Browse Forums Building A New House 1 Jul 13, 2022 11:21 am Hi all, Finally getting our new design locked down. Need to do a landscape plan (council requirement for DA). I've read on here a number of times that if you have a waffle slab you should (even must) have concrete aprons to protect the slab. Does this still apply if the slab sits on top of block retaining walls rather than at ground level? I've attached a pic below that may better communicate what I mean. Should I be looking to have a concrete apron around the house or will it be OK (at least where the slab isn't at ground level)? Thanks for your help! Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Waffle Pod Slab over retaining walls 2Jul 13, 2022 7:03 pm The Councils DA landscaping request should help you focus on other important issues that may effect your build and the adjoining properties after handover, should you choose to DIY later Before you give the builder any more monies Firm up the BA drawing, engineering, details and costs .ie, Storm water, boundary retaining, engineering, Drop footings, beams, concrete paths & steps etc. Make sure you have enough money in reserve and the builder doesn't leave you in a worse or impossible situation with trades, material and access..... ATM, you have a rough plan, waffle slab on a difficult block, and an estimate at best You want to avoid $ticker $hock well before the contract drawings and costs are finalised. If the BA process becomes too burdensome and you pull out you may loose all your deposit plus extra. Forewarned is forearmed Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Waffle Pod Slab over retaining walls 3Jul 13, 2022 7:13 pm StructuralBIMGuy The Councils DA landscaping request should help you focus on other important issues that may effect your build and the adjoining properties after handover, should you choose to DIY later Before you give the builder any more monies Firm up the BA drawing, engineering, details and costs .ie, Storm water, boundary retaining, engineering, Drop footings, beams, concrete paths & steps etc. Make sure you have enough money in reserve and the builder doesn't leave you in a worse or impossible situation with trades, material and access..... ATM, you have a rough plan, waffle slab on a difficult block, and an estimate at best You want to avoid $ticker $hock well before the contract drawings and costs are finalised. If the BA process becomes too burdensome and you pull out you may loose all your deposit plus extra. Forewarned is forearmed Yeah, been there done that. We first submitted DA in March 2020. Earlier this year builder canned the contract due to costs so this is round 2 with some design improvements. And this time they've told us landscaping is our problem whereas last time they were doing it. So I'm looking to do it properly (since I had to get the house plan updated myself to meet all the Council requirements since the builder just washed their hands of it) so if concrete apron is recommended then I will look to make sure it is included in our plan (on top of the volume of requirements from Council). Re: Waffle Pod Slab over retaining walls 4Jul 13, 2022 7:57 pm Ok they have stung you once don't be an idiot and get done again You'll need proper drawings , details , data and cost estimates Find someone local that can offer that up to you? If the builder owns the drawings and copyright then your re at his mercy? Your bargaining position is close to zero? Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Waffle Pod Slab over retaining walls 5Jul 14, 2022 12:06 am BanjoDan Yeah, been there done that. We first submitted DA in March 2020. Earlier this year builder canned the contract due to costs so this is round 2 with some design improvements. And this time they've told us landscaping is our problem whereas last time they were doing it. So I'm looking to do it properly (since I had to get the house plan updated myself to meet all the Council requirements since the builder just washed their hands of it) so if concrete apron is recommended then I will look to make sure it is included in our plan (on top of the volume of requirements from Council). Concrete apron is recommended for reactive soils, and the blocks where the water can pool against the walls (the flat ones) to keep it away from the slab. Your block seems to be sloped so you probably don't need it around the whole house. Having said that, I'd still do it as it makes it so much easier to walk around the house. Unless you have a reason not to. Re: Waffle Pod Slab over retaining walls 6Jul 14, 2022 9:22 am strannik BanjoDan Yeah, been there done that. We first submitted DA in March 2020. Earlier this year builder canned the contract due to costs so this is round 2 with some design improvements. And this time they've told us landscaping is our problem whereas last time they were doing it. So I'm looking to do it properly (since I had to get the house plan updated myself to meet all the Council requirements since the builder just washed their hands of it) so if concrete apron is recommended then I will look to make sure it is included in our plan (on top of the volume of requirements from Council). Concrete apron is recommended for reactive soils, and the blocks where the water can pool against the walls (the flat ones) to keep it away from the slab. Your block seems to be sloped so you probably don't need it around the whole house. Having said that, I'd still do it as it makes it so much easier to walk around the house. Unless you have a reason not to. Thanks for that. Much appreciated. Re: Waffle Pod Slab over retaining walls 7Jul 14, 2022 10:41 am Hey banjodan As an engineer I would be very concerned about your engineering and the builders costings to come at BA Don't get stuck on the the path and minor issues, Builders are experts at diverting you attention away to minor issues and then extracting monies for engineering, before you know it they'll say " It's not my fault what I thought was the compliant engineering has now changed and is more expensive ...?" OT It's