7 mistakes not to make in your bathroom remodel do let your.
Gap under bathroom door for ventilation.
My contractor just hung our fancy dancy un painted solid wood door slabs in my 100 year old house with solid hardwood floors throughout.
If more gap is required it is easier to trim a door than to lengthen it.
I have a problem with the door vents you are passively promoting.
The jumper makes sense in some cases.
There should be plenty of room under the bottom of the bathroom door to allow air to get into the room so the fan has a source from which to pull the air it needs.
Using the link you have provided it has a picture of a french full lite door with a vent that has removed a significant part of the door s base.
And for proper bathroom ventilation your exhaust fan needs to vent outside not into the attic or another area of the house.
If the bathroom vent can t get any air of course it isn t going to work the right way.
My mom has a house with a central return and as you suggest her doors have about a 1 5 gap underneath to allow air to flow.
I like the suggestions for wall ceiling jump ducts etc.
There is an approximately 1 5 gap at the bottom of the doors.
The flow dropped from an unrestricted 150 160 cfm down to under 100 cfm in each room.
However the size of that gap is very unlikely to be greater than 1 2 for any door.
There is a need for an air gap at the bottom for ventilation.
Check your bathroom door.
I think it is too big and think a 1 4 1 2 gap would accommodate any unevenness in our floors and allow us to use area rugs.