Improperly installed windows can allow for moisture to get inside the structure, opening the door (or in this case, window) wide open for mold growth. Frankly, this scenario occurs far too frequently in new construction, older buildings, and renovated homes. While homeowners don’t need to be absolute experts in the field of window installation, it’s important to understand the basics of a proper fit so that you can ask questions of builders or determine if they need to be replaced and done correctly.

HOW DOES MOLD ON WINDOWS OCCUR?

Before getting into the installation process, it’s useful to understand how mold on windows can occur in the first place. Aka, getting to know that fungus among us and why it loves our homes so dearly.

THAT HARDY MOLD

Mold is a type of fungus with over 100,000 species identified so far. Each species reproduces by releasing microscopic spores into the surrounding environment.¹’² Like the seeds of a plant, these microscopic spores will remain non-living particles until they land on a surface with the necessary components for life.

Thanks to their hardy nature, mold spores typically only need four things to begin growing, depending on the species in question.³

THESE FOUR COMPONENTS ARE:

1. Oxygen (they need very little, which is why they can grow inside of walls)
2. Temperature (40-90°F is preferred, but some species can live in extreme temperatures, which is how mold can grow in refrigerators)
3. Food (they eat pretty much everything, like skin cells, wood, and other organic matter)
4. Moisture (the often missing puzzle piece)

If these elements are present for 24–48 hours, that non-living spore will transition into a living organism. Also, like a plant, the living mold colony will put down roots called hyphae on the surface that it’s growing on. Once established, it will start that reproductive cycle and start shooting spores out into the air. Some species of mold can also create microscopic toxins called mycotoxins, further adding to the particle party in the surrounding space.⁴

A MOLD ON WINDOWS DEVELOPMENT STORY

When it comes to mold on windows developing, it often occurs from some type of structural issue that allows for moisture to creep in. A little gap here or a lack of vapor barrier there can let all of that outside moisture from high humidity, rain, and snow come indoors. And that’s not even including accidentally leaving the window cracked during a wet day outdoors.

WHY SHOULD YOU CARE ABOUT PREVENTING MOLD ON WINDOWS? FOR YOUR HEALTH

The lack of discussion and consideration of this indoor contaminant has left quite a large gap in the research needed to fully understand the impact mold exposure can have on health. While we know it can trigger adverse health reactions, the mechanisms behind its ability to impact health aren’t well understood yet. Several factors also make it a tricky subject to nail down.

THESE INCLUDE:

• Genetics
• Immune system status
• Species of mold
• Presence of mycotoxins
• Presence of bacteria
• Volume of exposure
• Length of exposure

Each variable plays a role in whether or not someone living in a home with mold growth will experience adverse health reactions and the extent to which these symptoms will occur. While one person may only have the occasional sinus infection, another may develop over 30 debilitating chronic symptoms or related conditions, such as Chronic Fatigue Syndrome or Chronic Inflammatory Response Syndrome.⁵’⁶

Mold’s ability to affect health, regardless of the mechanism, largely rests on the size of the particles in question. Both spores, mycotoxins, and bacteria are all small enough that they’re measured in a unit called microns, which is 1,1000th of a millimeter. To put it into perspective, you’d have to line up 1,000 microns to equal the distance between the two tiny lines on a ruler.

The EPA dubbed these types of particles particulate matter and breaks them down into two categories.⁷

THESE CATEGORIES INCLUDE:

• PM10: particles that have a diameter of around 10 micrometers or less.
• PM2.5: fine particles that have a diameter of around 2.5 micrometers or less.

Their small size means that they’re able to enter the body through inhalation, absorption, and ingestion.⁸ Some of the particles are so small that they can zip right through the body and straight into the bloodstream. Once they make their way inside, the body tags them as foreign invaders and deploys the immune system to eliminate them as soon as possible. This immune response is often what leads to symptoms and related conditions.

As the exposure continues, the immune system can malfunction, triggering potential autoimmune conditions in the individual affected as inflammation occurs throughout the body. The immune system can also get overloaded and overworked, leading to a buildup of toxins developing inside of the body and a long list of symptoms to go along with it. And, since mold can trigger a systemic inflammatory response, these adverse health reactions can occur in any part of the body.⁹’¹⁰’¹¹’¹²’¹³

SYMPTOMS OF MOLD EXPOSURE CAN INCLUDE:

• Headaches
• Chronic Fatigue
• Brain fog
• Mood swings
• Anxiety and/or depression
• Hormone imbalances
• Digestive problems
• Rashes
• Hair loss
• Coughing
• Sinus issues

Again, though, no two people react the same way to exposure. The potential for a reaction is enough of a reason to build awareness of this indoor contaminant and add preventative measures like avoiding mold on windows to our knowledge base.

PREVENTING MOLD ON WINDOWS THROUGH PROPER CONSTRUCTION

The best way to avoid mold on windows is to start on the right foot from the very beginning. Aka, proper window construction techniques.

Here’s what you need to know about window construction, whether you’re looking to put in a window yourself or make sure the professionals are well-versed in the importance of avoiding mold on windows and are taking the right precautions to prevent an issue.

STEP ONE

The exterior of the building should be clad with a moisture barrier to help create a building envelope system. This material could come in various forms. For example, while older homes often have 35-pound felt paper, newer buildings typically opt for a material such as Tyvek or even more progressive methods such as a zip wall system.

