I previously asked the question concerning the slope of a cement patio that abuts the foundation. The immediate answer was 1/4 inch per foot. Our local building inspector gave the same answer. The problem is, I can't find any reference to the standard in any version of the various building codes. Can anyone tell me where to find this in the codes?

IBC Section 1803.3 - Site Grading

I had a patio that was built level by the previous owner. That small detail cost me a couple of thousand dollars to replace damaged joists in the crawl space, and drains under the concrete patio.
I would give it 5/16 per foot or more depending on what you think will look and perform OK.