New vent block improves crawl space

Here is a great “before and after” photo comparison where I installed a vent block to replace, what frankly, was a big mess. This project was completed for a home in Avon by the Sea, NJ. Whenever we install a dehumidifier in a crawl space, we strongly recommend to homeowners to block the crawl space vents, which helps keep outside humid air from entering the basement (not to mention insects!). Installation of a commercial-grade dehumidifier is the single most important way for homeowners to prevent mold growth and other problems resulting from sustained high humidity in crawl spaces and basements. ideally, these subterranean areas should be encapsulated to keep humid air from entering the crawl space. Building scientists that study indoor airflow have found that vented crawl spaces do exactly what homeowners want to prevent —  allowing hot humid outdoor air enter the crawl space. There is a popular misconception that vented crawl spaces expel hot humid air, when in fact, the opposite is true. However, even if a homeowner decides to not fully encapsulate their crawl space, at a minimum, we strongly recommend that homeowners at least block the crawl space vents since these are, by far, the largest entry points for outside air.

To block the vents, we cut Silverglo insulation to size. SliverGlo insulation is an Expanded Polystyrene Foam (EPS) insulation that contains graphite. This lightweight, rigid, closed-cell insulation is 24% more efficient than over-the-counter batt and foam insulations. Its closed-cell structure provides minimal water absorption and low vapor permanence. As an added benefit, SilverGlo is coated with a mold-resistant aluminum that naturally enhancing primary sources of light, dramatically increasing the luminosity of even a single bulb. After setting in the insulation in the vent space, we then spray a hardening foam around the outside edges to completely block off any airflow.