What this video covers
The clip addresses painting over mold, which is the most common shortcut taken.
Paint is not a biocide. The colony continues growing on the material underneath, and because it now has a fresh organic layer above it, it commonly works back through and reappears through the new coat.
The takeaway
Painting buys a few weeks of appearance and costs you the ability to see what is happening. Treat and dry the surface first, then paint.
Read the full written guide: Mold on Painted Walls.