Bathroom woes

[longtallsally]

Hi,

I'm fighting a losing battle trying to eliminate mould from my bathroom. It's single storey flat roof with two outside walls and a window. I had cavity wall insulation fitted in spring but it seems to have made no difference at all.

The problem I have is with condensation running down the walls. There is an extraction fan, but probaly only extracting around 50-70 l/hr. Would doubling this help? And is replacing an extractor fan quite straightforward?

I constantly have to reseal and wash the walls to get rid of the mould but it's very tedious!

Any suggestions very gratefully received.

 

[Taylortwocities]

1. Check the fan's duct is actually going somewhere and is not blocked
2. It should be a timer fan. if it is, extend the over-run period
3. Make sure there is an adequate way into the room for air. If the door fits tight then the fan will not be efficient
4. Change the fan for a more powerful humidity type fan. Expect to pay £80 plus for a decent one.

 

[flameport]

There is an extraction fan, but probaly only extracting around 50-70 l/hr.

Hopefully that is a mistake - 50 litres per hour is so small, you wouldn't even feel the air moving.
Approved document F suggests a minimum of 15 litres per second. Even a £10 extractor fan will be rated at 80+ cubic metres per hour, which is about 22 litres per second.

 

[1john]

where is the fan located in relation to the door and window. as someone above mentioned, have you got about a half inch gap below the door?

 

[longtallsally]

thanks fo your replies.

The duct is not blocked, goes straight to outside.
There is a gap of about 1 cm below the door.
It doesn't have a timer as there isn't a switch live, but it does come on with the light, and I leave it on for around 20mins after a shower.
Yes I did get it wrong - I meant around 70m3/hr.
Fan is opposite to the door.

Hope that fills in all the gaps. I looked at replacement fans this morning, but they all seemed to be same power?

 

[longtallsally]

Me again - I think the only way around it is too up the fan. At the moment it's a 4'', but I think the only way of noticeably increasing the capacity is to fit a 6''.

Am I allowed to do this myself? and what's the best way about increasing the hole?

thanks!

 

[1john]

best way now would be to chain drill a bigger hole and chisel it out to the bigger size, an SDS drill with rotary stop is useful for this. Not a pleasant task.

 

[longtallsally]

thanks, think that might be above me! Will try to persuade someone else