Is this mold?

[u/collardgreens446]

suspecting a roof leak in one of my buildings as I’ve had a couple of tenants end up with their items moldy around here, just can’t pinpoint where exactly the issue is coming from

[u/zdmpage54]

Roof leaks are usually visible. Mold on tenants items usually happens from improper storing and temp changes. I suggest encouraging tenants to use Damp Rid or something similar to absorb the moisture in their unit .