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Which mold killer is best?

When mold crops up on your bathroom tile or basement walls, there’s no need to worry — it’s a common occurrence in many households. Excess humidity and poor ventilation are just a few of the causes for this unwanted health hazard. But instead of scrubbing with soap and water until your back aches, use a mold killer to quickly banish mold from your premises.

Our buying guide provides insight into what causes mold and which mold killers are best for your issues. Our top pick, Siamons Concrobium Mold Control, doesn’t contain bleach and kills mold and odors, eliminating the problem altogether.

What to know before you buy a mold killer 

Causes of mold

As a fungus, mold doesn’t require sunlight to thrive, so it multiplies quickly in dark corners by releasing spores into the air. As spores land on surfaces around your home, new mold colonies settle in. Mold is most likely to appear in dark, moist areas, sheltered from the sun, but warm enough to support growth. Windowless bathrooms are thus a perfect spot for this nasty invader. It doesn’t only grow in indoor environs, either: shady, waterlogged backyard spots — like near a swimming pool, for instance — are prime real estate for mold.

Reasons to worry

Why bother targeting mold? Spores released into the air can cause or exacerbate health problems like lung diseases and allergies. Severe mold infestations can even lead to death.

How to remove mold

Mold not only poses health risks, but it also damages surfaces. To get it out of your house, follow these steps:

  • Spray moldy areas with water to prevent spores from traveling through the air. This prevents the mold from spreading and keeps it from entering your lungs.
  • Use a scrub brush to remove the first layer of mold and expose the inner layers.
  • Spray with a mold killer product, following all manufacturer’s instructions. Most mold killers require the use of PPE (personal protective equipment). You should also check whether a product is safe to use on the surface you’re treating.
  • When you’re done spraying following the manufacturer’s guidelines, rinse the area to remove chemical residue.

What to look for in a quality mold killer 


Mold killers are very concentrated and strong and often contain hazardous, toxic ingredients that can burn your skin and irritate your respiratory system. When using a mold killer indoors, ensure the room is adequately ventilated and turn on any available fans. Open windows, doors, and turn on fans before applying the mold killing substance.


Check product labels to find out whether a product is safe to use multiple times. Most products can only be reapplied once a month after an initial application in an effort to prevent mold. Some should not be used as a preventative.

Gel vs. spray

A product’s active ingredients determine whether it’s effective against mold. Both gels and sprays pose a risk if proper precautions are not taken prior to application. Both types of mold killer can produce toxic fumes.

How much you can expect to spend on a mold killer 

You can pay between $10 to $25 for a 32-ounce bottle of mold killer. Budget products tend to be less effective than higher-cost options. The most expensive mold killers are usually professional-grade and require the use of serious protective equipment, like a full face mask.

Mold killer FAQ

Can I use a mold killer on any surface?

A. No. Read the product label carefully to determine whether it’s suitable for use on an affected surface. Many mold killers damage and discolor dyed fabrics, steel, copper, and aluminum surfaces. If you wish to remove mold on wood (e.g., backyard deck), check that the product is safe to use on wooden surfaces.

Should I take any safety precautions when applying a mold killer?

A. First and foremost, read mold killer labels and instructions thoroughly. Ventilate the area and don protective equipment before getting started.

What are the best mold killers to buy? 

Top mold killer

Siamons Concrobium Mold Control, Two-Pack

Siamons Concrobium Mold Control, Two-Pack

Our take: A wholly effective mold killer that kills mold at its root and eliminates accompanying odors in the process.

What we like: Doesn’t contain bleach and doesn’t produce toxic fumes like other brands. Neutralizes mold and its associated odors. Doesn’t have a strong scent and is versatile enough for use on a multitude of surfaces.

What we dislike: It’s effective but also quite pricey.

Where to buy: Sold by Amazon 

Top mold killer for the money

Tilex Mold and Mildew Remover, Three-Pack

Tilex Mold and Mildew Remover, Three-Pack

Our take: A budget mold killer suitable for treating mold on a range of surfaces.

What we like: Formula immediately gets to work on killing mold and mildew. It also eliminates stains in the process and works best on plastic and ceramic tiles. Inexpensive.

What we dislike: It produces potent fumes, so proper ventilation is vital.

Where to buy: Sold by Amazon 

Worth checking out

Method Foaming Bathroom Cleaner

Method Foaming Bathroom Cleaner

Our take: A foaming cleaner designed for bathroom use with a refreshing minty scent.

What we like: Removes mold, soap scum, mildew, and grime. Naturally-derived and non-toxic. Easy to apply. Great scent.

What we dislike: Not suitable for severe mold infestations.

Where to buy: Sold by Amazon 

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Steph Coelho writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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