Put a record together first
Note where you're seeing it, when it started, whether it lines up with rain or humidity, whether it's changed over time, and anything already tried. A few photos and rough measurements make the first call more useful.
Read the local context
A useful assessment starts with a few facts about the building rather than the visible growth. Establish whether there is a crawl space, and whether anybody has actually been into it recently, because in this climate that space is where a long-running problem usually sits unnoticed. Check that bath and kitchen fans vent through the roof rather than into the attic, which is a common and inexpensive cause. And note any history of water on the property, since an earlier event can leave contamination inside a cavity long after the surface was repaired.
Plan for what gets closed back up
A patch of discoloration rarely tells the whole story once a wall gets opened. Stronger plans deal with how water is actually entering, the humidity level inside the space, the condition of the framing, how the work zone gets isolated, and confirmation once finished. Ask the provider to spell out in writing what prep and post-work checks won't be visible once everything's closed up.
Weigh full proposals, not just the number
Check that each proposal covers protection of surfaces and contents, how the crew will access the area, the actual materials specified, any City of Rock Hill permits needed, post-work testing, cleanup, finish restoration, exclusions, warranty terms, and how change orders get handled.
What official local sources add
Neither record governs remediation, and their value here is diagnostic. The mapped drainage information tells you how water is supposed to move across the parcel, and a recurring moisture problem frequently turns out to be a structure sitting where that design has stopped working -- a blocked path, an eroded bank, or a neighboring lot regraded since. That is a record worth pulling because it points at a cause outside the building. Designation matters only if remediation ends in visible exterior reconstruction on a textile-era property.
Sources were reviewed June 20, 2026. Citywide preservation and stormwater guidance can't tell you one address's actual flood zone, drainage behavior, or historic-district status -- confirm those specifics, plus current permit rules, with the City of Rock Hill before authorizing anything.