What's the best permanent fix for a moldy closet?« Back to Previous Page

That sounds like a classic case of interstitial condensation, a very common issue in Marina apartments due to the high ambient humidity and constant temperature differentials between air-conditioned rooms and warm exterior walls.

The most effective long-term solution requires addressing the root cause: the temperature of that exterior wall. A standalone dehumidifier only treats the air's moisture, not the cold surface where condensation forms. The permanent fix is to improve the wall's insulation to bring its surface temperature closer to the room's air temperature, thereby preventing condensation from forming in the first place. For a built-in closet, this often means removing the backing (plasterboard/drywall) to install closed-cell spray foam or rigid foam board insulation directly against the exterior wall. This creates a thermal break. After insulation, the wall must be sealed with a vapour barrier before replacing the drywall to prevent any moist indoor air from reaching the now-colder exterior wall behind it.

Before any remediation, a professional inspection with a borescope camera is crucial to assess the mold growth's extent within the wall cavity. Simply wiping the visible spots is a temporary measure. For the contents, professional ozone or hydroxyl treatment can eradicate mold spores from fabrics like your jackets without harsh chemicals.

Finally, ensure the closet has adequate air circulation. Leave doors ajar occasionally and consider installing a small, passive vent grille in the closet door to allow conditioned air from the room to circulate inside, which will help maintain consistent temperature and humidity levels.