WHY DOES MY SLIDING PATIO DOOR SCRAPE AT THE TOP AND DIFFICULT (if not impossible) TO MOVE? When a new home is being built, an opening is often framed out for the sliding patio door assembly. But, before it can be inserted into the opening, a substantial “header” support beam is placed in the wall above to prevent the weight of the second floor or roof from putting pressure on the door as the house settles. Years ago, this was a steel I-beam. You will often see the edge of