Types of Bathroom Mold

Mold is a type of fungus you can find in the home, but the bathroom is a common place to find mold because of the damp environment. Since mold can be dangerous for your health and your home, it's important to recognize and prevent it. This guide details the most common bathroom mold types and offers tips on how to prevent mold in your bathroom.

Bathroom Remodel

Types of Bathroom Mold and Fungus

There are technically three different classifications of mold based on how dangerous they are to humans and animals:

  • Allergenic: These molds can trigger allergic reactions and allergy symptoms, even in people who don't normally have allergies.
  • Pathogenetic: These molds generally trigger symptoms in people who already have allergies or other immune sensitivities.
  • Toxigenic: These molds are highly dangerous and can cause significant health concerns.

Mold, mildew, and other types of bathroom fungus thrive in warm, wet places, making the bathroom an ideal habitat. The following are the five most common types of mold you will find in a bathroom:


A greenish-black mold commonly referred to as "black mold," Stachybotrys is a toxigenic type of mold. It may start out looking like small black points on drywall or wood, but it usually spreads and grows fairly quickly. Symptoms of exposure to this mold include respiratory issues, nosebleeds, headaches, and fatigue.


The Alternaria strand of mold is also common in bathroom spaces. As an allergenic type of mold, it can trigger allergic reactions in the upper respiratory system. Physical markers of Alternaria include a brown color and soft filaments that resemble hairs.


Ulocladium is often mistaken for Stachybotrys because of its black appearance — in fact, the two often grow together. This variety can be both allergenic and pathogenic and needs a constant source of water. It is more common with flooding and other significant water damage.


Cladosporium grows on textiles in areas with high humidity levels, so it is common in bathroom curtains and towels. Ranging in color from green to brown, this allergenic mold can affect both humans and pets.


This puffy white and green-looking mold grow quickly in wet spots, such as around windows or shower bases. This allergenic mold can cause coughing and sneezing, and certain strains can produce more severe symptoms. Trichoderma also contributes to wood rot, so it can compromise structures in the home.

How to Prevent Bathroom Mold and Fungus

You can prevent bathroom mold with a few tips:

  • Use the bathroom fan to circulate out humid air.
  • Always hang your towels to dry with plenty of surrounding airflow.
  • Spray your shower down with a cleaner daily if it experiences frequent use.
  • Replace separated or cracked tile grout.
  • Leave the shower curtain closed to ensure it dries out properly.
  • Dry any water splashes.
  • Watch for leaks.

If you see mold in your bathroom, it's imperative to call a mold remediation expert to assess the extent of the problem and protect your family from exposure. Home remedies, such as spraying the area with bleach, may help a small problem, but mold can burrow into structures, making it hard to get rid of without professional help.

Request a Job Estimate

Sometimes, getting rid of mold in your bathroom is not enough. Mr. Rooter Plumbing of Greater Syracuse offers shower repairs and replacements for tubs, sinks, and showers that are overrun with mold. Contact us to request a job estimate.