Jordon Scrinko
Published by Jordon Scrinko
Last Updated On: April 1, 2026

Mold in Condo? (Find Out Who Is Responsible)

Mold in a condo is a common issue, often due to water damage, excessive moisture, or spore contamination. It can cause serious health problems, decrease property value, and lead to costly cleanup. So, who's responsible for addressing mold issues—the condo owner, the condominium corporation, or both?

Having guided numerous condo buyers and owners through mold disputes and remediation processes, we've seen firsthand how unclear responsibility lines can complicate resolution. This guide will break down how mold responsibility is typically divided, what steps to take if you find mold, and how to prevent it from happening again.


Quick Summary

  • Mold can negatively affect a condo's resale value. Buyers are often wary of properties with a history of mold, even if the issue has been resolved.
  • Mold exposure can cause significant health problems, especially for individuals with asthma, allergies, or weakened immune systems.
  • As of our latest review, mold-related claims account for approximately 10% of all condo insurance claims in Canada, highlighting the significance of the issue.

Who Is Responsible For Mold Issues In Condos?

In condos, responsibilities for mold remediation can fall on both unit owners and condominium corporations, depending on the cause and location of the mold. Mold can often grow unnoticed for long periods and usually becomes noticeable only when visible or when its distinct odor becomes apparent.

Since mold-related disputes between homeowners associations (HOAs), unit owners, and condominium corporations are common, it’s crucial to understand where responsibility typically lies.

Who Handles Mold: Condo Owner or Condo Corporation?

In most cases:

  • Condo Corporation is generally responsible for maintaining and repairing common elements like structural components, ventilation systems, and shared spaces.
  • Condo Owners are typically responsible for maintaining the interiors of their units, including routine cleaning, repairs, and addressing any mold issues that originate from within their living space [1].

In a case involving an Ontario condominium, a unit owner discovered mold due to issues linked to the common elements, including exterior windows, the heating system, and ventilation. The condominium corporation claimed the mold was due to the owner’s choices, like improper use of the heating system.

Ultimately, the court ruled in favor of the owner, holding the condominium corporation responsible for the repair costs because the mold was deemed to be from building-related causes.

This case highlights that if mold stems from structural issues or shared elements, it’s generally the condo corporation’s responsibility to manage and cover the remediation costs.

Identifying Mold Issues In Condos

Mold is a widespread outdoor fungus, especially in moist environments such as woods [2]. Mold performs a vital function in decomposing decaying organic waste. However, mold spores may invade our residences, workplaces, and stores. Mold often grows in wet and moist environments, such as:

  • basements
  • kitchens
  • bathrooms
  • other places with high moisture levels

Alternaria, Fusarium, Memnoniella, Aspergillus, and Trichoderma are some common types of mold found in indoor environments.

Mold may develop on:

  • drywall
  • ceiling
  • tiles (encompassing floor, bathtub/shower, and walls)
  • curtains
  • carpets

It's a major problem for various reasons. A mold issue is directly linked to a range of health risks, including respiratory difficulties and skin and eye irritation.


Destructive Nature of Mold Diseases

Mold infestations are not just unsightly; they're structurally devastating. The infiltration of mold into critical areas like drywall and tiles ups the ante for further water damage and subsequent mold growth.

In severe cases, a rampant mold problem can necessitate extensive and expensive reconstruction efforts, which underscores the importance of either preventing or detecting mold early on.

 


Impact on Condominium Livability and Reputation

Mold's repercussions extend beyond physical damage to properties. A mold outbreak can drive tenants away, diminishing occupancy rates and, by extension, revenue.

Furthermore, mold can tarnish a building's reputation, making it less attractive to potential homebuyers and renters and potentially depressing property values.

These challenges require condominium management, unit owners, and occupants to deal with or control mold, preferably before a mold breakout.

Even though building management is accountable for specific areas, like ensuring that the plumbing is at no risk of leaks, drying common areas like the gym or swimming pool change rooms), and controlling moisture where they have control, each residential unit is also responsible for its maintenance.

Frequent showering, cooking, cleaning, and other everyday activities might cause increased moisture and water damage. If residents neglect to eliminate moisture (by employing exhaust fans) or maintain dry spaces, their apartments will be more susceptible to mold growth.

If uncontrolled, mold might spread to the building's structure and other units. Hence, homeowners must take responsibility for maintaining their units and determining if there are any traces of mold growth.

