If I use foam insulation on the outside (2") and in the 2 x 6 walls (from 4 – 5"), do I need to fill in the leftover space on the inside with fiberglass or Roxul, or just put the vapor barrier over it leaving 1 – 1 1/2" air space?
Foam insulation in interior walls
insulation
Related Topic
- Worry about condensation on plywood over rigid foam insulation in the attic
- How to apply foam board insulation behind a new recessed shelf in an exterior wall
- How are thermal (fire) barriers installed over foam insulation in a crawlspace
- Install Insulation board in the interior wall with House wrap on the exterior
- Add foam board insulation to the tiny house to increase energy efficiency
- How to add more insulation to the finished attic walls without trapping moisture
Best Answer
The space does not have to be filled but should not be between the two foam layers. The required R value does have to be met. To find your total R value: add the specified ratings for both foams. Why are you putting the vapor barrier on the inside? Is this code compliant where you are?