In older houses, it is common for crawl spaces to have open vents installed. It was believed that the vents would allow fresh air to circulate through the area to help relieve moisture and humidity from the room. However, the air outside is often more wet and humid than the inside. Moist air that enters a vented crawl space will condense on cooler crawl space surfaces, ruining insulation and encouraging mold, mildew and wood decay. That air will also be naturally circulated up through all of the other levels of the home. Encapsulating the crawl space with our CleanSpace crawl space liner is the recommended treatment for a vented crawl space in order to separate and shield the crawl space from outside conditions. Our Everlast crawl space vent covers won’t warp, rot or crack and, most importantly, they are airtight, helping to ensure a dry crawl space and more comfortable living area.