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Black Mold in House? Here’s What to Do

Utter the words ‘black mold’ in front of someone who’s lived in student accommodation, a mismanaged apartment, or a flooded home at some point in their lives, and we’re sure you’ll incite a rather impassioned response.

Black mold has a habit of popping up in the most inopportune places at the most inopportune times, and it can prove a real nightmare to get rid of it.

Fret not: read on to learn all you need to know about black mold, including how to get rid of black mold in house, the symptoms of mold sickness, and how black mold exposure actually impacts our health.

Symptoms of Black Mold in House

What is Mold?

Mold is a type of fungus that thrives in moist, warm environments with plenty of oxygen. Like most things, it has its purpose in nature (to break down dead leaves, for instance), but it’s far from ideal when it appears in your home.

Types of Mold


Otherwise known as black mold, stachybotrys is a supposedly toxigenic mold and the star of this article. It has an inky appearance, as if you had dropped black or dark green colored ink on wet paper, spreading out across damp, humid areas. 

Wallpaper, wood and cardboard are key surfaces it enjoys. It can contribute to breathing problems and allergies.

mold in the corner of the window


We owe a lot to this mold—if you recognize the name, it’s because it shares it with the antibiotic, and is responsible for its production. It’s allergenic, meaning asthma and other chronic respiratory problems and allergies will flare up in its presence. 

It’s a plush texture, blue-green in color, that spreads quickly. You’ll see it on aged fruits, but it also likes water damaged structures and objects.


There are over 500 different species of Cladosporium, and it’s a very common mold, so it can be a little hard to identify. It can appear as brown, green or black spots, similar to stachybotrys. 

It’s commonly found on carpets, wallpaper, and window sills, among almost anywhere else that is wet or damp. Postnasal drip, watery eyes and asthma flare-ups are to be expected.


Causes of Black Mold in House

Despite how many thousands of types of mold exist, they all share a lot in common. Across the board, wet, damp, or humid environments are perfect for colonization.

As such, flooding is a significant cause of black mold in the home. Even a small leak in the roof can create the perfect environment for mold to thrive in; once wallpaper and wooden structures get wet, mold will appear rapidly.

Black mold in particular is caused by condensation, so it can appear around skirting boards, in corners, on ceilings, or on other cold surfaces in bathrooms and kitchens, where hot water regularly condenses against the cold surfaces of walls, porcelain toilets and sinks. 

A white sash window with condensation covering the glass and small mold growths on the wood

Naturally, black mold will also thrive on a broken AC unit or the back of a freezer, where there is a contrast between the heat caused by the appliance and the cold, wet air it creates.

Is Black Mold Dangerous? Debunking the Myths

A lot of the rhetoric floating around about the dangers of mold is, in all likelihood, blown significantly out of proportion.

From a scientific perspective, symptoms of mold sickness are nothing more than allergy symptoms. Of course, no one wants to live burdened by a constant running nose and watery eyes, and black mold exposure certainly can’t be described as good for one’s health. 

Credit: The Dr. Bob Show

How to Get Rid of Black Mold in House

There are a number of ways to get rid of black mold. These can be thought of as short-term and long-term solutions.


This is particularly useful for bathroom sealant, which is a very commonly affected area. Check out the video below to see the cleaning hack in action.

Always make sure to wear gloves when using bleach and bleach products, and be wary of breathing it in too much. Leave the area that is being treated and make sure it is as well ventilated as possible by leaving windows open (household bleach isn’t technically toxic, it is worse for air quality than mold itself!) 

It’s also worth noting that putting bleach on colored surfaces or objects like carpets will completely alter the color, so if you don’t want to risk removing or damaging color, a gentler solution may be required. This won’t, however, be nearly as effective as bleach-based products.


While these techniques are affordable and great for obtaining quick results, the vast majority of people will notice the mold returns pretty rapidly. That’s because cleaning it away isn’t dealing with the root cause of the issue, which is likely structural. 

Structures impacted by a flood or leak will, in almost all cases, need replacing to completely eradicate the presence of black mold, particularly wallpaper and carpets that have gotten wet. In cold or humid homes, it can be impossible to get these structures totally dry.

