Mould around silicon on windows in main bedroom

[new2diy2012]

Hi all,

After my success of both the dishwasher installation and putting up a light from help on this forum, my quest now turns towards sorting the bedroom windows out.

We bought the property last year, and noticed it slightly then, and didn't think too much of it.

However the mould on the windows has gradually got worse and to the point of wanting to get it sorted out.
There is condensation on the windows in the mornings, sometimes a lot, sometimes very little.

Some pics are below:

To be honest, I haven't tried an awful lot, as other things have kept me occupied, other than cleaning it with a variety of stuff.

I presume re-siliconing is an option?

Or if anybody can point me in the right direction of what to do?


Thanks

Cheers

 

[freddiemercurystwin]

You need to eradicate the reason you are getting condensation otherwise no matter what you try the condensation and mould will return.

Do the windows have trickle vents? If not then this would be the first thing to do: retrofitting trickle vents in the head of the frames permit it.

 

[^woody^]

I don't think that is a condensation issue as such, rather you have a very cold section of wall there, which is allowing [normal] moisture to condense.

In addition, the silicone is probably not 'sanitary grade' and so mould is feeding off it

That gap up the side of the frame needs filling, the silicone needs replacing, and then either treat the area with fungicide, or fit some 3" bullnose plastic architrave in the wall corner, and this will remove the cold surface for moisture to condense on, and make it easier to wipe generally

 

[icewinder]

i had the exact same problem with my windows.I was renting so i had to find a solution and so what i did was ,

i took out all the silicon and bought about 2 cans of expanding foam.I masked up the UPVC and knocked about 1/2 inch gap into the cavity so i could get the can nozzle in and filled the gap making sure it didnt run everywere.

i gave it a day and cut off the excess foam and used a bathroom grade silicone.its 12 month now and not a sign of it coming back.

Basically its condensation coimng through the silicone and no matter how many times you scrub or replace the silicone it wont go till you do this.

Infact , are those pictures you posted from my houses ???

 

[foxhole]

Poor ventilation = Mold.

 

[icewinder]

I'll agree , poor ventilation in some cases will be the main factor for mould. I use to open the windows even when there was snow on the outside ledge and even at night. The missus use to go mad with the bedrooms all freezing.

It later turned out that a few yrs previous cowboy builders who installed the UPVC windows for the council had ripped out the old ones and the polystyrene ball installation had come out around all the windows upstairs.

The windows were virtually been held in with a couple of loose screws and silicone.
Once i used the foam all my probs ended , and to add , were the installation balls didn't fall out ( all the downstairs windows ) i never had a problem with mould.

 

[new2diy2012]

Thanks all for your replies.

Yes the windows do have trickle vents.

When we sleep, to be honest most of the time they are closed, as they let so much noise into the bedroom.
In the Summer it isn't an issue as such.

It's not just that wall pictured in the room, thats where the worst affected is, but top left of the window its slowly increasing and the right hand side of the wall/window is also similar but not as bad.

None of the other rooms have it, however we are obviously in the bedroom for the most hours in the day.

icewinder: I'm not quite sure what you mean?
"i took out all the silicon and bought about 2 cans of expanding foam.I masked up the UPVC and knocked about 1/2 inch gap into the cavity so i could get the can nozzle in and filled the gap making sure it didnt run everywere. "

I understand the remove all silicon and get some cans of foam, and mask up the UPVC.
The 1/2" gap into the cavity, could you explain in simple terms where?
When you say fill the gap, did you knock this 1/2" gap down the whole of the wall?

Cheers

 

[icewinder]

knock the plaster off the wall , only a bit between the window and the wall to expose the cavity, you can see the damp i had in my pics and by filling the cavity between this insulates the plastic and the silicon so so condensation travels.

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[icewinder]

Should have said , i even chiselled abit of the wooden sill away to get at the bottom as it was black along there. abit of filler, silicone, paint and no-one know's. Like i said , i suffered for years before i moved out to rent the place but i couldnt rent till i solved it and expanding foam worked for me.

 

[new2diy2012]

Thanks a lot for the pictures, they will help out a treat!

Yeah good idea about the window sill too.
What would I do about that plastic strip?
The one in the first picture.

when you say filler, just normal interior filler? Or something different?
I presume some branded decent stuff?

Silicon the same?

Any to recommend?

Thanks

EDIT: I get what you mean now about the pictures comment in your first reply lol!

 

[icewinder]

Glad you get me drift now i chiselled the wood cill away , foamed , cut it level and relayed the trim back on a bed of silicone and some heavy weight all the way along to push it down till it had gone off.
As for the sides ? again, cut the foam back, fill up to about 10mm shy of the window, let it go off, tidy it with some sandpaper, once dust free silicone back up.
Some ppl might say different but all's i can say expanding foam worked for me.



P.S. i bet when you pull the trim back and take some plaster away you have a gaping gap letting cold air to penetrate the silicone from the underside therefore creating mould on the inside.

 

[foxhole]

Afraid ice winders solution was based on misunderstanding about mold, cannot come thru silicon , only sits on the surface, cannot be eliminated by anything other than adequate ventilation. Mold is airborne, ventilation is only solution.

 

[icewinder]

well you might be right but in my case the insulation had gone from just below the upstairs cill's all round the windows, It was just as easy to foam it.
I know one thing , it cured it and 12 months on not a sign of damp to be seen with no need to leave the windows open all day.

Sorry i didn't mean to say come through the silicon what i meant was the cold cavity air travelling around the window to the plaster and silicon therefore making condensation and mould follows on.

 

[new2diy2012]

I understand what people are saying about ventilation.

But I can't leave the windows open all day and night, not paying money to heat the house for it to just go out the window.

I'm either going to go for icewinders solution, or just re-silicon it with some good stuff, and see what happens.

Either way, if I have to re-silicon or whatever once a year or so, it's got to be better than having the wall looking like it is, and the mold in the air breathing it in, which in turn isn't good for us.

Thanks all for the replies, I shall let you know how I get on.

 

[AronSearle]

If you have condensation due to cold bridging (poorly fitted window with insulation gaps around, poor quality window), extra ventilation only helps in the sense it makes the air in your house to cold to condensate on the cold window surfaces.

Ventilation is not the only solution, because that only suggests one cause.

I would recommend icewinders solution, far to many windows are fitted poorly, with inadequate insulation around the frame.

It "might" just be poor quality mastic (get the anti mould type), but it's not that big a job to do it as above.