Is it the intent of the Code to allow drywall
joint compound to be used as a "sealant" between
the ceiling gypsum board and the top plate?
Interpretation #6608
Published September 01, 2010
Original Request
- Code Version
- 2007
- Code
- BUILDING
- Code Description
- Chapter
- 13
- Section
- 606.AB.1.2.3
- Topic
Question
Answer Published 09/01/2010 at 6:48 PM
13-606.ABC.1.2.3 Ceilings requires specific location for
application of sealants. Please note this is in the
Residential section of the energy code. The term "sealed"
is not clearly defined in the Energy Code. If done
properly, the sheetrock applied to the roof truss system
would have a sealant applied at each wall intersection. The
local Building Official, generally through the plans
examiner by way of plan review and sign off, must approve
of the methos of sealing as required in the section. The
same requitrement exists in FBC-R Section N1106.AB.1.2.3
without a definition of sealed.
application of sealants. Please note this is in the
Residential section of the energy code. The term "sealed"
is not clearly defined in the Energy Code. If done
properly, the sheetrock applied to the roof truss system
would have a sealant applied at each wall intersection. The
local Building Official, generally through the plans
examiner by way of plan review and sign off, must approve
of the methos of sealing as required in the section. The
same requitrement exists in FBC-R Section N1106.AB.1.2.3
without a definition of sealed.
Commentary
This installation would prevent air infiltration from the
attic into the wall cavity. Then the wallboard would be
installed. The taping and "mudding" of the ceiling and
wallboards generally meets the requirement. The exact
materials used to accomplish the primarly seal is up to
the "approval" of the designer and local Building Official.
The process should be as specified on the plans. Another
alternative is to install an approved air barrier at the
ceiling plane and all penetration of the air barrier shall
be made in accordance with the air barrier manufacturer.
However, even the air barrier requires a sealant at the
exterior walls. Sec. N1106.AB.1.2 , Exterior joints or
openings in the envelope, specifies that "Exterior joints,
cracks or openings in the building envelope that are
sources of air leakage shall be caulked, gasketed,
weaterstripped or otherwise sealed in accordance with the
criteria in Sec. N1106.AB.1.2.1 through N1106.AB.1.2.5."