SOLVED. What's the likely cause (and fix) for this window mould please?

couriervanman

No need to take the trim off just keep it clean

ninjaef

Thanks guys, great advice. 
To be clear though, I should clarify again..

* Room heated during the day NOT at night as per the schedule i provided in the previous post.
* It DOES get cleaned I'm told but it just comes back after a fortnight or so.
* The clearing chemicals are as per my previous post.
* Window opened when room not used and not heated, for example during the weekend when she's out shopping and turns the TRV  down in the room

I'm going too remove the trim and check its not in the wall substrate and whether it's just that area or more. Well use silicone as recommended thanks. I'll come back with pics.

neilmcl

ninjaef said:

Thanks guys, great advice. 
To be clear though, I should clarify again..

* Room heated during the day NOT at night as per the schedule i provided in the previous post.
* It DOES get cleaned I'm told but it just comes back after a fortnight or so.
* The clearing chemicals are as per my previous post.
* Window opened when room not used and not heated, for example during the weekend when she's out shopping and turns the TRV  down in the room

I'm going too remove the trim and check its not in the wall substrate and whether it's just that area or more. Well use silicone as recommended thanks. I'll come back with pics.

I'm sorry but that is not a couple of weeks worth, that picture shows a build up of dirt and mould over an extended period. Again, you're wasting your time removing the trim, it's not going to help you either way. For the last time, it's basic, common and garden winter condensation most people get on their windows which is not being cleaned off and therefore turning to a spot of mould.

Just needs spraying down with something like this and left to do it's thing.

JGB1955

Jeepers_Creepers said:

Sorry - the level of black mould on that surface shows quite simply that it is not being cleaned up regularly, not even once a week. 

Dry it - scrub it clean - apply killer. Leave for an hour. Wipe clean. Keep it clean...

I agree - that looks like several weeks of mould.  And.... take the key out of the window lock - the insurance company wouldn't be happy with that....

couriervanman

OP that is not a weeks worth of mould and chief culprit is probably drying washing and not opening windows......if its not your house you wont know the true story

The trim does not need removing

Jeepers_Creepers

ninjaef said:

Thanks guys, great advice. 
To be clear though, I should clarify again..

* Room heated during the day NOT at night as per the schedule i provided in the previous post.
* It DOES get cleaned I'm told but it just comes back after a fortnight or so.
* The clearing chemicals are as per my previous post.
* Window opened when room not used and not heated, for example during the weekend when she's out shopping and turns the TRV  down in the room

I'm going too remove the trim and check its not in the wall substrate and whether it's just that area or more. Well use silicone as recommended thanks. I'll come back with pics.

Lordie... WHY is it being heated during the day? WHY, oh WHY?! If it NEEDS to be - because someone is using the room - then fair do's - you HAVE to. But if it's being heated because some misguided individual thinks it's the 'right' thing to do, then - well - they are misguided.

Yes, you CAN keep that room 'dry' by heating it like a furnace, but ALL you are doing is temporarily 'holding' that moisture in the warmed air - you have NOT got rid of it. Then, once you cool the room down (ie. overnight), it'll all come OUT of the air and cause these droplets.

So - pleeeeeez - is that room being used during the day? No? Well TURN THE HEATING OFF, CRACK OPEN THE WINDOWS, and KEEP THE DOOR SHUT (so it doesn't get fresh 'wet' air from the house. That's it - you will have a dry room.

Have a chat with your daughter - that is NOT being cleaned either regularly or properly. And the annoying thing is, to do this it a 5 minute job each morning. I lie - each morning only requires a ONE minute wipe-up using a paper towel. Once a week - at the most - you give it a 'clean'. I should know all this - it's my job. And I'm a bloke - I shouldn't have to put on rubber gloves...

Sorry - must dash. The washing-up needs doing.

(And I'm not 'kin kidding...) 

fenwick458

i've yet to find a way of removing that black mould from silicone or caulk. tried bleach, mould and mildew remover, hypochlorite, not of them seemed to work. if it really bothers you, just buy a scraper and remove it, then reseal with new white silicone.

Jeepers_Creepers

I find the Astonish product I mentioned to be very effective.

I use it in my shower every few weeks when mould starts appearing again on the silicone sealant. It tends to clear 90% very easily, if simply left for an hour or so. (I basically just leave it - the next person showering washes it away, and they come out real clean too...)

Stubborn mould stains need a second, longer soak; wipe it dry first so's the stuff makes good direct contact, and spray on. If you leave it for a few hours, it'll clean/bleach up pretty much anything.

ninjaef

couriervanman said:
if its not your house you wont know the true story

Mmmmm. Too true - who would know when it is not their house. 

ninjaef

@Jeepers_Creepers First , thank you for the continued help wand advice. I am not probably providing a clear enough synopsis. Let me try again if I may....
The room is heated if it needs to be heated. There are room stats in every room and each rad has a TRV on. If no one is in a room is it not heated. If it is heated then it is heated to around 18.5 to 20C - these days - depends on what room and who had turned up/down their TRV. If no one is in then they turn the heating off but there's usually someone in and about - well three people - in and around the home. So the heating is on when it needs to be and off when it needs to be and at a comfortable temperature in the rooms where it needs to be. Hope that provided some useful info.

I do feel there are two issues here and this is where I was seeking help as in what is **causing** the issue - that is the OP topic. How to treat it and remedies comes later for without determining root cause it is rather early to focus on the remedy. There is draught around where the mould is - this is why I am preoccupied with taking the seals off and examining the health of the window frame, any space filler used (expanding foam for example), and the condition of the wall substrate. I have agreed with her that I am going round tomorrow and taking the trims off. 

Someone mentioned a dehumidifier - great idea. I have one - fairly decent - that I will put in tomorrow. I also examined her other rooms and they are fine with no evidence of similar effect.
I will take pics tomorrow and come back - provided she's calmed down by then