How to Install Door Flashing

  • 1-3 hours
  • Intermediate
  • 50-100
What You'll Need
Peel and stick flashing
Sharp scissors
Spray bottle with cleaning material
Dry cloth
Tape measure
Masking tape

Door flashing is important if you want to protect your walls from rot, pests, mold and other weather-related issues. Door flashing can also help to create lower utility bills since you won’t have an exchange of air flowing through the doors. Installing door flashing isn’t a difficult process, and most people can accomplish this on their own in just a few hours. Here’s what you need to do.

Step 1 - Remove Old Flashing

Before you can install flashing you will need to remove any old flashing that’s in place. Depending on what type of flashing and how it was installed the method to remove it will vary.

Step 2 - Cut the Wrap

You will need to cut the house wrap. This needs to be done at the header with a 45 degree angle. This will create a flap. Use masking tape to temporarily place the flap out of the way.

Step 3 - Apply the Flashing

With the wrap out of the way you can begin to work on the door flashing. First you want to use the cleaning solution to clean around where the flashing will be installed. This will allow the sticky side of the flashing to adhere better. Make sure it’s completely dry before you start to attach the flashing. You will want to lap the flashing on the door jambs.

Follow the directions provided by the manufacturer for installing in in the rough opening of the door.

You will want to use the self-stick flash on the side jambs next. The flashing will need to overlap the edges of the sill and go down past it by at least one inch. Make sure it extends past the head by at least two.

Step 4 - Drip Edges

Install a drip edge that extends at least two inches on each side of the door. You will want to tuck this under the house wrap flap that you made in step 2. Doing this will prevent any water from damaging the heading of the door because it will just run away from the heading.

Step 5- Install Flashing at Header

Use the peel and stick flashing at the door header now. This needs to overlap the drip edge and the house wrap. The flashing in this area should be extended at least an inch beyond the jambs.

Step 6- Finishing Touches

You can now fold the wrap flap back over. Tape this down so that the material will overlap the flashing at the header.

And now you’re done. You can stand back and enjoy the fact that with a few simple steps and cheap material you’ve secured your door, walls and entryway against weather-related problems.