# Emt conduit on roof



## Gary1 (Dec 19, 2013)

Question I have (5) runs of parallel 3" EMT Conduits Each with (2) Sets of 400Kcm Alum & (1) #350 Gr Alum the run is 535 then 90Deg 35' for a total of 570' this run uses Cooper B-line Dura-Blocks for support on the roof at 8' apart 6" off of roof 3 x 3 x 12 on each end, My Inspector is requesting Expansion Couplings, I have never heard of this on a roof and what would be the Calculation for this , the area is Ontario, Ca Max ASHRAE for this area is 98Deg F (2% Wet Bulb Summer , Can not find Winter ? Need Help Don't understand why the expansion couplings run is 530 one direction then turns 90deg 33' to a pull box,m is he correct or not?


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## BBQ (Nov 16, 2010)

Here or at Holts the answer is the same.

The NEC does not require expansion fittings in EMT.

Job specifications might if these EMTs cross a building expansion joint.


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## Celtic (Nov 19, 2007)

Gary said:


> Question I have (5) runs of parallel 3" EMT Conduits .... on the roof
> ....My Inspector is requesting Expansion Couplings



Request denied!


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