How to Attach Air Vents and Screens in a Masonry Foundation

Traditional Metal-Foundation Vents and Screens

• 1

  Dry-fit the foundation vent and screen into the opening of the masonry foundation. Remove any small chunks of mortar that prevent the vent from installing properly, with a cold chisel and hammer.

• 2

  Combine quick-setting concrete mix and water in a bucket according to the directions on the bag of concrete. Use the smallest measurements on the bag, as you only need a little mortar to attach the vent screen.

• 3

  Insert the foundation vent and screen into the opening. Pack mortar around the outside edges of the foundation vent flange with a trowel, overlapping the masonry opening by a half inch. Smooth out the mortar evenly on all four sides with the trowel.

• 4

  Allow the mortar to cure for 24 hours before operating the foundation vent and screen.

Replacement Plastic-Foundation Vents and Screens

• 5

  Ensure the vent opening is free of debris. Remove any chunks of previous mortar with a cold chisel and hammer.

• 6

  Check the sides of the replacement vent for holes that accept a hex nut. There are usually two on each of the end sides.

• 7

  Place a nut into the hole, and thread a machine screw from the vent side through the nut, until the end of the screw threads are flush with the nut. Repeat for the remaining slots.

• 8

  Insert the barbed pins through the top and bottom holes of the vent.

• 9

  Push the insert into the masonry opening. The barbed pins grab the masonry at the top and bottom. Turn the screws clockwise with a Phillips screwdriver to secure the vent in place.