Black mould in bathroom in Sabadell: 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 Sabadell
80–280 €
Silicone replacement and antimould primer.
Contexto local · Sabadell
Sabadell's climate has high humidity year-round.
Sabadell is the largest city in Vallès Occidental, mixing dense old quarters (Centre, Creu de Barberà) with 1980s–90s residential estates (Can Llong, Can Rull). In the old town we deal with buildings whose shared old stacks and tight courtyards rule out external insulation, so we strengthen things from the inside. In the estates, high-rise blocks have single-phase panels we have to rebalance before installing AC or an induction hob. Sabadell has a large self-employed population, so we often convert workshops into homes with three-phase wiring that we re-rate to REBT. C-58 jams early, so first slots go to local clients.
- Comarca: Vallès Occidental
- Población: 215.760 hab.
- Parque de vivienda predominante: piso-moderno
- Año medio de construcción: 1970
- Códigos postales: 08201, 08202, 08203, 08204, 08205, 08206, 08207, 08208
Capital del Vallès Occidental, con tejido industrial textil reconvertido y barrios densos como Ca n’Oriac, Torre-romeu y La Concòrdia.
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 Sabadell normalmente el mismo día.
Pedir presupuesto gratisProblemas relacionados en Sabadell
Más sobre Damp, mould and paint
Sources and regulation
- CTE DB-HS 1 — Protección frente a la humedad — Código Técnico de la Edificación