Moisture and Mold in Your Home

Moisture and Mold in Your Home

Mold in your home is more than just an unsightly issue—it poses significant health risks. Mold often appears as dark stains on walls, especially in corners, around windows, behind furniture, or even hidden under wallpaper. Anyone who has dealt with mold knows how persistent and difficult it can be to eliminate. The best solution is to prevent such issues during the construction phase.

Mold growth is typically a result of damp building materials or excessive indoor humidity, often caused by inadequate ventilation. This problem is most common during winter, when significant temperature differences between the indoors and outdoors lead to condensation. After winter, it’s essential to inspect walls behind furniture, especially if mold has been a problem in the past.

Unfortunately, this issue is increasingly common in newly constructed buildings. Rapid construction schedules often leave insufficient time for proper drying and seasoning of materials. Additionally, thermal insulation in external walls and top-floor ceilings is sometimes inadequate. Poor insulation leads to condensation on "cold walls," while thermal insulation errors can result in thermal bridges—areas that are poorly insulated against cold and moisture. These bridges are common around windows, doors, and where walls meet ceilings or other walls.

Another source of moisture is leaking pipes within walls. Dampness can also occur due to capillary action from the ground, which happens when foundation or basement walls lack proper waterproofing.

How to Deal with Mold in Your Home

Anyone who has dealt with mold growth knows that simply removing the visible mold and cleaning the walls is not enough. The root cause of the mold must be identified and addressed. Excessive humidity in the room, often due to infrequent ventilation or faulty ventilation systems, is a common culprit. If windows are too airtight, consider installing air vents or replacing the windows with ones that have micro-ventilation. Additionally, a dehumidifier with replaceable cartridges can help control moisture levels.

For more severe issues, a renovation may be unavoidable. Mold growth often requires not only removal but also scraping off the affected plaster. Because mold spreads quickly, it's best to remove plaster from a larger area than just the visibly affected part. Removing mold spores minimizes the risk of recurrence. Once the surface is cleaned, apply a fungicidal agent. Repaired plaster should ideally be finished with specialized paint that has bactericidal or hydrophobic properties, which reduce moisture absorption.

It's essential to remember that mold spores settle throughout the home. Clean window frames, sills, and other surfaces with mold-removing agents. Wash all fabrics, including curtains, drapes, upholstery, and throws, to ensure a complete mold-free environment.

How Long Before Moisture Issues Appear?

From a client’s perspective, it’s difficult to determine whether the waterproofing of foundations or roofs was done correctly. Often, we only notice the consequences of poorly executed construction work.

Errors at the foundation level are usually invisible. For example, cracks in a "white tank" system—one of the most common waterproofing methods—tend to appear over time. Building settlement is a gradual process. Movement in the structure, leading to cracks, begins once the construction is covered and gains additional weight (e.g., finishing materials, furniture, and other household items). The first problems, including cracks, may emerge approximately two years after construction, as the structure starts bearing tons of extra load.

Horizontal waterproofing with roofing felt typically begins to allow moisture through seams after about 5–8 years, leading to capillary water absorption. The initial signs of dampness tend to appear gradually over time.

External waterproofing errors are also common. Masonry elements can start absorbing moisture as the materials age.

Even small issues, such as a hole in mounting foam, can lead to moisture problems. For example, prolonged UV exposure can degrade foam, allowing water to infiltrate the wall structure through tiny openings. Moisture migrates and can find its way into the building through even the smallest gaps, emphasizing the importance of high-quality materials and proper installation.