Insulating over double bubble insulation?

[tom-ky]

Is there any harm in insulation over the double bubble reflective insulation when enclosing a room? If it is ok should faced or un-faced insulation be used when do it over the double bubble?

 

[DC73]

The double bubble is going to act as a vapor barrier. If you need a vapor barrier and the double bubble is in the correct location for your climate, you can probably insulate over it but you sure wouldn't need a second vapor retarder which is what you'll get with faced insulation. I'd run this by some experts. There are building science gurus who hang out on the Q&A forum at GreenBuildingAdvisor. I recommend you check with them. I won't be surprised if they recommend you take the double bubble out.

DC