How to Add a Vent to a Cement Tile Roof

Set an extension ladder against the side of the house and then climb up the ladder onto the roof.

Use a stud finder to locate a pair of rafters beneath the roof with a cement tile set between them. Remove the tile from between the rafters by pulling it away from the roof surface by hand. If you cannot pull the tile by hand, use a small pry bar to help you wedge the tile from the surface before pulling it off. Clear just enough space to place a hole the size of the throat of the vent through the roof.

Place the vent onto the roof by sliding the top of the vent base beneath the row of tiles above the cleared space, and leaving the bottom of the vent base over the row of tiles beneath the cleared space. Mark the location of the vent hole onto the roof with a pencil. Set the vent base aside.

Cut through the roofing felt along the penciled circle with a utility knife and then pull the felt away.

Cut through the exposed roof sheathing with a saber saw, following the outline circle on the roof created with the felt removal. Remove the piece of sheathing material.

Place a layer of plastic roof cement onto the bottom of the vent base with a trowel. Slide the base back into place, slipping the flashing on the base beneath the row of tiles above.

Nail the vent base into place through the flashing and into the roof sheathing using 1-1/2-inch galvanized roofing nails and a hammer. Space the nails about every 4 inches around the perimeter of the base.

Contour the edges of the base flashing not under the top row of shingles onto the shingles to either side and running along the bottom of the base. Press down firmly on the flashing edges to bend them to the same shape as the surrounding tiles.

Cover the heads of the nails with plastic cement to seal the holes created. This should prevent water from seeping in through the nailed area.

Place a carpenter’s level across the top of the vent base if you’re using a two-part vent with a rotating turbine hood. Twist the body of the vent along the adjustment grooves running in a circle around the base of the vent body, and running in a descending spiral from the top of the vent body to the base. As you twist the body of the vent, the angle along the top of the vent base changes. Twisting the vent along the lower groove changes the angle in two directions, while twisting the groove running down the sides of the vent body changes the angle of the top of the vent in the other two directions. Twist the body until you have an angle that shows as level in the carpenter’s level. Remove the level.

Place the locking mechanism through the small slot on the interior of the vent. The mechanism is a small bar that extends through the vent and has a hole in the top that you can place a screw through from the exterior of the vent body to hold the lock in place. Secure the mechanism in place with the screw. This will ensure that the vent does not vibrate into an unlevel position.

Apply caulk to the adjustment grooves on the interior of the vent to seal the groove joint.

Set the hood over the top of the vent, aligning the mounting holes on the base of the hood with those on the top of the vent throat. Drive screws through each of the mounting holes to hold the hood in place.