How to Install Automatic Foundation Vents in a House With Siding

Remove the existing vent, using a flat pry bar or screwdriver, as appropriate. Measure the height and width of the vent opening in the foundation wall. Most vents are designed to fit a standard 8-by-16-inch opening. Confirm that the new automatic vent is the right size for your vent opening.

Clean all dust and debris from the vent opening. Prepare the new vent by installing the retaining clips, springs, or other fasteners that come with the vent assembly, inserting the clips into the left and right center slots and one on the bottom of the vent unit. Insert the barbed end into the vent slots behind the vent cover, with the barb facing out.

Press the flanged hex nuts or other fasteners that come with the assembly into the outside openings on the vent cover, through the two holes on each side. If necessary, use a tack hammer to tap the hex nuts into the holes to seat them completely. Screw the accompanying setscrew through each hex nut from the inside of the vent with a manual screwdriver. Allow these screws to penetrate the hex nut but not extend outside the vent cover.

Compress the clips or springs on the vent with your hands while sliding it into the vent opening from the exterior of the foundation. Push the vent as tightly as possible against the opening so it is flush with the foundation. Starting in the top corner, screw in the setscrew a half turn before moving around the vent cover to the next set screw, until all screws have been turned. Repeat until the screws are snug, but not tight.