What Causes White Mold In A House?

If I ask you, “Is there mold in your house? But that’s normal because there are many types and not all of them manifest themselves in the same way.

Not all molds are green or black! There are white and even pink.

The aesthetics of the walls and floors is the least serious thing when you have this type of fungus at home.

What is really harmful is your health because inhaling its spores can cause allergies and severe problems in your respiratory tract.

In this article to mold and moisture in the home by the Indoor Environment Division, you’ll see exactly how and why mold is so dangerous to your health.

What Causes White Mold On Walls?

Everyone knows that mold on walls is a sign of moisture. What we don’t know is how to get rid of it! We will provide you with some tips to get rid of this undesirable and tell you what to do if you are a tenant.

For mold to grow in a house, two conditions must be met: a suitable temperature, between 2°C and 40°C, and a fairly high humidity level (65%).

That’s why mold tends to show up first in the water rooms, namely the bathrooms.

Because, in addition, it also needs a place to colonize. Its favorite places are the joints of tiles (black mold) and plaster (white mold).

A house can easily become humid, even if it is inhabited, and, one could say, especially if it is inhabited; indeed, showers, baths, cooking fumes, the presence of plants or animals, even your own perspiration contribute to humidify the spores which are in the air and which will graft themselves on the walls.

This is why it is essential to help your home to evacuate its humidity: have your VMC (controlled manual ventilation) checked regularly, do not block the ventilators at the top of the windows, ventilate every day, by opening the windows wide, for at least 10 minutes, whatever the outside temperature.

You can add to this the use of an air dehumidifier. These recommendations also apply to saltpeter, which comes from water rising in the walls by capillary action: it contains many mineral salts.

It gradually moves towards the surface to take advantage of the ambient humidity it needs, leaving white traces (the salt) on the walls.

Is White Mold Harmful

When mold stains appear, it is a sign that moisture has condensed in the walls.

Unfortunately, it is accompanied by a characteristic odor, which can already be smelled even though no stains have yet appeared, especially if the mold has taken up residence behind visible materials (frame or structure).

Whether the stains are orange, greenish, or more often black or white, it is unhealthy to live in the affected rooms.

Indeed, mold is attributed to important health problems, such as fungus, allergic reactions, and, more seriously, respiratory tract damage, including asthma.

Be particularly careful when cleaning a wall of its mold: in addition to gloves and goggles, bring a mask so as not to breathe the micro-organisms released into the air.

It’s easier to keep mold from taking hold than it is to get rid of it once it’s there. Even so, if you do have mold on your walls, you can clean them with white vinegar.

Many cleaning solutions contain white vinegar and are an excellent alternative to bleach, which should be avoided in this case.

You can mix in a sprayer 3 measures of white vinegar for 2 measures of water, to which you will add, if possible, some drops of essential oil of tea tree to eradicate the mushrooms.

Spray on the stains, leave for two hours before wiping with a dry cloth.

If white vinegar is not available, use ammonia: soak a cloth in it to rub the stain, then rinse. If traces remain, remove them with hydrogen peroxide (1 part hydrogen peroxide to 2 parts water).

You can also dilute soda crystals in water to scrub stains with a sponge or use diluted baking soda, especially on the wallpaper, if it is washable.

Is White More Dangerous Than Black Mold

There are many species of molds, some more dangerous than others. Learn all about the most harmful mold families to your health, and limit your exposure today.

This lack of knowledge about mold comes from the fact that it impacts organisms in different ways.

Some people are naturally allergic to mold, while others will not be able to fight off the pathogens it produces.

Some molds produce deadly toxins that are designed to kill other organisms in order to survive. These molds can be divided into three categories.

Mold occurs in different shapes and colors and under different conditions. However, of the approximately 130,000 known species of mold, most occur in the wild in such low concentrations that there is no danger to humans.

However, if some of these molds settle in living spaces, they are often more than just a cosmetic problem.

Depending on the type and amount of mold, damage can occur to furnishings and building structures.

Excessive infestation of a home with mold also poses a health risk to the occupants. People with immune deficiencies are, particularly at risk.

Since the determination of the exact mold genus is only possible with laboratory technology, they are often distinguished in common usage by color.

Here, the classification is made into black, white, green, red, and yellow mold species.

Based on the color, the exact genus of a mold can not be determined in reverse, because the color itself varies in a genus and is often determined by the substrate on which the mold grows.

Therefore, a mold expert should always be consulted for professional mold identification.

Fact sheet: Black mold

Black mold on living room wall

Black mold or black mold is probably the best known and also most feared mold in living rooms and basements. About 40 genera of mold are visible as the black mold.

This type of mold often first shows up as small black spots. Only in the course of time these become larger, more numerous and form a gray-blue to black coating.

