Concrete pier required ?

Hi everyone,

This is my first post but I had been following the forum for a while to get more understanding what involved in building my first house.

I would like to ask people's opinion whether I am in the right position to raise my concern with my builder.

I am in the process of building a new home and it is almost to the lock up stage with one of the big volume builder (No company will be mentioned to avoid disrepute). Before the contract signing last year, I was given a quote of fixed site cost around 11k, and then for the final quote, the site cost has jumped to around 15k. I raised the question what caused the increase in site cost. The salesperson's reply: "There are lots of bore piers required"

Then this year after contract signing, when I received my site plan, I asked my coordinator why I couldn't see any bored piers on the plan. The coordinator forwarded me an engineering plan which has lots of bored piers on the plan. Recently, after they finished the foundation and put up the frame. I realised that there are no bored piers installed at all in the revised plan that has the building permit on it. Please note that the builder didn't notify me about the change and they claim they don't have to.

I found out that the builder changed its engineering company and re-do the soil test.
The first soil test report from Company "A" says "footing recommendation: "bored piers required"
The second soil test report from Company "B" doesn't include bored piers but put lots of contingency such as if there is a changed in soil component, or if built near the easement, the revised recommendation will be bored/piling system.
Both soil test reports showed that the site is classified as "P" due to the 100mm fill on top. If the fill is removed, it will be classified as H2. The company B said they sighted the compaction report done by the developer back in 2010 and the slab will just sitting on the compacted soil

I raised my concern with the builder as I believe the design with bored piers should be better and why did they change the design?. After 2 weeks of no answer and couldn't talk to anyone( the first week, they changed my site supervisor and my coordinator is on sick leave), they finally get back to me saying that they couldn't give credit back as my site cost is a fixed site cost. I told them what I was looking for was the answer of why they are changing the design of the foundation plan ? Is it to save cost ? Because I compared the two engineering plans from company A and company B. They look similar (slab strength, slab size, depth, etc) as the only difference I can spot is there are bored piers on one but not the other.

The construction manager came back to me saying that the two engineering companies use different methodologies. Company A used concrete piers to stiffen their slab. Company B used deepen edge beam and additional steel and he thinks it is a better solution and the additional concrete and steel are where my fixed site cost have gone. I worked in an engineering company and I showed it to my structural engineer colleague (Unfortunately,I am not a structural engineer) and he told me apart from the engineering plan from Company "A" has bored piers and those from company "B" has no bored piers, he couldn't see any additional concrete and steel on the plan.

I will meet up with the construction manager this week as he will go through with me the engineering plans related to my new home.

Have anyone had this kind of experience before ? I am more concerned of the build quality of the house rather than getting the credit back (Which I don't think they will do it anyway)

Any feedback is very much appreciated.

Thank you.

H2 means a highly reactive site, which means clay, which generally means more movement.

If it's any help, these are the Australian Standard Definitions for different sites:



Source: http://www.engineersaustralia.org.au/sites/default/files/shado/Divisions/Victoria%20Division/Groups/as2870_-_2011_2_part1.pdf

There is other good info here: http://www.engineersaustralia.org.au/sites/default/files/shado/Divisions/Newcastle%20Division/Branches/be_careful_of_as2870_presentation_27th_june_2012.pptx

I'm an engineer but not a structural engineer. Logic would say that if you have a H2 site then according to the definitions (very high ground movement and moisture change) you could reasonably expect the weight of a slab and the house on top of it would require some kind of support (i.e. piering or beams sitting on bedrock). The 100mm of uncompacted fill would increase the importance of adequate support for the slab.

You said that the two solutions were either piers or deepen-edged beams.

I guess the method used depends on the depth down to rock and the size of your slab. Do you know the depth down to rock? How large is your slab? Also, is there much of a fall (slope) on your site?

What really matters is what was 'included' in the contract. In the Sydney area at least most project-home builders give you a price based on an M-class slab. They generally also have clauses that allow them to charge more if they get their estimates wrong, even though they say the contract is a 'fixed-price' contract.

On the pricing front, did you specifically ask your builder to give you pricing for a H2 site? What was the description of the site cost 'inclusion'? What was the piering and drop-edged beam allowance?

If you are concerned that there is an issue with the slab design then you could always get an independent engineer to look at it.

