Mold is more than just an inconvenience on a construction site—it’s a warning sign that can lead to expensive delays, contract disputes, liability claims, and long-term structural problems. For commercial landlords, developers, architects, and contractors, understanding who is responsible when mold appears is essential to avoiding major setbacks.
But determining liability isn’t always simple. In fact, mold-related responsibility often depends on when the mold is discovered, what caused it, and what the construction contracts say—as well as whether negligence or construction defects played a role.
During Construction: Who Should Be Watching for Mold?
In the early phases of construction, contractors generally bear a significant share of responsibility for mold prevention. They are expected to follow industry best practices and take proactive steps to mitigate risk, such as:
- Keeping building materials dry
- Properly sealing the structure
- Controlling moisture and humidity levels
“Failure to protect materials from the elements—even for a short time—can quickly result in mold that halts progress and triggers liability.”
For example, if a contractor leaves framing or insulation exposed during a rainstorm and fails to dry it out before continuing construction, they could be held liable for any resulting mold damage.
However, contractors aren’t the only ones who may be on the hook.
Design Professionals May Share Liability
Architects and engineers can also bear responsibility when mold stems from design errors. Inadequate planning for drainage, ventilation, waterproofing, or site grading can create conditions ripe for water intrusion and mold growth.
If the building’s plans don’t account for local weather conditions, or if there’s insufficient airflow in areas like crawlspaces, basements, or rooflines, then the firm or individual responsible for those design flaws may face liability.
Developer Oversight: Cutting Corners Comes at a Cost
Developers who manage the project timeline and budget may also face exposure—especially if they:
- Push to meet deadlines at the expense of quality
- Approve change orders that eliminate moisture protection
- Ignore red flags raised during inspections
“Cost-saving shortcuts during construction can become multi-million-dollar headaches down the road.”
If a developer is actively involved in decision-making and fails to enforce proper quality controls, they may be found liable for mold that develops during or shortly after construction.
After Project Completion: Who’s Responsible Now?
Once construction is finished and the building is occupied, the issue of mold liability becomes more complex.
If mold is caused by poor maintenance, such as clogged HVAC filters, unreported leaks, or tenant misuse of equipment, responsibility may shift to the tenant or property management. In these cases, a contractor or developer might have no liability at all.
However, if the mold arises from hidden construction defects—such as improperly installed windows, flashing, or roofing—then the property owner may have grounds for legal action against the general contractor or subcontractors under warranties or negligence claims.
In many states, there are statutes of limitation and statutes of repose that define how long owners have to bring construction defect claims, especially in cases of latent mold damage that wasn’t immediately visible.
What Should You Do if Mold Is Found on a Project?
The discovery of mold during or after construction should never be ignored. It can cause extensive damage to both the structure and the project’s financial outlook. It may also trigger regulatory scrutiny, insurance disputes, or costly litigation.
Whether you’re a developer, property owner, general contractor, or tenant, seeking timely legal advice is crucial to understanding your rights and determining your next steps.
Protect Yourself—Contact the Legal Team at Lesak, Hamilton, Calhoun & Pontieri
If mold has become an issue on your construction project—or if you’re worried about potential liability—turn to the experienced attorneys at Lesak, Hamilton, Calhoun & Pontieri.
Our team has extensive experience in construction law, insurance disputes, contract enforcement, and mold-related litigation. We represent developers, owners, contractors, architects, and commercial landlords with practical, informed legal strategies that protect your interests and minimize risk.
📞 Contact us today to schedule a consultation and learn how we can help safeguard your project, reputation, and bottom line.