Build a Gable Louver Vent

Gable louver vents installed just under the roof line will work wonders to cool your home in the summer and reduce attic mold buildup in winter. While it is simplest to install gable louver vents when your house is being built, you can add them to an older home. Use these directions to build a gable louver vent for your home.

Step 1 - Determine the Size and Shape of the Gable Vent

The easiest shapes of gable vents to build are triangles and rectangles. Measure the space where you want to install the gable louver vent to pick the best shape.

Step 2 - Draw a Plan for Cutting the Lumber or PVC for the Vent

Your building plan for the louver vent must include the following: vent box walls 3/4-inch wide by 2-3/4 inch deep; face trim attached to the vent box, 2-3/4 inches deep; and 2-inch molding for your exterior wall. Louvers should measure 3/4-inch thick by 3-1/2 inches top to bottom. They will tilt at 30 degrees away from vertical, and should overlap the one above by 3/4 inch. Between each louver bottom, the exposed airspace will be no more than 7/8-inch.

Step 3 - Cut the Wall Space to House the Louver Vent

Measure carefully and check all measurements before cutting. Remove the drywall and check for wiring and pipes in the area where you are cutting. If cutting through a wall covered in aluminum siding, mark the cut lines on the interior wall, and cut through the siding. If you are cutting through a brick wall, use a diamond blade saw to cut through the bricks on the outside.

Step 4 - Assemble the Louver Vent

Build the vent box first, to the measurements you noted. Attach the face trim with waterproof glue and galvanized staples at corners and at 6-inch intervals down each side. Cut the louver pieces to the desired size, and affix them at the correct angle and spacing inside the vent box.

Step 5 - Insert the Louver Vent Into the Wall Hole

Apply a bead of silicone caulking to the bottom of the vent on the face trim, and insert the assembled louver vent into the wall. Secure it to the drywall on the inside with glue and galvanized staples.

Step 6 - Attach the Screen Wire and Screen Molding

On the back of the louver vent, attach the screen wire with staples. Fasten the screen molding to the screen wire with staples, and secure it to the drywall surround with waterproof glue.

Step 7 - Seal the Edge of the Louver Vent with Brick or Siding Molding

From the outside of the wall hole, insert the brick or siding molding around the finished gable vent. Seal the outermost edge with silicone caulking.