Taiwan’s high humidity, often exceeding 80% relative humidity (RH) for months at a time, makes mold one of the most persistent household problems. Whether you live in a small Taipei apartment or a suburban house in Taichung, mold can damage walls, ceilings, furniture, and clothing. More importantly, it poses health risks including respiratory irritation, allergies, and asthma exacerbation.

This article covers the causes of mold in Taiwan, step-by-step removal methods, and long-term prevention strategies that work in the local climate. We draw on widely accepted building science and product recommendations available from major retailers such as PChome, Carrefour, and Hardware stores like B&Q and Homebox.

Why Mold Thrives in Taiwan

Taiwan’s climate is classified as humid subtropical in the north and tropical monsoon in the south. Average annual relative humidity is around 80% in Taipei and 75% in Kaohsiung. During the plum rain season (Meiyu) from May to June and typhoon season from July to September, indoor RH can remain at 85-95% for days at a time.

Mold requires three conditions to grow: moisture, food source (organic material like wood, drywall, dust, or fabric), and a temperature between 20°C and 30°C. Taiwan provides all three year-round. Common problem areas include:

  • Bathrooms, especially ceilings, grout, and silicone sealant.
  • Kitchens, under sinks, around windows, and behind refrigerators.
  • Bedrooms, inside wardrobes and on exterior walls where condensation forms.
  • Storage rooms and closets, limited airflow.
  • Any room with poor ventilation, typical in older buildings or ground-floor units.

A 2021 study published in Indoor Air found that over 50% of surveyed homes in Taipei had visible mold in at least one room. The issue is so widespread that most real estate agents include mold inspections as part of the first-time rental checklist.

Health Risks of Mold Exposure

The World Health Organization (WHO) classifies dampness and mold as significant indoor health hazards. Common symptoms include nasal stuffiness, throat irritation, coughing, wheezing, eye irritation, and skin rashes. People with asthma or allergies are especially sensitive.

In Taiwan, where many people live in humid high-rise apartments with limited window opening, mold can become a chronic problem. Some mold species, such as Aspergillus, Penicillium, and Stachybotrys (black mold), produce mycotoxins that may be harmful with prolonged exposure. If you or your family experience persistent respiratory issues, consider consulting a doctor and having your home checked for hidden mold.

Identifying Mold in Your Home

Mold is not always visible. Look for these signs:

  • Black, green, white, or orange spots on walls, ceilings, or floors.
  • A musty, earthy smell.
  • Warped or peeling paint.
  • Dark stains on wooden furniture or flooring.
  • Frequent condensation on windows or walls.

Use a flashlight to inspect dark corners, behind furniture, and inside closets. Pay special attention to areas where plumbing runs through walls or where the exterior wall meets the floor.

Removing Mold: Step-by-Step Guide

1. Safety First

Before cleaning, wear protective gear: N95 or FFP2 mask, rubber gloves, and safety goggles. Mold spores become airborne during cleaning and can be inhaled. Open windows and doors for ventilation. If the affected area is larger than 1 square meter, consider hiring a professional mold remediation service.

2. Choose the Right Cleaner

Different surfaces require different cleaning agents:

  • Non-porous surfaces (tiles, glass, metal, plastic): Use a 1:1 mixture of white vinegar and water, or a commercial mold cleaner like 3M Mold & Mildew Remover (available at PChome for NT$180-250). Do not mix vinegar with bleach, it produces toxic chlorine gas.
  • Porous surfaces (wood, drywall, fabric): These are harder to clean. You may need to replace the material if mold has penetrated deep. For surface mold on wood, try a solution of 1 part bleach to 3 parts water (never on untreated wood) or a dedicated wood cleaner like Howard Restor-A-Finish.
  • Grout and silicone: Scrub with a stiff brush and a bleach-based cleaner. If the silicone is discolored, remove and reapply fresh silicone. B&Q sells silicone sealant from NT$89 per tube.

For stubborn black mold on walls, you can use a hydrogen peroxide solution (3% concentration) sprayed directly onto the area, let sit for 15 minutes, then scrub and wipe.

3. Cleaning Process

  1. Spray or apply cleaner generously to the affected area.
  2. Let it sit for 10-15 minutes to penetrate.
  3. Scrub with a stiff brush or sponge. Do not scrub dry, this spreads spores.
  4. Wipe clean with a damp microfiber cloth.
  5. Dry the area thoroughly with a clean towel or fan.
  6. Dispose of the cloth and sponge in a sealed plastic bag.

Do not use a vacuum cleaner unless it has a HEPA filter, otherwise it will blow spores into the air.

4. Treatment for Porous Materials

  • Drywall: If mold covers more than 10% of a drywall panel or the panel feels soft, cut it out and replace. Homebox sells 3x6 ft drywall panels for about NT$450 each.
  • Wood: Sand the surface lightly to remove top-layer mold, then clean with a wood-safe fungicide like Ronseal Wet Rot Wood Hardener (available at B&Q, NT$499).
  • Fabric: Washable items, machine wash in hot water with bleach if safe for the fabric. Dry completely in direct sunlight. For non-washable items like mattresses, spray with a fabric deodorizer and place in sunlight for several hours.

Prevention: Controlling Humidity Year-Round

Preventing mold is far easier and cheaper than removing it. The key is keeping indoor relative humidity below 60%, ideally between 40% and 50%. Here is how to achieve that in Taiwan’s climate.

