condensation I think from extractor fan....fix?

[angularbanjo]

Hi

Realise similar has been covered before but thought I would just check it out first.

Our upstairs WC has an extractor fan which is ducted out vertically through the attic. It's dripping water through the fan opening which I'm guessing will be condensation?
I've attached a photo of the vertical pipe coming up from the WC and out through the roof, it seems dry on the outside of the pipe, cobwebs, no streaks etc so I'm guessing the flashing round the outside is okay, so back to condensation.

Do you think it would be enough just to lag the pipe with insulating material or is there something else I should be doing?

See attached photo and thanks again in advance
Steve

ps: the long horizontal pipe just links into another fan in a nearby en suite in case you were wondering!

 

[stem]

It happens quite often and whilst insulation will likely reduce the quantity of condensation produced, it doesn't always eliminate it, so it's a good idea to have a condensate trap to catch and remove it. There's an example here Condensate Trap The trap should be in a vertical section of the duct at the lowest point, so that it catches any condensation that does run back towards the fan.

Each fan should have its own outlet. Because the airflow from each will never be balanced perfectly meaning one will take precedence over the other and if only one fan is running the extracted air could take the easier route back into the house through the fan that isn't operating rather than up the stack.

 

[angularbanjo]

Thanks, that makes perfect sense

 

[JohnD]

It will be a good start. Also run it for longer.

Is there a rain cap on the top of the pipe?

 

[angularbanjo]

It will be a good start. Also run it for longer.

Is there a rain cap on the top of the pipe?

Yes there is a rain cap. Problem with that WC is we tend to only use it during the night and then we don't put the light on (I sit, my aims not that good!) so the extractor fan rarely turns on.

 

[JohnD]

Is the fan too noisy? Show us a pic.

 

[angularbanjo]

Is the fan too noisy? Show us a pic.

No, the fan itself is fine, not too noisy. I just don't put the light on at 3.00am when I'm up for a pee to stop myself waking up any more than necessary !