# Insulating these basement windows



## gregzoll

All I did for my single pane leaky basement casement windows, was place Foil faced foam board over them, with the foil facing towards the outside, then caulked around the boards to hold them in. They have worked very well for the past two years, that I have had the windows sealed that way.


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## Windows on Wash

+1 to Greg's feedback.

If you don't need them, put rigid foam over theme.


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## ffemt121

Ok where should I put the rigid foam? Against the widow? They are louvered windows, so they don't close tight, but never seem to get rain in them, but I am worried about the possibility of snow piling up and being able to melt into them


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## gregzoll

See that first picture? You fit them as I stated, to fit over the windows, inside that pocket. If you think that the foam will stay there, if you just place against the wood paneling, it will just fall off, after you even caulked them.


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## gregzoll

The plus side is, it got rid of the scrap that I had laying around, after I sealed over the window in our Bath, before putting the Green board over it, when we remodeled our bath.


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## ffemt121

As I'm a new home owner, I don't have any foamboard laying around, but for 40 bucks or whatever a sheet, I'm sure I can find quite a few uses and maybe still have some spare


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## gregzoll

Sheets are not $40. Where ever you got that idea, who knows. No one ever stated that you had some laying around. I just gave you an idea that works.


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## ffemt121

I was looking at them at Home Depot the other day, uh oh, maybe I was looking at the wrong thing. Can you give me the name of what I looking for or a picture of it or something?


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## ffemt121

Greg,

Am I looking for something called Thermasheath Foam Insulating Sheathing? Also should I go for the highest R value they have or would that cause some sort of breathability problem?
Thanks,
Dean


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## Windows on Wash

R-Value has no impact on the permeability ratings. The thickness can change the perm ratings but most often, the facers are what cause dramatic shifts in the permeability ratings.

I think you are in danger of over thinking it a bit. Going over an R-10 is going to make that small area far more insulated than any other wall in the home at that point.

Get some 1" foam and cut it to fit. If you used the foil faced foams, facing it in towards the home and making it air tight would eliminate any relative humidity migration to the cold frame and stop wintertime sweating of the frame (assuming the moisture was coming from the air and not the concrete).


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## ffemt121

Wow Windows, you just blew my mind...that got way over my comprehension level. Let me try to dumb it down for me. 1" thick foam, cut it to fit. No need for the foil backed foam or making it entirely sealed. Is that what I should have gotten from that? Or did I go astray somewhere


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## Windows on Wash

I do like the foil faced foam as it help control moisture migration and is safer to be left exposed. Put the foil side to the interior of the home.

Cut it to fit and if you know you are going to replace the windows in the future, feel free to caulk it in place or tape it off with some masking take at a minimum.


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## ffemt121

Got it, funny you should mention replacing them, i was just watching you tube videos about how to do that. Doesn't look too difficult, measuring correctly seems the hardest part


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## Windows on Wash

Decent DIY'er and a sawzall can get it done.

That might be the best of both in this case.


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