Browse Forums Building A New House 1 Feb 10, 2021 8:13 pm So, we are thinking about building in the western suburbs of Melbourne. I know that there is some debate about whether waffle slabs or rafts slabs are better on those reactive soils and I understand that the vast majority of volume builders will only do waffle slabs. When speaking to the salespeople at those builders, they confidently say they will build what the engineers will recommend based on the soil test...does that mean that because they appoint the engineer as part of their contract they are confident that the engineer won’t recommend a raft slab, or am I being too cynical? Or, do the engineers generally offer options (ie, which waffle type or which raft type in their report)? I’m concerned that we will end up in a contract with a builder and that a raft slab would be best but will be locked in to a waffle slab. Also, has there been advances in those waffle slabs, or how they are used, over time so they are less troublesome in the past? Or were past instances waffle slabs that were done incorrectly please? Thanks! Re: Slab questions 2Feb 13, 2021 8:52 am Apples1975 So, we are thinking about building in the western suburbs of Melbourne. I know that there is some debate about whether waffle slabs or rafts slabs are better on those reactive soils and I understand that the vast majority of volume builders will only do waffle slabs. When speaking to the salespeople at those builders, they confidently say they will build what the engineers will recommend based on the soil test...does that mean that because they appoint the engineer as part of their contract they are confident that the engineer won’t recommend a raft slab, or am I being too cynical? Or, do the engineers generally offer options (ie, which waffle type or which raft type in their report)? I’m concerned that we will end up in a contract with a builder and that a raft slab would be best but will be locked in to a waffle slab. Also, has there been advances in those waffle slabs, or how they are used, over time so they are less troublesome in the past? Or were past instances waffle slabs that were done incorrectly please? Thanks! Waffle slabs are used because they are quicker and cheaper for builders. Beware when they are used on reactive soils. No advances. It is your money, your build and your house. If you want a different slab, then you can, it may cost more, but you will have peace of mind afterwards. If a waffle slab is used and there are problems with your home, during, after completion and latent defects e.g. slab heave/settlement causing cracking etc, it will be your problem and the builder will not take any responsibility even if they did not adhere to AS2870 (the surface drainage of a construction site shall be controlled from the start of site preparation until the end of construction). Read everything you can on this site about waffle slabs and slab heave. There is a long list. Also read these: https://www.drillology.com.au/?s=Waffle+slab https://cornellengineers.com.au/what-is-slab-heave/ Blogs: https://cornellengineers.com.au/?s=Waffle+slabs Get your own geotech https://www.drillology.com.au for soil test and engineer, then find a builder. Do your homework. Drive around the neighbourhood where there are new builds. You will soon work out who is not adhering to AS2870. Are temporary downpipes being used? Is their a slope away from the slab? Is there water pooling next to the slab? Is there drainage? BTW a salesperson is just that, they are no expert on building/engineering design. Their job is to get you to sign a contract and get the sales for the company. Best of luck Re: Slab questions 4Feb 14, 2021 9:53 am Harts BTW a salesperson is just that, they are no expert on building/engineering design. Their job is to get you to sign a contract and get the sales for the company. Best of luck Once the salesman job is done, the client has paid the deposit for the preparation of documents the engineering starts. Salesman are allowed to make mistakes, keep descriptions vague, act as a broker, etc,etc Watch out for poor documentation wording that includes To be advised (TBA), Unless notified otherwise (UNO) and It will sort out in the office later, by the time it's sorted you are out of pocket to the tune of 5% of the build cost and reluctant to pull out For your commitment the salesman earns Big Buck$..... OT it's time the whole housing industry is cleaned up and as owners you can do your part in getting better information and data to based your decisions on Estimating an OB in Adelaide Forewarned is forearmed Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Slab questions 5Feb 14, 2021 5:34 pm I had the same question when I was shopping for builders. Our salesperson said there was no choice of slab because they had to go with what their engineer said so they could warranty the build. OK, so I knew this was sales talk but still went with it because we couldn't afford to go with a builder that gave us a choice. But I still got an independent soil report, and it said that the choice the builder made was fine. But I still would have preferred a raft over a waffle. Countrybuilds Victoria Re: Slab questions 6Feb 15, 2021 1:34 pm I have 25 years experience as a Concrete Contractor in NSW. I have found Pod Slabs require less skill to construct. Most volume builders use concreters that specialise in Pod Slabs and their workers tend to be less skilled. They will do a better job of a Pod Slab than a Raft Slab. Re: Slab questions 8Feb 24, 2021 1:37 am MisterLevy I have 25 years experience as a Concrete Contractor in NSW. I have found Pod Slabs require less skill to construct. Most volume builders use concreters that specialise in Pod Slabs and their workers tend to be less skilled. They will do a better job of a Pod Slab than a Raft Slab. I live in WA and got some photos of my slab. I’m currently living away and cannot go on site to see works carried out. Relying on them to do their job correctly. A friend took some photos for me of the slab and I thought this might not be an acceptable standard of slab pour. Would you agree and will this cause issues later on? Thanks Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Slab questions 9Feb 24, 2021 2:25 am MisterLevy I have 25 years experience as a Concrete Contractor in NSW. I have found Pod Slabs require less skill to construct. Most volume builders use concreters that specialise in Pod Slabs and their workers tend to be less skilled. They will do a better job of a Pod Slab than a Raft Slab. 100% recent agree! Re: Slab questions 10Mar 01, 2021 10:19 pm Tbaby MisterLevy I have 25 years experience as a Concrete Contractor in NSW. I have found Pod Slabs require less skill to construct. Most volume builders use concreters that specialise in Pod Slabs and their workers tend to be less skilled. They will do a better job of a Pod Slab than a Raft Slab. I live in WA and got some photos of my slab. I’m currently living away and cannot go on site to see works carried out. Relying on them to do their job correctly. A friend took some photos for me of the slab and I thought this might not be an acceptable standard of slab pour. Would you agree and will this cause issues later on? Thanks Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Personally, considering your layout (study/work desks in bedrooms), I don't think you have any other option but to leave NW windows and make them as big as possible e.g.… 7 10470 We had this happen to us last year and got charged a variation. Try and give away as much as you can that is usable to charity otherwise if you are in Sydney I have a… 1 4494 Not sure what council area you are in. Some LGA's allow zero lot retaining walls. This usually occurs in greenfield developments but not often in established areas. You… 1 8229 |