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Condensation in steel buildings is a costly and preventable problem. When water seeps inside through leaks in a building’s exterior, it can saturate the insulation, causing corrosion on interior metal surfaces.

Over time, even surface-treated interior metal is susceptible to corrosion. Additionally, wet insulation can be a breeding ground for mold and mildew, creating a musty smell and contributing to respiratory problems for the building’s occupants.

To prevent condensation in metal buildings, it’s important to uphold a regular maintenance schedule and follow a few simple preventive measures.

What Causes Condensation in Metal Buildings?

Indoor condensation has many potential sources. Warm air naturally holds a certain amount of moisture, and as it cools down, it releases its moisture in the form of condensation. Beads of moisture on interior surfaces may come from indoor humidity, which could have one of several possible sources. For example, HVAC systems and human respiration can both increase humidity.

As warm air rises, it encounters cooler interior surfaces, which cause the warmer air’s moisture to condense. While these problems can be frustrating, each of them has a straightforward solution. To ensure that your building remains condensation-free, you can implement multiple solutions at once.

How Water Vapor Gets Inside

A building’s insulating materials include an interior barrier called a vapor retarder. This inner barrier is critical for keeping water vapor outside, but oftentimes it fails to do its job properly. Whether because of faulty installation or improper design, vapor retarder failure is one of the most common reasons metal buildings sweat.

While condensation on exposed interior surfaces can be damaging, condensation on hidden surfaces is much worse because it can lead to serious corrosion before anyone knows about it. The signs of concealed interior corrosion may include paint damage, cracked tiles, and damp insulation. In metal garages, concealed corrosion can cause damage to asphalt or concrete surfaces.

Prevent Condensation with Proper Insulation

The first line of defense against interior water vapor is insulation. Proper insulation works in several ways to keep moisture off interior surfaces. It keeps the temperature steady throughout the day so that the indoor air doesn’t hold excessive moisture or deposit it on surfaces.

Crucially, effective insulation works uniformly across all interior surfaces, eliminating thermal leakage. Hot spots can form in buildings with only partial insulation, so it’s important for the insulation to be continuous throughout the building.

Keep Out Condensation with Barriers

Most modern steel buildings have vapor barriers on all interior surfaces. These barriers reduce the flow of water vapor through the walls, eliminating a major source of interior condensation.

Vapor barriers form one of the layers in a building’s structural interior. Buildings without vapor barriers can benefit from a retrofitting of this important material. Barriers help prevent vapor from entering through windows, skylights, doors, floors, and other entry points.

Increase Ventilation in Your Building

In some metal buildings, increased ventilation can eliminate the source of airborne water vapor. If interior humidity comes from an indoor heat source such as motorized equipment or excessive building occupancy, opening doors and windows during the warmest times of the day can reduce condensation.

This strategy isn’t appropriate in all cases, however. If the weather is too hot or cold to leave the windows open, other strategies may be necessary.

A primary source of the leakage is improper ceiling insulation. When the insulation doesn’t fully make contact with the ceiling, it can allow warm spots to develop, leading to hidden condensation.

This form of condensation can be especially damaging because it corrodes ceiling panels while fostering mold and mildew growth in hard-to-reach places. To eliminate this common source of condensation, inspect your ceiling’s insulation regularly to find gaps where warm spots can form.

Water seepage in the flooring and foundation can contribute to indoor humidity and condensation. In many buildings, water can seep through the floor from the concrete slab underneath. This water can come from underground sources or roof runoff accumulating around the building’s perimeter.

Metal garages and buildings should have vapor barriers between the flooring and ground slab for adequate protection. Retrofitting a building with vapor barriers can be expensive, but it could extend the building’s lifespan. If a vapor barrier is too expensive to install, regularly draining water as it accumulates around the perimeter could help control seepage.

Use a Mechanical Ventilation System

Keeping steel buildings ventilated may require a mechanical exhaust and airflow system. Passive ventilation isn’t included in the design of most metal buildings because, by definition, they’re non-vented structures. However, mechanical ventilation is only required if a building’s HVAC system fails to maintain a temperature above the dew point.

Metal buildings offer a range of benefits for businesses in many industries, but they tend to sweat. Proper insulation, ventilation, and vapor barriers can help eliminate common sources of condensation.