Capping and
Vapor Barrier Continuity
COMPLETE THE VAPOR BARRIER TO THE WINDOW
   Run a Caulk Bead Down the  Window Frame to Seal the Vapor Barrier 
   to the Rough Opening Framing.  Or use Builders Tape to create Vapor
   Barrier between Wallboard and Window Frame - covering insulated gap.
VAPOR 
BARRIER 
CONTINUITY
Moisture-laden Air
Caulk
Jamb 
Extension
Builders
Tape
Vapor Barrier
NOTE: Vapor Barriers for all climates other than defined 
as "Humid" by ASHRAE (the Coastal Regions of Louisiana, 
S. Carolina, Georgia, and Florida,), Vapor Barriers are 
recommended on the interior, or "warm side" of the 
building wall. 
Window Fitters Guide to Window Installation 
21                ©2022 AWDI, LLC Do not reproduce without permission
NOTE: Illustration is for
reference only.  Actual 
profile of window and 
installation conditions 
may vary.
Vapor Barriers are usually violated when new
windows are installed.
Moisture laden air is allowed into the cavity
between the rough opening framing and the new
window frame. Allowing moisture into the cavity
can cause rot, mold or other degradation of the
installation and lower the thermal performance of
the new window unit.
SAMPLE MANUAL

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