What factors increase the likelihood of mold growth?

Location - some regions have a greater number of mold spores found in the air. Factors that affect this are:

• Humidity
• Amount of precipitation
• Temperature
• Windiness
• Number and type of plants and trees in the area

Time of Year - at different times of the year, there are climate and social factors that can increase the likelihood of mold growth. These factors can originate inside or outside of a property:

• Inside: During fall and winter, when it is colder, people tend to seal up their house and stay indoors, which traps moisture and humidity (humidity can be caused be more persons residing indoors and not allowing a property to “air-out”). This with the warmer temperatures brought on by furnaces, creates a more ideal environment for mold growth. Leaks from roofs, windows, walls, ceilings, or plumbing can dramatically increase the likelihood of mold growth if the moisture is allowed to sit for longer periods of time.
• Outside: During different time of the year there can be more or less mold in the air. In fall and winter when leaves fall to the ground, some plants die, and extra rainfall produces moisture, the decaying plant matter often releases a greater amount of mold into the air.

Household Plants - Certain plants attract the growth of mold, as the mold will feed off the plant matter or wetted soil. Dead or dying plants are more ideal for mold growth as mold plays a key role in the decomposition of organic matter. In addition, the presence of plants requiring wetted soil and water for their survival will increase the relative humidity indoors as much of this water evaporates into the air.

Plants around Property and Neighborhood – For similar reasons as stated above, a greater number of trees and plants will increase the likelihood of mold spores being present in the air. Some molds grow and feed off of living plants while many survive off of dead organic matter. These mold growths can release spores or mycotoxins into the air.

People – The more people there are living inside of a property, using the plumbing systems, sweating, breathing and coming or going increases the likelihood of mold growth and that there will be an increased number of mold spores in the air inside of a property. Use of plumbing, sweating, and breathing increases the relative humidity. Mold grows where this is moisture so this affects that likelihood. The process of coming or going from a property by its occupants increases the likelihood of additional spores being present in the air and mold growth as those occupants often bring back spores with them that become attached to their skin, hair, or clothing.

Indoor Pets – Pets, like humans, sweat and breath. These actions increase the relative humidity inside of a property, which increases the chances of mold growth. In addition, pets that are allowed outside can pickup organic matter and mold spores from the random terrains they travel through and bring them inside of a property.

California Renter's Rights with Mold Contamination

As renters in California, we have the right to live in a safe and healthy environment, which includes the quality of air in our homes, or Indoor Air Quality (IAQ). Mold spores circulating in the air can create harmful living situations and lead to health problems for you and your family.

California is one of only five states to have regulations against mold growth in rentals, recognizing that there is a potential health risk involved with mycotoxins (molds that produce harmful chemical toxins).

Children, the elderly and persons with compromised immune or respiratory systems are at the highest risk for health issues due to mold. Effects can range anywhere from allergic reactions to rashes or repertory issues.

State laws provide us, the renters, with the opportunity to fix the problems ourselves and deduct the cost from our rent. So if your landlord is lagging on fixing your property, you still have options. The Toxic Mold Prevention Act of 2001 (TMPA), established by the Department of Health Services (DHS), sets standards for mold levels in indoor air. The law also allows DHS to identify remediation standards for owners, contractors and landlords.

Mold growth is classified as a factor of inhabitable conditions and is required, by state law, to be taken care of by landlords according to Civil Code 1941.1, Green vs. Superior Court. This includes having proper inspections done by licensed mold inspectors and then having the mold removed from the property by qualified contractors. As tenants we have the right to hire inspectors ourselves to get this work done and take the cost out of the following month’s rent. However, you must give your landlord notice that you are having this work done and give him/her a proper amount of time to fix the issue.

It is also necessary for the mold growth to have been caused by faulty conditions to your home. Mold growth often occurs because of a leak from a pipe, roof or window. If the leak is slow and goes unnoticed for a long period of time, mold growth is practically a give-in and will need to be removed.

Mold growth can also be caused by your lifestyle as a tenant. If you have a lot of stuff in your home, or don’t properly ventilate while cooking and/or showering, condensation can build up in your home and cause mold growth. If this is the case, your landlord is not responsible for funding the repairs. However, if proper ventilation devices are not available in your home, then that is your landlord’s responsibility.

A properly licensed inspector should be able to find the cause of mold and you can figure out who’s at fault and should fund the repairs from there.

The most important factor to be aware of when it comes to mold in your home is the potential health risk involved. If you are feeling any symptoms while in your home, you should have it checked for mold. Even if you can’t see mold growth, that doesn’t mean it’s not there. It could be behind the paint on your walls, or in the drywall or just not visible to an untrained eye. If you are away from you home for a few days and these symptoms go away, that is a sure sign of issues in your home.
Even if you are not experiencing symptoms from mold, it can still affect your home and property. Mold can take away the integrity of the framework of your home and also your belongings. Things such as couches, mattresses, clothing, furniture, tables, etc. can all be ruined by mold growth.

It is important to know that under California law, repairs cannot be made by you, the tenant, and then deducted from your rent. You must hire a licensed professional to do the testing and work for you if you intend to have the work paid for by your landlord.