How to Clean Mold in Your Basement: Finally End Your Mold Problem (New 2022 Tips)

A moist environment encourages mold growth, and so controlling the humidity in your house is key to keeping mold at bay.

Molds affect the indoor quality of air. They have tiny spores that are airborne, which may cause irritation and allergic reactions, especially among people with asthma.

Mold usually appears in different parts of the house that are constantly wet and damp. This includes water damage zones such as the basement.

When water enters the basement, it takes a long time to dry it out since there’s little to no sun exposure and poor ventilation.

How to Clean Mold in the Basement: Quick Guide on Cleaning Agents that Work

  1. Bleach
  2. Vinegar
  3. Ammonia
  4. Hydrogen Peroxide
  5. Borax
  6. Tea Tree Oil
  7. Detergent

The Environmental Protection Agency recommends regular checking of mold growth and being proactive in recognizing signs and symptoms of mold activity.

What causes molds in your basement?

  • Condensation caused by humidity and cold temperatures collects in vents, pipes, and walls
  • Floodwater that goes into your basement is harder to dry
  • Leaky pipes in the basement or in nearby rooms
  • High humidity levels

Where does mold usually grow in your basement?

  • Ceiling tiles
  • Floors
  • Walls
  • Wall cavities
  • Wooden frames
  • Floor
  • Insulation
  • Pipes
  • Ducts and vents

Signs of molds in your basement:

  • Allergic reactions, skin irritation, or asthma attacks.
  • Your immune system is acting up and there are symptoms like watery eyes, runny nose, and itchy or sore throat.
  • A musty odor in your basement.
  • Small patches of mold that look like simple dirt.

How to test for molds:

  • Use 1-part bleach with 10-parts water.
  • Spray it into the affected surface and swab it with a cloth.
  • If the area is simply dirty, the sprayed surface will not change in color but if it does, then you are dealing with mold.

Categories of Molds:

  • Allergenic molds trigger allergic reactions and asthma attacks.
  • Pathogenic molds affect people with immune system disorders.
  • Toxigenic molds pose serious health risks.

Different Types of Molds:

  • Aspergillus– an allergenic mold that varies in color and is commonly harmless.

Some strains can cause aspergillosis in people with immune system deficiencies.

  • Alternaria– an allergenic type of mold mostly found under sinks and alongside tubs.

It has a velvet soft appearance and brown filaments resembling hairs.

  • Aureobasidium pullulans– an allergenic mold referred to as “sooty” mold.

It is commonly present under wallpapers and causes skin irritation when touched. It is light pink or gray at the beginning then turns to brown or black as it matures.

  • Mucormycetes– they appear fuzzy white puffs with long hair usually found in spoiled foods.

They trigger asthma and difficulty in breathing when inhaled. People with weaker immune systems can have mucormycosis.

  • Stachybotrys– also known as “black mold”, is a toxigenic mold that lives on woods and other organic matters.

It can cause headaches, nosebleeds, fatigue, and upper respiratory discomfort.

For black mold infestation, it is a good idea to go to a mold remediation specialist instead of tackling it on your own.

  • Chaetomium– this is a pathogenic and allergenic mold that develops after flooding or water damage.

This mold usually spreads within the interior wall before emerging at the surface so by the time it is visible, the damaged area is already expanse.

Inhaling its spores causes allergenic reactions.

  • Acremonium– these molds are often found in condensation lines and drainage pans.

It is difficult to identify due to its varied colors, but as it matures, it becomes powdery.

Inhaling causes eyesore, pneumonia, and difficulty of breathing. You need a mold remediation expert for this.

  • Cladosporium– green or brown and can be found in textiles like carpeting, curtains, and upholsteries.

It is an allergenic mold that causes sore throat, runny nose, and watery eyes.

  • Ulocladium– some strains of Ulocladium are pathogenic while some are allergenic.

They appear after water damage or flooding. It is black which is why it is sometimes confused with Stachybotrys.

Since it mimics black mold, it is best to consult with a mold remediation expert to avoid health risks.

  • Fusarium– appears on textiles like carpets and upholsteries and can survive even at near-freezing temperatures.

It appears pinkish or reddish spots.

Some strains are allergenic that can cause fever but some are toxigenic that can cause internal bleeding.

  • Penicillium– bluish-green mold with a velvet-like appearance.

