37 Cleaning of floor surfaces and preparation, namely, filling of cracks and leveling of floor surfaces for installation of flooring materials; preparation of ceiling surfaces for installation of ceiling materials, namely, installing frames and hanging wires; preparation, namely, cleaning and sanding of windows for installation of window treatments; construction project management in the field of flooring installations, ceiling installations, window treatment installations, installation of acoustic materials, installation of decorative panels, and renovation and construction of building interiors; installation of flooring, ceilings, acoustical and reflective ceiling panels, acoustical and reflective wall panels, decorative panels, decorative panels for use in lighting installations, and architectural acoustic products, namely, sound absorbers and diffusers, site built and pre-fabricated acoustic wall and ceiling panels and acoustical cloud installations; consultancy and advisory services relating to cleaning, installation, repair and maintenance of flooring, ceilings, acoustical and reflective ceiling panels, acoustical and reflective wall panels, decorative panels, decorative panels for use in lighting installations, and architectural acoustic products