All joints and seams must be sealed to create a truly continuous, effec­tive air retarder. Installation errors not only increase energy use but also increase the risk of moisture damage to a house. An air retarder, therefore, should be inspected carefully after installation and before other work covers it. Small holes in an air retarder can be repaired with polyethylene or foil tape, whereas large holes can be repaired with a large patch of polyethylene. Patches always should be large enough to cover the damage and overlap any adjacent wood framing. Sealant should be used to thoroughly seal the joint.