How to Make a Door More Airtight if It's Too Short

If a door is too short, you will lose precious heating and cooling resources through the crack at the bottom -- driving up your energy costs. A piece of heavy material wadded up at the threshold may help to keep the drafts out, but this needs to be replaced each time the door is used. An easier way to solve this problem is to raise the threshold so it comes up to meet the bottom of the door. If the gap is too large for this method to solve the problem, you will have to replace the threshold with a higher one.

Screwdriver
Claw hammer (optional)
Rags
Household cleaner
Aluminum threshold with vinyl weatherstripping

Instructions

- 1
  Loosen the screws that are holding the existing threshold down. Pry up the threshold with a flat-head screwdriver until it reaches its highest level. Close the door to examine the gap between the bottom of the door and the threshold. If a gap still exists, replace the threshold with an energy-efficient aluminum threshold that contains a weatherstripping.
- 2
  Loosen the screws on the threshold and remove them. Use a flat-head screwdriver to pry up the threshold. If you have a wooden threshold, use a small pry bar, or a claw hammer, to remove the nails or to pry up the threshold itself.
- 3
  Clean the door sill with a rag, water and household cleaner to remove all dirt and debris that may have accumulated. Inspect the sill. If it's worn or damaged, you will need to replace it. Allow the sill to dry before installing a new threshold.
- 4
  Lay a new, energy-efficient threshold on the sill. Lift up the vinyl weatherstripping, where you will find the holes for the screws. Install the screws, then lay the weatherstripping back down.
- 5
  Test the door and check the fit at the bottom. A gap of one-eighth inch is acceptable. If the threshold is too high, adjust the screws so it will sit lower on the sill.

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