PVC window mould on sealant

modelreject

Hi,

We have PVC windows in our house and they are mouldy due to condensation build up over the years. I don't want to pay someone to come out and redo so advice is greatly appreciated.

The mould is only on the sealant at the base of the frame and goes up about 12 cm at the sides. The rest of the sealant is fine.

1. Can I just take the mouldy sealant out with a knife and add new stuff or do I have to take out the whole thing?
2. Will I see a join if I only take out the mouldy stuff and add new?
3. What sealant should I buy (anti mould? best brand?)

Here is an image...https://skitch.com/clintonbeattie/rygu4/dreamweaver

Many thanks,
C

phill99

You can just try and cut out the affected arereas, but its better to do the whole thing. The mould could spread and then you would have to do that anyway. You need to get rid of all traces of the old stuff as the new stuff will have trouble adhering. Clean it down with methylated spirit before applying new.

Some people swear by Dow Cornings, although providing it its mould resiistant or anti fungal, it should be OK.

modelreject

As far as mould spreading, I think it is just where the water lies in the morning after the air has condensed on the window frame. I will remove it all just to be sure.

Is it safe to remove all the sealant. The window isn't going to fall on me? I'm overly cautious I know. lol

phill99

No, it won't fall out. Its fixed into the wall with frame fixers. The silicon is just there for cosmetic reason as much as anything

System

wont it just clean with an anti mould cleaner ?

tanith

I presume you are not talking about double glazed units here ? If they are then no way can you scrape out the sealer it will damage the windows permanently... if its double glazed units , I have the same problem I used to clean well with detergent and tooth brush but now I just open the windows every day till they are dry. That solved the problem

daveyjp

Before hacking at the sealant try some Dettol mould and mildew cleaner, available from supermarkets in a lime green bottle - it does what it says. Spray it on, leave for an hour or so and the mould will disappear - repeat if it doesn't go first time. Used it on our bath for years and the sealant is good as new.

A.Penny.Saved

The black mould can be eliminated using a bleach solution or just some bleach on a rag and wiped over leaving a little present but not enough to run.

Wipe it over some hours later and it should be gone. I get the black mould on tiles in the bathroom and some bleach always does the trick and costs very little.

ROY47

All of the above advise only cures it temporary

you need to scrape out the old sealer and then use this

http://stelmax.co.uk/1961sealant.php

I had exactly the same problem and consulted a realtive who fits pvc windows and he recommended that sealer

problem solved !! and no I don't work for them

have a look locally for pvc suppliers in your area

The main advantages with using Stelmax sealants are that they cure by solvent evaporation, leaving a smooth polymer surface.

Silicon sealants are completely different products and the two should never be confused. Silicons cure by absorbing water, most commonly in the form of atmospheric moisture. During this absorption the seal will attract any dust and dirt, but more importantly, the micro-porous nature of the surface left on the seal after it has cured will discolour more quickly exposed to any dust or particulate and can provide a home for bacteria, moulds and fungus.

This is why if you look at any white silicon seals, even after a short period of exposure to the outside, they can appear grey and dirty. A uPVC frame will stay clean and not attract dirt and dust because it has a smooth polymer surface, a white frame will stay white but when the seal goes grey it stands out clearly and can be observed at any number of installations...(go and have a look..).

and yes I have looked and it's true !!