Structural Drying in Occupied Buildings: Why Moisture Control Isn't Enough

When a building experiences water damage, the immediate priority is often to remove moisture as quickly as possible. Rapid structural drying helps prevent material deterioration, minimize business interruption, and reduce the risk of mold growth. In occupied buildings such as hospitals, long-term care homes, schools, laboratories, museums, archives, and commercial facilities, however, successful structural drying involves much more than removing water. It also requires careful planning, contaminant control, and protecting the people who continue to use the building throughout the restoration process.

Beyond Drying the Building

The goal of structural drying is to return building materials to an acceptable moisture content while minimizing disruption and preventing secondary damage. Achieving that goal, however, requires more than installing air movers and dehumidifiers.

Over the past several years, the restoration industry has placed increasing emphasis on proper containment whenever walls or ceilings need to be opened. These containment measures help limit the spread of contaminants such as mold spores, dust, or asbestos-containing materials when present.

Another important consideration is how restoration activities may affect the building itself. Many commercial and institutional buildings contain interconnected wall cavities, suspended ceilings, utility chases, and mechanical spaces that allow air to move between rooms. During structural drying, changes in airflow and pressure can disturb accumulated dust and other contaminants, potentially allowing them to migrate beyond the original area of water damage if appropriate controls are not in place.

"Structural drying is not simply about installing equipment and removing moisture," says François Radino, Account Manager at Polygon Restoration. "It also requires understanding how the building functions, how restoration activities may affect occupied areas, and what controls are necessary to protect the people inside."

Successful structural drying requires more than simply removing moisture. It also requires identifying potential pathways for contaminant migration and implementing the appropriate control measures before restoration work begins.

Understanding the Risks

The consequences of contaminant migration vary depending on the building and its occupants.

In healthcare facilities, airborne particles may present additional risks for patients with weakened immune systems. In schools, they can affect students and staff. Museums, archives, and libraries must also protect valuable collections from dust and environmental contaminants during restoration work. Even in commercial office buildings, poorly planned restoration activities can affect indoor air quality and disrupt normal operations. For this reason, every structural drying project should begin with an assessment of the building, not just the water damage.

Before restoration work begins, building owners and facility managers should ask questions such as:

How will air move through the affected area during structural drying?
Are wall cavities or ceiling plenums connected to occupied spaces?
What measures will be taken to prevent contaminants from spreading beyond the affected area?
Will containment or HEPA-filtered negative air be required?
How will occupants be protected while restoration work is underway?

Discussing these questions with your restoration contractor before work begins can help reduce risks and support a safer, more effective restoration process.

Following Industry Best Practices

In healthcare facilities, construction, renovation, maintenance, and restoration activities must be carefully planned to reduce the risk of contaminant migration and protect patients, staff, and visitors.

This approach is reflected in CSA Z317.13:22 – Infection control during construction, renovation, and maintenance of health care facilities, a National Standard of Canada. According to the standard, it establishes risk assessment processes and precautionary measures to help prevent exposure to contaminants released during construction, renovation, maintenance, and repair work. It also provides guidance for infection control risk assessments, containment strategies, pressure management, and other measures intended to reduce the spread of airborne contaminants.

Although developed specifically for healthcare facilities, many of the principles outlined in the standard can also be applied to restoration projects in other occupied buildings where protecting occupants and maintaining indoor air quality are priorities.

Ultimately, successful structural drying is not measured solely by how quickly materials dry. It is also measured by how effectively the restoration process manages moisture, controls contaminant migration, and allows people to safely continue using the building whenever possible.

Contact our team today to develop a structural drying strategy tailored to your facility and designed to protect both your building and its occupants.

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