I have the hardest time getting pictures to post.... Trying to post a picture of forms.

Find the manufacturer's instructions and show it to the plumbing and concrete subs.

When you are dealing with a slab, you have to know what pans you want and how the drain configuration is done - otherwise - they will simply block out the shower area and not pour anything - which is an option - then they can set the pan when it's selected and plumb accordingly. All they need to have is a rough idea on what end it's going to drain and put in a trap, etc.

The linear drains I have see are really just linear "on the top" and they they slope and drain under the grate / cover into a center or offset round drain hole - so they are not all that different than a regular drain - other than the placement on the edge vs the middle.

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