Removing Black Mould on Bathroom Ceilings and Walls

Black mould can be a common problem in many bathrooms, especially on the ceiling where it can easily take root and grow into an unsightly and unhealthy mess.

In this DIY guide we look at how black mould forms, why it commonly forms in places like kitchens and bathrooms and how you can get rid of it.

What Exactly is Black Mould?

Understanding what mould is will ultimately help with how to deal with it and get rid of it.

Mould is a type of fungus and features threads, like very dense cobwebs that grow together on a given surface and some of them are fertile enough to produce spores.

Spores are carried by moving things including air and especially warm air, which is always found in a bathroom.

The warm air travels upwards depositing spores on the ceiling. The spores then settle and grow to become mould.

The conditions mould likes best are when temperatures are above 70 degrees Fahrenheit and the relative humidity is above 70% and have a guess where those conditions are normally found ?!

What’s the Problem With black Mould?

Apart from its obvious horrendous visual appearance, black mould is also often accompanied by a nasty, musky damp smell and also some more serious problems, many associated health issues.

Kitchens and bathrooms, which often suffer from black mould issues, are typically fairly clean and sterile places, especially kitchens where food is prepared. The presence of black mould here can easily contaminate food causing numerous health issues.

As black mould thrives in damp and humid places, it’s not always the ceiling that is susceptible. Hidden, tight spaces such as those under sinks, behind toilets and the similar are also common areas for mould to form and as these areas can go uninspected for long periods of time, mould can become well established before it’s noticed and release many spores into the air.

Black Mould and its Affect on Health

As we have touched on above, apart from it’s visual appearance, black mould has been linked to a great many different health issues, including many types of respiratory problems.

The main reason that black mould is such a serious health risk is that as it grows it produces spores that carry toxins and as the spores travel through the air they can easily be breathed in, causing a multitude of issues including rashes and other skin conditions, sore throats, coughs and cold-like symptoms, wheezing and a tight chest and in extreme situations bad headaches, nausea and dizziness.

This is why you should never try and scrape away the mould; this will release the spores into the air in the form of a fine dust.

When exposed to black mould over a long period of time, as your body is constantly trying to fight off the various conditions is causes it can quite drastically weaken your immune system leaving you wide open to more severe medical disorders.

When black mould is found in habitable spaces such as living rooms and bedrooms, this is a much more serious issue. As occupants tend to spend much more time in spaces such as these they suffer much more prolonged exposure to any spores present, so if any black mould appears in such a room it needs to be dealt with immediately.

Why do Bathroom Ceilings get Mouldy?

The growth of black mould is in most cases the fault of condensation, this is particularly evident on bathroom ceilings and some kitchen ceilings due to the huge volumes of steam and moisture caused by bathing, showering and cooking.

The warm air laden with moisture comes into contact with a surface colder than it, such as a ceiling or tiles and that cools the air so that it can no longer hold the moisture which then condenses on that surface in the form of condensation.

If there is enough condensation, and especially if the environment is slightly warm such as on a bathroom ceiling or wall, then black mould can grow.

This is why condensation is typically found on windows and other colder areas. Find out more specific advice on condensation and how to prevent it here.

How to Prevent Mould Forming on a Bathroom Ceiling (or Kitchen)

As with many things the best form of cure is prevention and this is also the case for black mould. It’s better to stop it growing in the first place than to deal with it once it has.

Unfortunately, due to the nature of showering, bathing and cooking it’s absolutely impossible to reduce all of the moisture content in the air to prevent condensation and any resulting mould growth, however there are steps that you can take to reduce the chances and amount of mould forming:

• Ventillation: Ventillation is the single best defense against condensation and any resulting mould. Having some form of extractor fan above or as close to the moist air source as possible will suck it away and out of the building preventing it from settling on any cold surfaces
• Opening Windows: Another form of ventillation is to open a window whilst showering or cooking. Along with an extractor fan this will allow any moist air to escape outside, however this isn’t always practical, especially during colder months
• Reduce Moisture Content: Aside from an extractor and opening a window, another effective method is to try and reduce the amount of moist air by reducing the amount of time spent in the bath or shower and if cooking, put a lid over any pots to keep the steam contained
• Insulation and Heating: As condensation forms on cold surfaces, to stop it forming an effective method is to insulate those cold surfaces so they retain heat and also ensure that you heat your home correctly, keeping the internal temperature at least 16° to ensure surfaces are always warm, however due to the cost of heating this isn’t always possible
• Wipe Away Condensation: To stop mould forming where condensation builds up, an effective method is to just remove it as soon as it forms. This essentially means wiping it off any surfaces as soon as it starts to collect
• Get Rid of Mould: In a similar vein to the above, as soon as any mould forms, kill it and get rid of it (more on this below)
• Anti-Mould/Condensation/Mould Killing Paints: There are various anti-mould, anti-condensation and mould killing or sterilizing paints and additives available today that contain certain chemicals that help to prevent mould growing or condensation forming and also help to kill it off when it does. These are fairly effective but best not relied on as a total solution, rather as part of a series of preventative measures

