Q: How much space do i need to keep from ceiling to doorway?
A: At least 8"
Q:My door is in thickness of 35 mm,how can i fit it with the existing bolt ?
A:you can use the 5 mm black shim we put in package for roller bolt,then your door will be fit perfectly.
Q:Can i cut my rail to fit my space ?
A: Sure,rail can be cut in any length ,but make sure you were cutting the right length you need
Q:if i got a barn door with 40" width,will this rail suit for me ?
A:Yes ,rail length should be twice of door width