Browse Forums Building A New House 1 Aug 30, 2009 1:01 pm Hi All, Our builder has come to us and said that our soil test showed that we needed an M clas slab, but then proceeded to say that there a different grades of m class, and our slab was going to cost an extra $4000. I can not find anything to support these claims of different grades of M class. Has anyone else come across this or is our builder trying to get some extra money out of this. BTW, M class slab was an inclusion in our contract!!! Thanks for your input. Cassandra Re: Class M Slab, different grades?? 2Aug 30, 2009 4:17 pm cassluke, Unfortunately there are two types of M class soils. Straight M and M-D. M-D is for "deep-seated movements, characteristic of dry climates and corresponding to a design depth of suction change, Hs, equal to or greater than 3m." (according to 2.1.2 of AS 2870 The Australian Standard for Residential slabs and footings - construction). As an example if you are building a brick veneer house the edge beams will need to go from 400 to 500mm and the maximum spacing of internal beams will go from 5.0 to 4.0m also the wire mesh will go from SL72 to SL82. Check your soil report and this may help to clarify things. I hope that helps. View our blog at: http://room4acubby.blogspot.com/ Re: Class M Slab, different grades?? 3Aug 30, 2009 8:15 pm Sorry, I don't understand, if your contract said Class M Slab then its not your problem that there are different grades of Class M slab. In any case $4000 sounds a little steep I would ask for a break dwon Dan Re: Class M Slab, different grades?? 4Sep 01, 2009 5:17 pm Thanks for your replies guys, I am yet to see the soil report but my builder confirmed today that it is 'a lower class M rating' their exact words and that there is definatley going to be extra charges. My main query is now that if the contract stipulates that M class slad included should this not include M-D if this is what the class ends uo being?? Anyone who has had this problem before, we would greatly appretiate your input Thanks Cass Re: Class M Slab, different grades?? 5Sep 17, 2009 3:05 pm Hi Cass, Make sure you keep us up to date with your progress on this one, you absolutely have the right to complain...if they said M-class was included, and there was no fine print around that...you should stand your ground! Re: Class M Slab, different grades?? 6Sep 17, 2009 3:26 pm Our soil report came back as requiring an M class (which was the standard inclusion) but we also had to pay an additional $3,000 as we required 21 piers due to the site conditions (fill and drainage). I questioned the additional price and was given a breakdown of what the charge was for, not happy about it but at least they were able to jusity it. Building with Dennis Family Homes - Hartley 280 Location: Settlers Run, Botanic Ridge The Soil classification has little to do with piers. The purpose of the classing of the soil is to identify the clay content and the "average expected range of movement… 2 9816 I am not sure whether Perth has its own way of doing things in regards to this. Most of Perth has class A (sandy soil), except for some areas near rivers or hills. 2 12982 I don’t think so as the floor area over 300 square meters then it is class 3…. 12 17886 |