A vapour seal is an essential part of preventing moisture infiltration into or migration out of a critical space, such as a data processing centre or other room that contains sensitive electronic instrumentation. Essentially, a vapour seal is a barrier that prevents air, moisture, and contaminants from migrating through tiny cracks or pores in the walls, floor, and ceiling into the critical space. vapour barriers may be created using plastic film, vapor-retardant paint, vinyl wall coverings and vinyl floor systems, in combination with careful sealing of all openings (doors and windows) into the room.