Discovered old chimney flue in damp kitchen ceiling - best way to seal off?

[Ges1]

I had a damp patch in my ceiling, and after tearing out a portion, I discovered a disused chimney flue. Following it up, it terminated in the loft. Both ends are open, but I’d ideally like to prevent the problem of moisture hitting the kitchen ceiling again in the future.

Is it ok to seal off the bottom of the chimney flue, then fill with EPS beads all the way up to the loft and then just leave the loft end open?

Or, is there a better way?

Thanks everyone

 

[mrrusty]

Personally I'd seal the bottom and leave it open at the top, not filled.