Abstract: A carpet pad comprises a two-layer structure of a cushion and a barrier film formed of a synthetic polymeric material free of any fibrous substrate laminated thereto. The barrier film may be directly bonded to the cushion or bonded thereto using a layer of adhesive. The carpet pad is simultaneously impermeable to liquid deposited onto the pad from above the barrier film and permeable to moisture vapor at a moisture vapor transmission rate of at least 14.6 grams per square meter per twenty-four hours (14.6 g/m2/24 hours). The carpet pad is sufficiently durable to maintain liquid impermeability as measured by a Vetterman Drum Wear Test/Staining/Stain Cleaning Test after at least ten thousand cycles or under a pressure of at least eight pounds per square inch (0.56 kg per square meter) as measured by a Modified Mullen Bursting Strength Test.