Gable louver vents installed just under the roof line will work wonders to cool your home in the summer and reduce mold buildup in the winter. While it is simpler to install a gable louver vent when your house is being built, you can add them to an older home. If you follow these directions, of course.
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 inches 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 should tilt at 30 degrees away from vertical and overlap each other by 3/4 inch. Between each louver bottom, the exposed airspace should 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-bladed 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 a combination of waterproof glue and galvanized staples placed at the 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 Vinyl Siding
From the outside of the wall hole, insert the brick or vinyl molding around the finished gable vent. Seal the outermost edge with silicone caulking.