How to get rid of mold

Last updated: 2026-06-23

Getting rid of mold is really two jobs: removing the growth and fixing the moisture that caused it. Skip the second and the mold comes back, no matter how well you clean. For a small patch on a hard surface, this is a reasonable do-it-yourself project. For anything larger — or anything growing into your walls — it's a job for a pro. Here's how to tell the difference, and exactly how to do it safely.

First, decide: DIY or call a pro?

The US EPA's rule of thumb is size: if the moldy area is under about 10 square feet (roughly a 3-by-3-foot patch) on a hard, non-porous surface, most homeowners can handle it. Lean toward a professional when:

The area is larger than ~10 sq ft, or mold is in more than one room
Mold is on or behind porous materials — drywall, insulation, carpet, ceiling tile
It's inside the HVAC system or ductwork (don't run the system; have it inspected)
It followed a flood or sewage backup, or any contaminated (Category 3) water
Anyone in the home has asthma, allergies, or a weakened immune system
The mold keeps returning, or you smell it but can't find it

If any of those apply, skip ahead to when to call a professional.

What you'll need

An N95 respirator (not a basic dust mask), rubber or nitrile gloves, and non-vented goggles
Detergent or dish soap and water; a stiff scrub brush
Plastic sheeting and bags for debris; a fan or dehumidifier for drying

How to remove mold yourself, step by step

Fix the moisture source first. Find and stop the water feeding the mold — a leak, condensation, flooding, or high humidity. Cleaning mold without fixing the moisture only delays its return.
Protect yourself. Wear at least an N95 respirator, rubber or nitrile gloves, and goggles without vents. If you have asthma, allergies, or a weakened immune system, do not do the work yourself.
Seal off and ventilate the area. Close doors to other rooms and, if practical, open a window or run a fan to the outside. Avoid blowing spores through the rest of the house while you work.
Clean hard, non-porous surfaces. Scrub mold off hard surfaces — tile, glass, sealed wood, metal — with detergent and water. The EPA does not consider bleach necessary for this; physical removal plus drying is what matters.
Remove porous materials that can’t be cleaned. Moldy drywall, carpet, carpet padding, ceiling tiles, and insulation usually can’t be cleaned and should be bagged and discarded. Surface cleaning won’t reach growth rooted inside them.
Dry everything completely. Dry the cleaned area fully within 24–48 hours, using fans and a dehumidifier if needed. Mold cannot regrow on a surface that stays dry.
Verify and prevent recurrence. Keep indoor humidity between 30–50%, fix ventilation, and check the spot over the next few weeks. If mold returns, the moisture problem isn’t solved — reassess or call a pro.

Does bleach kill mold?

It's the first thing most people reach for, but bleach is not the hero it's made out to be. The EPA does not recommend it as a routine part of mold cleanup. On hard, non-porous surfaces it can remove staining, but it can't penetrate porous materials like drywall and wood, so it leaves the actual roots behind — and the water it carries can even feed regrowth if the surface isn't dried afterward. For most jobs, detergent, water, and thorough drying do the job. The growth coming out and the surface staying dry matter far more than what you spray on it. (Never mix bleach with ammonia or other cleaners — it produces toxic gas.)

Will the mold come back?

Only if the moisture does. Mold can't grow on a surface that stays dry, so the durable fix is environmental: repair the leak, improve ventilation, and keep indoor humidity between 30–50%. If mold returns to the same spot after a proper cleaning, that's your sign the water source was never fully resolved — or that growth is rooted in a material that needs to be removed, not scrubbed. For more on spotting hidden moisture problems, see signs of mold in your house, and on telling real mold from harmless look-alikes, mold vs. mildew.

When to call a professional

Bring in a remediation pro for anything beyond a small surface patch — large areas, porous or structural materials, HVAC involvement, post-flood or sewage situations, recurring growth, or health concerns in the household. A professional will contain the area to stop spread, remove affected materials safely, treat and dry the space, and fix the moisture source so it doesn't return. It's worth knowing the price range first — see mold removal cost — and then connect with a vetted local mold remediation pro to get matched.

Sources

Frequently asked questions

Can I remove mold myself?

For a small area — the EPA uses about 10 square feet (roughly a 3-by-3-foot patch) as the rule of thumb — on hard, non-porous surfaces, yes, with the right protection. Scrub with detergent and water, dry thoroughly, and fix the moisture source. Larger areas, mold in porous materials like drywall, or growth that followed a flood or sewage backup should go to a professional.

Does bleach kill mold?

Bleach can remove mold staining from hard, non-porous surfaces, but the EPA does not recommend it as a routine part of mold cleanup. It doesn’t penetrate porous materials like drywall or wood, so it leaves the roots behind, and the water in it can even feed regrowth if the surface isn’t dried. For most home cleanup, detergent and water plus complete drying works as well or better.

Why does mold keep coming back?

Because the moisture is still there. Mold returns to the same spot when the underlying leak, condensation, or humidity problem hasn’t been fixed — or when it was growing in a porous material that was cleaned on the surface but not removed. Recurring mold is a signal to find the water source, not just to re-clean.

How much does professional mold removal cost?

It varies widely by the size of the affected area, the materials involved, and whether there’s hidden growth — a small contained job is far cheaper than whole-home remediation after a flood. See our mold removal cost guide for current ranges and the factors that move the price.

What size mold problem needs a professional?

As a general guide, mold covering more than about 10 square feet, mold inside HVAC systems, growth on porous structural materials, anything following sewage or contaminated water, and any situation where occupants have health concerns all warrant a professional. When in doubt, a remediation pro can assess it before you open up a wall.