A Complete Guide to Preventing, Identifying, and Removing Mold in Homes

Mold, often an unseen intruder within your home, poses a serious threat to both your health and the structural integrity of your living space. If you suspect mold growth, taking immediate action is essential. In this complete mold guide, HVAC.com provides insights into common signs of mold growth, preventive measures, safe removal methods, and potential health risks associated with mold exposure in homes.

Health Issues Associated with Mold

The first thing to know about mold in homes is it can cause unexplained or sudden health effects, including exacerbated allergies and respiratory issues. In severe cases, mold can cause asthma attacks in individuals with asthma who are allergic to mold, according to the U.S. Environmental Protection Agency.

Prolonged exposure to mold can also contribute to sinus infections and can cause reactions such as sneezing, nasal congestion, skin rashes, and itchy eyes. This emphasizes the need to identify and address the source of mold to alleviate these allergic symptoms. Other signs of mold exposure can include an irritated throat, nose, and lungs, whether you are allergic to mold or not.

“Exposure to any mold species can potentially trigger adverse health reactions,” said Michael Rubino, a renowned mold and air quality expert who is the founder of HomeCleanse and president of Change the Air Foundation. “The longer the growth is present, the more these particles will build up in that indoor space. This leads to poor indoor air quality, increased exposure, toxic buildup within the body, and potential adverse health reactions.”

“Everyone responds to this exposure differently,” he added. “Genetics, the immune system’s health, exposure volume, and exposure time are some factors that will determine how you may respond.”

Tips to Prevent Mold Growth

Mold remediation services can be expensive, time consuming, and stressful. Mold prevention is the key step in avoiding the high costs associated with mold removal services and preventing potential health issues. Some tips to follow include:

Balance Humidity Levels

Elevated humidity levels play a significant role in mold formation. Indoor humidity should ideally be within the 30-50 percent range. During warmer months, humidity often rises above 50 percent indoors, creating moist, warm environments for mold to grow and thrive. 

If your air conditioner struggles to maintain humidity levels, consider installing portable dehumidifiers or a whole-house solution within your HVAC system to keep indoor humidity levels balanced. Purchasing a humidistat at a local hardware or big-box store can help you understand your home’s humidity levels and whether adjustments are needed.

Fix Water Leaks

Water is mold’s best friend. Any water leak can lead to mold growth within a day or two. Prevent mold by promptly addressing leaks in your home’s roof, walls, or plumbing, eliminating the moisture mold needs to grow and thrive.

Ensure Proper Ventilation

Proper ventilation within your home is crucial to prevent mold growth. Ventilation helps with maintaining humidity levels, promoting air circulation, and discouraging excess moisture accumulation, especially in enclosed spaces. Use exhaust fans in the kitchen and bathrooms while cooking and bathing, respectively.

Dry Out Your Home

After flooding or a plumbing emergency, completely dry out your home in a timely manner. Mold can form in as little as 24-48 hours.

Remove Damaged Carpet

Remove or replace upholstery and carpeting that has been soaked and cannot be immediately dried, as they can attract mold growth. Also, avoid using carpet in rooms prone to moisture, such as basements and bathrooms.

Use Mold-Killing Products

Maintain a mold-resistant environment in your bathrooms by regularly cleaning surfaces with specialized mold-killing products. These cleaning agents not only eradicate existing mold but also create a protective barrier, discouraging the recurrence of mold growth in these high-humidity spaces.

Repair Structural Issues

Rubino said cracks in the foundation can allow moisture to intrude during weather events, leading to mold. Meanwhile, faulty gutters that are broken, blocked, or improperly installed can allow water to pool in crawlspaces, windows, the roof, and along the foundation of the building.

Perform Regular HVAC Maintenance

Your HVAC system can be an ideal breeding ground for mold growth due to a lack of maintenance. If the condensate drain line becomes clogged, it can cause water spillage that leads to mold. A qualified HVAC contractor will check for clogs and moisture during a maintenance inspection.

Signs of Mold Growth in Your Home

From visible signs to health issues and water damage, several indicators may suggest the presence of mold in your home. Some of the most common include:

Visible Signs

Although mold can be hidden out of sight within walls and behind furniture or appliances, visible signs of mold should not be ignored. Search for any damp areas inside your home. Mold may be visible on walls, surfaces, and ceilings, indicating the need for mold removal.

