Footings ..help please

[damo152003]

Hi guys im digging my footings ready for mas fill on tuesday.
I have dug 1metre down and hit clay... anyway i dug a vit deeper the clay is only 100 mm thick and then it turns into like a crushed up coal with random bits of vroken pottery.
This is next to the the footings on a 1930s house but they just keep going. I gotto 1.8 metres and still this weird stuff.
Not sure what do if i hadnt dug any
more id be none the wiser because its clay at a metre.
B.c are coming tuesday but not sure what todo its only a single story extension and can see it getting expebsive now!
Is pilling going be an option? cheers

 

[RonnyRaygun]

Piling is always an option - it's usually an expensive option though...

I doubt that BC will allow you to found on the made ground you have uncovered, and you wouldn't want to anyway.

What was above the clay? more made ground?

 

[damo152003]

Hi its its normal earth down to clay then this stuff. I have dug down best part pf 2metres now and still not found the bottom of the orginal footings!.
There use be a brick factory close by my old man seems to think its coke.
i have dug another hole further down and that seems all to be clay.
See what b.c say if it was i hit good ground at 3 metres can i then just fill it all with concrete like we were going to or is that when piling comes in?

 

[^woody^]

With time, shoring, risk of collapse, cost of concrete etc, then it may be worth getting some piling quotes in on Monday

 

[damo152003]

My thoughts too. Might be this extension will be just to expensive if piling is required. No idea on cost but saying that fingers crossed its just this area!!!! il update tomorrow.

 

[^woody^]

Or a raft?

 

[damo152003]

Hi so today we started digging with the mini digger....
To cut a long story short dug down 2.5 metres and still very poor ground.
B.C signed over to a structural engineer for his thoughts.
So after standing round he showed up and were going with raft foundations bit of headache getting my head around it all but seems to be sinking in!
next step is ordering the steels and going from there!