How to Replace a Gable Vent

A white gable vent on a brick exterior.
  • 3-5 hours
  • Beginner
  • 150-200
What You'll Need
New gable vent
Building paper
Metal cap flashing
Utility knife
2x4 wood board

A gable vent plays a very important role in regulating heat and airflow into the attic. With time, your gable vent may wear out and need to be replaced. It is very easy to replace a gable vent as long as you have the right tools and materials, as well as the correct guidelines.

Step 1 - Ensure Safety

When replacing your gable vent, your first priority should be safety. Make sure your ladder is firm enough to support you on your way up to the roof. Make sure your roof is completely dry, as a wet roof could cause you to slip and fall. Finally, check for any loose and slippery roof shingles that could potentially cause an accident.

Step 2 - Remove Old Gable Vent

Climb up the ladder to remove the vent. Use the utility knife to scrape off caulk from around the vent. Take out all the nails or screws attaching the vent. Pull the vent and the vent framing from the attic slowly.

Step 3 - Prepare to Install New Vent

vent roof built into an ornate upper level of a house

Clean out the area where the original gable vent was located to remove any dirt and debris. Scrape off any excess caulk from the edges of the area. Take the 2x4 wood board and build a new frame to attach into the vent opening. Install the frame between the gable end and the studs by hammering it in using nails. Leave a clearance of 1/8 inch on all sides of the frame.

Step 4 - Attach Flashing

Take the building paper and attach it around the vent opening to act as flashing. The paper will prevent water from getting into the attic. Make sure the pieces of paper on the upper side of the opening overlap those beneath them. After lining up the paper appropriately, staple it into place. You can also apply caulk underneath the paper to hold it down before stapling it onto the frame.

Take the metal flashing cap and place it on top of the paper flashing at the top side of the vent opening.

Step 5 - Mount the Gable Vent

Apply caulk to the building paper you just attached. Take the new gable vent and apply more caulk under its flange to help attach it firmly to the opening. Lift the vent and fix it in the opening, making sure it fits well at the top, where there is the metal flashing. Use nails to secure the gable vent on the three remaining sides.