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Community and Q&A

Can I insulate my skylights? Zone 5A, CT

Jennifer M | Posted in General Questions on

My small ranch home has two skylights in the kitchen.  The black tile floors are wonderful in combination with the sun that pours in from these windows in the winter; in the summer, we fry.  May I (for a cheap fix until the end of Covid-19) place a couple of Roxul Safe and Sound batts under the windows to block the heat?  Is there another diy alternative?  Any advice for a permanent fix?

Thank you!

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  1. GBA Editor
    Brian Pontolilo | | #1

    Hi Jennifer.

    I'm not sure that you need insulation, you may just need to block the light. Heat transfer through space is called radiation. In other words, when the sun shines through your skylights, it warms interior surfaces like your black tile floor and the space gets hot. I have no experience with their effectiveness, but there are shades available for skylights. Maybe another GBA member has tried them and can point you toward a specific product.

    1. Jennifer M | | #2

      Thanks, Brian! I think it will be a good plan to use the shades in the future, but I am hoping for something I can do now with items around the house (CT is still on lockdown). I do have blackout curtain liners - maybe I can pin those up this weekend.

  2. ThirtyWest | | #3

    how about just some news paper or printer paper? I bet that would work fine as a temporary fix. roxul is a good product but it is messy.

  3. Expert Member
    Zephyr7 | | #4

    I wouldn’t use mineral wool here because it will make dust when you take it in and out. Use some think foil faced polyiso instead. The shiny foil facer will reflect out sunlight, which is where most of the heat is coming from, and the insulation value of the polyiso will help block what is left. Depending on the size of the skylight, you’ll probably want to use somewhere in the 1/2” to 1” range, with the extra thickness for structural strength more than insulating value.

    Don’t use these insulating panels in the winter though or you’ll have condensation issues.


  4. Walter Ahlgrim | | #5

    I do not think you need insulation you need to block the suns rays.
    If you are willing to get on the roof to put them up and down exterior shades would work the best.
    On the interior cellular shades would work well.

    1. Jennifer M | | #6

      Thanks, Walter! The website links are very helpful.

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