How to fix gap at the bottom of a door after installing new door bottom

Question

Last season I picked up these vinyl slide-on door bottoms that you slide onto the bottom of the door and screw in. They worked great on all of my doors except this one that has about a half inch of space between the door bottom and the threshold.

Here you can see that a children's book fits under the door:

I would like to fix this problem without purchasing a new door. It looks like the door is possibly not tall enough?

Answer 1

Either replace the vinyl slide on bottom with a brass one that is taller, or

• unhang the door by taking it off of its hinges.
• Put a 1/2" strip of wood on the bottom (glue works nicely)
• Repaint the door
• Install the door bottom
• Re-hang the door

Answer 2

Or get a sweep with larger "brushes"; for wide gaps I favor something like (They're available in both kerf-mounted and screw-on styles.)

Answer 3

If installing longer sweeps won't work consider these alternatives: 1) install an appropriate sized threshold to fill the space or 2) nail a filler strip to the door bottom that is sized to the gap and than install the door bottom.