Updated on 26 June 2026 · by Pepe, painter in Elche
Black mould on the ceiling and in the grout of the bathroom is one of the most common and most annoying problems: you clean it and a few weeks later it's back. I'm Pepe, a painter in Elche on the Costa Blanca, and I'll explain how to get rid of it properly and, above all, how to stop it reappearing every winter.
Why it appears (nearly always condensation)
The bathroom brings together three things mould loves: moisture (the shower), poor ventilation and cold spots (the ceiling, the corners, behind the door). The steam condenses there and the fungus grows. That's why it's so typical in internal bathrooms or ones without a window, and why it comes back if nothing changes.
What DOESN'T work
Wiping over with bleach cleans the mark from view, but it doesn't kill the root of the fungus or change the conditions, so it comes back. And painting over without treating is worse: the mould is still alive underneath and stains the fresh paint within weeks. You need to treat it and, at the same time, tackle the condensation.
How to remove it properly
The process that really leaves the bathroom clean and keeps it that way:
- Apply a fungicidal treatment that kills the fungus (not just wipes it off).
- Cut back and leave the area dry; remove any blistered paint if there is any.
- Paint with anti-mould, anti-damp paint made specifically for bathrooms and kitchens.
- Improve ventilation: an extractor fan, opening up a bit after the shower, not leaving wet towels around.
What paint and what I'll do for you
For these areas I use washable anti-mould paint (I explain which one in my guide to what paint for a damp bathroom and kitchen). I treat the mould, cut back and paint with a dedicated product so the bathroom comes out clean and stays that way; you'll find it in my bathroom and kitchen painting service and, if the damp is worse, in my damp and anti-mould one. The only thing paint can't replace is ventilation: with a bit of air, it won't come back.
Want the exact price for your project?
I will come and see it with no obligation and give you a fixed quote, free and the same day. You deal directly with me, no middlemen.
FAQ
- Why does the mould come back even though I bleach it?
- Because bleach cleans the surface but doesn't kill the root or remove the condensation feeding it. You need to treat it with a fungicide, paint with an anti-mould product and ventilate better; otherwise it reappears.
- Does anti-mould paint sort it completely?
- It helps a lot and, with a bit of ventilation, keeps it at bay. In a bathroom without a window an extractor fan is worth it: the paint holds the mould back, but the condensation has to get out somehow.
- Is bathroom mould bad for your health?
- It's best not to live with it: it can bother people with allergies or breathing problems. The sooner it's treated, the better for the house and for you.