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Why is There Mold on Window Sill?

8 minutes

Types of Mold Found in Homes 

The mold that can be found in your home comes in a very wide range of colors and looks. According to the CDC, the most common molds are Cladosporium, Penicillium, and Aspergillus. 

Mold can be brought into your home in a variety of diverse ways such as coming through your vents, through your windows and even on your clothing after being outside. After the spores have been transferred inside your home, they look for wet spots so that they can grow and reproduce. 

While there could be a wide range of molds that could be present the most concerning is stachybotrys chartarum, or more commonly known as black mold. Black mold is notorious for being hard to get rid of and could be a clear sign of problems with the functionality of your home. 

Symptoms of Mold Exposure 

The more common symptoms of mold exposure are:  

  • Itchy red eyes 
  • Watery eyes 
  • Cough 
  • Sore throat 
  • Shortness of breath 
  • Skin rashes that 
  • Sinus headaches 

Those who have asthma, or a mold allergy may have stronger effects to mold. According to the CDC, there have been recent studies that have pointed out that early exposure to mold in children could lead to the development of asthma. This is more so for children who are genetically prone to asthma as well. 

Where Does Mold Grow the Most? 

Mold does like to grow in the wet spots of your home where leaking has occurred such as your pipes, roof, walls, or any place where there may be leak and excess moisture. It will also grow on the window sill and between the panes from condensation. Mold around the windows is a clear sign that the windows have lost their efficiency and functionality and therefore should be replaced. 

Condensation Within Panes 

Especially during the winter season, Condensation can become more present around the window area. The dry warm heat from inside interacts with the cold moist air coming from outside therefore causing condensation. This condensation can then cause mold if left unchecked. We created an article on how to get rid of window condensation from inside and from the outside of the window.  

How to get rid of Mold on window Sill 


Vinegar is an excellent treatment for killing that mold that is present around the window. White vinegar has an extremely high acidity that will break down the mold organism. The best way to use vinegar is to put it in a spray bottle and then spray the area that is affected. You can then take a clean cloth and wipe away any remaining mold. If you have a tough spot of mold, you may need to let the vinegar sit for a few minutes before wiping it away. Keep the window open afterward to dry the area. 

Baking Soda 

Baking soda is another wonderful way to clean off the mold that is on the window. It is known that baking soda has natural cleaning properties that will kill the mold and also help to prevent it from coming back. To use baking soda, you will want to make a paste with water and then apply it to the area that is affected. You will then want to let it sit for about an hour before wiping it away with a clean cloth. 

You can also choose to mix the baking soda with vinegar to create a more powerful cleaning solution. To do this, you will want to mix equal parts baking soda and vinegar together and then apply it to the area that is affected. You will then want to let it sit for an hour or so before wiping it away with a clean cloth. You may need to repeat this process a few times to completely remove the mold. 

Chemical Mold treatments 

If you have a spot of mold that is tough to get rid of, you may want to try a chemical treatment. There are many distinct products on the market that are designed specifically for mold removal. You will want to follow the instructions on the product label and take any necessary safety precautions. You may also want to ventilate the area well when using any chemical products. Make sure that the chemical product you use is safe to use on the window material as well as the frame.  

Safety Precautions Prior To Cleaning Mold 

No matter what method you choose to clean the mold, there are some safety precautions that you should take. First, you will want to make sure that you are wearing the proper safety gear. This includes gloves, goggles, and a mask. This will help to protect you from any toxic spores that may be released into the air when you are cleaning the mold. You will also want to make sure that the area you are working in is well ventilated. You can do this by opening a window or door to let some fresh air in. After you have cleaned the mold, make sure to wash your clothes to make you do not spread the spores to other areas of your home. If you have any respiratory problems, you may want to consider having a family member or hiring a professional to do the job for you. 

How to Prevent Black Mold on Window Sill 

The best way to prevent mold is to keep the area around the window clean and dry. You will want to wipe down the window sill and frame on a regular basis. Make sure to dry the area well after you have cleaned it. You will also want to keep an eye out for any condensation and moisture on the window. If you see any, you will want to wipe it away and dry the area well. You can also use a dehumidifier in the room to help keep the air around the window dry. Taking these steps will help to prevent mold from growing in the first place. Make sure your exhaust fans are working and your family is using them when taking baths and showers as well as in the kitchen. Open windows and doors in your home to help to bring fresh air into your home. If your home has an air conditioner, make sure it is operating efficiently and the drip pan is clean and drain pipes are clear of debris.  

Leaving windows Open During the Winter Can Promote Mold Growth.  

One of the main causes of mold is moisture. When there is excess moisture in the air, it can condense on cold surfaces, such as windows. This can happen even if the temperature outside is not that cold. When this happens, it can create the perfect environment for mold to grow. Leaving your windows or doors open during the winter, when there is cold moist air in the home, can promote mold growth in your home.  

Is Mold Dangerous & Toxic to Your Family 

Mold can cause a variety of health problems, especially in young children, the elderly, and those with respiratory problems. Mold can cause coughing and wheezing, as well as aggravate asthma symptoms. In some cases, mold can even cause serious infections. If you or a family member starts to experience any of these symptoms, you should see a doctor as soon as possible. 

Although, in general mold is not something that should be taken lightly, there are thousands of diverse types of molds that are found across the world. It is almost impossible to tell if mold is dangerous without taking it to a laboratory and having it tested. The best thing to do is to monitor your home and clean the area where mold is present as soon as possible.  

Consider Replacing Your Windows With DaBella

If your windows are getting to the point where they are getting old in age and are no longer keeping the cold out or the heat in like they used to, it may be time to replace them. Old windows can develop gaps and cracks over time that can let in drafts of air. This can not only make your home less comfortable but can also make your energy bills go up and increases the chances for mold growth around the windows. Replacing your windows with newer windows can help to seal up any cracks and gaps and can also help to improve the insulation of your home. This can help to keep the mold away and can also help to lower your energy bills. 

If you are interested in learning more about DaBella’s replacement windows and sliding glass doors, our vinyl Glasswing windows have proven to be the homeowner’s choice for the last several years. Our windows and doors are backed by a manufacturer limited lifetime warranty and are energy star rated. They are also made of durable materials that will not warp or rot. This means that they will last for many years to come and will help to keep your home comfortable and energy bills low. Contact us today at 844-DaBella to learn more about our replacement windows and doors and to schedule a free in-home consultation.