How Do You Check Fire Door Threshold and Floor Clearance?

How Do You Check Fire Door Threshold and Floor Clearance? A fire door that is catching at the bottom is one of those faults where the obvious answer is often the wrong one. I have seen doors start catching after the floor has been changed, after a threshold has been fitted, after a door has dropped on its hinges and after a seal has changed position. The first job is to find out exactly what is touching what. Start with the contact point Open the door and look at the bottom edge. Then close it slowly. Watch the first point of contact. Is the timber leaf touching the floor? Is the threshold catching it? Is a drop-down seal touching the floor? Is the leaf moving down because the hinge side has changed? Those are different faults even though they can…