Tuesday, December 20, 2011

CONCRETE: Drafting Precision

Here's a question I THOUGHT I knew the answer to...but for the life of me I can't locate it any longer if it ever existed.

 

What defines the standard for concrete drafting precision?

 

I know that ACI 117 is about the as-constructed tolerance for concrete elements, but what about what is put on the drawings to begin with?

For instance, is it reasonable to show a spread footing foundation to the 1/16th of an inch, as recently came across my desk? I thought I remembered that there were specific precision allowances for different elements - for instance, to the half-inch, or the the nearest inch, etc.

 

Where is that found? Or is it?

 

Sorry, my mind is going. I can feel it.