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Windows - mold keeps growing, seal broken and condensation problems

Windows - mold keeps growing, seal broken and condensation problems

Old 03-07-13, 04:39 PM
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Windows - mold keeps growing, seal broken and condensation problems

Our house was built in 1978. The original windows are still in use, but the seals are broken in every window and condensation occurs every winter. Mold also is growing where the caulking is between the windows and vinyl and then it grows up on the window grills. Every summer wasps and flies enter through some of the windows too.
I was wondering if it is possible to remove (cut out with a knife) the caulking/mold and clean windows and then re-caulk all our windows? Is this silly and a waste of time? I am hoping this would possibly give us a little more time before we can replace them. I specifically want to do my daughters nursery because I don't like the draft or bugs that come in. Sadly, financially new windows are not an option.

Thoughts? Please let me know if you have any better ideas.

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Old 03-07-13, 07:58 PM
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All you need to do is replace the IGU (insulating glass unit). You do not have to replace the entire window. Any commercial "city glass" shop can do that for you.

You can clean any mold that is on the interior side of the window frame with Tilex mold and mildew remover. Clean it as often as is needed. Mold will come back if the conditions are right for it. Even after you replace the glass, you might get some mold on the interior trim of the window, because of condensation on the wood. Just keep cleaning it regularly and it won't be such a big problem.

If the mold has left stains, you might try the product "soft scrub w/ bleach". But if the mold has been there and it hasn't been cleaned for a long time, it can actually stain the wood/vinyl, and the stain won't come out.
Old 03-11-13, 11:38 AM
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As always, XSleeper's reply is right on the money, but after looking at your pictures I have a couple questions and thoughts.

First, when you say seals failed and condensation, are you getting condensation between the glass panes or is it on the inside surface of the glass where you can wipe it off?

If the condensation is between the lites of the dual pane or insulating glass (IG) units then you have seal failure, but if it's on the surface of the glass then there is a different issue to deal with.

Looking at your pictures the first thing that struck me is that you have both wood and vinyl windows. I suspect that someone changed some of your windows at sometime because you have at least two different spacer systems as well as both dual pane and triple pane IG's.

The very first picture in your group is a wood window that appears to have an IG unit (versus a single lite of glass) with surface condensation.

The third picture (great photo's btw) is clearly a vinyl window with a triple pane IGU and a stainless steel spacer. Looking closely, it appears that "cardinal" may be stamped on the spacer but I am not quite sure. If this is a cardinal IG with a stainless steel spacer, and if this window has moisture between the lites (inside where you can't touch it), then that IG may be under warranty yet. Cardinal introduced the stainless spacer in 1993 and it has a full 20 year warranty against seal failure. But, once again there is seal failure only if there is moisture between the lites, inside the airspace, and not on the surface where you can wipe it off.

The casement in the next picture is also a vinyl window with an IG. Probably dual pane, but maybe it could be a narrow triple IG? Probably not, but I am not 100% certain. Once again it appears to be condensation on the interior surface of the glass where it can be wiped off versus between the lites. If it is on the surface and not between the lites the IG seal is fine, but there are other issues involved.

The last picture is a vinyl window with a dual pane IG and an aluminum spacer.

XSleeper, your thoughts?

What concerns me in your pics is the amount of moisture that you have on the surface of the glass and the amount of mold, mildew, and so on. Based on what I am seeing in your pictures, I am going to suggest that your home is very humid inside, way too much moisture in the air.

If you are getting surface condensation on the inside glass surface of a triple pane, your humidity levels have to be out of sight. Are you running a humidifier and do you have bath fans, kitchen stove fan, any particular sources of moisture in the home?

Based on what I see from your pics, I am leaning towards your first concern has to be the humidity level in your home. If I am seeing the pictures wrong and all that moisture is between the lites, then that is a different kettle of fish.

Last edited by Oberon; 03-11-13 at 12:05 PM.
Old 10-17-13, 06:45 AM
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Sorry I just noticed that I got a reply now.
The moisture is between the panes. I can't wipe it off because it's between the glass.
The first picture is actually a picture of the window with the grill still in. We have awning style windows in the bedrooms in the back of the house, with a fixed/picture window above. They have wooden external grills. I took a picture of the mold on the wooden grill, and the other pictures show the mold that was under the grills, and the mold that was in the windows without grills. Our windows in the front of the house are tall bay windows that awning out side ways, not up and down like the other ones.
I was cleaning the windows every couple months to keep the mold away in the winter, but even all year long the mold grows. We have a hygrometer in the house and have moved it from room to room. Our house is set at 18 or 19 degrees celcius usually. I live in Southwestern Ontario. I will check the humidity level when I get home tonight and will write more.
Thank you for your help!

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