How to Remove Black Mould and Stop It Returning

Find the source before you clean

Mould needs moisture to grow, so the first step is always working out where that moisture is coming from rather than reaching straight for a cleaning spray. The most common causes in UK homes are condensation on cold external walls, a slow leak from a waste pipe or appliance, failed pointing or render letting rain in, and blocked or overflowing gutters.

Cold external corners, areas behind wardrobes pushed against outside walls, and windowsills in rooms with poor ventilation are the usual first places mould appears, because these are the coldest surfaces in the room where moist air condenses.

How to clean it safely

Open the window before you start so spores have somewhere to escape rather than spreading through the room. Wear gloves, goggles and an FFP2 mask, since disturbing mould releases spores into the air that can irritate the lungs, particularly for anyone with asthma or a respiratory condition.

Use a proprietary fungicidal mould wash rather than a generic household cleaner, and wipe rather than scrub where possible. Avoid dry brushing mould off a surface, since this is the single most effective way to send a large number of spores airborne at once.

• Ventilate the room before and during cleaning.
• Wear gloves, goggles and an FFP2 mask.
• Use a fungicidal wash designed for mould rather than a standard surface cleaner.
• Wipe rather than scrub or brush dry mould.
• Dispose of cleaning cloths rather than reusing them elsewhere in the home.

Dealing with soft furnishings and fabric

Mould on fabric, curtains or soft furnishings is harder to fully remove than mould on a hard surface, and items with significant mould growth are often better replaced than kept, particularly anything that cannot be washed at a high temperature. Mattresses and upholstered furniture with mould should generally be discarded rather than cleaned, since spores can remain within the material even after the surface looks clean.

Fixing the underlying moisture problem

Cleaning mould without addressing its cause is only ever a temporary fix. Condensation related mould usually improves significantly with better ventilation and more consistent heating. Leaks and building defects need a plumber or builder to resolve properly, and the wall will need to dry out fully before redecorating.

Habits that stop mould coming back

A handful of simple changes make a real difference to condensation levels in a home, particularly in winter when windows are kept closed for longer periods.

• Run extractor fans for around fifteen minutes after showers, baths and cooking.
• Leave a small gap between furniture and external walls to allow air to circulate.
• Keep background heating steady rather than switching it fully off and on in short bursts.
• Dry washing outside or in a well ventilated room rather than on radiators indoors.
• Wipe down condensation on windows each morning during colder months.

Before packing and storing belongings

If you are moving home, check items for damp or mould before they go into boxes, particularly anything that has been stored in a garage, shed or loft. Spores spread through a sealed cardboard box quickly, and the problem is often not noticed until the box is opened again weeks or months later in storage, by which point the damage can have spread to other items nearby.

Items that show any sign of damp or mould should be cleaned and fully dried before packing, or left out of the move entirely if the damage is significant. This is particularly important for anything going into long term storage, where airflow is more limited than in a lived in home.