1. Use Dehumidifiers Strategically

A dehumidifier is the single most effective tool for mold prevention in Taiwan. In a typical 30-40 ping (100-130 m²) apartment, a dehumidifier with a capacity of 10-16 liters per day is sufficient. The dehumidifier guide on EasyHome Taiwan recommends the Mitsubishi MJ-E160HN (about NT$18,000 at PChome) or the Panasonic F-YV32MJ (about NT$15,500) for large rooms. For a single bedroom, a smaller unit like the Xiaomi Smart Dehumidifier 21L (NT$9,995) works well.

  • Place the dehumidifier in central locations like the living room or hallway.
  • Keep doors open between rooms to allow air circulation.
  • Run it continuously during Meiyu and typhoon seasons.
  • Set the target RH to 50%. Do not set it below 40% as that can cause discomfort and static shock.
  • Empty the water tank daily, some units have a drain hose connection for continuous drainage.

2. Improve Ventilation

Bathrooms and kitchens should have exhaust fans. Run the bathroom fan for 20-30 minutes after showering. In the kitchen, use the range hood while cooking and for 10 minutes after. If your home has no exhaust fan, consider installing a window-mounted exhaust fan (available at Homebox for NT$800-1,500).

Open windows on dry days, but not during high-humidity rain events. In Taipei, the driest months are November to February. During these months, open windows for 15-30 minutes each morning to exchange stale air.

3. Address Condensation

Condensation occurs when warm, moist indoor air meets a cooler surface. This is common on single-pane glass windows, very typical in older Taiwanese apartments. Solutions include:

  • Double-glazed windows: Installation costs NT$15,000-30,000 per window, but they reduce condensation significantly. Companies like YKK AP Taiwan provide this service.
  • Window insulation film: A cheaper fix (NT$200-500 per roll at Carrefour). Apply to the interior side of windows to reduce heat transfer.
  • Weatherstripping: Seal gaps around doors and windows to prevent moisture-laden air from entering. Foam tape (NT$50-100 per roll) is available at B&Q.

4. Manage Indoor Moisture Sources

  • Dry clothes outdoors or in a ventilated room with the dehumidifier running. Use a drying rack near a window or on a balcony. Do not dry clothes indoors without ventilation, this adds liters of water vapor to the air. If you must use a machine, get a washing machine with a high spin speed (1,200+ RPM) and dry outdoors.
  • Fix leaks immediately. A dripping pipe or leaking roof can quickly breed mold. Check under sinks, around windows, and the ceiling above showers. If you discover a leak while moving in, it should be addressed as part of your moving house checklist.
  • Use a hygrometer to monitor indoor RH. Digital hygrometers cost NT$150-400 at PChome or Carrefour. Look for models that log data, like the Xiaomi Mi Temperature and Humidity Monitor (NT$195).

5. Maintain a Clean, Dry Home

  • Wipe down shower walls and bathroom mirrors after use with a squeegee (NT$50-100 at Daiso).
  • Keep shower curtains open after a bath to let them dry.
  • Do not leave wet towels on the floor, hang them on a towel rack or bar.
  • Clean kitchen countertops and sinks daily with a dry cloth.
  • Vacuum and dust regularly, dust is a food source for mold.

Long-Term Solutions for Mold-Prone Areas

Paint with Mold-Resistant Coatings

After removing mold, repaint the area with a mold-resistant paint. Brands like Dulux and Rainbow (Dulux Taiwan’s local brand) offer anti-mildew interior paints. A 5-liter can costs about NT$1,200-1,800 at Carrefour. For bathrooms and kitchens, consider using tile paint or waterproof epoxy (e.g., Nippon Paint’s Bodelac series, NT$1,500 per liter).

Use Silica Gel and Moisture Absorbers

For small enclosed spaces like closets and drawers, place moisture absorbers such as silica gel packets or container-type dehumidifiers (e.g., Hizex brand, NT$100-200 at PChome, with refill packs). Replace them when the indicator shows saturation.

Consider an Air Purifier with HEPA

While air purifiers do not remove mold growth, they can capture airborne mold spores and prevent them from settling. Look for units with a HEPA filter rated at least H13. Many modern units from Xiaomi, Philips, and Sharp are available in Taiwan for NT$4,000-12,000. Place them in the bedroom or living room for best effect.

When to Call a Professional

If mold covers an area larger than 1 square meter, or if you suspect mold inside walls, under flooring, or in HVAC ducts, contact a professional mold remediation company in Taiwan. Companies like MoldZero (based in Taipei) and EcoLife offer inspection and remediation services. A typical inspection costs NT$3,000-5,000, and remediation starts at NT$10,000 for a small area. For large infestations, the cost can reach NT$50,000 or more. In extreme cases, you may need to replace drywall and insulation. If you plan to address this as part of a larger renovation, also consult our guide to home buying costs to budget accordingly.

Also, note that many older apartments in Taiwan have decentralized gas utility setups, which can lead to leaks if pipes corrode, mold often grows near these leaks. If you smell gas or see signs of a leak, call the gas company immediately.

Mold and Your Air Conditioner

Air conditioners are both a cause and a solution for mold. They cool the air and produce condensation, which can collect in the drip tray and become a breeding ground for mold. Clean the indoor unit’s filter once a month during heavy use. For deep cleaning, hire a professional AC cleaning service (NT$2,000-4,000 per unit). Regular maintenance is also covered in our 2025 air conditioner buying guide.

Also, consider setting your air conditioner to a mode that runs the fan periodically after the compressor shuts off (often called