mould in bathroom

[Marvo]

Assuming a damp issue check for the obvious such as rising damp in walls or leaking plumbing in walls or above ceiling etc

You say there is a fan installed. The first 3 questions would be;

I the fan capable of moving between 10 and 12 times the volume of the bathroom per hour?
Is there a vent in the bathroom door for replacement air (make-up air) to enter?
Where is the fan discharging the humid air?

 

[mike the sparky]

The extraction rate is 110m3/hr, as I am aware the bathrooms have been well cleaned with bleach and the doors are left open after showering. The main problem is two teenage daughters! Will a more powerful extractor do any good? How about a 4in dia vent in the door?

 

[Guitarist]

Cutting down the showering time helps tremendously. My teenage daughter is on a 3 minute timer now

 

[ruston]

What they need is a big bottle of bleach, a pair of decent rubber gloves and a mask - and then give every surface a good going over.Don't mess with anything other than good old bleach!

Good old Domestos will shift it , but you need to get the air changes sorted as has been said ; and put the timer on max lol. Seriously though heat and air flow has to be considered, if it's a typical let the house could soaking with damp as has been suggested.Call manrose and give them the dimensions of the rooms an the will tell you the air flow you need.again.

To late again b/band dropped out

 

[Mark_Burgess]

Change the manrose for an airflow, xpelair or ventaxia.
Then fit Positive Input Ventilation (not into the bathroom directly), along with the bleach session should stop it from re-occuring.

 

[oldtimer]

Yep is the fan big enough and how long is the duct if its 1.5m or longer then you need centrifugal over axial also the fans take air out of the room is there a vent for fresh air to come in or a vent in the door is some old houses you could get Top Cats wallet in the space under the door.

One last point and please dont tell me I am racist I do repairs in rental properties and some of the tenants from the Indian sub continent have a LOT of bother with damp as the seem to do a lot of steam cooking throughout the day plus they will not and I mean not open a window or switch a fan on as it is toooooo cold in this country and tooooo expensive for electricity I have tried to explain that it is a culture problem and that they need to let the property breathe but to no avial

 

[Richard]

Cutting down the showering time helps tremendously. My teenage daughter is on a 3 minute timer now

I can just imagine the response if I suggested that in my house..!

 

[diditrain]

Guy i used to work with, said he had this problem in his bathroom until he fitted a heater in there. Turns it on for a few minutes after showering to dry the moist air up

 

[Richard Burns]

The extraction rate is 110m3/hr, as I am aware the bathrooms have been well cleaned with bleach and the doors are left open after showering. The main problem is two teenage daughters! Will a more powerful extractor do any good? How about a 4in dia vent in the door?

110m3/hr meets the minimum spec but if there is a lot of moisture generation then this may not be enough, however as said in other posts if the problem is continuous then look for other causes as well.
you only need a fairly small vent in the door for air flow, but it may also be worth looking at the likely air flow through the room if the door and fan are close together it may not clear the room.

 

[JB_]

Guy i used to work with, said he had this problem in his bathroom until he fitted a heater in there. Turns it on for a few minutes after showering to dry the moist air up

Yep, best way to keep the moist air moving is to keep the room warm.

Need to check for obvious water leaks first but heating the room will def help.

I've installed underfloor heating in several mould infested places, works a treat every time. Gives you a bitta work too