Choosing the Best Materials for Wildlife Exclusion and Home Sealing

Learn which materials effectively seal your home against pests and the elements, improving both security and energy efficiency.

By Garret Merkley · Explainer · Jul 25, 2026

Branched from Common Entry Points for Wildlife: How Pests Get Into Your House

Quick take

Effective wildlife exclusion uses different materials for different types of openings and pests.
Durable, chew-resistant materials like hardware cloth are crucial for preventing animal entry.
Sealants and foams are best for weatherizing and blocking small insects, but not for deterring larger animals.
Proper material selection protects your home from damage, improves energy efficiency, and safeguards health.

Wildlife exclusion and home sealing materials are the physical barriers used to block animals, insects, and the elements from entering your home through gaps, cracks, and openings. These materials are chosen for their durability, resistance to chewing, weatherproofing capabilities, and ability to create a secure, uninterrupted perimeter around your living space.

Understanding the Goal: Secure Your Home's Perimeter

The primary purpose of these materials is twofold: to physically prevent wildlife from gaining access and to seal your home against drafts, moisture, and pests. This means selecting materials that are not only robust enough to deter persistent animals but also flexible and durable enough to withstand weather changes and maintain a tight seal over time. The right material choice ensures that once an entry point is sealed, it stays sealed.

Choosing the Right Tool for the Job

Different types of openings and potential intruders require specific solutions. A small crack suitable for caulk won't stop a determined rodent, just as a large hole patched with foam won't deter a squirrel. Matching the material to the breach is key to long-term success.

**Hardware Cloth / Steel Mesh:** Made from galvanized or stainless steel, this woven wire mesh is essential for blocking larger openings like vents, attic gaps, and foundation cracks. Its strength and chew-resistance make it ideal for rodents, birds, bats, and larger animals. Available in various gauges (thicknesses) and mesh sizes (e.g., 1/4-inch to 1/2-inch).
**Caulks and Sealants:** Flexible compounds like silicone, acrylic latex, or polyurethane. They are perfect for sealing small cracks, gaps around windows and doors, utility penetrations, and joints. They provide excellent weatherproofing against air and moisture but offer little resistance to chewing animals. Silicone is very durable and weather-resistant; acrylic latex is easier to paint over.
**Expanding Spray Foam:** Polyurethane foam that expands to fill irregular gaps and voids. Useful for sealing around pipes, electrical conduits, and in wall cavities. Low-expansion foam is preferred for smaller, tighter spaces to avoid warping. While good for air sealing and blocking insects, it is not chew-proof and should be covered or combined with other materials where rodents are a concern.
**Sheet Metal / Flashing:** Thin sheets of aluminum, steel, or copper used to cover larger openings, reinforce corners, or create exclusion barriers along rooflines, soffits, and fascia boards. It's durable, weather-resistant, and difficult for most animals to chew through or dislodge.
**Concrete / Mortar:** Used for repairing cracks and holes in foundations, brickwork, and concrete slabs. Highly durable and impenetrable once cured, making it excellent for sealing ground-level entry points.
**Wood / Plywood:** For larger structural repairs, replacing damaged siding, or covering significant holes. Ensure it's treated or painted for weather resistance. While strong, it can be chewed through by persistent rodents if not combined with metal flashing or mesh.
**Gutter Guards:** Specialized mesh or solid covers designed to prevent leaves and debris from clogging gutters, but also effectively block birds, rodents, and insects from nesting in or accessing attics via gutters.

Choosing the right materials for wildlife exclusion and home sealing matters because it directly impacts your property's integrity, your health, and your energy bills. Properly sealed homes prevent costly damage from chewing, nesting, and waste accumulation by pests. They also stop drafts, reduce moisture intrusion, and improve indoor air quality, leading to a more comfortable and energy-efficient living environment. The best time to apply these materials is proactively, before an infestation occurs, or immediately after resolving a pest issue to prevent re-entry.

Can I just use expanding foam for everything?

No, expanding foam is excellent for air sealing and blocking insects, but it's easily chewed through by rodents and larger animals. For areas where wildlife might attempt entry, it should be covered with hardware cloth or sheet metal, or used in conjunction with a chew-proof barrier.

What's the best material to stop mice and rats?

For mice and rats, the best materials are chew-proof. Hardware cloth (1/4-inch mesh or smaller), steel wool (packed tightly into small holes), sheet metal, concrete, and mortar are highly effective. Avoid using just caulk or foam where rodents are a known problem.

How do I know what size hardware cloth to use?

The mesh size depends on the target animal. For mice, use 1/4-inch mesh. For rats, 1/2-inch mesh is generally sufficient, though 1/4-inch offers extra security. For larger animals like squirrels or raccoons, 1/2-inch or 1-inch mesh is typically adequate, but ensure the gauge (wire thickness) is strong enough to resist bending.

Do I need to remove old caulk or sealant before applying new?

For the best adhesion and a long-lasting seal, it's generally recommended to remove old, cracked, or failing caulk or sealant before applying new. Clean the surface thoroughly to ensure the new material bonds properly.

Is galvanized steel good enough, or do I need stainless steel?

Galvanized steel is generally sufficient for most residential applications as it's treated for rust resistance and is more affordable. Stainless steel offers superior corrosion resistance and longevity, making it a better choice for very damp environments or situations where maximum durability is critical, but it comes at a higher cost.