Foundations - Found Slate

[jono_h]

Just started digging my foundations and I'm down to solid slate at around 600mm below ground level. At the low point in the slate there is a small trickle of water running across. I was going to trench fill, is this still possible, or is it going to get expensive?

Can this be resolved with a Building Inspector who know's what he'd doing, or do I need a design from a Structural Engineer?
Is there a possibility I can pour on to the slate, linteling over the low spot to allow the water a passage?

Happy to pay for the SE, just trying to get an idea of how difficult this is going to be. Thanks.

 

[freddiemercurystwin]

Sounds a bit like shillet, quite common in Devon/Cornwall, not sure about elsewhere, if it is then it'll be solid as and you'll be able to bear directly on it, get your inspector out to have a look if you can, why do you need to create a passage for water?

 

[jono_h]

Thanks for the reply FMT,

I'm in Wales so I was expecting slate, but it could be shillet. I thought I'd need to create a passge for the water so that it doesn't affect the strength of the concrete, or caused problems when it found a new natural route. I'll probably keep digging and get the Inspector to have a look.

 

[freddiemercurystwin]

Slate or slate shillet I doubt you'll be able to make much impact.

 

[martygturner]

If it was me I would clear the bit by the brick work and get sight of the existing foundation. If the rock band hits a certain mechanical strength in your area, your BCO will know you don't actually need to pour any concrete , you can just clean off the surface and build off the rock..