Posted By jiboom
i have recently dug a soakaway. I have gone down the required depth but at this depth is a clay shelf. The building inspector passed the dig when i was half way down. I have a friend who builds and he tells me i need to dig through the shelf as water will not soakaway but turn my garden marshy.
I can see what he is getting at but my question is this:
if i went down say 6ft but the clay shelf was at 6ft 1 inch i would not know about it. So should i be worried i have found the shelf at the depth i needed to dig, as if it was just 1 inch further down i would have not worried about it but it would have been there.

Posted By martin gray1
My personal experience keep digging! (safely)
MG

Posted By Descarte
get some rigid plastic tubing and cut in half along the vertical not the horizontal, tape back together and hammer into ground, wiggle and wobble then pull out, split the 2 halfs and you will have your very own earth core which will show you where the clay layer extends too.

your local water authority may have some extra advice or guidance for you if you come up with any problems