How to treat and prevent mold on humid sea-facing wall?« Back to Previous Page

That black mould behind the wardrobe is a classic issue for sea-facing apartments in Marina, caused by a combination of high external humidity and a cold interior wall creating condensation.

First, do not just wipe it with bleach. This only removes the visible stain and can drive the moisture and hyphae deeper into the gypsum board. For a small patch, a proper cleaning solution of white vinegar or a dedicated mould remover applied with a scrub brush is more effective. However, the location behind the wardrobe suggests a persistent moisture problem that needs addressing.

The core issue is the temperature differential. The exterior wall is cooled by your AC, causing humid sea air to condense on its inner surface, essentially creating a wet environment perfect for mould. To prevent its return, you must break this cycle. Start by pulling the wardrobe at least two inches away from the wall to allow air circulation. Ensure your AC is serviced and draining correctly, and consider using a standalone dehumidifier in that room, especially during the more humid summer and winter months.

For a recurring or large-scale problem (over a few square feet), a professional assessment is recommended to check for moisture trapped within the wall itself. They can identify if there's a underlying leak and perform remediation that includes antimicrobial treatment and addressing the vapour barrier. In many cases, this is necessary to resolve it permanently. The process should always include a post-remediation verification test to confirm the spore count has returned to acceptable indoor levels.