damp, cannt find where is my damp course

i live in 1930 house and i removed the plaster on the inside wall because it had started to came away. i replastered it then 2 months back i lifted the laminated flooring and all semmed fine. about 3 weeks ago i noticed damp running along where the floor meets the wall and now my plaster is mouldy and the damp patch has now got even biggeron the floor and is starting to go up the wall. the guttering is good and the outside render seems fine.

i have paving slabs outside around the house so i lifted them but there seems to be a concrete kind of apron around the house which sticks out at ground level+- 300mm and is +-80mm thick. i dont know where or how to see where the damp course is to see if this is above it or not.

dpc is usually at internal floor level.

here is a link to some photos. i hope this is ok. if not i apologise

http://www.ultimatehandyman.co.uk/forum1/damp-dont-know-where-is-my-damp-course-t16971.html#152736

noseall said:

dpc is usually at internal floor level.

Click to expand...

Unless the floor is made of ...... ?

When it will be normally one course lower


(clue: how many times have you forgot about this when building the extension engineers up to DPC level, and then afterwards opening the back door)