Health and Structural Impact Assessment

Impact Category Severity Level Consequences
Health Effects Moderate to Severe Respiratory difficulties, skin irritation, eye problems, allergic reactions
Structural Damage Progressive Drywall deterioration, tile adhesion failure, wood rot, ceiling damage
Property Value Significant Reduced resale value, buyer reluctance, disclosure requirements
Insurance Claims High Frequency 10% of all condo insurance claims in Canada

Next Steps After Detecting Mold Problem

Upon the detection of mold in your condominium, it's imperative to take action swiftly to mitigate the potential health and structural hazards. The process of addressing a mold issue involves several critical steps:

  • Reach out to a certified environmental contractor specializing in mold remediation.
  • Arrange for a thorough inspection of the affected area to determine the extent of the mold problem.
  • Follow the contractor's recommendations for safely and effectively removing the mold.
  • Ensure that all mold-contaminated materials are disposed of according to safety regulations.
  • After mold removal, take measures to prevent future mold growth by addressing the source of moisture.

Yet, your mold management strategy must ideally begin with preventative steps, such as maintaining low moisture levels in your condo and keeping sensitive areas dry.

It would be good to insure your condominium with specified coverage for mold damage and mold remediation. 

Building managers can make the error of purchasing a comprehensive insurance policy without examining the type of coverage provided. Hence, check and review the insurance you are purchasing.


Effective Mold Prevention and Remediation Strategies

  1. Regular Maintenance: Keep your unit dry and well-ventilated. Regularly inspect areas prone to moisture, like the bathroom, kitchen, and basement.
  2. Address Leaks Promptly: Immediately report leaks to building management or hire a plumber if the issue is within your unit.
  3. Use Exhaust Fans: Run fans during showers or cooking to reduce moisture buildup.
  4. Check Insurance Coverage: Ensure your insurance includes mold damage and remediation, as this coverage can vary.

FAQs

1. How do I determine if mold is my responsibility or the condo corporation's responsibility?

Responsibility typically depends on the source of the moisture causing the mold. If mold results from common elements like building ventilation, exterior walls, or shared plumbing, the condo corporation is usually responsible. If mold stems from activities within your unit or personal negligence, you're typically responsible. Professional assessment may be needed to determine the exact cause.

2. What should I do if the condo corporation denies responsibility for mold that I believe is building-related?

Document all evidence supporting your claim, including professional assessments, photographs, and maintenance records. Review your condominium's declaration and bylaws, consult with a lawyer specializing in condominium law, and consider mediation services. The Ontario legal precedent demonstrates that courts favor unit owners when building-related causes are proven.

3. How much does professional mold remediation typically cost in condominiums?

Remediation costs vary significantly based on contamination extent, affected materials, and accessibility. Minor surface mold may cost $500-$2,000 to address, while extensive contamination requiring drywall replacement and structural repairs can cost $10,000-$50,000 or more. Professional assessment is essential for accurate cost estimation.

4. Will mold history affect my condo's resale value even after professional remediation?

Yes, mold history typically impacts resale value and marketability. Many buyers remain cautious about properties with mold history, even after successful remediation. Disclosure requirements vary by province, but transparency about remediation efforts and ongoing prevention measures can help mitigate buyer concerns.

5. How can I prevent mold growth in my condo unit effectively?

Maintain indoor humidity between 30-50%, use exhaust fans during moisture-generating activities, address water leaks immediately, ensure proper ventilation, and conduct regular inspections of high-risk areas. Professional HVAC maintenance and prompt reporting of building-related moisture issues are also crucial.

6. What type of insurance coverage do I need for mold issues?

Standard condominium insurance may have limited mold coverage. Ensure your policy specifically includes mold damage and remediation coverage, understand policy limits and exclusions, and consider additional coverage if standard limits are insufficient. Review your policy annually and after any mold-related incidents.

7. Who Is Responsible for Mold in a Condo in Ontario?

Mold responsibility in Ontario condos depends on the source and location of the problem. If mold originates from common elements like building leaks, faulty HVAC systems, or structural issues, the condominium corporation is typically responsible for remediation and costs. However, if mold results from issues within your unit such as poor ventilation, unreported leaks, or lifestyle factors, the unit owner is generally responsible.

Keep Your Condo Safe and Mold-Free

Mold in condos is a common but manageable problem. By understanding your responsibilities, performing routine maintenance, and taking prompt action, you can reduce mold risks and keep your living space safe and comfortable. Remember, staying informed and proactive is the key to effective mold prevention and remediation in a condominium setting.

For more condo articles & listings in Canada, visit Precondo.

References:

  1. https://www.ontario.ca/laws/statute/98c19
  2. https://www.cdc.gov/niosh/topics/indoorenv/whatismold.html