Leak in stately home where dukes reside (6)

'leak in' is the definition.
The answer and definition can be both substances as well as being singular nouns.
Perhaps they are linked in a way I don't understand?

'stately home where dukes reside' is the wordplay.
I cannot really understand how this works, but
'dukes' could be 'dd' (an abbreviation for duke written twice) and 'dd' is found in the answer.
'stately home' could be 'pile' (I've seen this in other clues) and 'pile' is located in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...

Can you help me to learn more?