EMT passing through building expansion joint

[NEC User]

The DCA inspector made a comment today that the electrical conduits passing through the building’s expansion joint require expansion couplings.
Is this required for EMT passing through the expansion joint? Per my understanding, EMT doesn’t require expansion couplings. The NEC doesn’t implicitly indicate the use of couplings as it does in other conduit type sections e.g. PVC has a sub-section titled 352.44 Expansion Fittings. Also, the coefficient of expansion for EMT conduit is not significant in areas where we don’t have sun exposure like the roof.

I'm considering telling the contractor to install a foot of flex conduit to transition across any joint.

 

[jumper]

300.4(H) Structural Joints.
A listed expansion/deflection fitting
or other approved means shall be used where a raceway
crosses a structural joint intended for expansion, contrac-
tion or deflection, used in buildings, bridges, parking ga-
rages, or other structures.

 

[ADub]

300.4(H) Structural Joints.
A listed expansion/deflection fitting
or other approved means shall be used where a raceway
crosses a structural joint intended for expansion, contrac-
tion or deflection, used in buildings, bridges, parking ga-
rages, or other structures.

Wouldn't every seam in a tip up wall structure count as a structural joint intended for expansion and contraction?


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[jumper]

Wouldn't every seam in a tip up wall structure count as a structural joint intended for expansion and contraction?


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No clue, never worked in a building using that type of construction.

 

[GoldDigger]

300.4(H) Structural Joints.
A listed expansion/deflection fitting
or other approved means shall be used where a raceway
crosses a structural joint intended for expansion, contrac-
tion or deflection, used in buildings, bridges, parking ga-
rages, or other structures.

I'm considering telling the contractor to install a foot of flex conduit to transition across any joint.

IMHO a foot of flex is not a listed expansion/deflection fitting, so the OP had better line up "approval" from the AHJ in advance

 

[jumper]

IMHO a foot of flex is not a listed expansion/deflection fitting, so the OP had better line up "approval" from the AHJ in advance

That and the flex is gonna look like dog doo doo.

 

[ADub]

No clue, never worked in a building using that type of construction.

Well it's a pretty common building method, by the letter of the code you couldn't run pipe horizontally along the seams without expansion provisions every 8' which is just ridiculous


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[GoldDigger]

Wouldn't every seam in a tip up wall structure count as a structural joint intended for expansion and contraction?


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Is there an expansion joint in any wall finish which bridges the gap between tip up sections?
If not, I would say that any expansion which might occur is incidental and not the purpose of the joint.

 

[ADub]

Is there an expansion joint in any wall finish which bridges the gap between tip up sections?
If not, I would say that any expansion which might occur is incidental and not the purpose of the joint.

There is about a 3/4 gap between sections that is filled with backer rod and then caulked. I know for a fact these wall sections move slightly but we don't consider it when install conduits because its inconsequential


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[kwired]

The DCA inspector made a comment today that the electrical conduits passing through the building’s expansion joint require expansion couplings.
Is this required for EMT passing through the expansion joint? Per my understanding, EMT doesn’t require expansion couplings. The NEC doesn’t implicitly indicate the use of couplings as it does in other conduit type sections e.g. PVC has a sub-section titled 352.44 Expansion Fittings. Also, the coefficient of expansion for EMT conduit is not significant in areas where we don’t have sun exposure like the roof.

I'm considering telling the contractor to install a foot of flex conduit to transition across any joint.

The PVC issue is to protect the PVC itself from it's own thermal expansion/contraction.

A building/structure expansion joint is put in place because they expect expansion/contraction of the building, and that joint is where they are allowing for movement. If you bridge across that joint with something that can't move with each side of the building it will strain the object you are bridging it with when the separate building parts do move.

 

[Fulthrotl]

The DCA inspector made a comment today that the electrical conduits passing through the building’s expansion joint require expansion couplings.
Is this required for EMT passing through the expansion joint? Per my understanding, EMT doesn’t require expansion couplings. The NEC doesn’t implicitly indicate the use of couplings as it does in other conduit type sections e.g. PVC has a sub-section titled 352.44 Expansion Fittings. Also, the coefficient of expansion for EMT conduit is not significant in areas where we don’t have sun exposure like the roof.

I'm considering telling the contractor to install a foot of flex conduit to transition across any joint.

if it's a designed expansion or movement area in a structure, then any non flexible raceway would require
expansion joints where it crosses.

http://www.cooperindustries.com/con...-emt_series_conduitexpansionjointsforemt.html

cooper makes them.

[h=1]XJG EMT Series Conduit Expansion Joints for EMT[/h]