How big are your piles, then?

[ToughButterCup]

Well, whatever size they end up, my eyes are going to water. That much is certain.

 

Here's the thing: our SE has given us a comprehensively specified  pile design. More than good enough as the basis for a tender. And slowly, the piling companies are coming round to visit the site, and then submit their tenders.

 

But each company has specified piles of differing specifications;

 

In terms of diameter ; one company suggests 220 mm, the next some 150 mm, and the rest 168 mm

 

Is it simply a case of the bigger the diameter of the pile, the shallower the 'drive' is likely to be?

[Calvinmiddle]

Ian

 

Going to nudge you again, and keep nudging you until you have told me you have done it.

 

Have you talked to Hilliard yet about digging a big hole and filling it up with stone.

 

www.tsd.ie

[ToughButterCup]

Yes, I have.

Hilliard's informal view is that it may well  not be viable. But that statement needs to be put in the context of a sensible estimate of what piles are going to cost. And that depends on a fair comparison of the tenders. Hence the concern about pile lengths - and diameters.

 

Simply put the question is: do fatter piles need less depth than skinny ones?

 

The Soil Investigation  (SI) report shows roughly 2.5 meters of MADE GROUND (page 17 for the diagrams). I had no idea what that (MADE GROUND) term meant until we had our Phase 2 Site Investigation - also confusingly called by some an SI  report).

We're sitting on top of quarry spoil, and that sits on top of what the glaciers decided to dump: clay and ground up sandstone. I had no idea you could get sandstone cobbles. We've got some to spare at just £5:00 each. Bargain!

[TheMitchells]

Picture please of those sandstone cobbeles.....

Next time I am passing Lancashire I may have to grab a few.

[ToughButterCup]

6 minutes ago, TheMitchells said:

Picture please of those sandstone cobbeles.....

Next time I am passing Lancashire I may have to grab a few.

Are you sure? Honestly?

 

If you want a bag full, Junction 33 on the M6 : we are 5 minutes (or less) away. 

You'd be welcome any way - we're perfectly placed for a stop-off just before (or after) the Lakes. We're really close to Forton Services

[TheMitchells]

Dont often get that way, being down in Oxfordshire but will give you a shout when we do.  I'd love to see the newts too, I feel they are part of the family as we've heard so much about them.

 

[Daedalus]

I'll bite on the piles ... 

 

The short answer to your question is no, in your case your piles should be going to the approximate same depth although it really depends on the geotech's initial interpretation of the SI. I would have thought that due to the shallowness of the mudstone all your pilling companies would be quoting around 5m deep piles. 

 

Out of interest who has given you prices and at what sort of unit rate. I would not recommend any locally based companies and in my experience only go with large national companies, even on the very smallest of jobs. although it depends on what the local reps are like. For comparison I've been quoted around £300 per pile (5m deep) recently using 225 dia, although that doesnt include mobilisation and other costs etc.

[PeterW]

I know this is a random thought but....

 

If piling needs to go down 2.5m through the made ground, can you not dig a hole and have a nice basement instead..? With a passive slab..?

[ToughButterCup]

2 hours ago, Daedalus said:

I'll bite on the piles ... 

 

The short answer to your question is no, in your case your piles should be going to the approximate same depth although it really depends on the geotech's initial interpretation of the SI. I would have thought that due to the shallowness of the mudstone all your pilling companies would be quoting around 5m deep piles. 

 

Out of interest who has given you prices and at what sort of unit rate. I would not recommend any locally based companies and in my experience only go with large national companies, even on the very smallest of jobs. although it depends on what the local reps are like. For comparison I've been quoted around £300 per pile (5m deep) recently using 225 dia, although that doesnt include mobilisation and other costs etc.

 

Thanks very much for what I suspect is an expert response. I say that because the quotes cite 5m as the expected depth. One mentions 6m as the expected depth, partly because the rep said he didn't want to under-estimate; and that there'd be a refund per whole meter not used.

 

Brave too; biting on piles 

 

Three local firms have given me prices, I'd like to keep their names out of the discussion at this stage; I'm happy to give you their names via PM if you like.

 

The unit prices (cost per meter) are as follows:

150 mm piles £ 180

168 mm piles £ 200

220 mm piles £ 210 or £260

 

I take the point about National Piling companies.

I have a recent copy of SPONS (2016) and I use that guide prices as a measure against which to judge other related issues such as Set Up costs and Idle Time.

