Mold has become an increasing headache to businesses, and lawsuits are becoming more common. There is even concern that mold and microbe claims will outpace asbestos litigation.

Most mold lawsuits involve a common theme: Conditions that fostered the growth of toxic molds, causing building damage and personal injury. The health reactions include allergies, asthma attacks, brain damage and even death. People with known health problems related to "sick building syndrome" or indoor air quality are perfect candidates for a toxic mold reaction.

The most common types of liability involve:

Claims against architects and contractors, especially reconstruction contractors.

Most of these claims are based upon a theory of negligence. Claims against contractors are usually developed around the concept that the contractor didn't allow sufficient time for interior wood or other material to dry before being sealed. Lawsuits against architects usually claim negligent design of a building or its mechanical infrastructure, creating "dead zones" or insufficient air exchange to prevent mold growth.

Reconstruction contractors have been involved in a variety of claims, including water loss due to broken pipes, snow or ice damage, and failure to create a dry environment prior to re-installing drywall and other materials. Defensively, contractors should always carefully document their efforts, including the moisture content of subflooring, joists, and studs.

Claims of condo owners against condo associations, or tenants against landlords.

These suits are usually related to common elements such as crawl spaces and attics where mold could grow. Landlords and condo associations are accused of failing to properly maintain the areas. Toxic mold claimants may look to the landlord or association to cover their medical expenses. Mold cases are a legal nightmare, because determining an exact cause can be difficult. For example, a leaky pipe could cause mold to begin growing, and the problem can be expanded by general moisture conditions in the building.

Claims of policyholders against insurance companies.

Insurers can be found liable for unreasonably denying coverage on a claim, failing to investigate the facts, and refusing to pay in an effort to force a favorable settlement. Bad faith claims are popular because most jurisdictions allow for punitive damages.

Mold lawsuits are also difficult, because of the number of parties involved. It's not unusual for a disgruntled building owner to sue the general contractor or his bonding agency. These parties might then begin suing subcontractors, architects or others involved in the construction. There could be 50 to 100 individuals or companies involved.

Damages for remediation of the mold (removal is similar to asbestos) in large office buildings can cost millions of dollars. In some cases, remediation of the mold was not possible, and demolition was the only solution.

Since it's difficult, if not impossible, to document where the mold started or what conditions allowed it to flourish, the best defense is well-documented project files, noting that proper construction methods were used with dry materials. A lawsuit is best defended before it is even filed.