Other types of mold (e.g. white mold) can also change color over time and then look like black mold.

These types of mold like moisture and infest any organic substrate.

Black mold likes to colonize walls in living rooms or basements, joints in bathrooms, wood paneling, as well as clothing, shoes, food, and more.

It is extremely hardy and grows at temperatures from about 0°C to 50°C. Since temperatures inside living spaces or building structures are usually between 5°C and 30°C, there will never be a lethal effect of temperature on mold.

Many types of black mold are toxic to the human organism because of their aggressiveness and resistance, and therefore it is imperative to remove them from living spaces if they appear there.

If you find mold in your home and your health is affected, it is important to determine the type of mold. Then you can remove it more easily.

PROFILE: White mold

white mold shoes

White mold is a secretive co-inhabitant. It often spreads undetected for a long time in damp niches or behind furniture. It is often only recognized when the fruiting body turns darker.

White mold is rather inconspicuous and difficult to detect, especially on light-colored walls.

At first, it appears only as white mold spots, later as a white to gray downy fungal carpet. If the fungus is not yet visible, a slightly musty odor may indicate the infestation.

White mold mainly attacks cooler wall corners, cold walls (e.g. basement or exterior walls), window reveals and niches behind furniture.

Like all molds, they require high humidity and organic substrate to grow. White mold can easily be mistaken for harmless efflorescence.

In popular belief, white mold is considered less dangerous because of its harmless appearance.

However, this is a misconception: white mold can also be a trigger for allergies, respiratory diseases, and skin diseases. It should definitely be removed.

Learn more about white mold in our detailed article.

Fact sheet: Green mold

Green mold on the back wall of a cupboard

Green mold is the most common mold on food and potting soil. Everyone is probably familiar with the furry green layer that coats fruit or bread, especially quickly.

Green mold does not appear grass-green, but rather blue-gray-greenish.

This is due to the fact that only the mature spore carriers are green, but the other components are white to gray in color.

Green mold usually shows up with a hairy, fluffy coating.

Green mold first often forms on fruits and fruit juices, bread and other grain products. It also thrives on moist potting soil.

Once the spores have matured, they can spread through the air throughout the home and infect not only food but also damp ceilings and walls.

Many types of green mold produce a toxin that is considered immunocompromising.

The spores are considered potentially hazardous to health and can irritate the respiratory tract and mucous membranes, as well as cause headaches, fatigue, and migraine-like symptoms.

First, you should eliminate the cause of the green mold. If the potting soil is moldy, replace the soil completely, clean the flower pots thoroughly and water less in the future as a preventive measure.

When repotting, the roots should be completely cleaned of the old soil so that, if possible, no contaminated soil is carried away with them.

Porous clay pots should be washed with hot water or replaced. Eliminate all moldy food in the home – fruit baskets, in particular, are often a source of green mold.

If there is a large infestation on walls, do not do it yourself, but call in an expert to remove the mold comprehensively and prevent it from returning.

Does Laundry Kill or Remove Mold Spores?

There are a number of do-it-yourself solutions for removing mold from your clothes using common cleaning products.

Keep in mind, however, that these methods only work for limited contamination.

Baking soda and vinegar are known to be effective in fighting mildew on clothing.

A teaspoon of baking soda combined with one to two glasses of vinegar will eliminate mold and mildew and its musty smell.

You can add this mixture to your washing machine during a wash cycle, or soak your clothes with this mixture in a basin for about an hour.

Borax is also good for killing mildew. It’s easy to get if you don’t already have it.

Add half a glass of borax to hot water and wait for it to dissolve before adding it to your laundry in your washing machine.

Alternatively, you can also use a glass of bleach, which you add to your laundry in the middle of the wash cycle.

Make sure that the clothes in it can handle the bleach, though.

If your mold problem is already large, however, these solutions will not last. It is strongly recommended that you call in a mold remediation professional.

To prevent mold from taking hold on your clothes, it is crucial to store your clothes in cool, dry areas where they will not be affected by the effects of moisture and lack of ventilation.

Mold, in fact, has a high potential to destroy the surfaces on which it takes root. If left untreated, it can quickly eat away at your clothes and shoes.

In addition, mold affects the health of those who come in contact with it, causing skin irritation, itching and many other problems, some of which have a long-term impact on your immune system.

Keep in mind that mold on your clothes is usually a symptom of a much more serious mold problem. It only becomes visible when it has grown over large areas, out of sight.

To find out if you have a mold problem in your home, call a mold inspection professional as soon as possible so that a team of experts can proceed with the decontamination and elimination of any mold that may be in your home.


by Richard Kelly

Having experienced significant success as a house flipper, I am often approached with questions about all things home improvement. That’s why I decided to start this site. My objective is to share all of the insights I have accumulated over the years so other people can design the homes of their dreams.