My site is a H2 site so I made sure that my builder has included adequate provisions for piers and drop-edged beams in my contract. i.e. piers to a depth of 2m and 5sqm of drop-edge beams. I also carefully checked the depth to bedrock on the borehole report for my subdivision (to determine what piering allowance was needed). I'm still hoping that that's adequate.

If you have signed contract based on a plan from "A" engineering company then bored piers are included on your contract price and any change is a variation to the contract. From what I see there should be a substantial credit to you.

Apart from the issue of credit, builder is not allowed to change your contract plan and specification without your consent.

It looks to me that the builder has used "A" to over engineer your slab then went to "B" to get the right design, reduce engineering and keep the change. Thousands of dollars for over engineering less few hundreds for design revision = tidy profit. It looks like you are ripped off big time.

If you want this looked at closely you can PM.

How many others are there that have been ripped off?

I would also expect that the volume builders would have a number of different boiler-plate slab designs that they can readily draw on as they are building the same designs over and over. I guess it doesn't take a long time for the engineering firms to adapt these boiler-plate designs for a new site.

Builders are (supposed to be) highly experienced and professional, their sales staff are trained to extract maximum profit

Average owner is inexperienced, ignorant (not meant in derogatory sense, it means ignorance of building and the building process) and probably naive and too trusting (I see it all the time)

The conditions for "lambs to the financial slaughter" are there. What will happen? It depends whether:

1 Builder is honest and decent.
2 Builder engages in "sharp practice"
3 Builder engages in unconscionable conduct
4 Builder is deceitful
5 Builder is incompetent
6 You have independent professional expert advice

If you ignore 6 you will be relying on luck, good luck!

I've tried to do as much homework myself upfront to find a builder that best matches number 1. My parents built I number of times so I have some idea of what to expect. I have found someone for my building inspections - I've taken some of your great advice from other threads onboard!

It's my pleasure to spread advice and I am pleased you have benefitted from it.
There is no substitute for homework, good on you.

Hi maximus,

Thank you for your comments,

The fixed site cost allows for

Site fall (up to 1000mm over site)
H class slab (or compacted P class lot specific)
Rock removal
Retaining wall (where indicated)
Fall protection
Storm and sewer connection
land up to 700sqm
ag drain (where required)
reestablishment survey

Unfortunately, they never include the foundation slab plan in the contract of sale. They only include the soil test report from the engineering company "A". And there is no description of the footing support shown anywhere in the contract document.

My lot is a compacted lot so it allows up to P class. However, the bored piers was only mentioned on the email conversation between the salesperson when finalising the quote and on the first engineering plan done by Company A which was sent by my very first coordinator (they already changed the coordinator 4 times)

Do you know how much roughly it costs to hire an independent engineer ? I am on a tight budget living on a single income.

I would like to stop the construction process if possible until my concern is cleared up but the builder say they still have by their 25 year structural warranty even though the design has changed. I will try to meet up with the construction manager to have him explain where the edge beam (additional concrete) or additional steel shown in the drawing. Couldn't see it anywhere on the plan. I will update you guys on what's going on.

This has really stressed me out and affecting my personal and work life. No more building a new house in the future. Hopefully this is not just the beginning.

But do thank you for the reply and advice

Hi building-expert,

I had just read at the contract again, the only statement of "bored piers" are on the footing recommendation on soil test report attached to the contract.

I strongly agree with you about the conditions for "lambs to financial slaughter". I am building with one of the well known famous builder and thought I would have a "peace of mind".

Thank you for the offer, but I am a single person living on a single income with tight budget. I will follow up with the construction manager if they really have used the alternative of deepened edge beam and additional steel to replace the bored piers.

I am trying to avoid using legal means as I heard it will be very costly and time consuming.

But, thank you for the feedback and advice, building-expert. I really appreciate it.

You could hire a building inspector. Their normal inspections are usually in the $250 to $400 range ( per inspection ). I had quotes via serviceseeking. Some charge a flat rate and others charge by the hour. I got a mix of quotes. One quote was from a building inspector. I also had quotes from architectural firms and an engineering firm. They would only quote an hourly rate. Some may help argue your case, some may not.

