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

Niv

Jeepers_Creepers said:

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.

Second this. That is what i use and how I use it too, great minds  

Jeepers_Creepers

coffeehound said:

I think that is a wee bit unfair to ninjaef.  They've already stated (though you seemed to miss it) that the room is well aired and heated.  As you say, this probably does happen in almost every home to a greater or lesser extent.  The bottom of window frames is likely to be the coolest spot in a room, and if it falls below the dewpoint overnight, then there's going to be condensation.  I get it in this room even though the heating has been on 24-7 for months and the RH is below 50%.  It doesn't necessarily mean inadequate heating or ventilation.

Possibly a bit unfair - but I don't think so.

Courierman has already pointed out (thanks) that Ninja claimed that the sill was cleaned regularly. It clearly hasn't been, and that's why there's a thick build up of mould - no other reason. The cure is so easy - mop up, scrub clean, and then mop it up again each morning - you won't have to scrub it clean again. Ventilate the room immediately afterward moping* each morn and no more condensation will form that day. When you then want to use the room, shut the vents and turn up the heat.

Repeat.

Job done.

Use mould killer when required to kill the spores and bleach the stains. I dunno - once a month? Use 'Grot Buster' if really needed to get it all clean for the first time, and then it shouldn't be needed again.

Ninja is clearly looking for a 'fault'. There is no reason to believe there is one.

*Clearly Freudian - I'm going to leave it :-)  

binao

Mould  may also damage the glass rubber surround.

Astonish contains bleach that kills mould faster than vinegar but may discolour or weaken rubber.

Have posters experienced any rubber damage with long term use of bleach containing products?

Or is vinegar better?

Jeepers_Creepers

binao said:

Mould  may also damage the glass rubber surround.

Astonish contains bleach that kills mould faster than vinegar but may discolour or weakens rubber.

Have posters experienced any rubber damage with long term use of bleach containing products?

Or is vinegar better?

Hmm, good point. I don't actually know, but I guess it's something you do need to be wary of. I guess leaving any bleach product sitting on a black surface, even rubber, could cause issues.

The use of mould killer shouldn't have to be a regular occurrence, tho'. Once you get the surface clean and free of mould that first time, it shouldn't come back provided you wipe all the condensation up on a daily basis. If it's dry, it won't form mould - end of.

coffeehound

Jeepers_Creepers said:
Possibly a bit unfair - but I don't think so.
<snip>

Yes, I don't disagree with the suggested preventative/remedial measures, it was where you stated the root cause was lack of ventilation and heating that was unfair.

Anyway, hopefully OP's intervention will help the situation.

Jeepers_Creepers

But that is the root cause. Isn't it?

I sense - as has others - that Ninja is looking for an external 'cause', something they can 'fix' and all will be well.

ninjaef

Right then, back home. 
Bad and Good.

First the Good
Long story but somewhere in the extended family tree (daughters fella's best man side) is a Glazier (Jack) who runs his own company but services commercial clients not domestic. Anyway he came round and discussed the issue today. As I reported yesterday I had removed the trim (as stated) and filled gap that runs some of the way along the bottom of the frame between the sill. The plan was to go back today to trim and sand the foam but Jack took most of it out RRRR to examine it - because I pointed out that a forumite on here was indicating that "the gap should be there and air flow is good", something along those lines. Lets just say he took 5 seconds to er - "reject that idea" (me staying polite here) . No - the frame has not been fitted correctly. Period. The correction is to fit new frame and units but as a stop gap until she can afford new windows - Jack filled it with some "squish sponge foam strips" (sorry I have no idea what is was but it wasn't expanding foam I had used from Screwfix). He then cut some proper fitting trim and sealed that into place. All done, no draughts and look like new.

The Bad,
The frame has not been fitted correctly and in addition, the units have failed (he keeps using the word unit whereas I would say "glass"). I think someone here mentioned that the glass has failed so well done! Another treat I didn't see or hear until this evening was a clothes dryer running next door in the box room. ER !!!!!! I exclaimed! "Oh yeah, I got the dryer a few months back". I cast my gaze to the window and it was shut. I asked why no venting and her reply "Ohh it keeps the house warm".  I couldn't believe it because I had asked her if she has a dryer or still dries clothes on rads - because that will generate humid air and lead to condensation on the windows -  to which she said "NO". Sigh !! After a discussion with Jack she came to her senses and will open the window in the box room when the dryer is on.

So that is about it.
She is now saving for a new bay window (and it's pretty big) so no doubt I'll be back around soon with a cheque book 

Thank you to everyone for the help advice and feedback. You've been a tremendous help and all your comments have helped to guide me along so many thanks. Apologies if you are still hard over on the root cause and sticking by your diagnosis and recovery action - but sadly I have to politely decline as I have took the advice of the Glazier guy so please don't be offended or post an angry followup - your time and input was welcome and was considered so thank you.

Marking this Solved.

couriervanman

Well when you friend Jack fits a new window she will still have the same problem with condensation unless she opens windows in morning and stops drying clothes

ninjaef

couriervanman said:

Well when you friend Jack fits a new window she will still have the same problem with condensation unless she opens windows in morning and stops drying clothes

He's not my friend - I don't even know the guy. Friend of the Son-in-law arranged it all out. He was helpful kind and didn't want any money for his time so that's fine by me - seemed like a genuine guy.

ninjaef

Oh I forgot to mention, the cleaning, she's "come clean" on that too. She said she cleans it "now and then" which knowing her means hardly at all. So well done to those who were challenging that aspect - you were right , albeit I think one of you got a bit passive aggressive about it, but you were right. I think the two of them will be having a "chat about things" later because he works all hours and she expects him to carry on working when he gets home at 8pm-ish every week day - sound familiar anyone