Wet ceiling near Bathroom Extractor Fan

[Vnary]

Currently have a damp issue, that needs to looked into, maybe due to pipes in the loft and want to know if the fan I have currently is good one or not and what is the best damp seal that people would recommend

https://www.screwfix.com/p/vent-axi...or-fan-with-humidistat-timer-white-240v/41748

It is a windowless bathroom, so would appreciate any suggestions / comments.

Thanks in advance

 

[Swwils]

There needs to be a route for air to get into the room, otherwise the fan will just be battling against trying to reduce the overall pressure in a whole room.

Usually this incoming air comes under the door, is it blocked?

Its also possible the duct is blocked or undersized or far too long for this type of fan - and this will have a big effect on performance.

The damp seen might actually be a leak, if that goes straight up and out the roof.

 

[JohnD]

Currently have a damp issue, that needs to looked into, maybe due to pipes in the loft and want to know if the fan I have currently is good one or not and what is the best damp seal that people would recommend

https://www.screwfix.com/p/vent-axi...or-fan-with-humidistat-timer-white-240v/41748

It is a windowless bathroom, so would appreciate any suggestions / comments.

Thanks in advance

it's either a leak or condensation above the ceiling. Damp seal will not cure either defect. You need to get into the space above the ceiling. Take a look and plenty of pics.

condensation can be caused by poor duct layout. The water pattern you show is not ordinary "condensation on the ceiling of an ill-ventilated bathroom" but it might be "condensation inside a duct" or "condensation in a roof space where the duct does not vent outside the building". It is very bad.

a leak can be caused by making holes in a roof, and will be worse in wet weather.

The quality of your fan is the least likely cause.

 

[ericmark]

Had some thing similar in dad's old house, it was flashing around the vent in roof and it was rain water damage. However @Swwils is correct, for air to change it needs both in and out, internal door vents

often allow air in, and are also often missing, you can get heat recovery units where air goes in and out though same hole in the wall, but extractor fans have to selected with care. Far too easy to seal a modern house, and cause flue gases to be drawn into a room.