I have a 13 month old house and we have been having trouble with the shower. The builder finally had the tile guys tear out part of the tile and found that the shower pan was damaged.

They are now replacing the fiberglass pan, however, they say it does not to be leveled or cemented/glued in place. Does anyone have any thought either way on this situation. Unfortunately the manufacturers instructions say level it but the builder says it doesn't need to be leveled.