Squirrels cannot chew through galvanized steel, stainless steel, 1/4 inch hardware cloth, solid brick, or cured concrete. Their front teeth grow constantly and they gnaw to keep them worn down, which is why wood, plastic, aluminum, drywall, and vinyl all fall apart in front of them. Hard metal and solid masonry stop them cold. Here is the full rundown so you know exactly what to use for exclusion.
The Short Version
- Squirrels chew through wood, plastic, vinyl, aluminum, drywall, and copper without much trouble.
- Galvanized steel, stainless steel, and 1/4 inch hardware cloth are fully squirrel-proof.
- Brick and concrete resist chewing, but they can exploit cracked mortar.
- Use 1/4 inch galvanized hardware cloth for every exclusion job. Chicken wire and 1/2 inch mesh are not enough.
Why Do Squirrels Chew?
Squirrels don’t chew your house out of spite or hunger. It is a biological need. Their four front incisors grow continuously, several inches a year, and gnawing on hard surfaces keeps them at a usable length. Without constant chewing, the teeth would overgrow.
Beyond keeping their teeth trimmed, squirrels chew to get at food and shelter. They gnaw through nut shells, bark, and eventually the building materials between them and a warm attic or a food stash. Knowing what stops them and what doesn’t is the whole game.
Complete Material Resistance Guide
Here is how common materials hold up against squirrel teeth:
| Material | Can squirrels chew it? | Best use for exclusion |
|---|---|---|
| Drywall / gypsum board | Yes, easily | Back it with 1/4 inch hardware cloth before patching |
| Wood (pine, cedar, plywood) | Yes, easily | Cover with galvanized steel flashing or hardware cloth |
| Vinyl siding | Yes, easily | Replace damaged sections with steel |
| Plastic (PVC, ABS) | Yes, easily | Protect with metal conduit or hardware cloth |
| Aluminum (soft) | Yes, with effort | Replace with galvanized steel for permanent protection |
| Copper | Yes, with effort | Use steel wool plus expanding foam as a temporary fill |
| Chicken wire / poultry netting | Yes, easily | Don’t use it; they chew right through |
| Expanded metal lath | Can be bent | Better than chicken wire, not as good as hardware cloth |
| Steel wool | Can be pulled apart | Temporary filler only, combined with caulk |
| 1/4 inch galvanized hardware cloth | No | The gold standard for all exclusion |
| Galvanized steel (22-gauge and up) | No | Best for flashing and durable barriers |
| Stainless steel mesh | No | Great for vent covers and chimney caps |
| Solid brick (fired clay) | No | Check mortar joints and repoint if worn |
| Concrete (fully cured) | No | Seal cracks wider than 1/4 inch with hydraulic cement |
| Glass | No | Not practical as a barrier, but fully resistant |
Materials Squirrels Chew Through Easily
These offer little resistance and should never be your line of defense:
- Drywall. A squirrel can punch through standard 1/2 inch drywall without much trouble. The gypsum core doesn’t slow the teeth down.
- Wood. Pine, cedar, and plywood are favorite targets, especially fascia boards, soffits, and eaves.
- Vinyl and plastic. Garbage cans, bird feeders, pipe insulation, and plastic vent covers get destroyed routinely.
- Aluminum. Soft aluminum in siding and gutters can be chewed, especially at edges and corners.
- Chicken wire. The name sounds right, but poultry netting is no match for squirrel teeth. Use 1/4 inch hardware cloth instead.
Common mistake: A lot of people buy 1/2 inch hardware cloth thinking it will stop squirrels. The openings are big enough for a squirrel to get its teeth into and pull apart. Always use 1/4 inch galvanized hardware cloth. The cost difference is small, but the protection difference is everything.
Materials Squirrels Cannot Chew Through
Build your exclusion plan around these:
- 1/4 inch galvanized hardware cloth. The single best material. Use it over vents, chimneys, eaves, and any gap bigger than a quarter, secured with screws and washers.
- Galvanized steel, 22-gauge or heavier. Ideal for flashing, roof-line barriers, and shields, installed at an outward angle to stop climbing.
- Stainless steel mesh. Best for chimney caps and permanent vent covers, since it doesn’t rust.
- Solid brick and concrete. Squirrels can’t damage the material itself, but they can work cracks in mortar or settlement gaps. Repoint aging mortar and seal foundation cracks.
When sealing a hole in wood or vinyl, back the repair with 1/4 inch hardware cloth before you patch the surface. The patch alone can be re-chewed. The hardware cloth underneath is the real barrier.
Best Materials for Squirrel Exclusion
For Attic and Roof Entry Points
Use 1/4 inch galvanized hardware cloth screwed down with washers over gable vents, soffit gaps, and ridge vents. Don’t rely on staples alone, since squirrels can pull the mesh loose.
For Chimneys and Vents
Install a stainless or galvanized steel chimney cap with 1/4 inch mesh. For dryer and bathroom vents, swap plastic covers for metal ones backed by 1/4 inch hardware cloth.
For Wiring and Cables
Run wires through galvanized steel conduit or wrap exposed sections with stainless steel mesh sleeve. Capsaicin tape exists but needs reapplying, so metal is the only permanent answer.
For Deck and Patio Furniture
This one surprises people, but squirrels chew deck furniture and railings too. For wooden furniture, metal or composite materials hold up better, and a capsaicin spray can discourage gnawing, though it needs refreshing. The same rule applies: if it is wood, plastic, or soft metal, a determined squirrel can get through it.
Frequently Asked Questions
Partially. They can pull loose steel wool apart, but tightly packed steel wool combined with caulk works as a temporary gap filler. For permanent protection, use 1/4 inch hardware cloth.
Yes. Schedule 40 PVC gives them little trouble. Use galvanized steel conduit for any wiring or pipe that runs through squirrel territory.
Yes. Pressure-treated wood resists rot and insects, not squirrel teeth. Cover any exterior wood squirrels target with galvanized steel flashing.
It depends on the gauge and mesh size. 1/4 inch galvanized hardware cloth is squirrel-proof. 1/2 inch mesh can be gripped and pulled apart, and chicken wire offers no protection at all.
Yes. Squirrels have been known to chew rubber brake lines, coolant hoses, and wiring harnesses under vehicles, and some soy-based wire coatings seem to attract them. A metal under-hood shield is the only reliable protection.
Bottom Line
The only materials that reliably stop squirrels are hard metals, galvanized steel and stainless steel, plus 1/4 inch hardware cloth. Wood, plastic, vinyl, aluminum, and drywall all lose. Don’t cut corners on materials: use 1/4 inch galvanized hardware cloth for every gap and opening, and back any wood or vinyl repair with metal. A little money spent on the right material now saves a lot of chew damage later.
