Latest Mold Prevention & Mitigation Guide for Property Managers

Your rental property is a major investment that needs to be maintained properly to remain valuable. If not, your tenants either leave or pay less rent, resulting in lower returns. Unfortunately, mold growth is one of the most serious threats to any property, especially if you live in flood-prone areas or humid climates. In fact, the National Center for Healthy Housing says that there are over 1,000 types of mold found in U.S. homes. If left unaddressed, it may cause health problems to your tenants, such as respiratory and skin irritation, eye irritation, and allergies. This may also lead to lawsuits for housing code violations or negligence. Moreover, it can damage the structure of your property.

Where Does Indoor Mold Come From?

Mold is a type of fungi naturally present in the environment. They reproduce through tiny mold spores that float through outdoor and indoor air. Mold spreads into indoor spaces when mold spores land on wet surfaces inside your building. 

They usually grow on paper, ceiling tiles, cardboard, and wood. When this occurs, molds produce allergens, which can cause allergies to some people.

Common sources of moisture include:

  • Leaking pipes
  • Condensation from air conditioning units
  • High humidity levels in bathrooms and kitchens
  • Water seeping up through basement floors or walls after flooding or heavy rain storms

How to Prevent Mold Growth in Rental Properties

Taking preventative measures to stop mold before it starts is much easier than dealing with infestations once they occur. Here are some tips for preventing mold:

Tip #1: Inspect Your Property Regularly

You may ask what “regular” means, but at least once or four times a year is reasonable. You don’t have to check it excessively as it evades the privacy of your tenants. Remember, it’s their right to be protected from any kind of invasion.

The only exception is when a disaster occurs, like sudden burst pipes or flooding caused by a heavy storm. In such cases, you should make your inspection part of the overall damage assessment. See signs of mold growth in areas, including the roof eaves, walls, and carpeting.

Tip #2: Check for Leaks and Condensation Problems

Leaking pipes are a major source of moisture that can lead to mold growth. During your inspection schedule, see water stains on the walls or ceilings, moisture around windows, and other signs of water damage.

Condensation starts as small water droplets that appear on cold surfaces like windows, walls, and pipes. This can lead to mold growth in the long term if left untreated. Check for condensation problems by feeling your walls and looking around pipes, ducts, and other areas where they may be present.

Tip #3: Keep Moisture-Prone Areas Well Ventilated

Proper ventilation is essential for preventing indoor mold buildup since it helps reduce humidity levels and prevents moisture from accumulating inside your property. Make sure your tenants are aware of proper ventilation techniques in areas susceptible to moisture, such as using exhaust fans in the kitchen and bathroom when possible.

Tip #4: Monitor Indoor Humidity Levels

High humidity levels can result in mold growth, so ensure your tenants know this risk. Use a humidity monitor in areas that may be prone to moisture problems, like basements or attics. You can buy this from your local home improvement store.

Keep an eye on the readings to ensure they don’t exceed 50%, as humidity levels can change throughout the day. If they exceed over 50%, take steps to reduce it through air conditioners, dehumidifiers, or opening windows if possible.

Tip #5: Enforce Your Property's Tenant Rules

Do your tenants know about your property’s rules for preventing mold growth? It’s always a good idea to emphasize this in your contract. These can include not storing anything on wet carpets and regularly maintaining any air conditioners or dehumidifiers they have in their units.

You might also want to consider adding provisions to your tenants’ leases or rental agreements that outline specific steps they should take to prevent mold and other types of water damage. An example could be regularly inspecting sinks, pipes, and areas near windows for signs of moisture accumulation or leaks.

Tip #6: Proper Maintenance and Cleaning

Regularly cleaning and maintaining your property is key to preventing mold growth. Have your maintenance staff check all plumbing fixtures, seal any holes and cracks in walls, replace worn-out caulking around windows, regularly clean the gutters, and inspect the HVAC system. 

If you spot moisture in your air conditioner or heating system that may lead to mold growth, act quickly before it can become a full-blown problem. Remember that while you cannot totally eliminate mold spores indoors, they will not multiply if you stop the conditions that support their growth.

Make sure to document all repairs made so that you have proof in case of tenant disputes or insurance claims.

A Step-By-Step Guide to Remove Molds in Rental Property

These steps are only applicable for minor mold infestation. Seek professional help for severe mold issues (at least 10 square feet of surface area).

  • Ventilate the area by opening windows or running an exhaust fan.
  • Wear protective clothing like gloves and a face mask.
  • Clean the mold with a damp cloth or sponge using a safe and effective solution.
  • Use specialty cleaners to help remove stubborn molds, like vinegar and tea tree oil solutions.
  • Dispose of all materials used in cleaning moldy areas properly, according to environmental regulations, so that it does not contaminate other parts of the property or cause health issues for tenants or neighbors.
  • Dry affected areas completely before any repairs are made since moisture is what encourages mold growth in the first place.
  • Encourage tenants to use dehumidifiers and air conditioners to reduce humidity levels in their rental units.
  • Take pictures or video recordings of any moldy areas before, during, and after clean-up to show evidence of your efforts should there be a dispute with a tenant later on.
  • Once the area has been cleared, conduct regular inspections every few months to ensure there are no new infestations.
  • Use professional mold remediation services in case of severe mold infestation. If you find that there is already a severe mold problem on your property, it’s best to contact mold removal experts. They are sufficiently equipped and experienced to take care of the problem properly and in a timely manner. This will ensure that your tenants remain safe and healthy and that the mold infestation doesn’t spread further.

Home-Made Solutions and How to Use Them to Remove Mold

When cleaning minor indoor mold growth, you can use the following DIY solutions with materials you can buy at your local grocery store:

Baking Soda + Vinegar + Water

  • Mix two parts of baking soda with one part of vinegar and one part of water.
  • Stir the mixture to make a thick paste.
  • Spread into the moldy area and let it dry.
  • Scrub away the mold and stains and wipe with water.


  • Juice 3 to 5 lemons into a container and pour over the moldy surface.
  • Leave it for 5 minutes before wiping it with a damp towel.
  • Reapply and scrub for tough mold stains, if necessary.

Tea Tree Oil

  • Mix one tsp of tea tree oil and 1 cup of water in a bottle spray.
  • Shake it vigorously for the ingredients to blend.
  • Use it t spray into the moldy area.
  • Leave it for at least 1 hour and wipe it with a dry towel or microfiber cloth.

Note: Other people may be sensitive to essential oils, so make sure to wear protective gloves to avoid skin irritation when doing DIY mold removal.

Hydrogen Peroxide (HP)

  • Pour a 3% concentration of HP into a spray bottle.
  • First, test a small surface area to prevent damage or discoloration.
  • If it’s safe, spray it into the moldy surface and let it sit for at least 10 minutes.
  • Scrub the area with just enough force to remove mold and stains.
  • If you see that the surface is clean, wipe it dry with a clean towel.