Check the UBC interprative manual, you will see how the code authority
interpret the ventilation for such attic system. See page 257 of the
Handbook to the uniform building code diagram "C".
Samir Ghosn, P.E.
Harris & Associates
At 06:37 PM 3/7/2001 -0500, you wrote:
>The UBC specifies that attic ventilation is required "where determined
>necessary by the building official". I'm trying to determine which
>cities, counties, etc. would require ventilation for a roof with an
>enclosed rafter design using 2x12 solid rafters, with ceiling board
>applied directly to the underside of rafters. The ceiling board would
>have a vapor barrier not exceeding 1 perm installed on the warm side.
>Any information regarding what jurisdictions either require or do not
>require attic ventilation for this type of design would be appreciated.