STEP TWO

Once the exterior of the home has been clad in this moisture or vapor barrier, the next step is getting it to terminate correctly inside the rough opening of the window. The exterior vapor barrier surface should extend through the horizontal and vertical surfaces of the rough opening and stop inside the interior component of the home. In short, it should exist between the framing and the drywall.

STEP THREE

When the exterior vapor barrier has been installed correctly, the next thing on the list is to install what’s known as a pan, which helps direct water outside and away from the frame. The newer, progressive methods of creating the pan often utilize butyl rubber. Historically, building professionals used materials such as copper, sheet metal, and lead to create these pans. However, butyl was found to be the superior material in the construction industry because it’s a self-sealing membrane. Essentially, that means that when you put a nail through the material, it will essentially seal around the nail penetration. When constructing the pan prior to setting the window, the pan should extend across the horizontal plane of the bottom opening and up at least 6 to 12 inches on each side. It should extend the full width of the horizontal, lower jamb surface out and down approximately three inches in front of the window’s rough opening.

These strips of butyl typically extend halfway or fully across the lower horizontal butyl. Once these two sections of butyl are applied, a cap of butyl should be placed along the upper horizontal nailing flange, crossing both vertical surfaces and overlapping. Make sure that this layer extends at least two to three inches past the vertical butyl surfaces.

STEP SIX

After this is installed, the siding of choice can be applied. Siding can be anything from vinyl to stucco, cedar shake, and so on.

REACHING THE DESIRED OUTCOME

This method, when completed correctly, creates a primary, a secondary, and a tertiary layer of protection against water intrusion into the interior components of the home. Water intrusion often occurs when there are no waterproofing properties installed over the nailing flange. Typically, this leads to water beginning at the top or midpoint of the window and slowly making its way inside behind the nailing flange, ending up at the lower horizontal surface of the window’s rough opening. This water will start puddling and eventually, thanks to the nature of moisture moving towards drier material, will begin to make its way inside the building and adversely affect the framing, drywall, extension jambs, and trim on the interior components of the window.

Such an event can lead to mold growth, which typically requires the removal of cosmetic surfaces around the window and the window itself to properly correct the issue and ensure contaminants aren’t present in the home that can trigger adverse health reactions.

Following these general directions can help ensure a moldy window scenario doesn’t occur in your home.

HOW DO YOU KNOW IF A WINDOW IS INSTALLED IMPROPERLY?

It can be difficult to 100% guarantee that a window has been installed correctly if you weren’t there for the process. That being said, there are a few signs that could point to a potential problem.

THESE SIGNS INCLUDE:

• A noticeable draft near the window
• Signs of water bandage, like peeling or bubbling paint
• Gaps in the window and the frame (inside or outside)
• Increasing energy bills due to heat let in by gaps in the window
• Fog or condensation in between double-paned windows

If any of these occur, it often indicates an installation problem.

TAKING PREVENTION EVEN FURTHER

Construction is a huge part of ensuring mold on windows doesn’t happen to your home, but the preventative measures don’t stop there. Once this process is completed, those living in the home can also add a few extra steps to their home maintenance routine to ensure issues like mold on windowsills or some other contamination situation don’t arise.

ADDITIONAL WAYS TO PREVENT MOLD ON WINDOWS INCLUDE:

One thing you should never use to handle a mold problem is bleach. ¹⁶

Once you have your tools in hand, you can jump in and get started.

STEPS TO GET RID OF MOLD ON A WINDOW INCLUDE:

• Put on your protective gear
• Place the Benefect Decon 30 into the spray bottle
• Thoroughly HEPA vacuum the entire surface
• Spray the surface with Benefect and allow this to sit for 30 seconds (do not allow this to air dry)
• Wipe the surface using a microfiber towel

Complete this process at least three times to ensure hard-to-remove contaminants like mycotoxins and bacteria are eliminated. It’s also a good idea to deep clean the surrounding areas as well, to remove any particles released by the mold colony. Once you’re finished, either discard your clothes or throw them in the wash with a botanical cleaner like EC3 Laundry Additive.

If it’s still discolored after your remediation efforts, mold could be growing behind the paint, and the surface needs to be removed.

After you’re finished, keep a close eye on the area. If the mold comes right back, there’s a musty odor, or you begin experiencing symptoms, it’s time to call in a mold inspector to see if there’s a hidden issue.

HOW DO YOU KNOW IF YOU HAVE A MOLDY WINDOW PROBLEM?

Figuring out if mold on windows is occurring in your home requires the use of the senses.

Colonized mold often creates an earthy, musty, damp smell while it’s growing due to releasing gases called microbial volatile organic compounds (MVOC).¹⁷ If this odor is coming from the machine, it means there is a problem inside.

HEALTH STATUS INSPECTION

To make matters more complicated, not all mold is visible, and not all growth creates a smell. In cases such as these, it’s important to listen to your body. If you or a family member develops chronic symptoms with no clear root cause, it could be a contamination issue in the home, like mold on windows. Also, if symptoms flare up or develop while in the room or near the window, that can indicate a problem. These responses are the body’s way of alerting you that something isn’t quite right.

Our bodies are amazing warning systems, which is hugely important when it comes to the environment around us and whether or not it’s helping or hurting our ongoing wellbeing. It’s up to us to listen to and figure out what the root cause is so that it can be eliminated.

If any of the three boxes above are checked off, it’s time to get started on creating a plan to properly get rid of mold on windows.

NON-TOXIC WINDOWS FOR ALL