The IICRC WRT body of knowledge clearly states thatcarpet cushion (pad, underlay)must be discarded when affected byCategory 2 water. Cushion is a porous material that readily absorbs contaminants and cannot be effectively cleaned or disinfected once exposed to water containing significant contamination.
The WRT manual explains that while some materials may be dried or cleaned depending on conditions, carpet cushion presents a high risk of retaining microorganisms, nutrients, and odors. Retaining contaminated cushion increases the likelihood of secondary damage and occupant exposure.
Wood framing and plywood subfloors may be restorable depending on contamination duration and extent, and oriental rugs require specialized evaluation. Category 2 contamination alone is sufficient justification for cushion removal under WRT standards.