Verify the code book itself before trusting any training guides. I had to redo a whole bathroom vent because of a mistake in the printed guide. Now I make a point of checking for corrections online before starting any job. It saves the headache of arguing with inspectors over someone else's typo.

Yeah, the water-cement ratio is important, but curing is just as key. I always make sure to keep the surface moist for at least a week. Do you use burlap or plastic sheets for that?

Nice of you to finally catch up with the rest of us.

My buddy in security told me a similar story last year. Your double-check method is honestly the smartest fix I've heard for that problem. Has logging the results ever helped you spot a pattern in the failures?