Mold On Wall

Mold is a type of fungus that, like all fungi, mainly grows on moist surfaces. Molds spread with the help of spores. These spores are all around us but cannot be seen by the naked eye. Mold spores enter your home either by the medium of air through open windows and doors or by clinging people, pets, or objects. Mold growth in your home can have adverse effects on your home and even on the health of the people living in it. Even though not all molds are harmful, some of them are toxic and can cause health problems in people who have weak immune systems. Mold exposure over a long period of time can cause allergic reactions in people who have a mold allergy. It can also worsen the condition of asthmatic people and cause respiratory problems in people with weak immune systems. So toxic molds pose a serious health risk to infants and old people. If you find any mold growth in your house, you must remove it completely as soon as possible.

       Unfortunately, there are a lot of areas in your house that provide suitable conditions for mold to breed. The one thing common in all these areas is that all of them have a presence of moisture. Following are some of the common breeding grounds for mold in your home:-

  • Under the kitchen sink.
  • On dishes that haven’t been dried properly.
  • In different areas of the bathroom that provide moisture, such as walls, bathtub, etc.
  • Refrigerator drip pans.
  • Air conditioners.
  • Plumbing leaks.
  • Bath toys of infants.
  • Mattresses.
  • Carpets and upholstery.
  • In the crawl spaces of basements and attics.
  • On walls, both interior, and exterior.

If you find an extensive growth of mold in an area of your house, you are suggested to hire a professional mold remediation service. A typical household doesn’t have the professional equipment and expertise that are needed to deal with extensive mold growth. Otherwise, if the growth covers a small area, you can remove it yourself if you choose to. But you must do it using the right equipment and product and also by the right method. You must also take certain precautions while doing this task.

         In this article, we are going to have a look at how to prevent and get rid of mold growth on walls. But before that, let’s have a look at some information about mold growth on walls.

Types of mold on walls

There are different types of molds that can grow on your walls. They can be identified by the different colors that they have. Following are the types of molds that you might find on your walls and your house in general:-

1.Black mold

Black mold is actually not just one specific type of mold. There are different types of black moles. But when talking about black mold, people generally refer to the Stachybotrys family of mold. There are two types of molds in the Stachybotrys family: Stachybotrys chartarum and Stachybotrys atra. The molds from the Stachybotrys family contain mycotoxin and pose health risks to people who are exposed to them over a considerable amount of time. Black mold or toxic mold is considered the most dangerous among all types of molds.

2.Yellow mold

Some types of fungus aspergillus are yellow in color and are called yellow mold. This type of mold can grow in any area of your house that has faced water damage. So in case, your walls have faced water damage, you might find yellow mold growing on them. One particular type of yellow mold called serpula lacrymans, can eat up the whole wooden structure that it grows on. That makes it very dangerous for your house. You must fix all water damages on surfaces and walls as soon as possible to protect them from this house eating mold.

3.White mold

There are three main species of white molds that grow in homes: Penicillium, Cladosporium, and aspergillus. White mold is colored so due to lack of pigmentation. People often mistake white mold on their walls for effervescence. So you must make sure to properly identify white mold growing on your walls.

4.Red mold

Red mold is not as harmful as black mold or yellow mold. It doesn’t pose any serious health risks. But it can still cause respiratory diseases in people with mold allergies, just like all other molds can. Regardless of whether they are harmful or not, the red mold must be removed as they are as unsightly as other mold types.

Causes of mold growth on walls

There are various causes of mold growth on or behind a wall. They are as follows:-

1.Water damage

Water damage is perhaps the most common cause of mold growth. Since it provides for the moisture that molds need to grow, a water damaged wall is a perfect breeding spot for mold. Getting all water damage fixed is the best way to prevent the growth of mold in or on walls. Besides preventing mold, getting the water damage fixed will also prevent further damage to the wall. Water is capable of doing a lot of damage to a wall in a matter of a few days.

2.Leaky pipes

A leaking pipe inside a wall can also cause the growth of mold by increasing moisture inside the wall. Once the mold gains a foothold inside the wall, it would be quite difficult to remove it. So you are advised to inspect your walls for any leaky pipes and get them fixed if you find one. Prevention is always the best measure to take. 

3.Building materials contain cellulose

Since cellulose is an organic matter, it is a food for all types of fungus. If your walls have building materials made of cellulose, they would make for a suitable breeding ground for mold. This is yet another factor of mold growth in your walls. Mold can also grow on the drywall.


Yet another factor that might contribute to mold infestation on your walls is condensation. You must not confuse condensation with dampness. Condensation causes damp in walls and the dampness causes mold growth. Condensation on a surface occurs when moist air comes with a surface that is colder than it. Since the surface of your walls is the coldest during winters, condensation is at its highest during that time. It causes mold to grow in areas like laundry rooms that have high humidity.

