The great thing about all of the different types of terrain available for our hobby is that we can create a different environment every time we play. But this can sometimes cause confusion with some players who may be used to the typical flocked tree and cereal box buildings. Nothing against the basic terrain items but the same rules of thumb applies to all types of terrain.
First make sure you and your opponent understand the terrain and rules that can apply to the pieces before playing.
If your playing a scenario or tournament game make sure to check the rules and/or cross reference any concerns with the TO before you begin.
Unfortunately if you can't resolve a problem with a piece of terrain with your opponent role a die and call odd or even to resolve an issue. Keep the game going.
Remember this is a game with a cool pieces of terrain on a table. Don't let the semantics of a piece ruin you hobby time.
I've had some question about how to play super-heavy walkers around the Pipe Works terrain. Fortunately Dr. Todd has a Imperial Knight army that he likes to run through the pipe works terrain like a jungle gym.
We've been having Super Heavy walkers simply ignore the ground level pipe works and not benefiting from any cover as well. Monstrous creatures can ignore any movement restrictions put can gain a cover save depending on the model size.
Level 2 pipe works definitely slow the super heavy walkers down. We've been having knight roll for difficult terrain to cross the taller pipe section. The models can also get a 5+ cover save for within 1" of the pipes. The same applies for monstrous creatures unless the model can comfortably fit under the level 2 pipes.
Remember these are just guidelines for you to use if needed. Use and play the terrain to your systems rules or groups style of play..