The most common color of mold found indoors is typically black or green, although it can also be gray, yellow, and orange. Mold textures can be slimy, furry, or have a powdery appearance. It can grow on several different surfaces, including leather, fabric, paper, sheetrock, wood, and soap scum. You’ll most often find it located near water, in damp conditions, or in areas with elevated humidity levels.

Water Damage

Mold needs water to grow and thrive, so water damage from plumbing issues, leaks, or flooding should be inspected for signs of mold growth.

Ideal Breeding Grounds

In addition to water damage, other factors can contribute to the likelihood of mold growth in your home including inadequate ventilation and damp, humid environments, often found in basements, crawlspaces, and bathrooms.

Musty Odor

A musty smell can also indicate the presence of mold. If you can’t visibly see mold but smell a musty odor, the mold could be hidden out of sight within walls or behind appliances. According to the EPA, hidden mold can often be found underneath carpet and pads, the backside of wallpaper and paneling, and the top side of ceiling tiles.

Inspecting, Testing, and Removing Mold in Homes

If you can visibly see mold in the house, prompt removal is imperative. If you suspect the presence of hidden mold based on a water leak or an unusually musty smell but cannot locate the mold, consider contacting a professional for mold detection services. They can thoroughly inspect your home for any signs of mold. If mold is growing on the backside of wallpaper, peeling off the wallpaper can lead to a massive release of mold spores, according to the EPA, highlighting the need for professional remediation.

If mold is discovered through either a DIY visual mold home inspection or by a professional, the Centers for Disease Control and Prevention (CDC) does not recommend mold testing, which can cost $300-$600. The CDC advises that all mold, no matter its type, should be removed, adding: “There’s not set standards for what is and what is not an acceptable amount of different kinds of mold in a home.”

Instead of home mold testing, focus on prompt and safe removal as well as preventative measures.

“Choosing the right products for prevention and remediation is key,” Rubino said. “EPA-approved botanical cleaners with surfactants are the best route. These nontoxic products will help lift particles to the surface so they can be wiped away and removed. From there, a HEPA vacuum cleaner and microfiber towels can be used to further eliminate particles from the indoor space.”

How to Properly Remove Mold

DIY Methods

If the mold is confined to a smaller area – typically less than 10 square feet – you can consider removing the mold yourself. DIY mold removal efforts involve using everyday household items such as soap and water or a bleach solution consisting of one cup of laundry bleach per one gallon of water. Avoid mixing bleach with other cleaning products such as ammonia, as it will produce a poisonous gas.

According to the CDC, wear goggles, rubber boots, and rubber gloves while you’re cleaning the affected areas, and open doors and windows to bring in fresh air. To avoid breathing in mold spores, consider wearing an N95 respirator, which is available online and at local hardware stores for about $12 to $25, according to the EPA.

Professional Remediation

While the CDC and EPA acknowledge that individuals can handle mold cleanup in their homes, there are certain situations where hiring a professional mold remediation service is strongly recommended. If the mold growth covers an area larger than 10 square feet, it’s within walls or in hard-to-reach areas, or if mold is present in HVAC systems, it is advisable to seek professional assistance. If you suspect mold in the HVAC system, turn it off to avoid spreading mold spores throughout your home.

Consider hiring a mold remediation expert if significant water damage has occurred or if the mold and water damage resulted from sewage issues.

Additionally, individuals with underlying health conditions, respiratory issues, or compromised immune systems should avoid direct exposure to mold and should opt for professional help to ensure thorough removal and proper safety measures. If the mold is caused by water damage from a severe flooding event, an expert can address the mold as well as the root cause of the moisture problem.

Professional mold remediation professionals possess the expertise, equipment, and protective gear necessary to handle complex and extensive mold infestations, minimizing health risks and ensuring effective and long-lasting removal. Before hiring a mold contractor, ensure they have experience safely removing mold in homes and follow guidelines from government or professional organizations such as the CDC and the EPA.

“A qualified individual will be able to determine if mold is in a home, what species are present, where the colony or colonies are, what the contamination levels are, and what caused the growth in the first place,” said Rubino, who also hosts a podcast called, Never Been Sicker. “Their inspection should span a few hours, thoroughly check every space in the house, and use various measuring techniques to assess the area.”

Mold Remediation and Cleanup Checklist

According to the EPA, the mold remediation process should not be considered finished until the following checklist has been completed:

• The source of the water or moisture problem has been fixed.
• Mold has been completely removed.
• No moldy smells or visible mold are present.
• Health complaints or physical symptoms have been eliminated.