Interpretation #6567

Published June 25, 2010

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Original Request

Code Version
2007
Code
BUILDING
Code Description
Building
Chapter
13
Section
13-404.AB.2
Topic
Insulation

Question

Is it the intent of Florida Building Code - Building Section 13-404.AB.2 to require R-19 insulation in a building with exposed ductwork and no ceiling?

Answer Published 06/25/2010 at 7:58 AM

No. Because there is no ceiling, there is no plenum or
ceiling cavity. Assuming that the space is not to be vented
to the building exterior, both the thermal envelope and the
pressure envelope are at the roof level. The R-19 requirement
only applies to roofs above plenums.

Commentary

The minimum roof R-value shall be not less than R-10 for commercial buildings, R-19 for multi-family residential buildings or as determined by the Method A performance calculation.