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is it a good idea to put foamboard covered with aluminum foil on top of windows in my attic?
(gregtech.eu)
Pretty much the title. It get quite hot here in Europe.
this post was submitted on 10 Aug 2026
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You can buy solar reflective film kits that let light in but reflect out 99% of infrared energy.
But that costs money :,(
Foam core and aluminum foil is free?
I found it the foam in the attic, probably left there by my aunt, and the foil was just there in the kitchen.
It's significantly cheaper than buying a special purpose product.
I mean, comparatively.
Sometimes you want to keep ALL the energy out. The films also act to trap thermal energy in too.
I've personally used superfoil, it keeps all the light energy out. 42°C outside, in a double glazed UK home, and I still didn't need the Aircon until mid afternoon.
Depends on the country. Look for Gila window film. It's expensive, but paid for itself in one summer.
Any link to one of these? Not sure what to look for.