Last weekend I had to install a new door in my home office. I felt confident having done this a few times already and also having watched enough YouTube DIY videos at 2x speed to visualize what by now seemed like a straightforward project.
So I got the old door out, cleaned up the rough opening, got the new one centered in place, then made sure the door opened and closed freely before embarking on the tedious task of plumbing the jamb before nailing and screwing it into place.
I started with the hinge side as you are supposed to, got it pretty darn close, put my shims in place, and hammered a 16d nail through the jamb just above all three hinges. I didn’t nail them all the way in, leaving enough head on the nail to be able to pull it out again should I need to adjust something. That soon came in handy when I went to close the door to check the fit, and the jamb was already too tight to close the door- something was out of alignment somewhere.
I stood back and looked at the spaces between the jamb and the opening on either side, noting they were uneven, and noting both jambs were just short of plumb in the same direction. So I pulled all three nails and used my pry bar to carefully crank the lower left corner of the door frame in the right direction to try and square it more.
Checked the plumb- a little better. Put a few more shims behind the lower hinge, nailed it, checked plumb again, and tried to close it- bonk. Too tight.
I pulled the nail again to see how else I could square it. I wondered if one side was riding higher than the other- it was going right on top of concrete on a forty-five year old slab- and my two-foot level placed against the top jamb reveal a little unevenness. So I added a few plastic shims under that side which got me level enough, checked the open/close, and thought I was back in business.
I shimmed behind the hinges; checked the plumb; nailed it; checked again; tried closing.
Bonk.
WTH? I could hear Alec Baldwin’s character in The Edge, screaming in desperate rage: “what one man can do, another can do!”
So I took a deep breath, pulled out all the nails once more, watched the door close easily, effortlessly. That’s when I realized I had been optimizing for the wrong thing.
The specification of a door working is not that it is so perfectly level and plumb that anyone who approaches it can take out their four-foot level and check that yes, it is indeed perfect. The specification of a door working is that it opens and closes.
The function of the level in this context then, is not to deliver geometric perfection but to give the installer directional confidence that the door will be square enough to be able to open and shut correctly.
So instead of fussing over getting the jamb perfectly plumb, I started optimizing for the door being able to close. I still used the level to get as close as I could, but I wasn’t going to let that get in the way of being able to close the door. And with this method- still checking things as I went, but prioritizing ‘being able to close the door’ over ‘being perfectly plumb’, I had door in place and working in a half hour. And the plumb was close enough, certainly to the imperfect human eye.
It only took me a few hours of putting in and pulling out nails, but eventually I put the first thing first and got it done.
