How to Use Screen Mesh to Guard Attic Vents Against Animal Pests

Mesh screen over an attic vent

The Spruce / Sarah Lee

Project Overview
  • Working Time: 30 mins - 1 hr
  • Total Time: 30 mins - 1 hr
  • Yield: One vent hole
  • Skill Level: Beginner
  • Estimated Cost: $5 to $10

It is said that small rodents, including mice and rats, can fit through a hole the size of a nickel. Even larger rodents, such as squirrels, can fit through surprisingly small gaps. These animal contortionists can easily fit through any unprotected ventilation holes in your roof eaves. Although many homeowners are not even aware that such holes exist, they are essential for attic ventilation, so you can't just cover them with wood. And even if you do, it may not repel rodents, bats, and birds, many of which can easily chew through wood.

The answer is to cover the holes with a type of metal mesh called hardware cloth. hardware cloth is fairly rigid mesh with heavy-gauge wire that is not easily damaged by animals. This will keep out pests without restricting airflow through the vent holes. Buy hardware cloth with 1/8-inch or 1/4-inch openings. Hardware cloth also comes in 1/2-inch mesh, but that is too large for barring rodents. Do not purchase chicken wire (sometimes called poultry netting), which has very thin, flexible wire with large gaps.

What You'll Need

Equipment / Tools

  • Tape measure
  • Flashlight
  • Extension ladder
  • Aviation shears or tin snips
  • Heavy work gloves
  • Hammer

Materials

  • Galvanized hardware cloth, 1/8 or 1/4-inch mesh
  • Galvanized roofing nails

Instructions

Materials needed to use screening to repel vermin in the attic

The Spruce / Sarah Lee

  1. Inspect the Holes

    Set up an extension ladder to reach the ventilation holes along the eaves. Inspect the holes with a flashlight to make sure they are clear of nest material or other obstructions. If necessary, clean out the holes to ensure proper airflow. You do not want to trap animals inside your home, so make sure the holes have no residents in them.

    Measure the area to determine how much hardware cloth you'll need. The mesh should extend at least 1inch beyond the edges of the holes. 

    Examining holes in an attic vent

    The Spruce / Sarah Lee

  2. Cut Hardware Cloth to Size

    Cut the hardware cloth mesh to size, using aviation snips or standard tin snips. Whenever possible, cut closely along the side of a wire to prevent having edges with sharp protruding ends. Wear gloves to protect your hands from the sharp metal.

    Cutting mesh screen to size

    The Spruce / Sarah Lee

  3. Cover the Hole

    Place the cut piece of mesh over the hole and secure it with roofing nails. Drive a nail every 2 to 3 inches along the mesh, making sure it lies flat to the wood surface. 

    Placing and securing cut mesh over the attic vent

    The Spruce / Sarah Lee