When mould has started to grow it is very difficult to stop it. As it grows, it can root its way down into plasterboard and plaster surfaces and once it’s in there it’s almost impossible to get out and the only solution then really is to remove the plaster or plasterboard and renew it – a lot of work and expense!

With the above in mind, it is always better to prevent it in the fist place.

If you cannot cure the problem by reducing the levels of condensation either by ventilating or using heating, as we have stated above a good preventative measure is to apply a paint containing with an additive to stop it or kill it.

In most cases this is fairly easy to do:

1. Paint your walls with a mould killer or steriliser to kill off any mould present on the walls and then clean off (following the instruction on the product that you choose)
2. Paint on a barrier solution
3. Once the barrier solution has dried you can now paint on your top coat. Mix fungicide additive with any emulsion you choose to stop the mould coming back

How to Get Rid of Mould on the Bathroom Ceiling

Even if you put in all the counter measures possible, wipe away an condensation as soon as it forms and insulate and heat problem areas correctly black mould can still form.

Despite this, it is possible to keep it in check relatively cheaply and easily. There are a number of solutions that will kill mould, although you may have to keep doing this on a regular basis to prevent it returning or getting worse:

1. Good old fashion bleach: Mix 4 parts water to one part bleach and apply liberally to the affected area. The bleach will kill the mould but be careful what surfaces that you apply the bleach to as this can damage paint. If you are unsure test it on a small unseen area first
2. Mould and mildew products: These are generally very efficient at removing the mould stains and killing the mould. They are readily available and will vary in price and effectiveness
3. Anti bacterial sprays: These are efficient mould killers and will not be bleach based so should not affect the paint work (always read the instructions). These are less effective at removing the mould stains, but are quick and easy to apply so are excellent to ensure that the mould does not return by giving a precautionary spray periodically

Of the options above, using a specialist mould and mildew removal product is probably the best way to go, it’s ready-made and you can simply apply it to the surface, so the following run through is based on this.

As most cleaners of this type contain bleach, you should always wear old clothes, gloves, goggle and also a decent mask!

• Step 1 – Choose Your Products: There are many different mould and mildew removal products available, but we find the Dettol Mould and Mildew Remover one of the best. To get the mould off, we find the best item to use is a scouring sponge, but if you don’t have one you can use an old rag



• Step 2 – Apply Mould Cleaner to Sponge: The best way of getting the removal product on to the mould is to spray it on to the sponge or cloth and then wipe it over the mould. Spraying it directly on the area can release much of it into the air, getting it everywhere so it’s safer to apply using this method. Squirt 2 or 3 applications on to the sponge or cloth in the centre



• Step 3 – Apply Mould Remover to Mould: With the remover on you sponge or cloth, gently wipe it over the mould ensuring that you leave a decent amount on the surface. Repeat the previous step and application again if needed. Once applied, leave the substance for 5 minutes or so to get to work



• Step 4 – Scrub Mould Away: Once the remover has Sat on the surface for a few minutes, use the scouring side of the sponge and gently scrub the mould away. Don’t scrub too hard as you don’t want to scrub any paint off also, although some coming off may be inevitable



• Step 5 – Wipe With Clean Water: Once the mould has been scrubbed away, rinse the sponge out with clean water and then thoroughly wipe the area over to remove any traces of mould cleaner and mould. Finally wipe the area dry using an old cloth

In summary, if you ventilate well and stop the condensation, you will stop black mould growth. This is very often hard to achieve and this is where you have to resort to treating the mould itself. There are a range of solutions that you can employ so you don’t have to have an unsightly bathroom ceiling covered in mould.

Other than the aesthetic benefits, there are definitely health benefits from reducing the spores by removing mould from bathroom ceilings.