Squirrels cause significant damage to a home’s structure and electrical systems when they gain entry for nesting or shelter. These rodents exploit small openings in the attic and roofline, seeking a warm, secure place, especially during colder months or when raising young. Because their incisor teeth grow continuously, they chew through materials like wood, plastic, and soft aluminum to enlarge entry points. The most effective long-term solution is installing a physical barrier known as hardware cloth or wire mesh. This material creates a robust, non-chewable seal over vulnerable openings, permanently denying access.
The Optimal Mesh Opening Size
The size of the mesh opening is the most important factor for excluding squirrels. Squirrels are highly flexible and can compress their bodies to fit through any gap larger than their skull. Since the common gray squirrel’s skull is typically two to two-and-a-half inches long, they can pass through surprisingly narrow spaces. Therefore, the recommended maximum opening size for an effective squirrel barrier is one-half inch (1/2″).
Mesh larger than one-half inch, such as one-inch chicken wire, is insufficient and poses a risk, especially for juvenile squirrels who can easily squeeze through. Using a one-half inch mesh ensures both adult and smaller squirrels are completely blocked. For comprehensive exclusion, especially against mice which can enter openings as small as a quarter-inch, opting for a one-quarter inch (1/4″) mesh is recommended.
Choosing the Right Material and Thickness
Selecting the correct material is just as important as the mesh size. Squirrels possess immense jaw strength, capable of generating up to 500 pounds per square inch of biting force. This power means materials like plastic mesh or thin aluminum screening are easily chewed through and must be avoided. The proper material for exclusion is metal hardware cloth, which is a welded wire mesh, not the flexible, weaker twisted hexagonal pattern of chicken wire.
Material Type
The most effective choices are galvanized steel or stainless steel hardware cloth. Galvanized steel is a cost-effective option that resists rust and provides excellent strength. For superior longevity, especially in coastal or high-humidity environments, stainless steel mesh offers the best corrosion resistance and is virtually impossible for a squirrel to compromise.
Wire Gauge
The wire’s thickness, referred to as its gauge, determines the barrier’s durability; a lower gauge number indicates a thicker, stronger wire. A 16-gauge wire is commonly recommended for its balance of strength and manageability. This thickness provides sufficient resistance against the constant gnawing of a squirrel’s incisors, ensuring the exclusion barrier remains intact.
Key Areas for Squirrel Exclusion
Squirrels often gain access by exploiting structural weaknesses or vents designed for airflow rather than animal exclusion. The highest priority areas for installing wire mesh are any openings that lead directly to the attic or wall voids.
These vulnerable areas include:
- Gable, soffit, and ridge vents, which are often constructed with materials squirrels can easily chew through or bypass.
- Uncapped or improperly screened chimneys, which require a secure, large-gauge mesh chimney cap.
- Common household exhaust vents (dryer, bathroom, and kitchen), as their lightweight flaps are simple for a squirrel to push or gnaw through.
- Areas of damaged wood, such as loose fascia boards or rotten soffits, which must be repaired and covered with the appropriate mesh.