In Newfoundland, the fog isn’t just a weather pattern; it’s a way of life. From the rugged coast of Stephenville to the historic streets of St. John’s, the arrival of "The Big Fog" brings a unique, quiet beauty to the island. However, as a home inspector with a "Contractor’s Eye," I tend to see the fog through a different lens. To a house, fog is more than just a coastal mood—it is a massive dose of airborne moisture that is constantly looking for a way inside. As we transition into the high-humidity months, understanding how this heavy coastal air impacts your home’s structural health is the best way to prevent costly repairs and ensure your investment stays dry.

From a builder’s perspective, moisture is the primary enemy of structural integrity. When the fog rolls in, the relative humidity outside often hits 100%, and your home begins a constant battle to stay dry. If a house doesn't "breathe" correctly, that saturated air gets trapped, which can eventually soften wood framing, degrade insulation, and create the perfect breeding ground for mold. This is why your Heat Recovery Ventilator (HRV) is your absolute best friend in a coastal climate. Its job is to swap out stale, humid indoor air with fresh outdoor air while managing heat loss. Now is the ideal time to clean your HRV filters and ensure the exterior intake vents are clear of debris or old winter salt crust. If you notice heavy condensation on the inside of your windows during a foggy stretch, it’s a clear sign that your HRV might not be balanced correctly or the humidity setting needs a quick adjustment.

Beyond the main mechanical systems, you shouldn't overlook the smaller "wet zones" of the home. Moisture accumulates fastest in bathrooms and kitchens, where daily activities add to the already high humidity. After a shower, it is vital to let the bathroom fan run for at least twenty minutes to fully clear the space. A quick way to check your fan's health is the "toilet paper test"—if it can’t hold a single square of paper against the grill when turned on, it isn't pulling enough air to fight off the Newfoundland dampness. Similarly, always use your range hood when boiling water in the kitchen. In a high-fog environment, that extra steam has nowhere to go but into your ceiling joists, where it can cause hidden damage over time.

Air circulation is equally important in the often-overlooked "dead zones" of a house. Mold loves stagnant air, which can easily get trapped behind large furniture or in deep closets. To prevent this, avoid pushing large couches or wardrobes completely flush against exterior walls. Leaving a simple two-inch gap allows air to circulate freely, preventing the wall temperature from dropping and creating "sweat" or condensation behind the furniture. If you have a closet located on an exterior wall, keeping the door cracked during heavy fog spells ensures it stays at the same temperature as the rest of the room, protecting your clothes and the drywall from dampness.

Finally, you must keep a close watch on the basement and crawlspace, where ground moisture is already naturally high. If your lower levels begin to smell "musty" when the fog hits, your humidity levels are likely climbing above 50%, which is the threshold where mold begins to thrive. Running a dehumidifier during fog season is a small price to pay to protect your foundation and flooring. You should also keep an eye out for efflorescence—a white, powdery substance on concrete walls. This is a tell-tale sign that moisture is being pulled through the masonry, a common occurrence when the Newfoundland ground is saturated and the air is thick.

Ultimately, a home should be a fortress against the elements, but even the strongest fortress needs a way to vent. By actively managing your indoor air quality and watching how your home reacts when the visibility drops outside, you can enjoy the coastal scenery without the worry of coastal rot. If you're ever unsure how your home is handling the humidity, a professional inspection using infrared thermal imaging can spot moisture hidden behind the walls before it becomes a major problem.