What Everyone Should Know About Roof Leak Mold Growth and Buildup

How Roof Leaks Cause Mold and It’s Not Pretty!

Struggling with roof leak mold growth and buildups?

In case of a roof leak and you are in need of a proper roof inspection we always recommend you hire a professional roofer.

But Before you do that we highly advise that you educate yourself on the process of a proper roof inspect for your roof. It’s to keep you safe and avoid getting a dishonest service. You’ll know if they’re thoroughly checking your roof and are honest with their assessment.

With that said, please read on to find out how to deal with a leaky roof and the mold growth that comes with it.

Are Roof Leaks Causing Mold to Grow in Your Home?

A leaky roof isn’t just irritating, it can also stimulate roof leak mold growth.

Mold is a type of fungus that grows in damp, dark areas. While plenty of factors may cause mold growth, a very common one is rainwater. Once rainwater leaks into your home, the indoor air humidity rises and your home becomes the perfect breeding ground for mold.

If you allow the mold to continue building up in your home, it will cause ventilation issues and air quality issues. The consequences are that your electricity bill will be sky-high.

On the health side of it, once fungi (mold) accumulate in your home, you may experience health issues like allergic reactions, sinus infections, and asthma attacks.

Because of the health risk associated with mold growth, you should act quick and either get your roof repaired or replaced depending on how severe the mold growth is.

Common causes of roof leaks include, but are not limited to:

  • Damaged shingles
  • Poor installation
  • Backed-up gutters
  • Flimsy roofing material

We’ll discuss in brief details about the types of mold you will usually find from a leaky roof that’s ignored over time.

Roof Leak Mold Growth on a brown roof of a beautiful white house

Roof Leak Causes Mold: Here Are the Types of Mold You Can Expect

We’ve found that there are 6 types of mold that can grow from a roof leak. It’s better that you know them and understands what they look and smell like so you can identify exactly what it is and get help asap!

Some of the most common types of roof leak mold you might spot around the house after a storm include:

1. Stachybotrys Chartarum

This type of mold has a jet-black color and gives off a strong, musty odor. It thrives in damp, enclosed spaces like chimneys, crawlspaces, wall cavities, and ductwork systems.

2. Fusarium

These fungi are characterized by their unique pink, red, and purple hues. They’re one of the very few mold spores that don’t have dark pigments. Exposure to fusarium may put you at risk of respiratory inflammation.

3. Penicillium

Penicillium grows on wet carpets, water-stained wooden furniture, and damp wallpaper. You can recognize penicillium mold spores by their bright color combination of blue, yellow, and green. They also produce a heavy, musty odor in humid weather conditions.

4. Cladosporium

Cladosporium fungi are some of the most commonly found types of mold, both indoors and outdoors. You’ll recognize them for their lime green pigment. They accumulate on old clothes, damaged wooden pieces, and unused fabric.

5. Chaetomium

Notice a damp, musty odor coming from your walls or pipes after a heavy storm? Then you may have a chaetomium infestation on your hands.

These fungi often build up in tight, wet spaces such as pipelines, crawlspaces, and drywalls. Chaetomium is known for its soft, cotton-like mold spores that turn white, gray, brown, and black as they age.

6. Alternaria

The Alternaria fungus is the most common type of mold in the country. In fact, you can spot them on carpets, sinks, bathtubs, toilets, ceilings, walls, trees, and even leaves. They have dark green pigments and emit a mild musty odor.

Note: No matter what kind of roof leak mold pops up, get rid of it quickly. These fungi produce mycotoxins and exposure can lead to health issues such as asthma, fatigue, and breathing difficulty.

As you can see these are the common types of mold you can find growing from a roof leak.

But where can you spot these?

Roof Leak Mold Growth image article of a wall that has mold in various spot. It doesn't look clean and could cause odor

Areas Mold Can Grow From Roof Leaks: Your Ceiling, Attic, and Walls

Checking for mold buildup caused by a leaky roof? Don’t forget these spots:

  • Ceiling: Your ceilings are directly under the roofing, so they’re the first place where roof leak mold growth occurs. The problem is that ceiling mold spores usually grow on the inside of structures, which makes them hard to spot unless you tear down the ceilings. But instead of checking every panel one by one, opt to do a visual inspection first. Only crack the ceiling if you notice signs of a roof leak.
  • Bathroom: Rainwater, soap residue, and bodily dirt are never a good combination. To prevent water damage and mold growth, make sure you keep your bathroom clean and dry at all times. If possible, mop the place dry after showering. Also, call your roofing contractor if you notice water leaking from the roof.
  • Walls: Do not take water-stained walls lightly. Once mold accumulates on them, they’ll be more prone to all kinds of water damage. Over time, this weakening can lead to structural damage and may compromise the integrity of your foundation.
  • Attic: Most people don’t take care of their attic. They simply use it as a storage space for unused items and never even bother to clean the area. If your roof leaks and the rainwater mixes with the dust in your attic, it’ll create the perfect environment for mold to thrive in.
  • Carpeted Floors: Carpets may look nice, but they’re also very prone to mold buildup. They absorb dirt, moisture, and bacteria on a daily basis. If you let rainwater drip on your dirty carpet, don’t be surprised to see roof leak mold buildup on it.
  • Laundry Room: Combine roof leaks with the moisture from your washing machine and you won’t be able to prevent water damage and mold growth. Apart from getting roof damage fixed, try leaving the door open. Doing so will allow the moisture to escape and keep the surroundings of your laundry room dry.
  • Underneath Wallpaper: Wallpaper crevices are the ideal place for mold to grow, because they’re dark, hidden, and if you have a water leak, damp. Plus, they contain cellulose, a substance filled with thousands of glucose units for mold to feed on. So if your walls have wallpaper glued on them, make sure you keep them dry and clear of rainwater.

These are just some of the areas susceptible to mold growth. Keep in mind that fungi can grow anywhere that’s damp, dirty, and humid, so don’t limit yourself to the places we mentioned.

Feel free to explore other spots that you feel mold might grow on, especially the ones where roof leaks often happen.

Roof Leak Mold Growth Article Image of an old roof that has nasty growth of mold and other bacteria, this is not what you want on your roof.

Proper Maintenance Twice per Year to Prevent Roof Leaks That Cause Mold

Roof leaks, water damage, and mold growth are natural occurrences that you’re bound to come across multiple times throughout your life. But that doesn’t mean you can’t protect yourself from them.

To prevent roof leaks from developing, do a visual inspection of your roofing at least once every two weeks. A good place to scan for cracks and holes is in your attic. If it’s raining, try tracing every water leak you see. Meanwhile, look for gaps where sunlight seeps in if it’s sunny outside.

If you don’t have time to check for roof leaks, hire a roofing contractor instead. Have them examine the entire area of the roof at least twice a year to uncover any possible cracks, gaps, or crevices where rainwater might seep in. These routine checkups ensure your roofing can stand strong against harsh weather conditions.

Also, call a professional mold remover or pressure washing company that does soft wash roof cleaning in Austin TX to wash off the mold buildup, thus extending the life of your roof by several years. Preventing mold growth is much cheaper and easier than mold remediation. Remember, the goal is to reduce your exposure to harmful fungi which may cause health issues.

For expert roof leak repair and inspection services, turn to Hometown Roofing ATX by calling (512) 707-9182 and booking an appointment with the team. We also provide sample estimates.


Hometown Roofing ATX
Phone: (512) 707-9182
Address: 12443 Tech Ridge Blvd #234, Austin, TX 78753