Water getting into conservatory floor where internal wall is the retaining wall in grade.

[rb1980]

Hi all have an issue where when it rains the grout on the floor gets wet patches . There’s also mould as you can see in the bottom right .
The conservatory wall in question is the retaining wall for the garden . Previously took plaster board out and the external brick wall was painted with some black bitumen type sealant I guess it must be and the wooden Batton screwed direct into this wall . Any ideas how I can stop water seeping in. There is a drainage channel where the outside window sill is.. Many thanks

 

[noseall]

Hi all have an issue where when it rains the grout on the floor gets wet patches . There’s also mould as you can see in the bottom right .
The conservatory wall in question is the retaining wall for the garden . Previously took plaster board out and the external brick wall was painted with some black bitumen type sealant I guess it must be and the wooden Batton screwed direct into this wall . Any ideas how I can stop water seeping in. There is a drainage channel where the outside window sill is.. Many thanks

The conservatory wall is a retaining wall?
Can you post an image of the outside please?