Crawl space encapsulation
Sealing a crawl space with a heavy vapour barrier over the ground and up the walls, usually combined with insulation, air sealing and humidity control.
What is Crawl space encapsulation?
Encapsulation converts a vented crawl space into a conditioned or semi-conditioned one. A heavy polyethylene liner is sealed to the ground and piers and run up the stem walls, vents are closed, the perimeter is insulated, and humidity is managed with a dehumidifier or a supply of conditioned air. Done properly it resolves the moisture, mould and wood-decay problems that vented crawl spaces suffer in humid climates. Done badly it traps moisture. Inspectors should note whether bulk water intrusion was addressed first, whether the liner is sealed or merely laid down, whether combustion appliances in the space still have adequate combustion air, and whether a dehumidifier is present and draining properly.