Cleaning Mould off Paint

Cleaning Mould Off Paint

By Ruth MacEachern

Product Manager

Mould is a common problem in many homes, especially in bathrooms and bedrooms where the air is often warm and humid. Mould is a type of fungus that grows on organic materials, such as plaster, wallpaper, wood, and fabric which causes stains on walls and can ultimately damage the fabric of your home. As it matures, mould produces spores to spread.  If inhaled these can be an irritant in your airways and cause issues for people with weakened immune systems and respiratory problems such as asthma.  Some species of mould also produce chemicals called mycotoxins which are extremely dangerous and can cause serious neurological problems.

What causes mould to grow

Mould typically grows best in damp and cool conditions. In most homes, water vapour released into the air by bathing, cleaning and drying clothes indoors will form condensation when it meets windows and exterior walls where the temperature is lower.  On porous surfaces such as a wall or ceiling, the condensation soaks through into the underlying material where it creates damp patches.

As mould spores from the air catch onto these damp patches, they start to grow into colonies of mould which can spread quickly below and above the surface.  Inside the wall, the mould colony is made up of narrow filaments called hyphae that form a mycelium.  On the surface of the wall, the black patches of mould are the fruiting bodies of the growth which is where more spores are released to spread around to other areas.

Once mould has become established in a home, it can be difficult to remove permanently.

Removing surface mould from paint

If you have found mould in your home, the first step should be to clean away the surface growth.  This will stop spores from being released and slow down the spread, but it will not remove the problem entirely.

You should seek professional help to clean mould in some cases:

• If you are suffering from mould allergies or have respiratory problems
• If the mould colony is more than one square metre in size
• If the mould is a toxic species such as Stachybotrys Chartarum which releases dangerous chemicals

For smaller areas of household mould, you can clean it off paint and walls carefully.

Start by preparing the area. You don’t want mould spores to spread to other parts of your home or contaminate your clothes or furniture. Therefore, you should cover the floor and any nearby items with plastic sheets or old newspapers. You should also wear protective gloves, masks, and goggles to avoid contact with the mould.

Choose a suitable mould remover product. The most effective method is to use either a specialist mould remover or fungicide or dilute bleach, but there are other cheaper, but less effective options available:

White vinegar. This is a natural and cheap option that can kill most types of mould. You can mix one part of white vinegar with one part of water and spray it directly on the mouldy area. Leave it for an hour and then scrub it with a brush or a sponge. Rinse with clean water and dry with a cloth.

Baking soda. This is another natural and inexpensive option that can also deodorize the area. You can mix two parts of baking soda with one part of white vinegar to create a thick paste. Apply it on the mouldy area and leave it for an hour. Then use a stiff brush to remove the paste and wipe it with a damp cloth.

Mould sprays are the most powerful and effective option to kill mould spores in the short term. You can buy a ready-made mould spray from a hardware store or supermarket.  Follow the instructions on the label and spray it on the mouldy area from a distance of 3 to 5 cm. Wait for 30 minutes and then wipe it off with a wet sponge or cloth.

Stopping mould from returning

Because mould grows from inside a wall or ceiling, removing the surface layer will not prevent the mould from coming back in the future.  Repainting the mouldy area with an anti-fungal paint can slow re-growth, but this can create an unpleasant smell during the drying process, and eventually the chemicals that stop mould growth will lose their effectiveness.

To stop mould from growing back on paint, you will need to reduce the humidity levels to stop condensation from forming and causing damp.  Simple ways to reduce the amount of water vapour in the air in your home include:

• Wipe away any condensation on windows or walls as soon as possible
• Avoid drying clothes indoors or use a dehumidifier if you do
• Ensure that you use extractor fans while bathing and cooking

If you find that mould grows back quickly, or that you are waking up to condensation on your windows each morning, it is likely that your home does not have sufficient ventilation to circulate air and reduce humidity.  Whole house ventilation systems such as the EnviroVent ATMOS PIV (Positive Input Ventilation) system help to stop condensation from developing and causing mould by drawing fresh filtered air into your home from outdoors to displace the humid air. 

Find out more

Improved ventilation is the only effective way of preventing mould permanently.  Our local specialists can visit your home to identify the causes of condensation that are leading to mould in your home.  Book a free home survey today by entering your postcode below.  A local ventilation expert will identify the cause of condensation in your home and advise you about the best way to prevent it from causing the mould that can be damaging to your health.