The four usual sources
A leak, condensation on cold surfaces, a blocked or underpowered extract, and an AC drain issue. Identifying which one you have is the whole job.
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Health & EnvironmentWhy Bathrooms Grow Mould Here, and What Fixes It
Mould is a moisture problem wearing a cleaning problem's clothes. Treating the growth without finding the water means doing it again in six weeks.
Why extracts fail here
Grilles clog with dust, ducting runs long, and in some buildings the extract vents into a shared shaft that is itself blocked. A bathroom that stays damp for hours after a shower has an extract problem, not a cleaning problem.
Surface versus structural
Growth on silicone, grout and paint is a cleaning and replacement matter. Growth that has gone behind tiles or into a wall cavity needs opening up, and painting over it makes it worse.
Silicone
Once mould has keyed into the bead itself, surface treatment achieves very little. Replacing the silicone is quicker and cheaper than repeated attempts to clean it.
Everything we do is scoped against indoor air quality testing, priced after an inspection and fixed in writing before any work begins.
Questions
Answered plainly.
It removes the visible colour on non-porous surfaces. On porous ones it bleaches the growth without removing the root, and it returns.
Surface growth in a ventilated bathroom is a nuisance. Persistent growth in a sealed damp space is worth investigating properly, particularly with respiratory sensitivity in the household.
No, and it can make condensation worse. Ventilation and extract performance are what matter.
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An inspection, a written scope and a price that holds. We will also tell you when the job does not need us.