One thing to bear in mind. There may be a clause in your contract about delays caused by the owner. My contract is the HIA NSW red contract and has the standard clause 9.4. Delays caused by the owner may lead to an increase of costs to the builder, which they could try and recover. Your contract may be different and hence the clauses relating to delays could be different.

Just a dose of reality

Your 25 year structural warranty is next to worthless because if something does happen, builder will try to avoid liability by saying it's your fault because of poor property maintenance. (I have seen dozens of cases of slab heave where builders are blaming owners, it's going to VCAT and it costs money)

In any case If you don't have hundreds of dollars for expert advice now you most certainly won't have thousands of dollars for legal fees to prosecute your rights in the future.

Geting independent inspector for your slab now it too late (unless it is for frame or other stage inspections) because you now have a contractual dispute.

All that aside it is more than likely that your home will be OK structurally, it just means you may have been ripped off (charged for piers that you did not get).

Hi Maximus,

Thank you again for the reply. I did hire the building inspector for the frame and going to have another two more inspections (pre-plaster and pre-handover). It is quite unfortunate that it is too late to have pre-slab inspection as the slab has been poured (Well, regret always come last)

Yes, I checked my contract again and it does have the similar clause like what you have, which the builder will charge certain percentage annually due to delay caused by owner.

Thank you.

Hi building expert,

Thank you again for your reply. Yes, you are right about the structural warranty issued by the builder. I was given the CSIRO foundation maintenance during the contract signing, and I opted to have the concrete footpath around the house for 900mm (I initiall opted 1000mm but they came back to me saying I built more than 60% of the house). I will also try do ta more proper landscaping after the handover if the budget allows.

I did had a building inspector for the frame inspection and going to do two more for pre-plaster and pre-handover. It is a shame that I didn't have the pre-slab inspection. Definitely don't want to be involved in legal issue, never got into one and hopefully won't have to experience one *cross fingered*

Agreed, I felt I had been ripped off and I always feels fascinated on how big corporate company works in Australia. Most of them just wants increased profit and reduced cost instead of delivering promises and quality services.

Thank you.

Hi if i was you dlnt believe anything the builder tells you 25 years warranties is such over rated crap when its only 10 years by law in Australia. All these volume builders offering such high warranties do you really think tbey will be around that long. There is others offering 30 years structural warranties, and another is offering life time warranties. I questioned them on youtube which i think i embarrassed them in front of so many people on youtube they said every excuse under the sun except if they will be around a life time and the fact they said they use 400mm waffle pod slab, i replied its still a dam waffle slab regardless of warranties. Waffle slabs are prone to water ingress via plumbing trenches and soon as that happens the damage is done there is no fix for slab heave unless they undsrpin all the house, most important is the soil test which is totally different then soil classification test. Fkr pored pier soil test can go as deep as 18 metres deep or unless they hit solid rock for piers to sit on creating a solid footing. Sodont beilive any bull crap builders spin, all tney are intrested in the bottom profit. They don't care a about clients they will spin so much missleading information just to get you to sign, once you signyour locked in no where to go, because the builders answer will be you should have reading your contract. Becarefull, ive been down this road 13 years ago and last 8 years legallly fighting our large volume builder the HIA contract is written up in favor of builders so new home owner has no hope in hell to understand what they are signing. Get a construction lawyer to go through your contract making sure your not been charged for things that you shouldn't be paying for. If you need more information. PM mei have plenty of information and building codes and standards that i have bought on line to educate myself i spend 3 or4 hours every day reading everything about building new home, and the information i have would make your head spin knowing the builder witheld the important information from you. Good luck pm me if you need to chat.

Yes they around and do honour those warranties

Transferable also

Just read the fine prints of the warranties I bet you will find some will be transferable and some don't. And to even thinking half of these volume builders will be around 25 to 30 years and one offering life time structural warranties. Got rocks in their heads. I am dealing with one now. So unless you have experienced the structural warranties which in Australia is only 10 years. So why offer 25 to 30 plus years on structural warranties when the law does not. Look I've been doing this legally for 8 years close to 9 years soon I know every trick in the builders book by now. All I will say if you believe in all that warranties good luck with that. When you have a claim against a builder in 12 or 15 Yeats time you will be told you have passed the law in Australia I forget the name. Good luck if you think that. God bless you.