Originally Posted by Ron6519
I don't understand the issue. You have air coming out of the vents and you want to seal what? The vents themselves? Air coming out the sides of the ceiling mounted vents?
From the outside of my house, I can see some hotspots (frost in some areas and not in others) on the roof directly above where the vents are located in the rooms.
I had plenty of insulation installed earlier in the year, so my guess is that the registers have some leaks in them....thus "air coming out of the siddes of the ceiling mounted vents."
With all my insulation, it may be less likely radiant heat getting through, but blown air.
Therefore, I'm considering DIY sealing the registers from the living space using either foil tape or mastic.
Or, hiring a contractor to get into the attic and find all the ceiling penetrations and sealing them.