Had a guy show me a simple trick for reading old blueprints that solved a 2 week headache

I was stuck trying to figure out some faded 1970s prints for a reno in downtown Nashville and a retired foreman pointed out I was looking at the wrong scale because they used a different standard back then. He told me to always check the title block date first before assuming anything. Anyone else run into this with old drawings?

3 comments

3 Comments

jessica7071mo agoMost Upvoted

Oh man that title block trick is gold. I had some 60s prints for a house in East Nash and spent a whole afternoon measuring stuff wrong because I was using the decimal scale instead of the architectural one. They did everything in feet and inches back then but the sheet said 1/4"=1' which is obvious once you see it but easy to miss when the print is all yellowed. Also watch out for handwritten revisions on tissue paper overlays, those can throw off the whole foundation layout if you don't notice them first.

drew_hart41mo ago

That whole thing about old prints not matching reality is something I see everywhere, not just in blueprints. My buddy bought a house from the 70s and the original floor plan showed a wall that was supposedly load bearing. Turns out it was just a decorative half wall the original owner threw up to hide their laundry pile. You gotta treat old records like a loose suggestion, not a promise. Kinda like reading a recipe from the 1950s where "a pinch" could mean anything from a dash to a whole handful depending on who wrote it, right?

karencampbell1mo ago

honestly is it really that deep? i mean yeah if you're measuring something critical like a load bearing wall i guess but most of the time you're just getting a rough idea. i've seen guys spend hours agonizing over old prints when the actual building was framed completely differently anyway. half the time the handwritten revisions are from someone's grandpa who guessed the measurements