expansion joint

Not a plumber. Homeowner/DIYer doing research. I'm looking at digging a trench for a sewer line for a garage and connecting it to main sewer line in my house. There's a part of the Minnesota plumbing code that I'm a bit confused about. I'm trying to figure out what they mean by "expansion...

I'm installing a freestanding tub in my basement (on a concrete slab). The tub comes with an ABS expansion joint in order to drop the tub down and connect to the trap and also has clearance for an above floor rough in. In the spot that I want the bathtub to be, I can't use a traditional waste...