HORIZONTAL shower ducting - full of water

[PFMarconi]

Not being a DIY person, I would welcome your views re. shower ducting.
Two months ago we had a new bathroom fitted and for the first time, an extractor fan.
Due to an RSJ being next to the bathroom, the plumber opted to run the ducting through the loft and out at the gable end of our bungalow.
Last night, having noticed mould on my sons bedroom ceiling, I went into the loft and found the ducting full of water.
Having spoken to the plumber today, he says that the problem is with the temperature in the loft and the timer of the fan.
He is due to arrive on Wednesday to lag the ducting and increase the timer on the fan, so that it still carries on after the person has finished in the bathroom.
My gut feeling is that the 15 feet of HORIZONTAL ducting is wrong. I believe that the problems would be solved by re-routing it vertically just a few feet up through the tiles.
Any views are greatly appreciated.

Thanks
Paul

 

[Nige F]

15 feet of horizontal PIPE 110mm soil - would be ok. Was he Gas Safe . Through the tiles you expect him to be able to do that . he wouldn`t know what a lead slate was

 

[PFMarconi]

Thanks for your fast reply Nige.

The piping is corrugated and the water has gathered between the joists, partly because of this.
When I tried to move the water to the end of the house last night, I was unaware that the piping was in sections - consequently I ended up with water pouring out into the loft.
Not sure about width - without squeezing into loft again.

As for Gas Safe. Just checked his invoice and there is no mention of membership of any organisation. My wife heard of him through a couple of recommendations in our village here in Cumbria.

The bungalow has ordinary tiles on, not slate.

Thanks again.

Paul

 

[Bahco]

You should make the ducting as short as possible rerouting through the bathroom wall if possible.

Is it a 4 inch fan by any chance as it sounds like it is not pulling enough out?