Barndominiums are the perfect fusion of rural charm and modern living. These metal structures, known for their durability and cost-effectiveness, have surged in popularity across the country. But if you’ve recently moved into one or have lived in one for a while, you might have noticed something a bit unsettling—your barndominium feels damp. That clammy feeling in the air, condensation on windows, and even mold in corners can all point to one issue: humidity control. This post breaks down why barndominiums are particularly susceptible to humidity problems and, more importantly, what you can do about it.
Why Is Humidity a Problem in Barndominiums?
Humidity refers to the amount of moisture in the air. When levels are too high indoors, it can lead to:
- Mold and mildew growth
- Warping of wood and drywall
- Musty odors
- Damage to electronics and furniture
- Increased allergy symptoms
Most barndominium owners notice excess humidity in the form of condensation on windows, damp walls, or a general “sticky” feel inside the home. The problem is especially noticeable in humid climates, or during rainy seasons, but even dry areas can experience moisture buildup inside a poorly ventilated or insulated barndominium.
Metal Structures and Moisture: A Love-Hate Relationship
Unlike traditional wood-framed homes, barndominiums are typically built using steel framing and metal siding. While this makes them fire-resistant, termite-proof, and long-lasting, metal comes with a few caveats:
- Metal Conducts Temperature Changes Quickly
Metal walls and roofs heat up quickly under the sun and cool down just as fast when the sun sets. This rapid shift creates a scenario where condensation can form, especially when warm, moist air comes in contact with cool metal surfaces.
- Lack of Porosity
Metal doesn’t “breathe” like natural wood. In traditional homes, some moisture is absorbed and released by porous materials. In a barndominium, the moisture tends to stay trapped unless there’s intentional airflow and ventilation.
- Sealed Tight, Traps Moisture
Many metal buildings are constructed to be airtight for energy efficiency. Ironically, this can trap moisture inside, especially if no ventilation or dehumidifying strategy is in place.
Common Sources of Indoor Moisture in Barndominiums
Before diving into solutions, it’s important to identify where all that moisture is coming from. Here are the usual suspects: Daily Living Activities Cooking, showering, laundry, and even breathing all release water vapor into the air. A family of four can add several gallons of water vapor to the air each day just from normal activities. Poor Ventilation If your barndo isn’t vented properly, moisture has no way to escape. Lack of exhaust fans in bathrooms and kitchens or insufficient attic ventilation can trap humid air inside. Improper Insulation Inadequate or poorly installed insulation allows warm, moist air to reach cold metal surfaces, which leads to condensation. Leaky Plumbing or Roof Hidden leaks are a less obvious but serious source of moisture. Even a slow drip from a pipe or roof can increase overall humidity, especially in enclosed spaces like wall cavities or under floors. Crawl Spaces and Slab Foundations Some barndominiums are built on slabs or over crawl spaces. If these areas aren’t sealed and vapor-barriered properly, moisture can seep up from the ground and infiltrate your interior air.
How to Control Humidity in Your Barndominium
Now that we understand the causes, let’s explore practical ways to combat excess moisture in your metal home:
- Install Proper Insulation (the Right Way)
Insulation doesn’t just keep your barndo warm or cool—it plays a major role in humidity control. The right type and placement can stop condensation in its tracks. Best Options:
- Closed-cell spray foam: Acts as an air barrier and vapor barrier in one. Perfect for metal buildings.
- Rigid foam board: Durable and water-resistant, ideal for walls and ceilings.
- Fiberglass with vapor barriers: Works if installed with proper vapor control measures.
👉 Tip: Always ensure there’s a vapor barrier between the interior and the exterior metal wall.
- Use a Dehumidifier
A high-capacity whole-home dehumidifier can be integrated into your HVAC system or installed as a standalone unit in humid-prone areas. Smaller units work well for:
- Bathrooms
- Laundry rooms
- Basements
Monitor indoor humidity with a hygrometer. Ideal indoor humidity is between 30%–50%.
- Improve Ventilation
Ventilation helps air circulate and prevents moisture from stagnating. Key Areas to Vent:
- Kitchen: Use range hoods vented to the outside.
- Bathrooms: Install and use exhaust fans with timers.
- Laundry Room: Make sure dryer vents are sealed and lead outdoors.
- Attic or Roof Space: Ridge vents, soffit vents, and gable vents help control attic moisture.
Also consider Energy Recovery Ventilators (ERVs), which introduce fresh outdoor air while removing indoor moisture.
- Seal Air Leaks
Moist air can enter from outside through tiny gaps in your structure. Inspect and seal:
- Door and window frames
- Baseboards
- Electrical outlets
- Roof seams
- Plumbing penetrations
Weatherstripping, caulking, and foam sealants work well for closing gaps.
- Use Vapor Barriers
Install vapor barriers in crawl spaces and under slab foundations. This prevents moisture from wicking up from the ground. For best results, pair vapor barriers with insulation and proper floor sealing.
- Conditioned HVAC System
Running your HVAC system helps regulate both temperature and humidity. Ensure your unit:
- Is properly sized for your square footage
- Includes a humidity control function
- Is maintained regularly (clean filters and ducts)
Smart thermostats with humidity sensors offer automatic adjustments and alerts when moisture levels rise.
- Design With Moisture in Mind
If you’re still in the design or renovation phase, consider these ideas:
- Overhangs and gutters to direct rainwater away from walls and foundations
- Elevated slab or pier foundation to prevent ground moisture problems
- Breathable wall assemblies with ventilated rain screens behind siding
- Sloped site drainage to keep water flowing away from the structure
Signs Your Humidity Problem Is Out of Control
Sometimes excess humidity goes beyond discomfort and enters the danger zone. Watch for these warning signs:
- Visible mold growth on walls, ceilings, or around windows
- Peeling paint or wallpaper
- Warped wood floors or cabinetry
- Musty odors that don’t go away
- Condensation inside insulated walls or attic spaces
- Increased allergy or asthma symptoms
If you see any of these, take immediate steps to dry out the interior and consult a moisture remediation professional.
Final Thoughts
Humidity in a barndominium isn’t just an annoyance—it can be a serious threat to your home’s structure and your family’s health. The good news? With the right combination of insulation, ventilation, and mechanical control, your metal home can feel just as dry and comfortable as any traditional house. Whether you’re just starting your barndominium build or trying to fix a damp situation, tackling humidity head-on will ensure your unique home stays cozy, healthy, and structurally sound for years to come.