mould in bathroom

[mike the sparky]

Hi guys, I have a mould problem in two houses belonging to a landlord. Both have had a referb of sorts and both have installed a manrose 25w in-line centrifugal fan which I think may not be powerful enough. The rooms are approximately 2.5m lxdxh and have no windows or natural ventilation. One of the fans has been on a humidistat control for about 4 months and as I am aware has not turned off yet. The tenants have been advised to deep clean and remove all items that can harbour mould spores. Any advice much appreciated

 

[telectrix]

if you have an outside wall, bash a hole and fit a vent.

 

[Dave 85]

I'd always use a timer fan, switched with the lights over a humidistat. Never had much faith in them.

 

[StuSpiers]

what kind of building are we talking about?

If it is a concrete pre-fab which has been 'modernised' by that I mean central heating & double glazing then mould will appear.

Ventilation may not help that situation - having lived in a house with those problems I would recommend a bulldozer.

 

[mike the sparky]

Sorry no outside wall. Possible plans for a sun-light tube, don't think this will help.

 

[telectrix]

but how can you live in a bulldozer? sleep in the scoop?

 

[Richard Burns]

You may find that the extract ventilation is not enough if the rooms are not adequately heated, you would also need to know the extract ventilation rate achieved by the fan, the wattage is not a good guide to the rate of air flow.
As you seem to have persistent problems then a professional assessment of the ventilation, usage, and air flow may be needed.
Is there a gap in the entry door sufficient to allow the air to flow through the room or is the room sealed when closed?

 

[needasparks]

You could check they are NOT leaving the door open during or after showering and make sure any airvent holes are covered up or moist air will not be removed as air takes the easiest route. The only place air should enter is under the door at the most.

 

[Strima]

Sounds like the plaster/walls could be damp as well, would be an idea to probe them with a damp meter if you can lay your hands on one.

Problem with mould is, once it gets a hold there's no real easy way of getting rid of it short of knock all the plaster off and running a dehumidifier for a few weeks which is not ideal.

 

[Octopus]

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!

 

[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.