AirQualitySource

Can You Remove Mold Yourself? When to DIY and When to Hire a Pro

AirQualitySource Editorial Team · Published September 14, 2026 · Updated September 14, 2026 · 4 min readResearched and written with AI assistance, reviewed by our editorial team against primary sources. Every quote links to its source. Editorial standards

The short answer: a small patch of mold is often a do-it-yourself job. The EPA's rule of thumb is about 10 square feet — roughly 3 feet by 3 feet. Below that, the EPA says that "in most cases, you can handle the job yourself."1 Bigger areas, hidden mold, contaminated water, or health concerns are the signs to bring in help.

How big is too big?

There are two different numbers you may see, and they mean different things.

Size What it means
EPA guidance About 10 square feet Below this, most people can clean it themselves.1
Texas licensing 25 contiguous square feet Below this, the work can usually be done by people who are not licensed.2

The EPA figure is advice about what is sensible to take on yourself. The Texas figure is a legal line for when state mold licensing comes into play. A patch between the two can usually be cleaned without a license in Texas, but it is past the size the EPA describes as a do-it-yourself job.

When to hire someone even for a small area

Size is not the only factor. The EPA points to a professional when:

  • The water was sewage or contaminated. Call "a professional who has experience cleaning and fixing buildings damaged by contaminated water."3
  • The mold is in your heating or cooling system. Don't run it — the EPA says it "could spread mold throughout the building."4
  • The mold is hidden behind wallpaper, drywall, or paneling. Opening it up can backfire: the EPA notes that removing wallpaper "can lead to a massive release of spores" if mold is growing underneath.5
  • You have health concerns. "Consult a health professional before starting cleanup."6

How to clean a small area safely

Protect yourself

The EPA and CDC recommend similar gear:

  • A respirator. The EPA says "you may want to wear an N-95 respirator" to limit your exposure to airborne mold.7
  • Gloves. "Avoid touching mold or moldy items with your bare hands."8
  • Goggles. The EPA recommends goggles "that do not have ventilation holes."9 The CDC's list is "rubber boots, rubber gloves, and goggles."10
  • Fresh air. The CDC says to "open windows and doors to provide fresh air."11

Clean what can be cleaned, and throw out what can't

  • Hard surfaces such as tile, glass, metal, and sealed counters: "Scrub mold off hard surfaces with detergent and water, and dry completely."12
  • Porous materials such as ceiling tiles and carpet "may have to be thrown away if they become moldy."13

Remove it — don't just kill it

Spraying something on mold and leaving it is not a cleanup. The EPA explains why: dead mold "may still cause allergic reactions in some people, so it is not enough to simply kill the mold, it must also be removed."14

And don't cover it up: "Do not paint or caulk moldy surfaces."15

Should you use bleach? The agencies differ

This is one place where the EPA and CDC give different advice.

  • EPA: using a biocide such as chlorine bleach "is not recommended as a routine practice during mold cleanup."16
  • CDC: lists bleach as one option on hard surfaces, alongside household products and soap and water — a solution "of no more than 1 cup of household laundry bleach in 1 gallon of water."17

Both agencies agree that detergent or soap and water works on hard surfaces, and both give the same warning if you do use bleach. The EPA: never mix bleach with products that contain ammonia, "because toxic fumes could be produced."18 The CDC: mixing bleach with ammonia or other cleaners "will produce a poisonous gas."19

How to know you're done

Mold that comes back usually means the water did. The EPA says a cleanup cannot be considered finished until you have "completely fixed the water or moisture problem."20

If you want confirmation, the EPA notes that surface sampling "may be useful to determine if an area has been adequately cleaned or remediated."21 See Do you need a mold test?

If you hire a company in Texas

Hiring a licensed company changes the process, even for a small job:

  • A licensed remediator follows the full rules at any size. The state licensing agency says that "regardless of the size of the area," a licensed remediation contractor must follow the law and rules, including a work plan based on a protocol written by a licensed mold assessment consultant.22
  • That means two separate firms. The same licensee cannot do both the assessment and the remediation on the same project.23

You can browse licensed Texas mold companies, filtered by assessment or remediation, each with its state license number and the date we checked it.

