How to Install Soffit Vents Properly

Grab a flashlight and go into the attic. Find the area in the attic that's located between two vertically aligned rafters near an existing roof vent. Inspect the area to make sure rafters and soffit joints will not block a new soffit vent. Drill a hole in the center of the area you found and place a wire hanger through that hole so that it will show on the outside. Perform this step for each vent location.

Make a template out of a piece of material such as a cardboard box that's an inch smaller than the width and length of the original soffit vent so that you'll have a mounting surface for the new vent. Cut out the template using a utility knife. Puncture a hole in the center of the template.

Position a ladder directly below your placement for the first soffit vent. Place the center of the template over the center of the drilled hole you made in the attic. Check to see if the edges on the template have adequate spacing or distance on all sides. Trace the template's design on the soffit (the area underneath the roof edge) using a marker. Drill a hole in each corner of the outline you made.

Place your reciprocating saw in one of those holes and cut from one hole to the next hole until the cutting is complete. Place the center of the vent over the center of the opening you made and hold it in place until you secure it with the screws provided in the package. Perform Steps 3 and 4 repeatedly until the installation is complete for all vents. Now, head back into the attic.

Grab a flashlight and a quarter-cup of water. In the attic, get close to a roof vent. Dip a fingertip into the water and stick it up close to the roof vent. If your finger starts to feel cold or cool, you have proper ventilation; if it doesn't feel cold or cool, you will need to add more soffit vents or add a different type of vent, such as a ridge vent.