Black mould in bathroom in Sant Adrià de Besòs: causes, cleaning and lasting fix
Resumen rápido
Bathroom mould is usually condensation, not a leak.
¿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.
Coste orientativo en Sant Adrià de Besòs
80–280 €
Silicone replacement and antimould primer.
Contexto local · Sant Adrià de Besòs
Sant Adrià de Besòs's climate has high humidity year-round.
Sant Adrià de Besòs is small but very fragmented: La Mina, El Besòs and La Catalana are three different building realities. In La Mina we work in PERI-refurbished blocks whose kitchens and bathrooms are still 1970s originals — the tiling lets go on the first sounding. La Catalana keeps low fishermen's houses refurbished inside while preserving the façade, so we coordinate any visible change with the council. Sea and river air force siloxane façade paint and stainless hardware. Kerb-side parking is usually possible, which cuts the cost of bulky-material jobs versus central Barcelona.
- Comarca: Barcelonès
- Población: 38.260 hab.
- Parque de vivienda predominante: mixto
- Año medio de construcción: 1980
- Códigos postales: 08930
Frente marítimo del Besòs con la Mina, polígonos industriales reconvertidos y nuevas promociones en La Catalana.
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.
¿Prefieres que vayamos nosotros?
Diagnóstico y presupuesto en Sant Adrià de Besòs normalmente el mismo día.
Pedir presupuesto gratisProblemas relacionados en Sant Adrià de Besòs
Más sobre Damp, mould and paint
Sources and regulation
- CTE DB-HS 1 — Protección frente a la humedad — Código Técnico de la Edificación