Short answer
A patch smaller than about ten square feet on a hard, non-porous surface — tile, glass, sealed countertop — is reasonable to clean yourself. Anything on drywall, insulation, wood framing, carpet or cabinetry, and anything larger, should not be a DIY job.
The risk is not just exposure while you work. Scrubbing colonized drywall aerosolizes spores into the rest of the house, which turns a contained one-room problem into a whole-home problem — we are called out to clean up that exact mistake regularly.
The other half is that DIY never addresses the water source, so the growth returns in the same spot within a season.
Why it matters in San Diego
A little mildew on a shower grout line in a Mission Beach rental? Clean it. A black patch spreading across a bedroom wall in Oceanside, or a musty closet in a Spring Valley home? That's usually water you can't see, and scrubbing the surface doesn't fix it.
Most San Diego mold that comes back after DIY cleaning is fed by slab leaks, roof leaks or bathroom fans venting into the attic instead of outside. The visible spot is just where it showed up.
How we handle it
When you call, we'll tell you honestly if it's a DIY job. Our inspection is free, so it costs nothing to find out. If it's small and dry, we'll explain how to clean it.
If it's bigger, we find the water first, then remove the material under containment — the way it's done when mold removal is your only job.
Signs it's time to call us
- More than about 10 square feet of growth
- Growth inside walls, the attic, crawlspace or HVAC
- It came back after you cleaned it
- Anyone in the home is getting sick
Mistakes to avoid
- Using bleach on drywall or wood
- Sanding or dry-brushing mold, which spreads spores through the house
- Painting over it with 'mold-resistant' paint
Related questions
What should I wear for a small DIY job?
At least an N95 mask, gloves and eye protection. Bag the waste and keep doors closed.
Can you just look and tell me if I can handle it?
Yes — that's what the free inspection is for.