Browse Forums Building A New House 1 Jul 30, 2014 2:39 pm Hi,
I'm building a new house and would like to get a view on my site costs and concrete pier costs that my builder has provided. I've got a feeling that they are excessive but as I'm not a civil engineer and cannot really judge.. The costs are provided below - 4 - 1 Provide 200mm (approx) site cut and 300mm (approx) fill to building area including soil removal as necessary to achieve a level building platform. Riser pipes to be provided to cut area where required by the Building Surveyor for clients future landscaping. $1,100 The land however looks pretty flat with the naked eye. 4 - 2 Provide rock removal for the excavation of drains due to rock encountered at shallow depths $2,718 as per soil report 4 - 3 Provide 385mm high "E" Class Waffle Raft slab in lieu of standard "M" class, as per soil report and preliminary slab design $9, 131 4 - 4 Provide concrete piers to the Waffle Raft slab as per the soil report and preliminary slab design $14, 060 4 - 5 Provide additional steel reinforcement due to "P" class site, as per soil report and preliminary slab design $3,643 Just wondering what is the cost of the concrete piers and whether it is excessive. I can see on my engineering plan the builder will use 48 400 mm diameter concrete piers 600 mm deep. Not sure, if the total site costs are justifiable. I'm building a 27 sqs house on an empty block of land that looks flat to naked eye but has a soil classification of P. Any thoughts or suggestions would be appreciated. Thanks in Advance! Re: site costs/ concrete pier costs 2Jul 30, 2014 4:59 pm Hi roller (no pun intended), Item 4-1. Cut and Fill. This is not much cut and fill - and yes, it would look almost flat to the naked eye. But if it is required (ie, it's not "perfectly" flat land) then the $1,100 is reasonable for the earthworks. Item 4-2. Rock removal. It really depends on exactly how much rock they are removing for this price. Without knowing quantity it's difficult to determine value. Something that it would be worthwhile checking though is whether that is the actual (fixed) amount that it will cost you based on the investigations that the builder (or the builder's consultant) has done. If it's not "fixed" then you might be up for more cost if more rock is found. Also, if it isn't "fixed", is there the option for it to be reduced if the amount of rock found is less than anticipated? Items 4-3, 4-4 and 4-5. Waffle slab and extra reo. Sorry, I've been out of the industry too long to know whether this is a reasonable cost or not. Just so you know though, the P class soil is considered highly reactive (ie, can move a fair bit) which is why the slab needs to be designed differently. For our build we had to upgrade our slab design due to the soil being H1 (compared to "M" which is what is typically allowed for). This cost an extra $5k, but keep in mind that the style of slab construction is inherently the same, it is just "beefed up" a bit. Yours is a completely different method of constructing the slab. Hopefully this has kick-started someone else who can add to the areas I am not sure on Seksui KDR in Sydney (2015-2016) Links --> | H1 thread | Final plans | Timing of works updated 9/3/16 | Re: site costs/ concrete pier costs 4Jul 30, 2014 7:28 pm roller you have the worst possible soil report so site costs will seem excessive. as Ponzu said you can always sell up and buy again, i guess there's no guarantee you wont get another e class site unless you put a subject to soil report clause in the contract. Re: site costs/ concrete pier costs 5Jul 30, 2014 9:59 pm Roller Just to clarify what you have Class"p" slab with piers on a extremely reactive soil which has shallow rock . If you have rock at a shallow depth then extremely reactive soil may be over the top. Does the soil report say floaters or bedrock or is it in the fill ? Re: site costs/ concrete pier costs 6Jul 30, 2014 11:57 pm Ha ha. We have P-E soil. Welcome to Adelaide, the home of crappy extremely reactive soils. Re: site costs/ concrete pier costs 7Jul 31, 2014 1:31 am Don't get it wrong. Class P does NOT necessary means that you have highly reactive soil. Class P is problem site. There is usually a reason that follow this class. ie: lots of trees / plants with big roots and abnormal moisture, site too steep with thick grass etc.. The report usually will state if the cause for the problem can be removed or rectified, what class the soil can be treated as. It can be a steep site with rocks underneath and thick grass all over where once the grass are removed, the site can then be treated as class A. So it depends, get more detail on your soil test report to see. Also, don't trust your naked eye for anything that look flat. You will be surprised how bad the slopes for a "flat" land can be. Re: site costs/ concrete pier costs 8Jul 31, 2014 7:12 am Agree with the above. Our builder gave us a copy of their report. It was P site but suitable for a M slab. Also we have exactly a meter fall over our site (fortunately included) but even so looking at the site I thought it had the gentlest is slopes. It was not till our neighbour (who is an excavator) brought out a dumpy (?) level that I knew there was any slope to speak of. http://camdenbuild.blogspot.com.au/ by invite only please pm me Re: site costs/ concrete pier costs 10Jul 31, 2014 11:59 am roller Hi, Thanks for your replies.. Any thoughts on the concrete piers costs? Do you guys think they are ok or excessive? how many piers and to what depth? http://www.betterthansheets.com.au - Why use sheets for curtains in your brand new home use Better Than Sheets Temporary Paper blinds instead! Re: site costs/ concrete pier costs 11Jul 31, 2014 12:50 pm Quote: I can see on my engineering plan the builder will use 48 400 mm diameter concrete piers 600 mm deep. suspct, as per the OP's opening statement. "48 400mm" I take it as meaning 48 piers at 400mm diameter x 600mm deep. Stewie I should have followed up on this thread. So, the pier foundation wasn't large enough on the side it was leaning towards, and the NBN cable went through the pier, just… 8 12114 Just be careful with building stability during construction, that is when the structure may be weakened, refer to your engineering drawings for stability methodology. 1 7215 |