Interpretation #7998
Published September 27, 2017
Original Request
- Code Version
- 2014
- Code
- ENERGY
- Code Description
- Chapter
- 4
- Section
- Residential
- Topic
- Minimum Required Insulation R Value for R405 Performance Method
Question
Is the minimum roof/ceiling insulation r-value an R-30 or R-38 for the Performance Method R405 based on section R405.2?
Answer Published 09/27/2017 at 8:22 AM
Neither. R405.2.1 requires a minimum insulation level for ceilings of at least R-19 and in cases where there is insufficient space for R-19 insulation, R-10. The provisions of R402 requiring R-30 or R-38 ceiling insulation are not mandatory but prescriptive requirements.
Commentary
None