Foot Fall Underlayment and the flooring material to be installed must acclimatize, in their sealed packaging, in the room where they are installed for at least 48 hours, at a temperature of at least 65° F. Before starting your installation of Foot Fall, make sure the sub floor is permanently dry and free of dirt, dust, grease, and other foreign matter. Trapped moisture may cause wood to rot. Foot Fall may be glued down to sub floor, though not required. If an adhesive is to be used, we recommend CX-941 polyurethane adhesive. A V-notched trowel and 50-100 lb. carpet roller will be required.