How to Replace a Crawl Space Vent
- 1). Remove the mortar that holds the vents in place. Use a hammer, masonry chisel and pry bar as necessary. Wear safety glasses and gloves. Clean up your edges.
- 2). Measure your vent opening using a tape measure. Make sure that the faceplate of the vent that you purchase overlaps the opening on all sides by at least 1/4 inch. Prefit your vent to make sure that it fits flush to your foundation.
- 3). Apply a thick bead of silicone along the back of the faceplate, and press the silicone into your foundation masonry. Make sure that the faceplate overlaps the opening on all sides and is straight and level.
- 4). Thread a lock nut onto one threaded rod so that 3/4 inch of thread remains. Do this with both threaded rods.
- 5). Pick up a threaded rod with the lock nut toward you. Reach inside the faceplate and locate a hole in the faceplate. Thread the nut and screw it toward you until the lock nut rests against the faceplate. Use a 7/16-inch wrench to tighten. Repeat on the other side with the second rod. You should have 5/8 inch of thread visible.
- 6). Pick up the backer bar. Reach through the faceplate opening into the crawl space. Slide the backer bar so that it spans the masonry width of the vent opening from the back side. Slide the threaded rod through the backer bar, and use a wing nut. Do this with both rods, and tighten the wing nuts so that there is pressure pulling the faceplate into the silicone.
- 7). Place your screen door insert or winter door insert in place over the threaded ends, and use a knurled nut to hold it on.