Measure once, cut twice

One of the first rules I learned in do it yourself house renovations was “Measure Once, Cut Twice” and of course the reverse, “Measure Twice, Cut Once”.

The latter is definitely the least expensive way to go.

I learned it the hard way. In spite of being told of this rule before I began my amateur carpentering journey, that was one of my first mistakes. I was fitting a new door in an upstairs bedroom and realized I had to trim the edges of the door to get a good fit. I measured the door opening and was on my way downstairs to trim the door down with my skill saw when the phone rang. I spent about 10 minutes on the phone and after hanging up the call, instead of going back upstairs to re-measure, I relied upon my memory which afterward I found out was not as good as I thought it was.

The door opening was thirty-one and seven eighth inches wide; so I thought. The used door I was fitting was thirty-two inches. So I just needed to trim off an inch and an eighth and it would be a good fit. Wrong. The door opening was thirty, not thirty-one. So I hacked off an inch too much and ended up having to buy another door.