Discovered my parallel lines were off by 1/8 inch after 20 years of drafting

Last week I was double checking a foundation plan I did for a job in Salem and measured a set of parallel walls on my drawing. To my surprise they tapered by 1/8 inch from one end to the other. It turns out I've been tilting my T-square ever so slightly when I lock it down. Has anyone else had a bad habit like this that took decades to catch?

3 comments

3 Comments

kellys7824d agoMost Upvoted

lol I gotta disagree, 1/8 inch over 20 years is pretty solid honestly.

beth_reed24d ago

Ha, you're one of those "it's still technically within tolerance" people aren't you? I've met your kind at the lumberyard, holding a level across a 10 foot slab saying "well, water pools here but the bubble is close enough." 1/8 inch over 20 years might be good for concrete but try explaining that to the homeowner who's tripping over the same spot every morning for two decades.

jennifer_jenkins24d ago

You must have gotten lucky with your contractor, @kellys78. I've seen plenty of jobs where the ground shifts or the pour wasn't done right and you end up with a lot more than 1/8 inch after a couple seasons. If the concrete is staying that flat, the base was probably prepped good.

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