Interpretation #7075

Published September 27, 2012

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Original Request

Code Version
2010
Code
RESIDENT
Code Description
Residential
Chapter
11
Section
402.4.1
Topic
Air Barriers

Question

Is it the intent of the statement "The following shall be caulked, gasketed, weatherstripped or otherwise sealed with an air barrier material, suitable film or solid material." Does use of the word "or" before otherwise provide an exception that if a housewrap that qualifies as an air infiltration barrier is on the outside of an exterior wall that no air infiltration barriers are required on the inside or elsewhere?

Answer Published 09/27/2012 at 4:28 PM

House wraps may serve as a building envelope air barrier in
accordance with the definition of Air Barrier. The
configuration of the conditioned and unconditioned spaces
within the building may require additional air barriers.
The definition contains a maximum air leakage rate that
must be met by the house wrap.

Commentary

Table 402.4.2 provides a list of required inspections in order to comply with the visual inspection option of 402.4.2.2. In this Table it stipulates that the area behind the tub/shower shall have an air barrier between the exterior wall (with insulation)and the tub/shower. Additionally, it requires that electrical boxes on exterior walls be installed inside the air barrier or be air sealed type boxes.