Carpentry Notes

How Tommy does pre-hung doors

Tommy does pre-hung doors (if video still around).

  1. Set a level reference mark horizontally across opening (on either side of the wall).

  2. Measure down from the mark to the floor to determine whether floor out of level. This will help determine which jamb must be cut.
  3. Measure from bottom of shortest jam and trace the reference mark across the door (jam edges only—don't mark on the door) then, measuring from that mark to the top of the pre-hung unit, mark down the other jam the same distance from the top to place that mark.

    Note: When marking from bottom of shortest jam, allow 716 for tile if floor unfinished. When the door is in place, these marks on door jam edge and wall opening will line up. There should ample and even crooked space at the top under the header; this will be corrected (hidden) by casing.

  4. Determine plumb of hinge jamb using long level and pre-shim with brads to hold the shims. Set the door in place,* the hinge jam, predrill hole in jam over one shim and screw down. Add more shims as necessary and at least two more screws.

  5. Shim and attach the strike-side jam paying attention to lifting jam to make marks align.

* If the opening slants out of plumb, nothing can be done: just follow it matching jam with studs and sheetrock thickness. The door cannot be used to correct that in the way it can across the other axis.