On 4 Oct, 17:40, stevelup wrote:
Hi

Looking for some advice please.

Our house has an extension which was built in 1989 (not by us).

I am in the process of laying a wooden floor in one continuous run
through the old and new space created by the said extension. The gap
between the old and new had been filled with some kind of levelling
compound which was both cracked and far from level so I decided to rip
it up and start again. What I found was a little concerning.

The cavity is full of rubble and sand and there is no membrane that I
can see. I've linked to some photos below and would appreciate advice
on how I should proceed.

http://www.cre.co.uk/misc/sl/IMG_021...l/IMG_0212.jpg

Thanks,

Steve

Dear Steve
Short of digging under and finding (or not!) the membrane and
connecting the two you have little choice but to make the best of it
I would try to get down as far as possible into the oversite and lay
some ballast, then I would put a dpc injection fluid onto the exposed
bricks and then apply water proof concrete made up with SIKA and Feb
SBR and hope for the best!
Chris