Browse Forums General Discussion Re: H Slab - Screw Piles 21Feb 08, 2019 3:32 pm Agree as well, I would rather pay a bit extra and have my slab properly engineered (even overengineered slightly), than shopping around to try to do the slab as cheaply as possible Re: H Slab - Screw Piles 22Sep 22, 2019 5:26 pm Engineer Sort off stumbled across this forum so will attempt to assist. The depth of pile should be according to AS2870 table 2.5. This table relates suction change (Hs) with climatic zone. In Mel the climatic zone is either 2 or 3 with screw pile depth min 2.3m or 2.9m. The requirement for screw piles is to go 1.25Hs As2870 G6.3) to get below the zone where movement can occur, however this requirement does not exist for concrete bored piers - something I hope will be consistent in the future. A good screw piling company will comply with the code. Screw pile price has come down quite a bit in the past few years and when you consider the uncertainty of final cost of concrete piers and potential weather delays. From my understanding, the industry was rattled a few years ago with waffle slabs and homes cracking - this may be a reason for a more conservative approach to classifying sites. There are good options for reactive sites, one of which is a suspended ground floor slab http://www.polyvoid.com.au which has a track record of minimal cracking from reactive soils and compares very well cost wise. I must declare that I work for http://www.katanafoundations.com.au and http://www.polyvoid.com.au - however I am a Professional Engineer so my first obligation is to the broader community to assist where I can. Hi there, Hijacking this thread somewhat however a friend of mine is building in North Kellyville and upon visiting the site last week we found a delivery of ~32 Katana screw piles. This week however upon visiting, there has been concrete piers poured and the pallet of Katana screw piles remains untouched. There's also 3 trenches dug on the lower side of the site, but as far as I know there's no drop edge beam on this side of the plan. What would the reason be for this? The delivery details on the pallet are correct for the site so it's not a mix up with sites... Hoping you can shed some light! Thanks Helena Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: H Slab - Screw Piles 23Sep 22, 2019 6:33 pm Hi snowlaina_80 Welcome to the forum Ask the Builder for revised certified engineering drawings and a Variation Order Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: H Slab - Screw Piles 24Sep 22, 2019 8:35 pm [quote="Engineer":32f07vj2][quote="building-expert":32f07vj2]Welcome to the forum Mark and it is proper that you have upfront declared interest in the companies where you work. That is a decent approach and I for one would have confidence in listening to what you have to say.[/quote:32f07vj2] Thanks - day one and I got a call and assisted where I could. My interest is really in assisting folk with getting the foundations right. Everyone spends lots of time looking at taps and tiles only to live in a home with cracks in it - that's not right. If it is a while after the build - like a wet spell after many dry years - it goes to the insurer and we never get to hear about it. That means little feedback to the code committees like AS2870. Look forward to productive discussions.[/quote:32f07vj2] Hi Engineer (Mark), If you need some feedback regarding movement and waffle slabs for the code committees for AS2870, happy to provide details and where things went wrong. My home will require demolishing due to the failures. All involved need to stop hiding behind their lawyers and insurance companies. details lodge with your CoucilRe: H Slab - Screw Piles 25Sep 23, 2019 7:48 am StructuralBIMGuy Hi snowlaina_80 Welcome to the forum Ask the Builder for revised certified engineering drawings and a Variation Order I forgot to mention The VO is required in following the contract documents and by law.. The photos should be dated and checked against the engineering details Once the slab is poured.. it becomes proof of what was done on site OT, you paid for those screw piles, the builder can ask his engineer to have them replaced with concrete piles, but you will require 1. Signed VO (your signature) 2. The cost difference 3.Certified Engineering details 4.Certified Surveyors Stamp 5.Structural Changes Lodged with your Council Thanks for the photos Cheers Chris Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: H Slab - Screw Piles 26Sep 23, 2019 8:06 am Thanks for the advice. In what circumstance would a project home builder specify screw piles? Is it due to soil classification test? I thought it was odd when I saw them... Also what are the 3x trenches for? This is sitting underneath the main bedroom on the low side of the block, however when I say low side of the block the contour from left to right is a total fall of ~1m Note that this perimeter wall will also be the location for the rainwater tank 5000L and aircon unit. Is it reinforcing for the weight of the rainwater tank? Re: H Slab - Screw Piles 27Sep 23, 2019 8:41 am Snowlaina_80 Thanks for the advice. In what circumstance would a project home builder specify screw piles? Is it due to soil classification test? I thought it was odd when I saw