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.
Equipment / Tools
- Tape measure
- Extension ladder
- Aviation shears or tin snips
- Heavy work gloves
- Galvanized hardware cloth, 1/8 or 1/4-inch mesh
- Galvanized roofing nails
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.
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.
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.