Water in extractor fan duct in windowless bathroom

[ElsieJ]

Similar to posting by Steve73 on 10/01/2008.

I live in a flat, second floor. Neighbour below me has been having some problems with water in the duct of the extractor fan in her bathroom, and has had to have to fan disconnected. The managing agents cannot find what the problem is - they have been on the roof and fitted a new cap on the pipe which leads from the duct to the outside of the building, on the roof, directly above the bathroom. Each flat has its own 'pipe' on the roof. The water in the duct is clean and fairly intermittent. The managing agents are now suggesting that I employ a plumber to see if the 'leakage' is coming from my bathroom, but I am reluctant to do this as I feel pretty sure that this is not the case, and would be an expense and upheavel for me if nothing could be found.

Could this water be purely condensation? The extractor fan and duct is situated very close to the shower.

Any suggestions would be gratefully received.

ElsieJ

 

[Burnerman]

The condensation from the shower is pulled through the bathroom fan, where it is (hopefully) expelled to the outside.
However, if the fan has a long and largely horizontal run to the outside, this is what happens. The same occurs if the duct has loops or hollows in it...the water condenses in there. Flexible ducting is notorious for this.
So - and its easier said than done - the ducting to the outside needs to be as short as possible and straight to the outside - and preferably insulated if there are any draughts close to it.
I would imagine that all of the apartments have this problem to some degree.
John