Since black mold is caused primarily by condensation, dealing with existing heating or humidity issues will help keep mold from returning. 

Having a professional fix or install proper ventilation to bathrooms and kitchens will be a great help, since effective ventilation will alleviate condensation issues in areas that are frequently wet and experience fluctuations in humidity and temperature. 

A warm, humid environment with cold walls will be very prone to black mold. Professional mold removal services should be contacted, but their ability to permanently remove mold will also be limited if the cause is a structural issue; in which case, other fixes to the home can be recommended by the professional.

5 Essential Ways to Prevent Black Mold

1. Ventilation

Black mold adores a wet, warm environment rife with condensation. Homes without proper ventilation are therefore at far greater risk of black mold colonization than those with. 

So ensuring your entire home is ventilated properly is the most important factor in preventing black mold. Bathrooms and kitchens should take priority.

2. Heating

Condensation occurs when warm air hits a cold surface, so keeping your home warm and dry is another major factor in preventing black mold, since it appears where condensation occurs. 

Other than putting the heating on, structural fixes, like insulating the roof and double-glazing windows, are effective ways of keeping the temperature of your home more constant (and saving money and energy in the long run).

3. Structural repairs

If your home has been damaged due to flooding or leaks, proper structural repairs will be worth the hassle in the long term. Damaged drywalls, carpets, and ceilings will be next to impossible to get the mold off permanently unless they are replaced. 

This can be costly, but for the sake of safety and hygiene, we would recommend getting the appropriate structural repairs where possible. Professional mold removers should advise as to this.

Credit: The Handyman

4. Mold resistant products

If you’ve ever attempted DIY in your home, you might have come across various products that market themselves as mold resistant. 

Products like mold resistant paint and mold resistant drywall will help prevent the occurrence of black mold through anti-microbial properties—within reason, of course. 

If your home floods, these products won’t be sufficient, but they are worth looking out for if you intend to carry out any work in your home.

5. Dehumidifier

A good habit to get into is occasionally monitoring the humidity of your home. You can then use either a dehumidifier or an air conditioner to alter the air quality as needed. 

‘Industrial’ dehumidifiers are loud, but will draw out a lot of water from the air. Subtler, more stylish options are available as ‘air purifiers’, and there are various other kinds of dehumidifying products available, like packs that you can place near windows or in wardrobes to keep clothes dry.


Can I remove black mold myself?

However, black mold is known for recurrence—if you notice this, seek professional mold removal services, and consider pulling the trigger on any structural repairs or amendments that need completing.

How long can you live in a house with black mold?

There isn’t a set period you can live in a house with black mold. Mold spores are everywhere, constantly. Those who suffer from allergies or existing respiratory problems will want to treat it quickly. Even if you feel that it doesn’t bother you, it is unhygienic and will attract other pests. The longer you let it spread, the harder it will be to deal with.

Can black mold in your house hurt you?

Do you have to get rid of everything if you have black mold?

If you have experienced flooding or leaks, there is a high chance a professional will recommend removing and replacing what is damaged. That doesn’t mean the entire contents of your home, though! Making the structural changes necessary to improve the internal environment of your home is what will help keep mold from returning once removed.

How to check for black mold in your house?

Mold inspections can be carried out by professional removal services, but in all likelihood, you’ll notice it yourself. Black mold smells earthy, like dirt or leaves, and damp. It also has a very distinct pattern and shape; you’ll notice black, inky patches. If the mold is in the ceiling or behind ceiling tiles, it might not be quite so obvious, in which case, consider having a professional mold inspection carried out for peace of mind.


You can breathe a sigh of relief: it turns out that the horror stories surrounding black mold are, in reality, somewhat exaggerated. Still, it’s a real nuisance to deal with, and it will have an impact on air quality in the home, bringing on severe allergies in many people.

By dealing with structural concerns, you can permanently remove black mold from the home. Otherwise, shorter-term solutions, like applying bleach-based products, can rapidly reduce the presence of black mold and help you gain some peace of mind over the hygiene of your home.