Newly built bathroom mould - how to sort it and who is liable: builder or architect?

Paul_Varjak

You say the mould is on the toilet pan etc? What does that mean? I think it more likely that the mould is on the cistern. Maybe wiping the condensation off the cistern after each shower could help?

Try adjusting the overrun timer on your fan to its maximum, or leaving the lights on after your shower (and the door open) or installing a fan that has a humidistat.

It could be you have some leak in your new bathroom! If the mould is around the toilet check there is no water leak around the cistern - I had this problem once and it caused mould to form.

Finally, you could try taking a shower together! That way you will use less water and less water = less condensation!

dampdaveski

Asker,
I come across this situation regularly.
the chances are the architect specified an extractor fan that meets building regs, HOWEVER if your bathroom is quite big and as you say it's an internal bathroom and I assume it has no opening windows, there is a good chance the extractor is simply not powerful enough to give the required air changes in the bathroom.
What sort of extractor fan is it?
Is it fitted into the ceiling?
A 4" axial fan (ie like propellor blades) fitted in the cieling won't have enough power to overcome the additional resistance that ducting adds. Basically your fan might be rated at extracting air at 15 litres a second BUT it won't be discharging air to the outside at 15 litres a second because of the length of ducting.
If adjusting the fan to overrun for longer doesn't work you will need to consider upgrading the fan to a continous duty type, these are usually a centrifugal fan (ie instead of propellor blades they have a drum a bit like a paddle steamer wheel) these fans give a lot more air movement for less effort AND can overcome ducting resistance much easier).
the type of fans I install are the Nuaire Genie Range and the Envirovent filterless extractor fan
Google both names and you should get more info easily.

Hope this helps
DD