This issue affects both the door's aesthetic quality and performance. Any Mueller Roll-Up Door larger than 119 square feet will include a chain hoist. // --> Experience the convenience of downloading all your essential documents in one place! If you are going to carpet the floor, shim the door jambs off the floor about 3/8. of the door will vary by manufacturer. Reference the sideroom and headroom requirements in the charts below for the overlap amounts. Other general and specific features of the 1950 commercial door include: Push-up, hand chain and internal electric operations. Leave a headroom of 14, or 12 minimum. Door size should match rough opening*. Or:I still need help with my door or window header. Every second counts when there is a fire that needs to be fought.