Originally Posted by
Stew Denton
Stan,
Great post, and the comments by those, such as Stephen, who have also had considerable experience is much appreciated.
Back in the day I carpentered we used chalk lines a lot. I still use a chalk line part of the time to mark lumber for cutting and other purposes. Like some of the others I have also used string lines to check straightness. I also have and have used plumb lines, they can sometimes be used when nothing else will do or even can work. The old Stanley, and other brands, of chalk boxes can also be used as a plumb line, as you know, and in fact they were designed to do exactly that.
The discussion as to how to lay out a door jambs and dead flat surface was much appreciated, very well and clearly written, and extremely interesting. However, often times when installing a door jamb and door, though, for me it has been almost entirely in an existing house in existing walls in a remodeling effort, and as such getting the door to trim out nicely with the existing wall was as or more important than getting it dead flat.
Because of that I normally start by mounting the hinges on the hinge side of the jamb,and then mark the hinge locations on the door itself by placing the door against the jamb with the correct gap at the header location and then use a utility knife to mark the hinge locations against the hinges that are mounted on the jamb. I then mount the hinges on the door and test them on the jamb.
Next I begin by leveling out the header of the jamb with my really good old Sands level that I bought new in the early 70s and have taken really good care of now for nearly 50 years. I then use a 6' level to get the hinge side of the jamb dead plumb and straight using shims and big finish nails. (I spent a significant amount of time, years ago, to determine which of the spirit level vials glasses were dead true on my level. Not all of them are.) You also have to check the door to make sure it is flat, straight, and square. I then mount the door on the hinge side of the jamb and true up all of the remaining edges with shims and finish nails to get all the gaps looking right. Lastly the stops go in.
However, I have to run the jamb true with the wall as much as is possible so the door casing can trim out the jamb and look good. It is a game of compromise and truing so the door will look good and work correctly.
Stew