Sealing casement windows

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Billbill84

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IMG_8947.PNG IMG_8948.PNG IMG_8949.PNG IMG_8950.PNG 1) Ok every casement window in my house has that dark discoloration on the bottom corners of all the sashes! Why does this happen?
2) some windows have rotted sashes on bottom of sash, could this be from poor seal?
3) What's the best way to seal the wood? Is there a polyurethane used for windows?
 
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My thought is condensation. Clean them up good sand them and use some good water based poly. If some are rotted they may need a bigger repair or replaced in whole or part.
 
My thought is condensation. Clean them up good sand them and use some good water based poly. If some are rotted they may need a bigger repair or replaced in whole or part.
Condensation? What makes you say that? i hadn't noticed any condensation on any windows this past winter but then again I didn't really look I was too busy on other projects. So far this summer I know definitely there has not been any condensation on windows. I'll look closer. What time of year is window condensation typical or is it just based off temp difference in vs out? Thx
 
It’s a guess. From your pics it looks like the bottom piece and the top surface next to the glass. If the sash is rotting from the bottom up I would say water is getting below weeping holes plugged etc.


It doesn’t take much moisture to cause the black mold to start and many times it is moisture cycling between wet/dry that does damage. Like watering a garden.


Without being there all we can do is offer some guesses sometime. No one replied to your question for 10 days so I hopefully gave it a bump if nothing else.
 
Condensation is the most likely cause. Deep jambs and /or high moisture levels (50% plus relative humidity) will result in condensation in lower corners of windows. Best to lower interior humidity to less than 45% in winter time or allow more circulation near windows, heavy insulated drapes or close drapes with no circulation will exacerbate the problem.
 
It’s a guess. From your pics it looks like the bottom piece and the top surface next to the glass. If the sash is rotting from the bottom up I would say water is getting below weeping holes plugged etc.


It doesn’t take much moisture to cause the black mold to start and many times it is moisture cycling between wet/dry that does damage. Like watering a garden.


Without being there all we can do is offer some guesses sometime. No one replied to your question for 10 days so I hopefully gave it a bump if nothing else.
Thank you for this! I think you are correct on a condensation issue!
 
heavy insulated drapes or close drapes with no circulation will exacerbate the problem.
Yes!!! The previous owner was an older woman so, heavy drapery was there! She had extremely thick and ugly drapes over every window they were so gawdy and heavy! Heavier than a burning jacket if you are familiar with that they're thick. Should note that I removed all them drapes and hopefully it will dry things up a bit before I seal stuff. Thanks for pointing that out!! It helps with understanding possible root cause for a better corrective action! Thx!
 

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