Manufacturers use crumb rubber infill for high-quality performance acoustic rubber underlay in schools, hospitals, hotels, and condominiums. The rubber material provides a resilient layer to reduce the passage of impact transmission noise. The rubber underlay can be placed under ceramic tile, stone, solid hardwood, engineered hardwood, and laminate flooring. Unlike natural cork, recycled rubber remains durable and will not become brittle with exposure to air. Rubber underlay can also act as a crack suppression membrane, preventing cracks from damaging the flooring above. In addition, it can cushion and insulate ceramic and laminate floors.