roof penetration ?

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copper chopper

Senior Member
Location
wisconsin
can anyone point me to an article in the nec that says we have to duct seal all conduits that penatrate roofs, I know its there somewhere but i cant find it..
 

iwire

Moderator
Staff member
Location
Massachusetts
300.7 Raceways Exposed to Different Temperatures.

(A) Sealing.
Where portions of a cable raceway or sleeve
are known to be subjected to different temperatures and where
condensation is known to be a problem, as in cold storage
areas of buildings or where passing from the interior to the
exterior of a building, the raceway or sleeve shall be filled
with an approved material to prevent the circulation of warm
air to a colder section of the raceway or sleeve. An explosionproof
seal shall not be required for this purpose.

(B) Expansion Fittings. Raceways shall be provided with
expansion fittings where necessary to compensate for thermal
expansion and contraction.
 

kwired

Electron manager
Location
NE Nebraska
You are sealing because of different temperatures at each end of the raceway causing condensation and not just because it is penetrating a roof. If it is a typical through the roof service mast and the lower end is still outside the building you don't have to seal that particular raceway.
 
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