What’s the Difference Between Mould and Mildew?

If you have had a condensation problem in your home for some time, you will often find that damp patches have developed.  These can become the perfect breeding ground for mould and mildew.  Patches of black mould or green and white mildew on walls are an unpleasant sight, but they can also be bad for your heath.  Understanding the difference between mould and mildew is the first step toward removing the problem and preventing it from coming back in the future.

Mould and mildew both grow from spores that are present in the air.  These microscopic particles can be carried for long distances and fall on surfaces. 

Without the right growing conditions, the spores remain inert, but if they land in damp areas with limited air flow to disturb them, they can quickly grow into large colonies and release more spores that will spread around your home.

Mould and mildew are both types of fungus, and are related, but there is a clear difference between them, and they are quite easy to tell apart.

What does Mould Look Like

Most household moulds that grow as a result of condensation damp are black and tend to be found on ceilings or walls in wet rooms such as bathrooms, or around windows.  The moulds typically appear to be moist and shiny, and grow as flat patches on the surface which stand out against white paint making them obvious to spot.

Some types of mould are harmful to health.  Stachybotrys Chartarum, (toxic black mould) releases a mycotoxin that can cause a nasty reaction in people with respiratory problems such as asthma.  If you suspect that you have an infestation of toxic black mould, you need to contact a professional company to have it removed.

What does Mildew Look Like

By contrast to the dark colours and wet look of mould, domestic mildew is usually white or very light green.  Rather than having a smooth and flat surface, the mildew is covered in thin white filaments known as hyphae.  These filaments are what spreads mildew to other areas.  When they break off in the air, they can create new colonies wherever they land.

More often than not, mildew will grow in areas where it is not disturbed by the movement of air.  You will often find mildew behind large pieces of furniture or in cupboards where the temperature and moisture levels can be very stable.

Tracking Down Mildew

The first sign of mildew in a home is usually a musty smell.  As mildew grows and begins to create spores, it can become quite pungent with an instantly recognisable smell.  If you discover a strong, musty odour in rooms, it won’t take long to find the source.  Mildew grows best in warm and moist conditions with poor airflow, so you will often find it behind wardrobes or large pieces of furniture, inside cupboards, and in corners.

Removing Mildew

The most effective way of removing mildew from surfaces in your home is with an anti-fungal cleaning product – although dilute bleach will work well too.  These chemicals kill off the spores and the fruiting bodies of the mildew and will remove some discolouration from underlying surfaces. 

When cleaning mould or mildew, you should wear gloves, a mask and eye protection to prevent inhaling the spores.  Dispose of any cloths and protective equipment you have used to clean the mildew so that you don’t spread any remaining spores elsewhere in your home.

If the mildew has been growing for a long time, it can leave dark stains on paintwork that is hard to remove.  Painting over those surfaces with an anti-fungal paint can slow regrowth, but it is not a permanent solution.

Preventing Mildew

Unfortunately both mould and mildew will grow back unless you take action to get rid of the conditions that allowed them to become established in the first place.

The most common cause of both mildew and mould growth in British houses is condensation damp.  Improving the airflow in your home to reduce humidity– through extractor fans in bathrooms or kitchens, or even a whole house ventilation solution will prevent condensation from being a problem and stop mould and milder growth for good.

Find out More

If you are worried the health risks of mildew in your home, contact us today to speak to your local ventilation specialist.  You can book a free home survey which will identify the root cause of your mildew problem and find out about the best solution for your needs.