them... You're Welcome The engineer specifies the footing details and piling, not the builder, piles are used in a number of instances, uncontrolled fill, differential settlement, building adjacent to sewer lines,etc Snowlaina_80 Also what are the 3x trenches for? This is sitting underneath the main bedroom on the low side of the block, however when I say low side of the block the contour from left to right is a total fall of ~1m You are familiar with the plans, looking at the geotech report, engineering footing/slab details and on site taking photos several times a week during the entire build? when asking for advice photos only take you so far and more info helps (the better the info the better the reply, this also helps others) Try putting up the site photos with images of the plans /engineering, delete the builders info or Leave a PM It saves guessing or receiving no reply at all I always tend to comment when I see a red flag..that's just me.. trying to help out the Battlers & Punters Snowlaina_80 Note that this perimeter wall will also be the location for the rainwater tank 5000L and aircon unit. Is it reinforcing for the weight of the rainwater tank? Possibly, the water tank will require a raft slab. Cheers Chris Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: H Slab - Screw Piles 28Sep 23, 2019 11:15 am StructuralBIMGuy Snowlaina_80 Thanks for the advice. In what circumstance would a project home builder specify screw piles? Is it due to soil classification test? I thought it was odd when I saw them... You're Welcome The engineer specifies the footing details and piling, not the builder, piles are used in a number of instances, uncontrolled fill, differential settlement, building adjacent to sewer lines,etc Snowlaina_80 Also what are the 3x trenches for? This is sitting underneath the main bedroom on the low side of the block, however when I say low side of the block the contour from left to right is a total fall of ~1m You are familiar with the plans, looking at the geotech report, engineering footing/slab details and on site taking photos several times a week during the entire build? when asking for advice photos only take you so far and more info helps (the better the info the better the reply, this also helps others) Try putting up the site photos with images of the plans /engineering, delete the builders info or Leave a PM It saves guessing or receiving no reply at all I always tend to comment when I see a red flag..that's just me.. trying to help out the Battlers & Punters Snowlaina_80 Note that this perimeter wall will also be the location for the rainwater tank 5000L and aircon unit. Is it reinforcing for the weight of the rainwater tank? Possibly, the water tank will require a raft slab. Cheers Chris Thanks Chris again for your advice. As mentioned it's not my build, its a friend of mine so I don't have the geotech report or the full plans on hand with me. I've only got a contour plan with what looks like a peg out plan & the RL levels on it. I will try and catchup with them ASAP and have a look so we can review what you've mentioned. I've previously built, hence why I'm aware of documenting all stages of the build and been to the site weekly to take detailed photos. Just can't be too careful Re: H Slab - Screw Piles 29Sep 23, 2019 11:17 am StructuralBIMGuy The engineer specifies the footing details and piling, not the builder, piles are used in a number of instances, uncontrolled fill, differential settlement, building adjacent to sewer lines,etc The RHS boundary has a concrete encased sewer line running the full length of the block just off the boundary Re: H Slab - Screw Piles 30Sep 23, 2019 1:49 pm Snowlaina_80 StructuralBIMGuy The engineer specifies the footing details and piling, not the builder, piles are used in a number of instances, uncontrolled fill, differential settlement, building adjacent to sewer lines,etc The RHS boundary has a concrete encased sewer line running the full length of the block just off the boundary The screw piles may be for the angle of repose regarding the sewer line as it may be to deep for conventional bored piers. This will depend on the depth of the sewer pipe. Screw piles can go much deeper than conventional bored piers. Just a guess but should be of the engineers drawings. Re: H Slab - Screw Piles 31Sep 25, 2019 7:22 pm Snowlaina_80 StructuralBIMGuy The engineer specifies the footing details and piling, not the builder, piles are used in a number of instances, uncontrolled fill, differential settlement, building adjacent to sewer lines,etc The RHS boundary has a concrete encased sewer line running the full length of the block just off the boundary Here is one of my examples ( Engineering & Site checking) for sewer piling Visually it's self explanatory Checking Concrete Piles IMO this is the cheapest method..poring everything (ie Footings and Piles) at once hth Chris Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs If what you describe is correct then the brick wall has been dry lined with villa board. That basically means that the villa board is glued to the brick wall with… 3 8297 Thanks for the insights, that makes perfect sense, and yeah, I will be leaning on the experience of the excavator operator entirely. 6 16103 4 6168 |