Mice can be a real nuisance in homes. They chew through food packaging, damage wiring, and leave droppings that can spread diseases. Many homeowners try to tackle a mouse problem themselves before calling an exterminator, and one popular do-it-yourself approach is using steel wool to block up any holes or gaps where mice can enter.
But not all steel wool is the same. Steel wool comes in different grades, with lower numbers indicating a finer, thinner wool made of smaller diameter strands. The grade makes a difference in how well the steel wool works to deter mice. So what grade works best?
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Grades of Steel Wool
Steel wool is assigned a grade number from 0000 to 4 that denotes the thickness of the strands. The finer the grade, the thinner the wool strands are. Here is an overview of the different grades of steel wool:
0000 (Super Fine)
– Strand diameter of 0.012 inches
– Very thin, flexible, and dense wool
– Smoothest grade of steel wool available
– Easy to tear and conform to gaps
– Used for very fine polishing and finishing work
000 (Extra Fine)
– Strand diameter of 0.015 inches
– Thin, flexible, and dense wool
– Occasionally used for mice exclusion
– Main uses are smoothing wood and fine polishing
00 (Fine)
– Strand diameter of 0.018 inches
– Flexible wool that is easy to mold and stuff
– The most commonly used grade to deter mice
– Also used for smoothing and cleaning surfaces
0 (Medium)
– Strand diameter of 0.023 inches
– Stiffer, coarser strands than finer grades
– Harder to fit into narrow gaps and holes
– Used for general purpose cleaning and maintenance
1 (Coarse)
– Strand diameter of 0.030 inches
– Thick, stiff, rugged strands
– Too hard to fit into small openings
– Used for scraping, paint removal, and scrubbing
2 (Extra Coarse)
– Strand diameter of 0.033 inches
– Very thick and rigid strands
– Far too thick for deterring mice
– For heavy duty scraping and cleaning
3 (Super Coarse)
– Strand diameter of 0.045 inches
– Thickest, roughest grade available
– Fibers are stiff and rigid
– Used for extremely heavy cleaning and scraping
– Not suitable for mice exclusion
4 (Extra Super Coarse)
– Strand diameter of 0.050 inches
– Maximum thickness steel wool grade
– Very stiff, thick, and rough
– For heavy duty paint removal and industrial cleaning
– Much too large for deterring mice
Best Grades of Steel Wool for Mice
When it comes to choosing a grade of steel wool for keeping mice out, super fine 0000 and extra fine 000 are too thin and fragile. On the other end, grades 1 to 4 are too thick to fit into narrow openings. The most suitable grades of steel wool for blocking mice entry points are:
00 (Fine)
Steel wool grade 00 is the optimal choice for deterring mice. The thin, flexible 00 grade fibers can fit into cracks and holes as small as 1/4 inch wide. This allows the steel wool to be stuffed tightly into any openings where mice may gain access. The fine strands also allow the steel wool to mesh and intertwine, creating a dense barrier that mice cannot chew through.
Grade 00 steel wool is soft enough to mold and pack tightly into spaces, yet it still provides abrasion and deters gnawing. This combination of flexibility and durability makes grade 00 the top recommendation for DIY mice exclusion.
0 (Medium)
Steel wool grade 0 can work well for mice exclusion in some circumstances. The slightly thicker 0 grade strands create a barrier too strong for mice to chew through. The thicker fibers may also provide more long-lasting protection compared to finer 00 grade.
However, grade 0 steel wool can be harder to fit snugly into narrow openings since the strands are stiffer. There is also some risk that mice can gradually gnaw through and loosen thicker grade 0 fibers over time. But for stuffing medium to large gaps and holes, grade 0 steel wool can be an effective deterrent against mice.
| Grade | Strand Diameter | Good For Mice Exclusion? |
|---|---|---|
| 0000 (Super Fine) | 0.012 inches | No, too fragile |
| 000 (Extra Fine) | 0.015 inches | No, too fragile |
| 00 (Fine) | 0.018 inches | Yes, optimal grade |
| 0 (Medium) | 0.023 inches | Yes, for larger gaps |
| 1 (Coarse) | 0.030 inches | No, too thick |
| 2 (Extra Coarse) | 0.033 inches | No, too thick |
| 3 (Super Coarse) | 0.045 inches | No, too thick |
| 4 (Extra Super Coarse) | 0.050 inches | No, too thick |
Tips for Using Steel Wool on Mice
When using steel wool for a do-it-yourself mice exclusion project, here are some tips to get the best results:
Choose 00 or 0 Grade Wool
Opt for grade 00 or 0 steel wool designed for mice deterrence. The finer 00 grade works for most openings.
Buy More Wool Than Needed
It takes a lot of steel wool to pack cracks and holes. Having extra will prevent running out halfway through the job.
Use Plenty of Wool
Don’t skimp on the amount used. Stuff openings completely full to make an impenetrable barrier.
Compress the Wool Tightly
The more densely packed the steel wool is, the better it will withstand chewing. Use a screwdriver or other tool to cram in tightly.
Seal with Caulk or Spackle
For long-term results, seal over the steel wool with caulk or spackling compound to prevent loosening over time.
Look for New Openings
Mice will look for new entry points if old ones are blocked. Check for less obvious gaps in siding, vents, etc after excluding them initially.
Pair With Other Deterrents
Use steel wool alongside traps, peppermint oil, moth balls, or other deterrents for the best chance of success in getting rid of mice.
Conclusion
Steel wool can be an effective barrier against mice when used properly. Grades 00 and 0 work best, as they combine flexibility to fit smaller gaps with durability to withstand chewing. Always pack steel wool densely into openings and consider sealing with caulk or spackle for long-lasting results. Pairing steel wool exclusion with other deterrent methods will improve success in keeping mice out for good.