I wouldn't worry about it. I would think about building a rack or storage shelf for them, and using 2x6 for the base - will keep them off of direct connect with the floor, and should help to keep them dry if you experience flooding.
You guys have me worried with all this talk about keeping the temperature and humidity consistent. I keep my balls stored in my detached garage - no HVAC of any kind, and not well insulated. Last winter the temps got down to 26 (25.
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in there, and this summer they've gotten as high as 90 (89.
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. Temps measured at around 7 feet and almost in the center of the garage.
Out of the 100 balls I've owned, I've only had 5 crack on me. 1 of those was a Titan SE stored in the house (constant temp of 72-75) - but it had been plugged and redrilled. It cracked from the thumb slug all the way around. 1 other (Orbit Extreme) was a simple crack in the bridge. 1 (V2 Sweet) cracked from the x-hole to the fingers, and them from the fingers almost around to the thumb - it was a 2nd and probably had other issues. I had a Mutant that cracked - again it had some plug work. The last one cracked all the way around, but was a ball that I was using for testing different plugging material. The plug was never cut down. It sat in the corner for several years, so no idea when it actually cracked.
Most of my balls are stored in bags and boxes. I've left a few sitting in ball cups on my work bench, but I've never left them sit directly on the concrete floor. I guess the worse I've done is sit them on a piece of
Dricore subfloor that we had left over from a kitchen remodel. They sit on shelves with at least a 2x4 as the base and I never stack them more than 2 balls high.
Like charlest said, most problems seem to come from drilling (although my Orbit Extreme was a single drill and hadn't been touched in over 2 years when the bridge cracked).
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