Browse Forums Building Standards; Getting It Right! Re: M-class Slab on P class soil 13May 30, 2018 7:28 am Interesting. Will need opinion of some of the other forum members who are professional geological engineers to comment. One thing I did notice is that they never hit rock. It’s wet clay all the way and they stopped at 1.8m depth. I also got M class soil but I hit rock at 1.2m and kept hitting rock until they stopped at 1.6m so it seems a bit suspicious that you can arrive at the same M rating without hitting bedrock. Anyway will be interested in what Geo1 and insider think. Re: M-class Slab on P class soil 14May 30, 2018 10:18 am bentleigh_boy You could have hired your own Geotech/Civil Engineer to specify footing and he would have explained everything to you. Unfortunately, builders don't give you access to their engineers..for obvious reasons I suggest you turn your focus onto what is a reasonable cost for your m-Type footings Slab for garage - is engineer over engineering it? Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: M-class Slab on P class soil 15May 30, 2018 10:35 am bentleigh_boy, I PMed you the geotech engineer my builder used. They seem to be pretty good. Re: M-class Slab on P class soil 16May 30, 2018 10:45 am The Issue isn't with the Engineers report, kirashogun Once you have handed over a deposit to the builder and signed, the builder can charge whatever he wants for big ticket items It's up to bentleigh_boy now to scrutinise the cost if he thinks it's going to be too high, then his option is to pull out and lose his deposit Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: M-class Slab on P class soil 17May 30, 2018 11:21 am StructuralBIMGuy The Issue isn't with the Engineers report, kirashogun Once you have handed over a deposit to the builder and signed, the builder can charge whatever he wants for big ticket items It's up to bentleigh_boy now to scrutinise the cost if he thinks it's going to be too high, then his option is to pull out and lose his deposit Thanks for your comments, The cost is not an issue here as I have fixed site cost in the contract. I'm only worried coz everyone I know questions me "why do you have M-slab on P-class site?" and honestly I have no answer to that. Everyone is suggesting to look into it and so I'm looking for some feedback here. I asked the builder the same question and got a pretty standard expected reply " Thats what the engineers have suggested and you don't have to worry about such things as you have a 25yr guarantee" I just want be sure its safe and that the builder isn't cutting corners. Re: M-class Slab on P class soil 18May 30, 2018 11:24 am kirashogun bentleigh_boy, I PMed you the geotech engineer my builder used. They seem to be pretty good. Thank you kirashogun, much appreciated. Will talk to them for sure. Can I ask which builder you used and where did you build? M-class Slab on P class soil 19May 30, 2018 11:26 am bentleigh_boy StructuralBIMGuy The Issue isn't with the Engineers report, kirashogun Once you have handed over a deposit to the builder and signed, the builder can charge whatever he wants for big ticket items It's up to bentleigh_boy now to scrutinise the cost if he thinks it's going to be too high, then his option is to pull out and lose his deposit Thanks for your comments, The cost is not an issue here as I have fixed site cost in the contract. I'm only worried coz everyone I know questions me "why do you have M-slab on P-class site?" and honestly I have no answer to that. Everyone is suggesting to look into it and so I'm looking for some feedback here. I asked the builder the same question and got a pretty standard expected reply " Thats what the engineers have suggested and you don't have to worry about such things as you have a 25yr guarantee" I just want be sure its safe and that the builder isn't cutting corners. The more important question is your builder engaging in structural engineer to custom design your slab. A class P requires a custom design regardless of underlying soil conditions. I find it interesting that they never hit rock but till can call the soil grade M without producing a Ys value within 5mm accuracy as Geo1 alluded to. Regardless you should receive a custom slab design done by qualified structure engineer. PMed you with my build details. Re: M-class Slab on P class soil 20May 30, 2018 11:32 am kirashogun bentleigh_boy StructuralBIMGuy The Issue isn't with the Engineers report, kirashogun Once you have handed over a deposit to the builder and signed, the builder can charge whatever he wants for big ticket items It's up to bentleigh_boy now to scrutinise the cost if he thinks it's going to be too high, then his option is to pull out and lose his deposit Thanks for your comments, The cost is not an issue here as I have fixed site cost in the contract. I'm only worried coz everyone I know questions me "why do you have M-slab on P-class site?" and honestly I have no answer to that. Everyone is suggesting to look into it and so I'm looking for some feedback here. I asked the builder the same question and got a pretty standard expected reply " Thats what the engineers have suggested and you don't have to worry about such things as you have a 25yr guarantee" I just want be sure its safe and that the builder isn't cutting corners. The more important question is your builder engaging in structural engineer to custom design your slab. A class P requires a custom design regardless of underlying soil conditions. I find it interesting that they never hit rock but till can call the soil grade M without producing a Ys value within 5mm accuracy as Geo1 alluded to. Regardless you should receive a custom slab design done by qualified structure engineer. So what exactly is a custom design slab? do they go deeper for piers? I'm waiting for them to send me the final foundation slab plan. But here is a preliminary siting plan they gave at contract signing. They have however removed the concrete to the front portico in the final drawings. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ 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 13098 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 9853 I don’t think so as the floor area over 300 square meters then it is class 3…. 12 17936 |