Site Investigation Borehole and BC

[swisscheese]

 Our build requires piled foundations and I'm getting a series of quotes in.

We have previously had the Soil surveys done and the SE was happy with it and designed accordingly, however one of the Piling quotes indicates we would require a 20m Site Inspection Borehole to be done to satisfy Building Control.  I must say I've not come across this, and before I 'try' and contact BC does anybody have any knowledge of this.

Thanks

[Declan52]

If you are going the piling route a borehole is usually done to confirm what is actually there so your piles are made to the correct length or you could be paying for 20m piles but they only go to 15m or worst case they go to 30m.

Not sure why BC need to be told as your SE is signing off the design. Phone the company and query why.

[swisscheese]

Thanks for getting back

We had the Soil survey done, test bores to 12m, impact testing, loads, lab samples etc etc.

All under the SE's direction - so I'm not getting why this particular Piling Co. say a 20M SI bore is required for BC, other quotes don't indicate this.

I'll have to try and get hold of BC

[PeterW]

Question to ask BC is what documentation do they need from your SEng for the piling design - don't ask them if they want a new 20m hole or the answer will always be yes !

[ToughButterCup]

Well SwissCheese, neither do I. My fingertips are burning a bit... a producer identifying the specification necessary. Hmm, I'd wonder about that.

[Declan52]

If your test holes came back with enough information that you only need to go to 12m it seems a bit daft to want to go to double that. Only explanation would be a history or deep lying peat/ very soft silt in the area but if this was a concern who ever done your test holes would have tried to prove it was there or not.