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_0210.jpg
http://www.cre.co.uk/misc/sl/IMG_0211.jpg
http://www.cre.co.uk/misc/sl/IMG_0212.jpg


Thanks,

Steve