Return to the Old House Forum | Post a Follow-Up

 o
Condensation on Skylight After Insulating...Is This OK

Posted by chipster_2007 (My Page) on
Sun, Nov 6, 11 at 13:56

I just insulated the skylight that is in my cold attic with 1 1/2" of a foam square, foiled on both sides. I thought I had a good tight fit until I took down the foam block today and noticed some condensation on the lower part of the skylight , about 10% of surface area of the glass). It had onlly been up there for 24 hrs. Is this to be expected or is there something else I need to do to resolve this? Thanks


Follow-Up Postings:

 o
RE: Condensation on Skylight After Insulating...Is This OK

Warm air from the attic is hitting the cold skylight. The tighter the attic -to-house interface is and the more insulation, the less likelihood there is for condensation to appear.


 o
RE: Condensation on Skylight After Insulating...Is This OK

So, you are just trying to insulate the skylight for winter?

Why? The attic is in the cold zone, right? If you want additional insulation, it needs to go between the cold zone and the warm zone - eg the attic floor. It really doesn't help to try to insulate a cold attic from the cold outdoors.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Old House Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here