Signs of mold on walls

If there is mold growth on your walls, it will show some signs. These signs would be helpful to you for the purpose of detecting mold growth in your house. Following are the signs that might indicate the presence of mold in your walls:-


When there is mold on the surface of your wall or behind it, it will certainly cause discoloration. This is perhaps the easiest sign to help you detect a mold problem. If you see an unexplained discoloration at any part of your wall, you might want to inspect it for the presence of mold.

2.Musty odor

Mold problems always cause a musty odor. This is another sign that you are certain to get if there is mold in your home. If you have been experiencing an unexplained musty odor in your home, it could be due to mold. You are suggested to inspect your home for mold if you get this sign.

3.Soft and moist surface

Another sign that you must look for mold on a surface is whether the surface feels moist and soft. If you find it to be soft and moist, it might be due to mold growing on the surface. Though there can be other reasons for it too. But if it is unexplained, then you are suggested to inspect the surface for mold.

4.Health problems

Exposure to toxic mold for an extended period of time can cause the following problems:-

  1. Allergic reactions: Exposure to mold for an extended period of time can cause allergic reactions in a person with mold allergy. These include sneezing, runny or blocked nose, skin irritation, wheezing, etc. If any person in your home who has mold allergy starts showing these symptoms, it is probably an indication of mold in your house. You might want to inspect your house for mold in this case.
  2. Respiratory problems: Exposure to mold problems can cause respiratory problems in people who have weak immune systems and people who have mold allergies. It can also worsen the condition of asthmatic people. Mold exposure mostly affects people with weakened immune systems, such as old people and infants.

If any person in your home is having any of the mentioned health problems inexplicably, you must get your home inspected for the growth of mold. It is not to be taken lightly.

How to get rid of mold on walls

Once you find mold growing on your walls or behind them, the next step is to get rid of them as soon as possible. You must kill the mold regardless of its type. All molds are bad for your house. If the mold has grown over an extended area, you must hire professionals from mold remediation service. A typical household wouldn’t have the professional equipment or expertise required to deal with an extensively grown mold. But it is a different matter if the mold has grown over a small area. In this case, it is possible to deal with mold problems in a few simple steps. But for that, you would need the right equipment and follow the right method.

        Following are the equipment and products that you need for effective removal of molds from your walls:-

  1. Personal protective gear such as rubber gloves, N-95 respirator mask, and goggles.
  2. Scrub brush
  3. Spray bottle
  4. Sponge
  5. Plastic sheeting
  6. Garbage bags
  7. Bleach solution, baking soda solution, white vinegar solution, tea tree oil, mild soap, commercial mold cleaner (any one of these products).


       Having arranged for the products mentioned above, you can move on to the mold removal process. You can effectively kill off mold from the walls by the following methods:-

1.Removing molds from painted walls

In case of mold removal on a painted wall, you must use a white vinegar solution or tea tree oil. Both of these products can be domestically prepared. Moreover, these products are completely organic. All you have to do is spray the solution on the mold-infested area. After that, you must seal the area for two days. During these two days, you must completely restrict people from this area. After the end of this period, you must check if the mold is gone from the surface. Also, you must arrange for proper ventilation in the room you’re working in so that you don’t inhale the mold. Otherwise, it might cause health problems.

       If the mold has not left the surface after two days, you must use a strong commercial mold cleaner. There are a lot of suitable commercial cleaners available in the market. You must choose the best one that you can get in order to get the best results.

       After removing the mold, you must use mold-resistant paint to repaint the wall. This would prevent any future mold infestation on the wall.

2.Removing molds inside walls

Removing mold from inside the wall is a difficult task. It would need professional expertise and equipment to get the job done. To effectively remove mold inside a wall, you would need to have the outer layer removed and inspect the inner layer. After this, you must scrub the mold-infested layer thoroughly using the scrub brush. But due to the nature of this task, you must hire professionals from a mold removal service.

      In order to prevent any future mold infestation inside the walls, you must get any water leak inside the wall fixed.

3.Removing molds from bathroom walls

Bathroom walls are the most prone to molds among all the walls. This is mainly due to the damp conditions of the bathroom. Also, the growth of molds is faster in the bathroom walls as compared to those of other areas. To remove molds from bathroom walls, you can use a bleach solution to scrub the infected area. You can prepare this solution domestically. The right way to prepare it is to add 1 part bleach to 10 part water.

       If the homemade bleach solution doesn’t work, you must get a strong commercial cleaner. In order to prevent future infestations, you must: 1) Use the exhaust fan for at least 10 minutes after using the shower, 2) Inspect the grout lines and change the grout lines if broken, 3) In case your bathroom has plastic shower curtains, don’t let water droplets gather on them.

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