Hi,
Ive been looking at a new Clarendon 2 storey ballina house that has recently been built on land to purchase (prolly built round 7 mths ago).
I requested the soil reports from Clarendon for the site it was built on as I wanted to research as much as possible about it.
The soil report on the front page say that according to Australian Standard xxxxx (cant remember the # off top of head) it is Category M - moderately reactive - which is quite common in QLD?).
The report then outlines a recommended slab which appears to be a 31 ish cm deep waffle pod slab with some wires all through it etc.
So i guess my question is, not being an expert in the area - but reading a ton of things about clay soils that doesnt sound too impressive...
does it sound reasonable from what ive seen and assuming the builder has provided the right info that theyve done the most appropriate build for the site classification?
hope that makes sense.. and too think i didnt even consider what soil my first house was built on when i bought it!
i guess im worried about it cracking in two or sliding away or whether a future pool would cause problems in the yard etc
Im also getting a building inspection done too.
Opinions appreciated
Thanks
Hi Halford
In Sydney, most soils are clay and end up being M or H class - H is one step above M (thicker slab, more reactive clay soil)
It's the engineer's responsibility to create a slab according to the soil composition. I suppose you could take the soil test to an independent engineer and get them to review what was done.
Halford, the australian standard referred to is A.S.2870.
Site classifications in order of stability are A, S, M, M-D, H, H-D, E, E-D & P.
All slabs in a residential application are generally 100mm thick with the edge beams, & if applicable to the soil type, the internal beams sized in depth according to the construction type.
i.e Class M weatherboard home would have beams a minimum of 300 deep, a brick veneer 400mm deep & a solid brick home 500 or 800 deep.
The soil report will nominate the actual depth required to go down to to reach the required bearing pressure under the beams so it is conceivable that a class M brick veneer home could have beams a minimum of 400 deep but may need to be excavated deeper to say 600 or maybe 700.
A site may have the required bearing pressure at say 300 down but if there is localised fill under a part of the house from for example a large tree that has been removed then the beam will possibly need to go down deeper in that area. [ small areas may be able to be spanned by the beam ]
Hope that clarifies.
Hello,
Why the soild is reactive? Is there a land fill? If it is then check what is underneath the landfill. If there is no landfill waffle is ok. If there is a landfill you will fill cracking.
cheers
kate
Can you elaborate please Kay. I don't understand.