Hi Everyone!
Sorry if this question already has been asked. I saw a lot of similar one, but still decided to ask.
Currently I am in process of buying a block. The offer is subject to soil test (S, M or H). Site was classified as "P" due to a poor bearing capacity, the depth of uncontrolled fill and abnormal moisture conditions. It is almost 2.8 m of fill, initial moisture is 12.5%, and final is 16.1%.
Then sales agent provided me with the compaction certificate of the controlled filling. Also, she asked builder to provide a worst case scenario compared to H type. Below is his e-mail:
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Worst case scenario, if it has to be P, based on the soil test piers will have to be approx. 2m deep to reach firm ground
You'd be looking at:
- Excavator with 450 auger: $900
- Concrete pump: $800
- Concrete 20Mpa: say 9 cubic meter = $1,500 (based on 30 piers @ 2m)
- Labour: $800
TOTAL = $4000 inc gst
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Personally I am doubt that extra cost compared to H type is only $4,000 because I assume piers need to go at least to 3 meters to firm ground (extra $1,000 for cement). He doesn’t have house design to say that it will be only 30 piers (Can it be 60-80????). It said nothing about moisture. Manpower and equipment could cost differently.
I am trying to understand whether it is really $4,000 extra or I should cancel the deal. Please let me know your thoughts about this extra costs estimation, what other costs could pop up? What is the realistic extra cost I should be prepared for?
Thanks in advance for your help!