What To Do if You Find Mould in Your Bathroom
By Ruth MacEachern
Product Manager
Dec 01, 2025
Mould is more than just an unsightly nuisance in the bathroom; it can pose genuine risks to your health. Mould spores thrive in damp, humid environments, and once established, they can spread rapidly. Exposure to mould can cause allergic reactions, respiratory issues, and exacerbate conditions such as asthma.
Vulnerable individuals, including children, the elderly, and those with weakened immune systems, are particularly at risk. Beyond health, mould can damage surfaces, weaken grout and sealants, and even threaten the structural materials hidden behind tiles and walls.
How to Clean Mould Effectively
If you find mould in your bathroom, it’s important to act promptly and safely. Here are the recommended steps to tackle small to moderate areas of mould:
Start by opening windows and doors to increase airflow before you begin cleaning. If you have one, turn on your extractor fan so that any mould spores that are released into the air are removed as quickly as possible.
For severe mould, dilute bleach or a special fungicidal spray may be required, however for lighter patches, or if you want to avoid using harsh chemicals, you could use white vinegar, lemon juice or bicarbonate of soda as a paste – all these will kill the mould.
Apply your cleaning agent to the affected area and leave it for 15 minutes to kill off the mould, then use a stiff brush or non-abrasive scrubber to clean tiles, grout, glass, and plastic.
After cleaning with a brush, thoroughly rinse surfaces with clean water and dry them with a towel or allow them to air dry with good ventilation.
When cleaning mould, wear gloves, a face mask, and goggles to avoid inhaling mould spores, or having them meet sensitive skin. You should dispose of any cloths and brushes used when cleaning mould to prevent contaminating other areas of your home.
Where bathroom mould comes from
Mould requires moisture and organic material to grow, both of which are abundant in bathrooms. The reasons why you are most likely to find mould growing in your bathroom is the presence of condensation which is caused when steam from bathing, showering, or drying towels on radiators cannot escape from the room quickly and comes into contact with cold surfaces such as tiles, mirrors, and walls.
On porous surfaces such as painted walls and silicone seals, pockets of moisture can develop and form damp patches where the mould will thrive.
Extractor fans are essential for reducing mould
While regular cleaning helps to keep on top of mould, long term prevention hinges on proper ventilation which means ensuring that your bathroom extractor fan is suitable. Extractor fans remove moist air before it can settle on surfaces, drastically reducing the chance for mould to develop, but they need to be sufficiently powerful and properly located to work effectively.
UK building regulations, state that in a bathroom without an openable window the extractor fan needs to be capable of extracting at least fifteen litres of air per second (l/s). For bathrooms with toilets, this same standard applies. The fan should be ducted to the outside and continue operating for a set period after the light is switched off (typically 15 minutes), unless it is continuously running at a lower rate. Models such as the EnviroVent Cyclone 8, features a sensor that measures humidity and then automatically adjusts the power level to remove water vapour as quickly as possible which helps to stop mould.
As well as being strong enough, the fan needs to be mounted close to ceiling level on a wall opposite the door and away from electricity sources. This arrangement means that air is directed away from the rest of your home and vented outside rather than contributing to damp patches elsewhere.
Find out more
Mould is a health hazard, particularly if you have children, elderly people, or people with underlying health conditions in your home, so it’s important to reduce the risk. If you have problems with persistent mould in your bathroom we can help. Enter your postcode below to book a free home survey from our local ventilation specialists. They can visit your property, identify the sources of condensation that are leading to mould and provide you with help and advice about the best solution.
