Trial pit for structural engineer but hit shallow bedrock??

[Greenmonster]

Hi there,

 

On my tenth house restoration, but this is the first big build, I'm a mechanical engineer to trade and have own kit ie digger, dumper etc, but need some building advice please.  I have a structural engineer coming out on Monday to assess extension plans, the office have asked for 2 pits, one where the rear corner meets the old house gable wall (area of house from 1908), and the other out where the center of the gable wall where the new extension will be.

 

The new gable wall pit dig went fine, mostly all soil, eventually hit bedrock but pretty much at 1.2m, but all seemed okay.  However the pit to inspect the foundation area next to the old house (also on a slope), has hit bedrock after just 350-400mm, I’ve cleared the area right back for 2m, and it’s literally just all bedrock.  The structural engineers office just stated 600mm deep to expose existing foundations, so does what I’ve done depth wise look okay for the structural engineer visit, current minimal 1900 footing seem to be mostly / sufficently exposed? Or does part of the bedrock need removed also for inspection?

 

Any advice would be greatly appreciated, thanks Stephen (Dollar, Scotland)

Edited June 26, 2021 by Greenmonster

[Roys]

Can’t say what you should, do but when I got my workshop foundation trench dug I hit bed rock at about 800mm on one corner of the build, stretching about 3 m out in both directions. BC made be get an engineers report, the engineer told me it was pointless pecking out solid rock but I did have to put rebar in at the transitions between soil and rock.

It was 15 years ago so things might have changed since then including my memory.

Good luck