[ToughButterCup]

2 hours ago, PeterW said:

I know this is a random thought but....

 

If piling needs to go down 2.5m through the made ground, can you not dig a hole and have a nice basement instead..? With a passive slab..?

 

Gordon Bennett Pete. Please delete that comment before SWMBO sees it. She'd go mad with ideas.

 

And I won't sleep tonight for thinking about it. 

Why? It's a typically German approach to building: put the garage, workshop, cold store, kids' room, bike store, home cinema in there.

[jack]

16 minutes ago, recoveringacademic said:

It's a typically German approach to building: put the garage, workshop, cold store, kids' room, bike store, home cinema in there.

 

Yep.  We briefly spoke to a German architect at a building show once, and as soon as we mentioned a plant room he got very excited and started verbally laying out a basement for this and all the other stuff you list above.  We backed away slowly.  He's still there talking about it for all I know.

[ToughButterCup]

Well, there's no hope for me now. I'm resigned to a few nights of ................

 

'...Well Jack said.....' or '....PeterW says that too...' and '...Well, we could have a really good [xyz] if we had a basement...'

 

[PeterW]

Where else are you going to park the mini digger when you've done......?

 

 

[SteamyTea]

It is strange that we don't design in basements in the UK.  You would think that with our unrealistically high land values that we would.  I supposed that it comes down to the marginal price.

Mind you, with our shoddy building practices we would all end up with either cheap underground swimming pools or very large rainwater harvesting tanks.

[Daedalus]

15 hours ago, recoveringacademic said:

 

 

The unit prices (cost per meter) are as follows:

150 mm piles £ 180

168 mm piles £ 200

220 mm piles £ 210 or £260

 

 

 

Yikes!

 

I should have clarified that my price was Per pile (in 5m lengths) not per meter. I've just gone and double checked that number and it was actually £220 per pile, i.e. £44/m/pile. with an EO of £45 per m if the piles need to go deeper. 

 

Also, not sure what your scheme looks like but getting your piles and ground beams done by the pilling company is always (alot) more expensive, although it is easier!

 

[Bitpipe]

18 hours ago, PeterW said:

I know this is a random thought but....

 

If piling needs to go down 2.5m through the made ground, can you not dig a hole and have a nice basement instead..? With a passive slab..?

 

1 hour ago, SteamyTea said:

It is strange that we don't design in basements in the UK.  You would think that with our unrealistically high land values that we would.  I supposed that it comes down to the marginal price.

Mind you, with our shoddy building practices we would all end up with either cheap underground swimming pools or very large rainwater harvesting tanks.

 

We did a basement for just this reason.

 

Architect was dead against it (due to ignorance) but we just went to a good structural engineer and stuck to a sensible shape (i.e. the footprint of the house above) so just under 100m2 internal floor area. Ground investigation was key to driving the structural design & waterproofing strategy. We went for an open box design to maximise flexibility and minimise costs so have a timber suspended ground floor instead of a solid slab.

 

We built it to passive standards, adapting the design of the MBC passive slab (i.e. it sits on 300mm of EPS 200 and has 200mm EPS 70 wrapped around it) and it dovetails nicely with the MBC frame above. Used a local groundwork contractor who builds domestic and commercial sub ground structures and used warrantied SIKA waterproof concrete, perimeter land drain to soakaway and clean stone backfill - it went in about a year ago and has always been bone dry.

 

We imported relatively inexpensive GRP lightwells from MEA in Germany and the basement is beautifully bright - just putting down the flooring now (Karndean) and have four large 20m2 rooms with 2.5m ceilings and a hallway - earmarked for home cinema, gym and general kids space. Plant room in there too for MVHR, boiler, UVC and other gubbins.

 

It cost about £120k for all the groundworks and probably about £15k additional finishing costs, so about £1350 /m2. That's to increase the usable footprint of the house by about 50%.

 

Best part was the planners did not bat an eyelid.

[ToughButterCup]

Only just got to this. Thanks for the response.

 

Debbie and I have to talk about this. Not to do so would be unwise. Another sleep-deprived night ahead.

Shouldn't have stated  if I can't take a joke.

[iSelfBuild]

You might want to try Wolfenden Concrete too who are in Barnoldswick: http://www.wolfendenconcreteltd.co.uk/durapile

 

I visited them last week and spotted them producing piles there, I'm not sure if they install as well... their site doesn't make it clear.