2022 11:55 am Update: I contacted 3 more engineers and they all gave differing opinions on ways they would go about it. They all suggested that bored piers can be used since the tree's around the vicinity of the slab have been removed. The difference in excavation & concrete was about 4-5 cubic meters less if it was done this way (or up to 10m3 less if I were to push the envelope)so it wouldn't be worth my time to apply for new drawings and a variation to the building permit (that's assuming that the building surveyor even accepts it). Next time I go through this process I will reach out to multiple engineers with the geotech report beforehand and go from there. Live and learn! Re: Is my engineered slab overkill ? 7Aug 29, 2022 9:21 am Vilnow Update: I contacted 3 more engineers and they all gave differing opinions on ways they would go about it. They all suggested that bored piers can be used since the tree's around the vicinity of the slab have been removed. Thanks for the update, most don't post after seeking professional advice The differing alternate solutions can only be certified by engineers and not concretors. Vilnow The difference in excavation & concrete was about 4-5 cubic meters less if it was done this way (or up to 10m3 less if I were to push the envelope)so it wouldn't be worth my time to apply for new drawings and a variation to the building permit (that's assuming that the building surveyor even accepts it). At a quick guessitmate there may be 50m3 of concrete at $400m3 approx. (L & M) = say $20K cost A 10% savings of $2K is hardly worth it, as the concretor will credit back the material and not the labour a moot point. "It's always too much concrete...the labour costs are the same?" lol, you didn't move a wheelbarrow? As for the Surveyor, unfortunately, he may not except the changes... it's a great gig for someone that doesn't understand AS3600 nor the math calculations involved, they just rubber stamp whatever the engineer hands them (humour) An area that needs to be addressed through legislation, my2c Vilnow Next time I go through this process I will reach out to multiple engineers with the geotech report beforehand and go from there. Live and learn! 100% Just make sure you get a preliminary engineering estimate before you start. Cheers chris Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Is my engineered slab overkill ? 8Aug 29, 2022 12:12 pm StructuralBIMGuy Vilnow Update: I contacted 3 more engineers and they all gave differing opinions on ways they would go about it. They all suggested that bored piers can be used since the tree's around the vicinity of the slab have been removed. Thanks for the update, most don't post after seeking professional advice The differing alternate solutions can only be certified by engineers and not concretors. Vilnow The difference in excavation & concrete was about 4-5 cubic meters less if it was done this way (or up to 10m3 less if I were to push the envelope)so it wouldn't be worth my time to apply for new drawings and a variation to the building permit (that's assuming that the building surveyor even accepts it). At a quick guessitmate there may be 50m3 of concrete at $400m3 approx. (L & M) = say $20K cost A 10% savings of $2K is hardly worth it, as the concretor will credit back the material and not the labour a moot point. "It's always too much concrete...the labour costs are the same?" lol, you didn't move a wheelbarrow? As for the Surveyor, unfortunately, he may not except the changes... it's a great gig for someone that doesn't understand AS3600 nor the math calculations involved, they just rubber stamp whatever the engineer hands them (humour) An area that needs to be addressed through legislation, my2c Vilnow Next time I go through this process I will reach out to multiple engineers with the geotech report beforehand and go from there. Live and learn! 100% Just make sure you get a preliminary engineering estimate before you start. Cheers chris Appreciate the insight, Chris. This has been quite an interesting experience! One thing that really confused me was that I couldn't obtain the engineering services from outside of Victoria as they can't sign off a form15 for structures in VIC even though it's a class10. I thought everyone played by the same rules with Australian standards. Engineering timber is certainly a less fuss option, times cheaper to supply and install and better withstands humidity. 1 16054 Thanks Simon, I guess I'm no concerned with the volume of the noise rather that dead and hollow sound and feel that is associated with floating floors. But I'm not sure… 3 6220 Thanks for the insights, that makes perfect sense, and yeah, I will be leaning on the experience of the excavator operator entirely. 6 16322 |