Can I clean a small mold patch myself?

A small patch on tile is a different job from a wet wall that sat through a weekend. The EPA puts a size on the first one.

The 10 square foot line

The EPA cleanup page says that if the moldy area is less than about 10 square feet, less than roughly a 3 foot by 3 foot patch, in most cases you can handle the job yourself. The same page is the one to read for how to clean hard surfaces and when to throw porous things out.

The EPA mold guide still comes first: clean the mold and fix the water problem. If you scrub the grout and leave the leak, the patch usually returns.

When that line does not apply

Sewage and outdoor flood water change the job. The CDC cleanup page says to throw away porous items that stayed wet with flood water and cannot be cleaned, and to remove drywall and insulation contaminated with sewage or floodwater. A 3 foot patch of flood-soaked drywall is not the EPA's tile-and-soap job.

If the smell is in a closet you cannot see into, or the wall feels soft, treat it as hidden moisture. Do I need a mold test before cleanup? is the page for that.

What that means in a humid house

In a coastal city like Wilmington, summer humidity stays high enough that a cleaned patch can stay damp if you do not run a fan or a dehumidifier. The EPA asks you to keep indoor humidity below 60 percent after the room is dry. What to do when you find mold in the house is the full order.