11 Surprising Ways Mold Spread In Your House

by | Dec 17, 2022 | Mold Damage, Mold Repair, Reconstruction, Remodeling, Restoration, Water Damage | 0 comments

Mold spores thrive in a moist environment, and mold can spread rapidly with just a few drops of water. This is why removing wet and humid areas from your house is essential. Mold has many different shapes and sizes.

It can grow anywhere and be seen as white powdery substances on damp surfaces or areas like plumbing, wallboards, and carpets, which is usually not a cause for concern. The black spots are harmful and need to be taken care of. These spots are the signs of mold growth and can spread quickly within your house if you ignore them. Here are some surprising ways mold spreads in your home.


Mold spores are tiny and can travel through the air. They can land on surfaces where moisture is present, such as window sills or water damage from a leaky roof. The mold will then start to grow and release Harmful Black Spores that will spread throughout your home.

Water Damage

Moisture caused by rain, humidity, spills, or condensation can help mold growth in your home. Mold spores collect in damp areas like wet carpets and basement walls. After heavy rains, water recedes slowly, allowing mold to form along baseboards and electrical boxes below the water line.

Rusting of Metal

Mold growth can also occur on surfaces in direct contact with moisture, such as metal roofing, vent pipes, plumbing fixtures, and other areas where condensation builds up. The mold spores will attach to the wet metal surface and grow. This growth may cause damage like rusting or pitting.

Direct Transfer

Molds spread when damaged objects are moved from one area to another without cleaning them thoroughly. Most of these materials are damp, so they easily hold on to molds and other organisms that enter their surface.

Indirect Transfer

Molds grow in kitchens, bathrooms, and other humid areas close together because they are nearly always well-ventilated. Dust generated in air vents near a water source encourages mold growth on mechanical parts.

Areas with Poor Lighting

Mold growth is often associated with dark, damp environments such as basements or attics. In well lit areas, mold spores can easier be seen and removed. However, a lack of light also limits your ability to see mold growth on surfaces. This makes it harder to eliminate the mold before it causes damage.

Sewer Outfall

Occasionally, mold growth may be caused by water flowing from a sewer line into your home. Sewer water contains high levels of bacteria and other harmful substances that can damage items like drywall, insulation, and carpets. If you see water or mold coming up through the flooring or walls of your home, call a professional to inspect the source of the leak.

Interior Water

Entering through plumbing systems or leaking pipes, water causes high humidity inside homes that support mold growth. Any undetected water leaks, including a leaky plumbing joint under the sink or basement, can create the perfect environment for mold growth.


Mold growth is often associated with damp environments, but flying insects can also cause it. These tiny creatures leave a moldy residue on surfaces they land on. Once mold spores are in the air, they can easily spread to other areas of your home.

Spiders rarely invade homes, but their skin and webs can carry molds. Molds found on the spiders’ droppings commonly create mildew that can spread in damp areas.


Wooden furniture may be infested as well. Furniture can be a closet for molds known as “fungus gnats” that live on spiders’ hairs and wrap around furniture. Yard furniture, unpainted shelving units in basements and garages, old mobile homes, etc., can be infested with mold-causing fungus gnats (Mycoplasma hominis) that cause damp conditions conducive to the growth of Mycotoxins.


Building properties of different materials can trap molds and mildew rather than dry them out. New drywall damaged by moisture (corrosion, rot, etc.) will support the growth of molds and fungus spores in humid areas. Mites too, may become a problem, particularly in soil containing high salts. They can bring these fungi into the home and be a source for mold growth in older residential buildings, including those built with concrete, tile, etc.

How do you keep mold out of buildings and homes?

Mold can be prevented by limiting air penetration into your home or building. (Doors, windows, and vents should not always be opened.) Minimize humidity in buildings to less than 40% relative humidity with a dehumidifier if necessary.

Keep dirty rags, tools, and equipment in plastic bags when possible. Mold-contaminated clothes must be washed separately from other items. Clean up spills promptly before they dry. Avoid storing food in damp places; wet pantries, sinks, and basements are especially problematic.

Good ventilation also is a great way to protect a home or building from toxic molds and mildew.

Mold can spread through your home in surprising ways. Most people are unaware of the potential for mold to spread throughout their homes, but it must be taken seriously. If you suspect a problem with mold in your home, contact a professional who can help you identify the cause and help you get rid of it.


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