What causes mold in a house during winter?

Many people think of mold as an issue primarily in the fall, summer, and spring, yet it can also pose a problem in winter. Mold doesn’t die, it merely enters a dormant state. While the cold temperatures of winter may make mold less visible, it remains a potential hazard in households just like during warmer seasons.

Even though winter’s chill can inhibit mold growth, dormant mold is not without its risks. In most regions, snow and ice will eventually melt. This water reactivates the dormant mold, causing potential damage. Water damage does not discriminate against the season.

It should be noted that certain mold species can thrive even in freezing or Arctic temperatures. However, in most cases, mold simply enters a dormant state when the temperature drops to freezing. Thus, preventing mold growth in winter is crucial.

It’s important to understand that fluctuations in temperature create ideal conditions for mold growth. Mold behaves differently in the cold, particularly within ice, snow, and water. The regular cycle of freezing and thawing leaves outdoor surfaces damp. When temperatures drop below 60 degrees, moisture evaporation is slowed. Bursting often occurs in freezing pipes. Furthermore, the frozen ground and dormant vegetation outdoors slow down moisture absorption, leading to the accumulation of standing water.

As part of nature’s decay process for organic matter, mold continues to grow both indoors and outdoors. Microscopic mold spores, akin to seeds, can easily become airborne due to disturbances and ventilation. These spores begin to grow when they land on a damp surface or object. Mold spores flourish in warm, moist environments. Winter brings additional moisture with extra rain, melting snow, and ice. Additionally, indoor heating due to colder outdoor temperatures can raise the temperature inside our homes. Keeping an eye on melting ice and snow can help prevent mold growth during winter.

Why Mold Grows in the Winter

Mold, a type of spore-producing fungus, has the ability to thrive in various environments, both indoors and outdoors. These spores disperse through the air, finding a suitable dwelling on damp surfaces or objects.

So, what triggers mold growth in our homes during the winter? Well, mold spores flourish in warm, moist conditions. As winter arrives, it brings an abundance of moisture from rain, melting snow, and ice. Additionally, the colder months prompt higher indoor temperatures due to heating systems.

It’s important to note that mold spores are present in all indoor settings. While it’s impossible to prevent their existence, there are measures you can take to ensure your home is less hospitable for their growth and colonization.

Indoor Condensation

Condensation is the process by which water vapor transforms into a liquid state. It occurs in two ways:

Cooling the air until it reaches its dew point.

Saturation with water vapor until it can no longer hold any additional water.

Condensation is an inevitable occurrence and is the reverse reaction of evaporation, where liquid water transitions into a vapor state.

Areas such as windowsills and door frames are often exposed to moisture due to condensation. Additionally, spaces with poor air circulation, like behind walls or in closed closets or attics, can experience increased mold growth.

During the winter, it’s important to investigate certain places and objects in your home where mold is likely to develop:

Walls and wallpaper

Roofs, particularly on the attic side where there is metal or glass

Windows and sills

Pipes

Wood surfaces

Ceiling tiles

Insulation

HVAC systems (including plumbing and drainage)

Ductwork and registers

Regular inspection of these areas can help prevent mold growth during the winter season.

Ventilation

While HVAC systems are intended to be designed with consideration for floorplans, ductwork systems, and temperature variations in homes, the reality is that this analysis is rarely carried out. Developers often rely on existing floorplans, and HVAC systems are frequently installed or replaced without accurate calculations or balancing. One crucial aspect of a healthy home is the continuous movement of air, as proper ventilation plays a vital role in preventing the formation of mold and the accumulation of dust.

Some Homeowners Mistakenly Introduce Indoor Humidity

While some may find it absurd, maintaining indoor humidity is not a priority for me. However, I understand that dry, cold weather can cause discomfort for individuals, particularly when it comes to sinuses and moisture-related issues. Consequently, many people resort to using humidifiers to introduce moisture into the air. It is widely acknowledged that humidity levels should be kept below 60% to prevent the growth of mold. Unfortunately, most humidifiers fail to reach these desired levels, and ironically, they can even contribute to mold proliferation. As air, along with dust particles, is drawn into the humidifier, it comes into contact with water and a filter. Regrettably, these filters are notorious breeding grounds for mold growth. Consequently, when the humidifier pulls air through the mold-infested filter, it unwittingly disperses mold spores into the surrounding air.

Decomposing Fall Leaves and Soil

Mold spores can easily be brought indoors, hitching a ride on shoes, clothing, and even pets, originating from leaves and soil. As autumn arrives, the decaying and crumbling of fallen leaves become a breeding ground for mold growth, an integral part of the natural process. It’s nearly impossible to completely rid your yard of all leaves, and in my experience, as you clear them, more will inevitably continue to fall. Additionally, any rainfall only aids in the breakdown of leaves.

Insulation, Attics and Crawlspaces

In the event of a small roof leak, there is a possibility that the insulation may absorb water for extended periods. This can lead to the saturation of the insulation with mold-contaminated water.

Such contamination may result in minor dampness on ceilings and walls. As the weather warms, the mold will activate and proliferate, affecting the paper backing of the drywall and wooden studs. It is imperative to replace the moldy insulation and perform necessary repairs on the drywall and cleaning of the wooden studs.

Storage

It is common for individuals to store belongings in cardboard boxes within basements and attics. However, due to limited air ventilation in these unfinished areas, moisture and dust accumulation is prevalent. Cardboard and other paper materials readily absorb moisture, leading to the growth of mold and decomposition.

Things To Do This Winter to Prevent Mold Growth

Ensure that every area of your home is kept clean and well-ventilated to the best of your ability.

Keep humidity levels below 60% and ensure proper air circulation. If necessary, consider investing in a dehumidifier.

Maintain dryness and cleanliness in areas prone to mold growth. Regularly clean surfaces and objects that are susceptible to mold, paying special attention to windows, sills, corners in the kitchen, showers, and bathrooms. Stay vigilant for any signs of leaking or flooding. Remember to wash and dry bathmats, kitchen and bath towels, and other moisture-absorbing fabrics. Consider using mold-prevention products when cleaning your home, especially on hard and porous surfaces.

Don’t neglect outdoor water management maintenance. Regularly inspect areas outside your home where water may enter, such as gutters, outside windowsills, sheds, and drains. These areas can become breeding grounds for standing water, which can lead to decay and water penetration into your home.

Rapidly Address Leaks

Regularly inspect drains and exposed plumbing in and around your home for any signs of leaks. Areas affected by water damage, whether from leaks or flooding, provide an ideal environment for mold to grow and spread rapidly. That’s why it is crucial to promptly identify and repair leaks to prevent mold growth.

Exercise Caution When Storing Items for Winter

Many of us store summer clothes, camping equipment, outdoor gear, and other warm-weather items in basements, garages, sheds, or other out-of-the-way spaces. Ensure that all items are thoroughly cleaned and dried before storing them. Whenever possible, store summer gear in plastic tubs (avoid cardboard boxes) or on shelving units that are elevated from the ground. This will help keep them dry throughout the winter, even in the event of leaks or flooding.

Test Your Home for Mold to Safeguard Your Property and Family

Call Restoreez to schedule a professional mold inspection and testing. Our certified professionals will conduct a thorough assessment of your home, including areas that are prone to moisture and mold growth. With expert guidance from Restoreez, you can take proactive steps to address any existing mold issues and prevent future problems.