Expansion fittings

[olly]

I am running 3/4 PVC indoors that goes under a 4" concrete floor, it is in contact with the earth and then back up through the concrete floor to j-boxes. (ALL INDOORS) Do I need an expansion coupling in between the box and floor? There will never be a 100 degree temp swing.

This place sits on bed rock on the top of a mountain, it won't be moving.

 

[jaylectricity]

Use the table to calculate the actual movement. There is a column for whatever degree temperature swing. Choose the one you find applicable.