Black mould in bathroom in Barcelona: causes, cleaning and lasting fix
Riesgo medio · con precaución
Resumen rápido
Bathroom mould is usually condensation, not a leak.
Need help right now?
Call us or message on WhatsApp. Fixed quote within 24 h, no obligation.
¿Qué está pasando?
Shower steam pushes humidity above 80%.
Causas más probables
Poor ventilation after showering
altaSmall fan or blocked duct.
Failing silicone seals
altaAfter 3-5 years it loses its biocide.
Thermal bridge on outer wall
mediaBuildings without insulation have cold corners.
Pasos de diagnóstico
- 1
Clean with diluted bleach
Spray, wait, scrub.
⚠ Parada de seguridad: Never mix bleach with ammonia. - 2
Replace blackened silicone
Cut out and apply sanitary silicone.
- 3
Improve post-shower ventilation
Run the fan 15-20 min after.
Cuándo llamar a un profesional
Call if it returns in 2-3 weeks or exceeds 1 m².
Want us to take a look? Fixed quote within 24 h.
Coste orientativo
80–280 €
Silicone replacement and antimould primer.
Contexto local
Barcelona's climate has high humidity year-round.
Preguntas frecuentes
Is bathroom mould a health risk?
For asthmatics and young children, yes.
Does bleach kill mould completely?
Surface only — if it penetrated it returns.
Related problems
Rather have us come over?
Same-day diagnosis and quote across Barcelona.