Rat and mouse article
Steel Wool vs Copper Mesh for Plugging Rodent Holes
Both are stuffing, not a seal. In Florida humidity, copper mesh holds up better than steel wool. Either one works best packed tight and covered with mortar or sealant, and UF/IFAS's own list leans on metal sheet, hardware cloth and mortar.
Copper mesh is usually the better choice in a humid Fort Lauderdale house, because steel wool rusts and leaves stains where it gets wet. But neither one is a complete fix on its own. Both are stuffing. Rodents can pull loose material out of a hole, and the UF/IFAS rodent-proofing list doesn't include either. It names sheet metal, perforated metal, hardware cloth, mortared brick, cement mortar and concrete.
So the honest answer is: use copper mesh as a filler for small, odd-shaped gaps, pack it tight, and lock it in with mortar or sealant. For anything bigger, use the UF/IFAS materials.
Steel wool
Steel wool is cheap and easy to find. Rodents don't like chewing it. The trouble in South Florida is moisture. Steel wool rusts, and in a garage, under a sink, at a slab edge or anywhere near the coast it breaks down and leaves rust streaks on stucco and paint. Once it's crumbling, it's easy to pull out.
It can still work indoors in dry spots, like a gap behind a cabinet or around a pipe under a sink that stays dry, if it's packed tight and covered. Mice in walls removal shows where those indoor gaps usually are.
Copper mesh
Copper mesh, sold in rolls for pest exclusion, holds up much better in humidity. It doesn't rust like steel wool, it's easy to cut and stuff, and it springs back to fill uneven gaps. It costs more than steel wool and still isn't a seal by itself. A determined rat can work loose stuffing out of a hole.
Want a technician to look at it?
Your call goes to an independent local rodent control provider in Broward County. Same-day appointments are often available.
What UF/IFAS lists instead
The UF/IFAS rat and mouse control publication lists these rodent-proofing materials:
- Sheet metal, 26 gauge or heavier
- Perforated metal, 24 gauge or heavier, openings no more than 1/4 inch
- Hardware cloth, 19 gauge or heavier, openings no more than 1/4 inch
- Brick with mortared joints
- Cement mortar (1:3 mix) and concrete (1:2:4 mix)
How to use mesh the right way
For small gaps around pipes and wires:
- Clean out the gap
- Pack copper mesh in tightly, deeper than a rodent can reach
- Cover it with mortar, patching compound or a quality sealant so it can't be pulled
- For anything wider than about an inch, use hardware cloth or sheet metal fastened over it
Where each one fits on a Broward house
Mesh stuffing is good for the ragged gaps around AC refrigerant lines, plumbing under sinks and wire penetrations. Hardware cloth is the right fix for soffit vents, gable vents and crawl space vents. Tile eave ends usually get purpose-made closures or mortar. Garage doors need rubber or vinyl seals sized to the door, plus metal at the corners if rats have chewed them.
Avoid expanding foam as the main barrier. Rats chew through it. It's fine as a filler behind metal.
Do it yourself or hire out?
Gaps you can reach from the ground or under a sink are a weekend job. Roof edges, tile eaves and gable vents on a two-story house are work for someone with the right ladder and experience on tile. A provider doing rodent exclusion should list every opening and the material for each. How small a hole can a mouse fit through shows where to look.
Near the beach and the Intracoastal
Salt air speeds up rust on anything made of plain steel. In homes near the ocean and the Intracoastal, steel wool can rust and stain within a season, and cheap screen and fasteners corrode too. If you live close to the water, use copper mesh for stuffing, and ask any provider what metal they use for vent screen and flashing. Stainless or coated hardware lasts longer in salt air.
Check your patches
Whatever you use, look at the patches every few months and after storms. Signs of trouble are mesh pulled partly out of the hole, fresh gnaw marks on sealant around it, rust stains, or droppings near the spot. A patch rodents keep working at is a patch on an active route, and it needs a stronger fix like hardware cloth fastened over it or mortar.
What a provider will usually use
Providers doing exclusion on Broward homes tend to rely on hardware cloth and sheet metal for vents and larger gaps, purpose-made closures or mortar for tile ends, and mesh plus sealant for pipe and wire holes. If a quote lists only foam and steel wool, ask why, and ask what will be done at the roofline.
Common questions
Will mice chew through steel wool?
They avoid chewing it, but they can pull loose steel wool out of a hole, and it rusts in Florida humidity. Pack it tight and cover it.
Is copper mesh better than steel wool?
In a humid climate, usually yes, since it doesn't rust like steel wool. Both work best covered with mortar or sealant.
What does UF/IFAS recommend for sealing?
Sheet metal, perforated metal and hardware cloth with openings no larger than a quarter inch, mortared brick, cement mortar and concrete.
Can I use spray foam with the mesh?
As a filler behind or over mesh, yes. Foam on its own gets chewed through.
Still hearing them?
Your call goes to an independent local rodent control provider in Broward County. Same-day appointments are often available.
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Sources
General information only, not legal or medical advice. Rules change, so check the linked sources for the current version.