While it is a powerful antibiotic, some strains are allergenic and pathogenic leading to asthma attacks, and sinusitis.

This requires mold remediation experts.

  • Trichoderma– white or olive green with a puffy appearance. Some strains produce mycotoxins that can cause lung infections, liver failure, even cancer.

Treating Trichoderma requires mold remediation experts.

How to clean molds in your basement:

Safety reminders before cleaning:

  • Use protective gear like face masks, non-porous or rubber gloves, dusk masks or respirators, and goggles.
  • If using bleach, never mix it with ammonia or other cleaners as it will produce toxic gas.
  • Open windows, doors, and vents.
  • If the affected area is large for you to clean (10 square feet or more), or if you suspect that the molds in your household belong to toxigenic categories, get professional help.

What to prepare:

  • Bleach ( for cleaning solution: 1 cup of bleach to 1-gallon water)
  • Stiff-bristled brush
  • Pail
  • Scrub brushes/sponges
  • Spray bottles
  • Other supplies (as needed): borax, white vinegar, ammonia, hydrogen peroxide, tea tree oil, detergents, steam cleaners, etc.
  • Dry your area if there is residual water.
  • Tape some plastics to contain your basement.
  • Ventilate it with some fan, make sure to turn off the HVAC to avoid the spread of molds.

Cleaning agents to remove mold in your basement

  • Bleach (never mix bleach with ammonia)
  • Mix 1-part bleach to 10-part water and put in a spray bottle.
  • Spray over non-porous materials only. Bleach is not an effective cleaning solution on porous surfaces.
  • If there are dirt marks, simply wipe them with a cloth. No need to rinse with water.
  • Vinegar (use white distilled vinegar)
  • Simply put it in a spray bottle and spray over the moldy areas.
  • Let it sit for one hour.
  • Clean the area with water using cloth.
  • Ammonia (Only use ammonia on hard, non-porous surfaces)
  • Create a mix of 50% ammonia and 50% water in a sprayer and spray it over the affected area.
  • Leave for 2-3 hours then rinse with water.

NOTE: Make sure the label says “clear ammonia”.

  • Hydrogen Peroxide (good to use for any material and surface)
  • Put 3% concentration in a spray bottle.
  • Saturate moldy areas with the concentrate.
  • Leave for 10 minutes.
  • Scrub to remove stains.
  • Wipe with cloth to remove residues.
  • Borax
  • Create a solution with 1 cup borax to 1-gallon water.
  • Make sure that you vacuumed the area prior to application.
  • Use a scrub brush to brush the mold off.
  • Leave the area to completely dry. No need to rinse the borax solution off.
  • Detergent
  • Simply mix water and detergent and use it to scrub mold off any surfaces.
  • Tea Tree Oil
  • Prepare a 1-tsp oil to 1-cup water solution.
  • Spray the solution on the moldy surface.
  • Leave the area to dry. No need to rinse.

How to prevent mold build-up in your basement

  • Control humidity levels between 30%-50%.
  • Immediately fix leaky roofs, broken window seals, and pipes to avoid water damage.
  • Ventilate your showers, laundry rooms, and basements.
  • Make sure to dry areas after it was flooded.
  • Use air conditioners or dehumidifiers during humid seasons.
  • Avoid using carpeting in areas that are prone to moisture build-up.
  • Regularly clean your vents, exhaust fans, heaters, and air conditioners.
  • Use HEPA Vacuuming Mold at least once a week. You can also install HEPA filters.
  • If cleaning is not appropriate, remove any materials that have already been severely damaged by molds.


When should I call the professionals?

When you have a large area of mold activity or when you are unsure if you are dealing with toxic molds.

Can I get rid of molds completely?

There is no way to absolutely get rid of them. They are part of our everyday life. Simply follow some tips in regulating their growth and in preventing them from invading your homes.

Where can I find hidden molds?

Molds are usually hidden in the upper side of ceilings, under wallpapers, under your sinks, and along your pipes.


Molds are serious problems when left untreated.

Make sure to regularly clean and check areas that are prone to water damages and moisture accumulation for early prevention of mold growth.

Mold buildup is easily preventable with regular cleaning.

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D. Hahn

DIY guru, dad, husband, blogger. When I'm not creating life hacks I'm teaching my kids how to fix stuff after their dad breaks it.

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