Sources reviewed for this article

Each number in the article points to the exact passage below. We read every page on the date shown and checked that each quote appears on it word for word.

  1. 1.“If the moldy area is less than about 10 square feet (less than roughly a 3 ft. by 3 ft. patch), in most cases, you can handle the job yourself, follow the guidelines.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  2. 2.“Please note that in most instances, areas of visible mold of less than 25 contiguous square feet can be cleaned up by people who are not licensed.”Texas Department of Licensing and Regulation, Mold Assessors and Remediators FAQs. Accessed September 14, 2026.
  3. 3.“If the water and/or mold damage was caused by sewage or other contaminated water, then call in a professional who has experience cleaning and fixing buildings damaged by contaminated water.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  4. 4.“Do not run the HVAC system if you know or suspect that it is contaminated with mold - it could spread mold throughout the building.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  5. 5.“For example, removal of wallpaper can lead to a massive release of spores if there is mold growing on the underside of the paper.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  6. 6.“If you have health concerns, consult a health professional before starting cleanup.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  7. 7.“In order to limit your exposure to airborne mold, you may want to wear an N-95 respirator, available at many hardware stores and from companies that advertise on the Internet.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  8. 8.“Avoid touching mold or moldy items with your bare hands.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  9. 9.“Goggles that do not have ventilation holes are recommended.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  10. 10.“Wear rubber boots, rubber gloves, and goggles during cleanup.”Centers for Disease Control and Prevention, Mold. Accessed September 14, 2026.
  11. 11.“Open windows and doors to provide fresh air.”Centers for Disease Control and Prevention, Mold. Accessed September 14, 2026.
  12. 12.“Scrub mold off hard surfaces with detergent and water, and dry completely.”US Environmental Protection Agency, What are the basic mold cleanup steps?. Accessed September 14, 2026.
  13. 13.“Absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy.”US Environmental Protection Agency, What are the basic mold cleanup steps?. Accessed September 14, 2026.
  14. 14.“Dead mold may still cause allergic reactions in some people, so it is not enough to simply kill the mold, it must also be removed.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  15. 15.“Do not paint or caulk moldy surfaces.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  16. 16.“The use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  17. 17.“Mold can be removed from hard surfaces with household products, soap and water, or a bleach solution of no more than 1 cup of household laundry bleach in 1 gallon of water”Centers for Disease Control and Prevention, Mold. Accessed September 14, 2026.
  18. 18.“Never mix chlorine bleach solution with other cleaning solutions or detergents that contain ammonia because toxic fumes could be produced.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  19. 19.“Never mix bleach with ammonia or other cleaners. This will produce a poisonous gas.”Centers for Disease Control and Prevention, Mold. Accessed September 14, 2026.
  20. 20.“You must have completely fixed the water or moisture problem before the cleanup or remediation can be considered finished.”US Environmental Protection Agency, A Brief Guide to Mold, Moisture and Your Home. Accessed September 14, 2026.
  21. 21.“Surface sampling may be useful to determine if an area has been adequately cleaned or remediated.”US Environmental Protection Agency, Mold Testing or Sampling. Accessed September 14, 2026.
  22. 22.“Regardless of the size of the area affected by mold contamination, if a licensed MRC is hired by the consumer, the MRC must comply with the requirements in the law and rules, including the development of a work plan that follows a protocol developed by a licensed Mold Assessment Consultant (MAC).”Texas Department of Licensing and Regulation, Mold Assessors and Remediators FAQs. Accessed September 14, 2026.
  23. 23.“However, you are not allowed to conduct both mold assessment and mold remediation activities on the same project, unless you are employed by a school district and working on a project for that school district.”Texas Department of Licensing and Regulation, Mold Assessors and Remediators FAQs. Accessed September 14, 2026.

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