My builder framed the joist opening, but wouldn’t install. Feared liability. I installed myself. Only comment is that I wish I instructions had been more clear about necessary clearance for motor mechanism. Install the control Organismus: Depending on the type of control system you’ve chosen, follow the manufacturer’s instructions to https://attic-lift-systems53197.wikilentillas.com/1520929/fragen_Über_attic_lift_kit_revealed