funny how when you walk out from one builder to another when you tell them why they all say we aren't like that "you can do it yourself latter and save money? Later on you find out they threw you under the bus and it would have been best to do it first off during construction "They never say it's going to be difficult to DIY so i'll help you" It's always the cheapest quickest way out for themselves, hence the client does it Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Waffle Pod Slab over retaining walls 8Jul 14, 2022 12:13 pm BanjoDan strannik BanjoDan Yeah, been there done that. We first submitted DA in March 2020. Earlier this year builder canned the contract due to costs so this is round 2 with some design improvements. And this time they've told us landscaping is our problem whereas last time they were doing it. So I'm looking to do it properly (since I had to get the house plan updated myself to meet all the Council requirements since the builder just washed their hands of it) so if concrete apron is recommended then I will look to make sure it is included in our plan (on top of the volume of requirements from Council). Concrete apron is recommended for reactive soils, and the blocks where the water can pool against the walls (the flat ones) to keep it away from the slab. Your block seems to be sloped so you probably don't need it around the whole house. Having said that, I'd still do it as it makes it so much easier to walk around the house. Unless you have a reason not to. Thanks for that. Much appreciated. also normally you'd get a document from engineers with 'care instructions' for your slab, that should also have some additional information and explanations. Re: Waffle Pod Slab over retaining walls 10Jul 14, 2022 2:44 pm StructuralBIMGuy Hey banjodan As an engineer I would be very concerned about your engineering and the builders costings to come at BA Don't get stuck on the the path and minor issues, Builders are experts at diverting you attention away to minor issues and then extracting monies for engineering, before you know it they'll say " It's not my fault what I thought was the compliant engineering has now changed and is more expensive ...?" OT It's funny how when you walk out from one builder to another when you tell them why they all say we aren't like that "you can do it yourself latter and save money? Later on you find out they threw you under the bus and it would have been best to do it first off during construction "They never say it's going to be difficult to DIY so i'll help you" It's always the cheapest quickest way out for themselves, hence the client does it Do you mean engineering for the landscaping or just overall? Re: Waffle Pod Slab over retaining walls 11Jul 14, 2022 2:58 pm Who owns the design, you or the builder? If you own the design your designer is doing you a disservice by not advising you to complete all the documentations for quoting If the builder owns the design they'll put their hooks into you for more monies to the point where you can't back out without loosing the lot Shop around and get all the Engineering, geotech, storm water, footings, slab, retaining, wind loading, etc Make sure you understand what's involved work out approx. costs Forewarned is forearmed Cheers Chris Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Waffle Pod Slab over retaining walls 12Jul 14, 2022 3:20 pm StructuralBIMGuy If the builder owns the design they'll put their hooks into you for more monies to the point where you can't back out without loosing the lot Builder owns the design and we are well and truly at the above point. Had I known what I know now I would have done things differently. But, we can't change the past, all we can do is try and make the best of the hand we are dealt. Hence coming on here and clarifying things like this before I put a spec together for a landscape designer. Re: Waffle Pod Slab over retaining walls 13Jul 15, 2022 10:40 am Yep, in hind sight we are all experts. short points for others 1. Sounds like the builder doesn't give a cr@p about your difficult block and what happens to you after handover... LOL, what ever you do it'll always be your fault 2. Be firm with the builder as there is no contract without a landscape approved plan (Good to see Councils are stepping in on the landowner side) 3. Again you'll need proper certified plans, data/proofs and approx. estimates Why? Because builders and trades are experts at seizing on non certified (read Bullsh!t) drawings, details , fake realistic coloured renderings and then pulling your pants down with "... that's not compliant..". 4. Unfortunately you are locked into the builder not so with the landscaper, so get 3 landscaping quotes. 5.check the builders site engineering and variation costs along with the landscaping. Tell them both " The whole project depends on team approach or the project lapses".. be firm... gauge the builder response...He has more to loose On the other hand if he is beyond negotiating, then it's over. 6.7.8 OT that's where Engineering Bim comes in handy, Imo it's the only valid negotiating tool.ie certification, data/proofs,etc Sorry I'm in Perth and way too busy, but my method has proved extremely valuable for my clients and i only take on projects where we have copyright control of design, engineering, data/proofs and gladly give clients access. ( so avoiding legal issues with w@nkers trying to clip the ticket and clients paying for it) Happy to discuss in a pm Cheers Chris Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Waffle Pod Slab over retaining walls 14Jul 17, 2022 7:22 am Better to do it well/properly - even if you pay more. In 5 years it won't matter to the builder. 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 9978 One corner of my shed slab will be directly over a 1400mm diameter concrete soakwell. Is it feasible to fill the soakwell with concrete then lay the shed slab over the… 0 681 Thanks for the insights, that makes perfect sense, and yeah, I will be leaning on the experience of the excavator operator entirely. 6 16402 |