What Causes Mold on Windows?

Discovering mold on windows can be a regular occurrence under certain circumstances so it can be useful to know why it occurs. Being aware of what to look out for can help you to rectify the problem as well as ensure that the problem doesn't keep coming back.

Plant Life

As pretty and decorative as pot plants and vases of flowers can be, they can also be damaging when stored on window sills. The close proximity to the windows can result in the transfer of organisms which can result in mold on windows. Though the plant life may appear unaffected by the presence of the natural materials that make them up, they react differently with different materials. Bacteria can be present in soil that can affect the materials that it comes into contact with.


Mold on windows can be the result of the window area being subjected to an increased temperature. You will often find that this is the case where the method of heating the room lies directly below the window, as radiators often are. If possible, move the heat source to another location or increase the amount of ventilation that the room enjoys.


Debris and grime left to remain on glass panes can provide fuel which can result in mold on windows. Mold will feed on all matter of different materials with dirt being just one of them and it will continue to grow as long as it has a source of food and the conditions are suitable. Ensuring that the windows remain dirt-free will help to prevent mold spreading.    


The difference in temperature between the inside and outside of the glass can result in condensation. This water can cause mold on windows as it thrives in damp conditions. The wet and steamy conditions of bathrooms and kitchens means that this will often be a problem in these rooms. Increase ventilation in the rooms where water is often used and remove any condensation that does develop by wiping it away with a dry cloth.  


If a weatherization method is absent or defective, water can be allowed to enter the property and cause mold to develop. Fit a weatherization method where you do not already have any, especially when it comes to older windows. If you have a weatherization method in place, but mold is still a problem, check to make sure that it has not developed a defect and repair or replace if it has. Make sure that the method that you choose is suitable for the type of window.  


You are likely to find that there is a difference between windows that are opened regularly and those that are not. A lack of ventilation can result in mold growth as moisture and mold spores in the atmosphere will not have an escape route. In addition, the absence of fresh air can also be the cause of the increased temperatures that mold benefits from. If opening the windows to provide ventilation is not suitable, consider fitting vents or air bricks.