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Unheated Porch Ceiling Insulation?

H

hughdint

Member
Joined
Apr 20, 2015
Messages
67
Location
United States
I have an inspector that wants me to insulate the area in the attic above an unheated front porch. He says that the because it is "one attic" that the insulation must be over the entire ceiling to maintain the thermal envelope. The insulation that is currently there covers the heated area but stops short as the ceiling. This is for a home renovation/addition in Atlanta, GA. Logically this sound bogus to me but what can I cite form the code to make my case?
 
The requirement only applies to the heated "ceiling" area the attic terminology is improper...Best I can do quickly

N1102.2 (R402.2) Specific insulation requirements (Prescriptive).
In addition to the requirements of Section
N1102.1, insulation shall meet the specific requirements of
Sections N1102.2.1 through N1102.2.13.
N1102.2.1 (R402.2.1) Ceilings with attic spaces. Where
Section R1102.1.2 would require R-38 insulation in the
ceiling, installing R-30 over 100 percent of the ceiling area
requiring insulation shall be deemed to satisfy the requirement
for R-38 wherever the full height of uncompressed
R-30 insulation extends over the wall top plate at the
eaves. Similarly, where Section R1102.1.2 would require
R-49 insulation in the ceiling, installing R-38 over 100
percent of the ceiling area requiring insulation shall be
deemed to satisfy the requirement for R-49 insulation
wherever the full height of uncompressed R-38 insulation
extends over the wall top plate at the eaves. This reduction
shall not apply to the U-factor alternative approach in Section
R1102.1.4 and the total UA alternative in Section
R1102.1.5.
 
BUILDING THERMAL ENVELOPE. The basement walls,
exterior walls, floor, roof and any other building elements that
enclose conditioned space or provide a boundary between
conditioned space and exempt or unconditioned space.
 
steveray said:
The requirement only applies to the heated "ceiling" area the attic terminology is improper...Best I can do quickly

N1102.2 (R402.2) Specific insulation requirements (Prescriptive).
In addition to the requirements of Section
N1102.1, insulation shall meet the specific requirements of
Sections N1102.2.1 through N1102.2.13.
N1102.2.1 (R402.2.1) Ceilings with attic spaces. Where
Section R1102.1.2 would require R-38 insulation in the
ceiling, installing R-30 over 100 percent of the ceiling area
requiring insulation shall be deemed to satisfy the requirement
for R-38 wherever the full height of uncompressed
R-30 insulation extends over the wall top plate at the
eaves. Similarly, where Section R1102.1.2 would require
R-49 insulation in the ceiling, installing R-38 over 100
percent of the ceiling area requiring insulation shall be
deemed to satisfy the requirement for R-49 insulation
wherever the full height of uncompressed R-38 insulation
extends over the wall top plate at the eaves. This reduction
shall not apply to the U-factor alternative approach in Section
R1102.1.4 and the total UA alternative in Section
R1102.1.5.
Click to expand...
Thank you for your response.
 
steveray said:
BUILDING THERMAL ENVELOPE. The basement walls,
exterior walls, floor, roof and any other building elements that
enclose conditioned space or provide a boundary between
conditioned space and exempt or unconditioned space.
Click to expand...
He may be hung up on the wording that does not say "ceiling" instead says "roof"
 
Is the attic space between the top of the existing ceiling insulation and the bottom of the roof not vented already? if so, I can't see where the issue would be. A vertical barrier to cover the sides of the insulation from wind washing would be required, but not to insulate the porch roof.
 
What I mean to say, is if there is outside air in the attic already, what difference does it make if you add more outside air.
 
The inspector's request makes no sense. Ask for a code section or you may need to go to a more senior level staff member.
 
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