The saw is one of the oldest carpentry tools in the world. Records documenting their use date back to ancientEgypt. No records however have been found indicating when the adage of measure twice cut once found its way into the construction lexicon. My guess would not long after the first saw was invented.
The saw had remained basically unchanged until modern times when they were able to be manufactured. The greatest innovation taking place in the 20th century with the introduction of the electric powered saw. Electric power spawned the creation of new types of saws. Specialty tools that made cutting not only easier, but quicker.
Electric powered saws also had the unforeseen consequence of providing for new levels of spectacular hacking.
While inspecting the floor structure in the basement of an older house I happened upon an interesting construction choice.
Floor structure seems at times to be the bane of plumbers and more often wannabe plumbers. All those boards obstructing a clear run for pipes. What's a contractor to do?
Go to the tool box and find the electric powered saw of course. Modern construction technology at it's best.
Floor structure can be cut or drilled. Cutting and notching is not advisable, but allowed following certain specific parameters. In the case of support beams cutting is generally never an acceptable practice, all though limited drilling is allowed.
This particular house I was inspecting had two solid wood support beams. The two beams ran perpendicular to one another. At this juncture was actually two seams. The beam that ran from side to side was two sections of solid wood with the front to back support joining at this point. The seams were all appropriately supported on a lally column. The issue at this important structural point was that one of the side to side support beams had been notched several inches in order to install a heating pipe. A second pipe, that appeared original, (this says the concept of drilling instead of notching is not new) was installed thorough a drilled hole. The notch effectively reduces the beams over all size and thus its strength to the distance from the notch to the uncut edge less the hole.
The question is why notch when drilling would not have compromised the beam. Most likely it was easier to install the pipe by notching.
Apparently thou shall not notch became a lost practice in later years.
Or someone wasn't thinking.